biozonation and biochronology of miocene through pleistocene

Newsletters on Stratigraphy Vol 453 221ndash244 ArticlePublished online September 2012

Biozonation and biochronology of Miocenethrough Pleistocene calcareous nannofossils from low and middle latitudes

Jan Backman1 Isabella Raffi2 Domenico Rio3 Eliana Fornaciari3 and Heiko Paumllike4

With 10 figures and 4 tables

Abstract Calcareous nannofossils are widely used in Cenozoic marine biostratigraphy At present the twomost widely used calcareous nannofossil biozonations were established approximately 40 years ago Thesewere derived from marine land sections and Deep Sea Drilling Project rotary cored sediments Over nearlythree decades we have generated Miocene through Pleistocene calcareous nannofossil data from deep seasediments in low and middle latitude regions The sediments used here have been mostly recovered using theadvanced piston coring technique generating less core disturbance and complete recovery via multiple pen-etration of the sediment column at single sites A consistent trait in our work on calcareous nannofossil bios-tratigraphy has been to use semi-quantiative methods in combination with short sample distances closeenough to capture the details of the abundance behaviour of individual calcareous nannofossil taxa Such datarepresent the foundation of the new biozonation presented here which still partly relies on the pioneeringwork presented by Erlend Martini and David Bukry about 40 years ago A key aim here has been to employa limited set of selected biohorizons for the purpose of establishing a relatively coarsely resolved and stablebiozonation We present 31 biozones using a new code system CNM1ndashCNM20 Calcareous NannofossilMiocene biozones 1 through 20 CNPL1ndashCNPL11 Calcareous Nannofossil Plio-Pleistocene biozones 1through 11 As the new biozonation encompasses 23 million years the average biozone resolution becomes074 million years ranging from 015 to 220 million years A single biohorizon is used for the definition ofeach biozone boundary Auxiliary markers are avoided as well as subzones in order to maintain stability to the new biozonation Virtually every biozone holds one or several additional biohorizons These togetherwith all biozone boundary markers are assigned age estimates derived chiefly from astronomically tuned cyclostratigraphies

Key words calcareous nannofossils biozonation biochronology Miocene-Pleistocene

copy 2012 Gebruumlder Borntraeger Stuttgart GermanyDOI 1011270078-042120120022

wwwborntraeger-cramerde0078-042120120022 $ 600

Authorsʼ addresses1 Department of Geological Sciences Stockholm University SE-106 91 Stockholm Sweden E-Mail backmangeosuseCorresponding author Jan Backman Phone +46-8-164720 Fax +46-8-67478972 Dipartimento di Ingegneria e Geologia (InGeo) ndash CeRSGeo Universitagrave degli Studi ldquoG drsquoAnnunziordquo Chieti-Pescara viadei Vestini 31 66013 Chieti-Pescara Italy E-Mail raffiunichit3 Dipartimento di Geoscienze Universitagrave degli Studi di Padova via G Gradenigo 6 35131 Padova Italy E-Mail domeni-coriounipdit elianafornaciariunipdit4 Center for Marine Environmental Sciences (MARUM) University of Bremen D-28359 Bremen Germany E-Mail hpaelikemarumde

1 Introduction

About 40 years ago a series of calcareous nannofossilbiostratigraphic zonations was established for variousparts of the Cenozoic stratigraphic column (Hay et al1967 Gartner 1969 1971 Bukry and Bramlette 1970Martini 1969 1970 Martini and Worsley 1970) Thesewere all based on the study of marine land sectionsandor rotary cored Deep Sea Drilling Project sedi-ments a drilling technique characterised by low re-covery and disturbed cores (JOIDES Journal June1979 wwwodplegacyorg) Biozonations for the en-tire Cenozoic were developed by Martini (1971) andBukry (1973 1975 1978) Martini introduced 25 Pa-leogene and 21 Neogene zones (NPNN zones)whereas Okada and Bukry (1980) codified Bukryrsquos19 Paleogene and 15 Neogene zones (CPCN zones)In addition Okada and Bukry (1980) also codified20 Paleogene and 24 Neogene subzones These twozonal systems are still widely used in spite of Bukryrsquos(1973a) insightful comment that ldquo the continuing re-covery of deep-ocean sediment sections by the DVGlomar Challenger at various latitudes will providethe material needed to thoroughly evaluate the strati-graphic and geographic ranges of coccolith speciesThis will permit more consistent zonationrdquo Bukryrsquoszonation was ldquonot intended to be exhaustive but sim-ply illustrates the basis of a low-latitude open-oceancoccolith zonationrdquo He thus aimed to establish a gen-eral framework for relative dating of open ocean sedi-ments rather than producing the highest possible reso-lution This spirit is adopted here together with thegeneral aim to produce a ldquomore consistent zonationrdquo

Among us a paper by Rio (1974) was the first in astill ongoing effort (Fornaciari et al 2010 Agnini et al2011) to generate biostratigraphic data using Cenozoiccalcareous nannofossils Many biostratigraphic stud-ies of Cenozoic calcareous nannofossils present data inthe form of range charts characterised by qualitativeestimates of relative abundances of taxa in widelyspaced samples As discussed by Backman and Raffi(1997) it is difficult to judge the quality of individualbiohorizons from qualitative presence-absence listingsin range charts Inspired by the work of Thierstein etal (1977) we developed methods to acquire censusdata (Backman and Shackleton 1983 Rio et al 1990aRaffi 1999) By combining census data with shortsample distances we aimed to improve both the strati-graphic precision and resolution by which calcareousnannofossil biohorizons were determined Census datahave the advantage that they permit independent as-

sess ments of the abundance behaviour and distributionof taxa and hence the quality of the biohorizons Wehave subsequently generated much data showingabundance variations of biostratigraphically importantcalcareous nannofossil taxa from marine sediments ofCenozoic age representing different low and middlelatitude paleoenvironmental settings

We here synthesise Miocene through Pleistocenedata in order to a establish a basic biostratigraphicframework for relative dating of marine sediments using calcareous nannofossils This synthesis clearlyrelies on the pioneering contributions by Erlend Mar-tini and David Bukry as many of the biohorizons theyused for zonal boundary definitions have proven toprovide consistent results Several of their zonalboundary defining biohorizons however have provenless practical and explains the need for a revised bio-zonation Our approach has been to employ a limitedset of selected biohorizons in order to establish a rela-tively coarse and stable framework taking into accountthe biostratigraphic data that we have produced overnearly three decades consistently using semi-quanti-tative methods and short sample distances In additionwe here present some previously unpublished bios-tratigraphic data

A secondary purpose has been to provide age esti-mates for all biohorizons Age estimates of individualbiohorizons are presented with their calibration refer-ences In the Miocene through Pleistocene interval theindependent age control is provided primarily by as-tronomically tuned cyclostratigraphies

2 Biozones defining biohorizonsand a revised biozone codesystem

A biostratigraphic unit or biozone is a body of stratathat are defined on the basis of its unique content se-quential distribution absence or combinations there-of of fossils Here we use selected calcareous nanno-fossil biohorizons to establish a revised biozonationfor the Miocene through Pleistocene interval

The major advantage of using a logically organisedzonal scheme e g Zone CN5 is relatively older thanZone CN6 etc is its ease of use compared to learningand remember the names of the many taxa providingindividual biohorizons and biozone boundary defini-tions In our view biozones in a zonal scheme shouldrepresent a relatively coarse and stable framework us-

J Backman et al222

ing carefully selected biohorizons for defining zonalboundaries rather than seeking to achieve the highestpossible resolution Other biostratigraphically usefulbiohorizons occur in virtually every biozone We pre-fer to list these as biohorizons and their proper relativepositions within the biozones as intra-zonal markersrather than to employ all or most of them for zonalboundary definitions for the purpose to give stabilityto the zonal scheme and keep it simple These latterpoints have motivated our reluctance to introduce sub-zones Each biozone boundary should be defined by asingle biohorizon It follows that the use of ʻauxiliaryʼbiozone boundary markers is to be avoided

Biozones may be defined using different conceptsWe follow Wade et al (2011) for five logical types ofbiozones that can be based on stratigraphic distribu-tions of calcareous nannofossil taxa These zones in-clude1 Taxon Range Zone (TRZ)2 Concurrent Range Zone (CRZ)3 Base Zone (BZ)4 Top Zone (TZ)5 Partial Range Zone (PRZ)

However Wade et al (2011) used Lowest Occurrence(LO) and Highest Occurrence (HO) for categories 3and 4 respectively The commonly used acronym LOmay refer to both Last Occurrence and Lowest Occur-rence in calcareous nannoplankton biostratigraphy(e g Rio et al 1984 Fornaciari et al 2010) We thusprefer to use Base (B) and Top (T) respectively to de-scribe the stratigraphic lowest and highest occurrencesof taxa (Fig 1) This practice is not new (Roth et al1971 Raffi et al 1993 Backman and Raffi 1997) andis considered unambiguous in comparison to HO and

LO The Base and Top concepts are here used in achronostratigraphic sense Although avoiding the useof LO and HO terms for the types of biohorizons in ourproposed new calcareous nannofossil zonation we ad-here to the five types of biozones that were introducedby Wade et al (2011) and that can be applied to all bio-zones introduced below

In our calcareous nannofossil biostratigraphy wehave used three concepts that differ from the absolute-ly topmost or basalmost stratigraphic presence of taxaIt is not uncommon that the first evolutionary appear-ance of a taxon is characterised by discontinuous oc-currences of rare to few specimens for some strati-graphic distance below its continuous presence athigher abundances Similarly a tail of discontinuousoccurrences of rare to few specimens may exist aboveits continuous presence at higher abundances A typi-cal example of this phenomenon is illustrated belowby the Base of common Discoaster asymmetricus Insuch cases the absolutely lowest or highest occur-rences are considered to provide a less reliable bios-tratigraphic signal when compared to the base and topof the continuous occurrences of the taxon at higherabundances In such cases we use the concepts Basecommon (Bc) and Top common (Tc) Several otherpossibilities to codify such biohorizons have been published although we here refer to them as Tc or Bc Another more unusual concept that we have adoptedis the cross-over (X) in abundance between two taxaThe two taxa may or may not be ancestor and descen-dant taxa The key problem is that low and discontin-uous abundances towards the end of the range of a (insome cases ancestor) taxon and in the beginning of therange of another (in some cases descendant) taxonmay be difficult to determine precisely in terms of

Biozonation and biochronology of Miocene through Pleistocene calcareous nannofossils 223S

tratig

raph

y

younger

older

Biohorizon 2

Biohorizon 1

AA B A B A B A B C

Species ATaxon RangeZone - TRZ

Species A amp BConcurrent Range

Zone - CRZ

Species ABase Zone - BZ

Species ATop Zone - TZ

Species CPartial RangeZone - PRZ

Fig 1 The five logical possibilities for biostratigraphic characterization of biozones Redrawn after Wade et al (2011)

stratigraphic depth In cases where the cross-over oc-curs between ancestor and descendant taxa the prob-lem may be extended to include presence of interme-diate and overlapping morphotypes although thecross-over in abundance between the ancestor and de-scendant taxa may be readily determined The cross-over in abundance between Helicosphaera euphratisand Helicosphaera carteri is an example (see below)that do not appear to represent a direct ancestorde-scendant (Haq 1973 Perch-Nielsen 1985) yet bios-tratigraphically useful transition The transition be-tween Ceratolithus acutus and Ceratolithus rugosuson the other hand represents an illustrative example ofan ancestor-descendant biostratigraphically usefultransition (Backman and Raffi 1997)

Moreover we use intervals in which an establishedspecies or genus temporarily disappears to re-appearhigher up in the stratigraphic column Such absence in-tervals provide meaningful biostratigraphic informati -on in a few cases We thus refer to Base absence (Ba)for the temporary disappearance of Reticulofenstrapseudoumbilicus from the upper Miocene stratigraph-ic records and Top absence (Ta) for its re-entrancehigher up in the upper Miocene stratigraphic columnSimilarly we use Ta for the biohorizon provided by there-appearance of specimens 4 μm among the Pleis-tocene genus Gephyrocapsa Specimens 4 μm firstappears in the lower Pleistocene followed by a strati-graphic interval of absence before this size class re-en-ters the stratigraphic record about 203 kyrs later Sizechanges among the genus Gephyrocapsa have sincelong been successfully employed for stratigraphic sub-division of Pleistocene sediments (Gartner 1977 Rio1982) including the re-entrance of specimens 4 μmfollowing an absence interval of such large specimens(Raffi et al 1993)

Thus we employ seven concepts to characterisebiohorizons (B Bc Ba T Tc Ta X) which are usedto define five different types of biozones (CRZ TZBZ PRZ TRZ Fig 1) as illustrated by Wade et al(2011)

In Cenozoic planktonic foraminifera biostratigra-phy recent revisions have introduced a biozone codesystem that adds a code letter for each series and anumber system that begins at the base (= biozone 1) ofthe series (Berggren and Pearson 2006 Wade et al2011) We follow this system here introducing a newcode system for the Miocene through Holocene cal-careous nannofossil biozones We prefer to merge thePliocene and Pleistocene in our chosen biozone codesystem which is hence grouped into two units Plio-

Pleistocene (PL) and Miocene (M) The followingcodes are used (CN = Calcareous Nannofossil)1 CNPL1 to CNPL11 Pliocene through Pleistocene

Holocene biozones 1 through 112 CNM1 to CNM19 Miocene biozones 1 through 20

A new Paleogene biostratigraphic zonation will be pre-sented shortly in a different contribution following theabove approach and hence using CNO for Oligocenebiozones CNE for Eocene biozones and CNP for Paleocene biozones The GSSP definitions of the Mio cene Pliocene and Pleistocene series boundaries(wwwstratigraphyorg) are based on cyclostratigraphy(base Pleistocene base Pliocene) and magnetostratig-raphy (base Miocene) It follows that the above twogroups of calcareous nannofossil biozones do not ex-actly coincide with the series boundaries but are closeenough to justify the code system Of the four existingMiocene through Holocene series the Holocene is tooyoung (0012 Ma) in order to be distinguished bios-tratigraphically and the controversial PliocenePleis-tocene boundary is not distinguished in order to avoidfuture potential problems in the case that the boundarydefinition will change Here we have chosen to use thechronostratigraphic scheme of Lourens et al (2004)which places the base of the Pleistocene at the top ofthe Gelasian Stage at an age of 181 Ma

3 Age estimates of biohorizons

Age estimates in the Miocene through Pleistocene in-terval are chiefly derived from astronomically tunedcyclostratigraphies These estimates are considered torepresent an improvement from our previous synthesis(Raffi et al 2006) and include new calibrations Forage estimates of biohorizons derived from correlationto Pleistocene Marine Isotope Stages (MIS) we usedLisiecki and Raymorsquos (2005) MIS boundary estimatesFor age estimates derived from orbitally tuned litho-logic cyclicities (magnetic susceptibility) in ODP Sites925 and 926 we used Shackleton and Crowhurstrsquos1

(1997 Leg 154 CD-ROM Materials Chapter 03 textfiles) agedepth tables For age estimates derived from

J Backman et al224

1 These age estimates from ODP Site 926 in the westerntropical Atlantic Ocean differ slightly from those originallypresented by Backman and Raffi (1997) from the identicalsite who used an early (unpublished) version of Shackletonand Crowhurstrsquos (1997) astronomically tuned magnetic sus-ceptibility records

orbitally tuned lithologic cyclicities (gamma ray wet-bulk densities) in ODP Leg 138 sites we convert-ed the estimates from Shackleton et al (1995) to thetimescale of Lourens et al (2004) For age estimatesderived from lower Miocene cyclostratigraphies inODP Hole 926B and ODP Site 1218 we used the or-bitally tuned data produced by Paumllike et al (20062007) In addition to astronomically tuned cyclostrati-graphic age data we have used magnetostratigraphyfor a few late Miocene biohorizons (Schneider 1995)

In the literature there is an abundance of previousage estimates for each biohorizon presented here e gBerggren et al (1985 1995) and the numerous InitialReports volumes (see Explanatory Notes) of the OceanDrilling Program Here we show only our own cali-brations generated from low and middle latitude set-tings

4 Biozone definitions in the Miocene interval

Biozones are presented in chronological order fromolder to younger The biohorizons that are used for de -

finitions of the CNM biozones are summarized inTable 1 Age estimates of zonal boundary markers andadditional biohorizons in the Miocene interval aresummarized in Table 2 The average error of age esti-mates for the 41 Miocene biohorizons is 002 mil-lion years as deduced from Table 2 (depth uncertaintydivided by sedimentation rate) An overview of theCNM zonation in a chronostratigraphic context andcomparison with Okada and Bukryrsquos (1980) and Mar-tinirsquos (1971) Miocene zonations is shown in Figure 2

Name Zone CNM1 ndash Sphenolithus conicus PartialRange ZoneDefinition Partial range of the nominate taxon be-tween the Top of Sphenolithus delphix and the Base ofSphenolithus disbelemnosReference section ODP Site 1218 (central part oftropical Pacific Ocean)Estimated age 2306 Mandash2241 Ma (Fig 2 Table 2)Duration 065 million yearsRemarks Martini (1971) defined Zone NN1 by thedisappearance of Helicosphaera recta and the appear-ance of Discoaster druggii The following zone NN2encompasses the interval from the D druggii biohori-

Biozonation and biochronology of Miocene through Pleistocene calcareous nannofossils 225

Table 1 Biohorizons used for definitions of Miocene biozones

J Backman et al226

T Discoaster quinqueramus (553)

CNM6

CNM5

D hamatus TRZ

Okada amp MartiniCALCAREOUS NANNOFOSSIL ZONES

A primus BZ

D signus CRZ

this study

60

70

80

90

100

110

120

130

140

150

160

170

180

190

240

200

210

220

230

T Nicklithus amplificus (598)

B Nicklithus amplificus (682)

B Amaurolithus primus (739)

B Discoaster berggrenii (820)

T Discoaster hamatus (965)T Catinaster

T Catinaster coalitus (970)

Ba R pseudoumbilicus (880)

Ta R pseudoumbilicus (709)

Bc Discoaster surculus

B Discoaster pentaradiatusB Discoaster loeblichii Discoaster neorectus

B Catinaster

Bc Discoaster kugleri (1188)Tc Discoaster kugleri (1160)

T Sphenolithus heteromorphus (1353)

Tc Cyclicargolithus floridanus

T Helicosphaera ampliaperta (1486)

B Sphenolithus heteromorphus (1775)

B Sphenolithus belemnos (1901)

Tc Discoaster deflandrei (1569)

T Coccolithus miopelagicus (1094)

T Triquetrorhabdulus carinatus (1918)

B Catinaster calyculus (1071)

T Coronocyclus nitescensTc Calcidiscus premacintyrei (1257)

T Cyclicargolithus floridanus


B Discoaster signus (1573)

CNM11

CNM4

CNM7

CNM8

CNM9

CNM12

CNM13

B Sphenolithus disbelemnos (2241)

B Sphenolithus delphix (2338)

X Helicosphaera euphratis H carteri (2089)

B Helicosphaera ampliaperta (2043)

Tc T carinatus (2210)

CNM1

CNM2

CNM3

CNM18

CNM17

CNM16

CNM15

CNM14

CNM19

NN2CN1c

CN1b

CN2

CN3

CN4

NN3

NN4

NN6

NN7

NN8

CN5a

NN9

NN10

NN11

NN5

CN5b

CN6

CN8b

CN8a

CN7

CN9b

CN9a

S conicus PRZ

S disbelemnos T carinatus CRZ

C3An

50CNPL1 C acutus TRZ

T rugosus PRZ

D quinqueramus TZ

N amplificus TRZ

D berggrenii BZ

D bellus BZ

R pseudoumbilicusPRZ

C coalitus BZ

S heteromorphusBZ

CNM10

Dvariabilis PRZ

C exilis PRZ

D kugleri TRZ

S belemnos BZ

H carteri PRZ

H carteri PRZ

B Discoaster bellus

B Ceratolithus acutus (536)

C6Cn

C3Ar

C4n

C4Ar

C3Br

C4An

C4r

C5r

C5n

C5Ar

C5An

C5AAnC5AArC5ABnC5ABr

C5ACn

C5ADn

C5BnC5ADr

C5ACr

C5Br

C5Cn

C5Dn

C5En

C5Cr

C5Dr

C6n

C6r

C6AAr

C6Ar

C6Bn

C6An

C6Br

C6Cr

C5Er

C3n

C3rNN12CN10b

GPTS Epoch

B Discoaster druggii (2259)

CN1a

B Ceratolithus atlanticus (539)

MIO

CE

NE

OLI

GO

-

late

mid

dle

early

late

T Minylitha convallis

B Discoaster neohamatus (1047)

Ta Cyclicargolithus abisectus

CN10a

NN1T Helicosphaera recta

NP25

Bc Reticulofenestra pseudoumbilicus

B Minylitha convallis

BIOHORIZONSprimary and additional

T Sphenolithus belemnos (1796)

CNM20

C premacintyrei TZ

T Sphenolithus delphix (2306)

B Discoasterhamatus (1049)

coalitus (1079)

calyculus (965)

Bukry 1980 1971Stage

Mes

sini

an

Zancl

Torto

nian

Ser

aval

lian

Lang

hian

Bur

diga

lian

Aqu

itani

anC

hatt-

ian

CE

NE

Age (Ma)

Oligocene biozone

Fig 2 Miocene through Pleistocene biozones and biohorizons are plotted versus the biozonations of Martini (1971) andOkada and Bukry (1980) and the Geomagnetic Polarity Time Scale (GPTS Lourens et al 2004) Abbreviations are ex-plained in the text and in Table 1 Zancl = Zanclean


Table 2 Age estimates of biohorizons Biohorizons defining biozone boundaries are marked in bold mcd ndash meters com-posite depth Acronyms used for depth and age columns are SC97 ndash Shackleton and Crowhurst 1997 DAS95 ndashSchneider 1995 LL04 ndash Lourens et al 2004 PAumlL06 ndash Paumllike et al 2006 PAumlL07 ndash Paumllike et al 2007

1 (y) ndash younger side of geomagnetic polarity chron (o) ndash older side of geomagnetic polarity chron

zon to the disappearance of T carinatus Okada andBukry (1980) employed the interval between the dis-appearances of Sphenolithus ciperoensis and Dicty-ococcites bisectus and the end of the ldquoacmerdquo of Cycli-cargolithus abisectus to define Subzone CN1a the interval between the C abisectus biohorizon and theappearance of D druggii to define Subzone CN1b andthe interval between the D druggii biohorizon and the appearance of Sphenolithus belemnos to defineSubzone CN1c However the biohorizons provided by H recta D druggii T carinatus D bisectus andC abisectus all show problematic distributions as ex-pressed for example by Rio et al (1990b p 182ndash183) ldquoHelicosphaera recta rarely occur in oceanicsediments [ ] because H recta and D bisectus arerare the established relationships may be of only localvaluerdquo They also remark that ldquono acme was recog-nized [ ] of C abisectus Medium-sized C abisectusare distributed as high as up as the lower part of ZoneNN4 with no increase in abundance evident in the interval between the LO of S ciperoensis and the FOof D druggiirdquo Rio et al furthermore discuss the prob-lems of the sporadic occurrences of D druggii and noticed the ldquoshort acme interval of Sphenolithus del-phix slightly below the FO of D druggii at all thesites investigatedrdquo At Site 709 in the tropical IndianOcean D druggii appears 3 m above the disappear-ance of S delphix within a single core (Core 709C-21X) (Fornaciari 1996) This suggests that D druggiihas a time transgressive appearance probably occur-ring a few hundred thousand years earlier in the tropi-

cal Indian Ocean compared to its first rare occurrencesin the central tropical Pacific Ocean (Table 4) In con-clusion the set of biohorizons employed by Martini(1971) and Okada and Bukry (1980) for biostrati-graphic subdivision of the uppermost Oligocenethrough lowermost Miocene stratigraphy is presentlyconsidered to be of limited quality

An abundance plot of the two taxa used for definingZone CNM1 is shown in Figure 3 The Oligocene-Miocene boundary at 23030 Ma (Lourens et al 2004)falls 30 ka after the onset of Zone CNM1 (Fig 2)shortly after the disappearance of S delphix

Name Zone CNM2 ndash Triquetrorhabdulus carinatusSphenolithus disbelemnos Concurrent Range ZoneDefinition Concurrent range of the nominate taxa be-tween the Base of S disbelemnos and the Top of com-mon T carinatusReference section ODP Site 1218 (central part oftropical Pacific Ocean)Estimated age 2241 Mandash2210 Ma (Fig 2 Table 2)Duration 031 million yearsRemarks This zone corresponds to the lower parts ofboth Zone NN2 of Martini (1971) and Subzone CN1cof Okada and Bukry (1980) respectivelyRemarks on assemblages In this short biostrati-graphic interval the nominate taxon S disbelemnos isnot particularly abundant but is consistently recordedin the low latitude Indian Pacific and Atlantic oceans(Rio et al 1990 ndash referred to as S dissimilis ndash S belem-nos intergrade Fornaciari et al 1993 ndash referred to as

J Backman et al228


2 Unpublished PhD thesis plot shown in this study3 Paumllike et al (2005) rmcd ndash revised meters composite depth4 httpdoipangaeade101594PANGAEA547797 Paumllike et al (2006 reference 7)5 This biohorizon occurs 3 m above Top S delphix in the Indian Ocean ODP Hole 709C (Fornaciari 1996 see 2

above)

S dissimilisS belemnos Paumllike et al 2006 Shackle-ton et al 2000) and in the Mediterranean region in-cluding the OligoceneMiocene GSSP Section ofLemme Carrosio (Fornaciari and Rio 1996 Raffi1999) An abrupt decrease in abundance of T carina-tus has been observed well prior to its exinction in low-er latitudes which provides a more distinct biohorizonthan its final disappearance At ODP Site 1218 (Fig 4)the decrease occurs over a 10 cm interval from an av-erage of 24 specimens per mm2 in 79 samples abovethe decrease to an average of 415 specimens per mm2

in 149 samples below the decrease Here the changethus represents a factor of six decrease in abundanceThe Top of common T carinatus is near identical interms of age in tropical Pacific Site 1218 (2210 MaTable 2) and tropical Atlantic Site 929 (2203 MaFlower et al 1997 Shackleton et al 2000 age esti-mates converted to the La_2004 astronomical solutionby Heiko Paumllike)

Name Zone CNM3 ndash Helicosphaera euphratis PartialRange ZoneDefinition Biostratigraphic interval between the Topof common T carinatus and the abundance cross-overbetween H euphratis and H carteriReference section ODP Site 1218 (lower biohorizon)and ODP Site 926 (upper biohorizon)Estimated age 2210 Mandash2089 Ma (Fig 2 Table 2)Duration 121 million yearsRemarks This zone corresponds to an interval in thelower part of Zone NN2 of Martini (1971) as well asof Subzone CN1c of Okada and Bukry (1980) Theuse of a biohorizon provided by an abundance cross-over is a modified version of the Partial Range Zoneconcept as presented by Wade et al (2011) This abun-dance cross-over provides a useful biohorizon how-ever to subdivide the relatively poorly resolved bios-tratigraphic interval of the lower MioceneRemarks on assemblages Data showing the cross-over between H euphratis and H carteri were origi-nally presented by Fornaciari (1996) and here plottedin Figure 5


B Sphenolithus disbelemnos

Number of specimens per mm 2

B Sphenolithus delphix

T Sphenolithus delphix

C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n

Fig 3 Abundances of taxa defining biozones across theOligocene-Miocene boundary at ODP Site 1218 in the trop-ical Pacific Ocean Positions of geomagnetic polarity chronsand revised meters composite depths (rmcd) are from Paumllikeet al (2005) Abundances of taxa are expressed as numbersper unit area on the smear-slides investigated

200 400 600 800 1000

80

85

90

95

100

Tc Triquetrorhabdulus carinatus


CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one

Fig 4 The sharp 6-fold decrease in abundance of T cari-natus to values here at ODP Site 1218 in the tropical Pacif-ic Ocean defines the Tc T carinatus biohorizon Positions ofgeomagnetic polarity chrons and revised meters compositedepths (rmcd) are from Paumllike et al (2005) Abundances oftaxa are expressed as numbers per unit area on the smear-slides investigated The OligoceneMiocene boundary is de-fined at the base of Chron C6C2n (Lourens et al 2004)

Name Zone CNM4 ndash Helicosphaera carteri PartialRange ZoneDefinition Partial range of the nominate taxon be-tween the abundance crossover between H euphratisand H carteri and the Base of Sphenolithus belem-nosReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 2089 Mandash1901 Ma (Fig 2 Table 2)Duration 189 million yearsRemarks This zone corresponds to the upper parts ofZone NN2 of Martini (1971) and Subzone CN1c ofOkada and Bukry (1980) The use of a biohorizon

provided by an abundance cross-over is a modifiedversion of the Partial Range Zone concept as present-ed by Wade et al (2011)Remarks on assemblages Base of Helicosphaeraampliaperta occurs in the lower part of this biozoneAn overlap in the ranges between T carinatus andS belemnos was demonstrated by Fornaciari et al(1990) from the Indian Ocean and by Raffi et al(2006) from the Atlantic Ocean Previously Perch-Nielsen (1985 p 443) remarked that ldquoThe FO ofS belemnos [ ] usually is found slightly below theLO of T carinatusrdquo Low abundances in combinationwith sporadic occurrences of T carinatus toward the

J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100

H carteriH euphratis

Dep

th (m

cd) i

n O

DP

Hol

e 92

6B

Proportional relationship () of two helicosphaerid taxa

400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4

Fig 5 Abundance cross-over between H euphratis (dotted line) and H carteri (solid line) from ODP Hole 926B in thewestern tropical Atlantic Ocean (Fornaciari 1996) Upper inserted panel shows an enlargement of the critical interval whichdefines the CNM3CNM4 biozone boundary

end of its range makes this marker less reliable (Raffiet al 2006)

Name Zone CNM5 ndash Sphenolithus belemnos BaseZoneDefinition Biostratigraphic interval between the Baseof the nominate taxon S belemnos and the Base ofcommon Sphenolithus heteromorphusReference section ODP Site 926 (lower boundary)and ODP Site 925 (upper boundary)Estimated age 1901 Mandash1775 Ma (Fig 2 Table 2)Duration 126 million yearsRemarks This zone corresponds to Zone CN2 ofOkada and Bukry (1980) and encompasses most ofZone NN3 of Martini (1971)Remarks on assemblages This biostratigraphic in-terval corresponds to the common and continuousrange of the nominate taxon S belemnos that shows asharp decrease in abundance at the top of the biozoneoccurring about 02 million years prior to the appear-ance of S heteromorphus (Fig 6) The calibration ob-tained for the latter biohorizon at ODP Site 926 (thisstudy) conforms (within 001 million years) with thecalibration suggested by shipboard data at ODP Site925 (Curry Shackleton et al 1995)

Name Zone CNM6 ndash Sphenolithus heteromorphusBase ZoneDefinition Biostratigraphic interval between the Baseof the common nominate taxon S heteromorphus andthe Base of Discoaster signusReference section ODP Site 925 (western tropicalAtlantic Ocean)Estimated age 1775 Mandash1573 Ma (Fig 2 Table 2)Duration 202 million yearsRemarks This zone approximately corresponds tothe lower part of Zone NN4 of Martini (1971) and isnearly identical to Zone CN3 of Okada and Bukry(1980) The latter used the end of the acme of D de-flandrei to define the top of Zone CN3 whereas the ap-pearance of D signus is used here as a zonal boundarymarker Rio et al (1990) introduced ldquothe drop in abun-dance below 30 of D deflandrei and the concomi-tant appearance of the D tuberi ndash D signus group todistinguish the NN4 (CN3) and NN5 (CN4) Zones insites where H ampliaperta is missingrdquo The Base ofD signus and the Top of common (Tc) D deflandreiare separated only by 004 million years (Table 2Fig 7)Remarks on assemblages The genus Calcidiscus ap-pears within this biostratigraphic interval


316

318

320

322

324

3260 5 10 15

0 20 40 60 80

Magnetic susceptibility

Sphenolithus heteromorphusSphenolithus belemnos

Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200


ODP 926A (Nmm2) ODP 926B (Nmm2)

CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a

Fig 6 Disappearance of S belemnos and appearance of S heteromorphus as recorded in ODP Site 926 The abundance dis-tributions of the two taxa are expressed as number of specimens per unit area of the smear-slide (Nmm2) Peaks and troughsldquoardquo to ldquofrdquo in magnetic susceptibility shows a striking correlation between Holes 926A and 926B in a critical interval

Name Zone CNM7 ndash Discoaster signusSphenolithusheteromorphus Concurrent Range ZoneDefinition Biostratigraphic interval between the Baseof the nominate taxon D signus and the Top of S het-eromorphusReference section ODP Site 925 (lower boundary)and ODP Site 926 (upper boundary)Estimated age 1573 Mandash1353 Ma (Fig 2 Table 2)Duration 220 million yearsRemarks The upper part of this zone corresponds toZone NN5 of Martini (1971) Zone CN4 of Okada andBukry (1980) used two biohorizons to define the baseof Zone CN4 (Sphenolithus heteromorphus Zone)namely Top common D deflandrei and Top Heli-cosphaera ampliaperta which are separated by about08 million years (Table 2) Here Top H ampliapertait is not used for a zonal boundary marker due to thediscontinuous and scattered distribution in its upperrange The appearance of D signus occurs close to thedistinct decrease in abundance (Tc) of D deflandrei inthe tropical Indian Pacific and Atlantic (Fig 7)oceans and in the mid-latitude South Atlantic (Rio etal 1990 Shackleton et al 1995 Raffi et al 2006 Za-chos et al 2004)Remarks on assemblages Calcidiscus premacintyreiappears and gradually increase in abundance withinthis biostratigraphic interval In Mediterranean sec-tions the upper part of this biostratigraphic interval ischaracterised by the common presence of the small

Helicosphaera walbersdorfensis that provides a use-ful biohorizon for regional biostratigraphy (Fornaciariet al 1996)

There exists some confusion regarding the taxo-nomic status of D signus We consider that D signusis a valid species and that Discoaster petaliformisMoshkovitz and Ehrlich (1980) and D tuberi(Filewicz 1985) both are junior synonyms of D signusBukry (1971) In Nannotax (httpnannotaxorgcon-tentdiscoaster-petaliformis December 2011) how-ever it is argued that ldquoThis form was independently il-lustrated by Filewicz (1985) as D tuberi Theodoridis(1984) as D signus and Moshkovitz amp Ehrlich (1980)as D petaliformis The forms illustrated are of thesame age (NN4ndash5) and extremely similar They areclearly the same taxon and given their distinctive formand restricted range it is useful to distinguish themD signus is an inappropriate name for them sinceD signus as described by Bukry (1971) lacks centralknobsrdquo The last statement is inconsistent with Bukryrsquos(1971 p 48) description ldquoa prominent knob forms thehub for the six equally spaced raysrdquo And under re-marks Bukry continues ldquoThe long slender bifurcationat the end of the rays and the prominent central knobin association with the long slender rays combine toproduce the diagnostic appearance of the speciesrdquo

Name Zone CNM8 ndash Calcidiscus premacintyrei TopZone

J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925

Relative abundance ()0 10 20 30 40 50 60 70 80

D signus D deflandrei

Fig 7 Appearance of D signus and sharp decrease in abun-dance of D deflandrei in ODP Site 925 from the westerntropical Atlantic Ocean Both categories represent relativeabundances versus the total number of all Discoaster spp

276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926

Calcidiscus premacintyrei (specimensmm2)

CN

M8

CN

M9

275

Fig 8 Disapperance of C premacintyrei as recorded inODP Hole 926B

Definition Biostratigraphic interval between the Topof S heteromorphus and the Top of continuous nomi-nate taxon C premacintyreiReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 1353 Mandash1257 Ma (Fig 2 Table 2)Duration 096 million yearsRemarks This zone corresponds to the lower parts ofboth Zone NN6 of Martini (1971) and Subzone CN5aof Okada and Bukry (1980)Remarks on assemblages The final part of the rangeof Calcidiscus premacintyrei is shown in Figure 8Cyclicargolithus floridanus sharply decreases in abun-dance while Reticulofenestra pseudoumbilicus andTriquetrorhabdulus rugosus begin to occur continous-ly within this biostratigraphic interval Specimens be-longing to the Discoaster exilis group prevail withinthe Discoaster assemblages of the biozone

Name Zone CNM9 ndash Discoaster variabilis PartialRange ZoneDefinition Partial range of the nominate taxon be-tween the Top of common C premacintyrei and theBase of common Discoaster kugleriReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 1257 Mandash1188 Ma (Fig 2 Table 2)Duration 068 million yearsRemarks This zone corresponds to the upper parts ofboth Zone NN6 of Martini (1971) and Subzone CN5aof Okada and Bukry (1980)Remarks on assemblages The successive disappear-ances of Coronocyclus nitescens Cyclicargolithusfloridanus and Triquetrorhabdulus serratus occurwithin this biozone whereas Calcidiscus macintyreigradually increases in abundance

Name Zone CNM10 ndash Discoaster kugleri TotalRange ZoneDefinition Biostratigraphic interval characterised bythe total range of common nominate taxon D kugleriReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 1188 Mandash1160 Ma (Fig 2 Table 2)Duration 028 million yearsRemarks This zone corresponds to the lowermostparts of both Zone NN7 of Martini (1971) and Sub-zone CN5b of Okada and Bukry (1980)Remarks on assemblages Among the Discoaster as-semblages six-ray stubby forms prevail includingD kugleri Discoaster musicus and Discoaster bollii

The interval of common and continuous presence ofD kugleri has been observed in the tropical Pacificmid-latitude northern and tropical Atlantic and in theMediterranean (Raffi et al 1995 Backman and Raffi1997 Hilgen et al 2003)

Name Zone CNM11 ndash Discoaster exilis Partial RangeZoneDefinition Partial range of the nominate taxon be-tween the Top of common D kugleri and the Base ofCatinaster coalitusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 1160 Mandash1079 Ma (Fig 2 Table 2)Duration 081 million yearsRemarks This zone encompasses the upper 80 ofboth Zone NN7 of Martini (1971) and Subzone CN5bof Okada and Bukry (1980)Remarks on assemblages In the tropical Atlantic andthe Mediterranean Coccolithus miopelagicus disap-pears within upper CNM11 In the tropical Pacifichowever this species disappears within Zone CNM12about 033 million years later In the Mediterraneansections the disappearance of representatives of smallhelicoliths such as H walbersdorfensis and Heli-cosphaera stalis occurs within this biostratigraphicinterval and provides biohorizons useful for regionalbiostratigraphy (Fornaciari et al 1996)

Name Zone CNM12 ndash Catinaster coalitus Base ZoneDefinition Biostratigraphic interval between the Baseof the nominate taxon C coalitus and the Base of Dis-coaster hamatusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 1079 Mandash1049 Ma (Fig 2 Table 2)Duration 030 million yearsRemarks This zone corresponds to Zones NN8 ofMartini (1971) and CN6 of Okada and Bukry (1980)Remarks on assemblages This short biostratigraphicinterval marks the beginning of a series of subsequentappearances and extinctions of taxa occurring trough-out the late Miocene It is characterised by the appear-ance of the first star-shaped asteroliths with pointed slen-der rays namely Discoaster brouweri (6 rays) and Dis-coaster bellus (5 rays) and the presence of Discoastercalcaris The genus Catinaster evolves within the bio-zone whereas D exilis disappears in its upper part

Name Zone CNM13 ndash Discoaster hamatus TotalRange Zone


Definition Biostratigraphic interval characterisedby the total range of the nominate taxon D hamatusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 1049 Mandash965 Ma (Fig 2 Table 2)Duration 084 million yearsRemarks This zone corresponds to Zones NN9 ofMartini (1971) and CN7 of Okada and Bukry (1980)Remarks on assemblages Shortly after the appear-ance of the nominate taxon D hamatus the six-rayedDiscoaster neohamatus occurs Discoaster bolliiC coalitus and Catinaster calyculus disappear close tothe top of the biozone

Name Zone CNM14 ndash Reticulofenestra pseudoum-bilicus Partial Range ZoneDefinition Partial range of the nominate taxon be-tween the Top of D hamatus and the Base of the in-terval of absence (Ba) of R pseudoumbilicusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 965 Mandash880 Ma (Fig 2 Table 2)Duration 085 million yearsRemarks This zone corresponds to the lower parts ofZone NN10 of Martini (1971) and Zone CN8 of Oka-da and Bukry (1980) respectively Bukry (1978) usedthe appearance of both Discoaster neorectus and Dis-coaster loeblichii to define the top of the Discoasterbellus Subzone (top of CN8a) Among the adjacent bio-horizons (Base D loeblichii Base D neorectus orBase Discoaster pentaradiatus) the Base of absence in-terval (Ba) of R pseudoumbilicus is here considered torepresent a more useful criterion for zonal boundarydefinitionRemarks on assemblages Minylitha convallis andDiscoaster pentaradiatus appear within this biozoneThe use of the Ba concept for defining the top of thisbiozone differs from the strict definition of a PartialRange Zone as presented by Wade et al (2011)

Name Zone CNM15 ndash Discoaster bellus Base ZoneDefinition Biostratigraphic interval between the Baseof the interval of absence of R pse udoumbilicus andthe Base of Discoaster berggreniiReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 880 Mandash820 Ma (Fig 2 Table 2)Duration 060 million yearsRemarks This zone corresponds to the upper parts ofZone NN10 of Martini (1971) and Zone CN8 of Oka-da and Bukry (1980) respectively The use of the

Base absence concept for definition of the base of thisbiozone differs from the strict definition of a BaseZone as presented by Wade et al (2011)Remarks on assemblages The interval of almost to-tal absence of R pseudoumbilicus in upper Miocenesediments (the so-called ldquoR pseudoumbilicus para-cmerdquo) has been observed in different ocean basinsfrom the tropical Indian Pacific and Atlantic oceans tothe Mediterranean (Rio et al 1990b Gartner 1992Takayama 1993 Young 1990 Raffi and Flores 1995Backman and Raffi 1997 Raffi et al 2003) Discoast-er bellus and transitional forms between this speciesand Discoaster berggrenii occur within the biozoneThis biozone also holds e g in the tropical PacificOcean the short-ranging Discoaster loeblichii andDiscoaster neorectus which Bukry (1978) used in hisbiozonation

Name Zone CNM16 ndash Discoaster berggrenii BaseZoneDefinition Biostratigraphic interval between the Baseof the nominate taxon D berggrenii and the Base ofAmaurolithus primusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 820 Mandash739 Ma (Fig 2 Table 2)Duration 081 million yearsRemarks This zone corresponds to the lower part ofZone NN11 of Martini (1971) and Subzone CN9a ofOkada and Bukry (1980)Remarks on assemblages Discoaster quinqueramusappears just after the nominate taxon D berggreniiand with Discoaster surculus characterises the Dis-coaster assemblages Minylitha convallis disappearswithin this biozone

Name Zone CNM17 ndash Amaurolithus primus BaseZoneDefinition Biostratigraphic interval between the Baseof the nominate taxon Amaurolithus primus and theBase of Nicklithus amplificusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 739 Mandash682 Ma (Fig 2 Table 2)Duration 057 million yearsRemarks This zone corresponds to the middle part ofZone NN11 of Martini (1971) and to Subzone CN9bof Okada and Bukry (1980)Remarks on assemblages The beginning of the lateNeogene horseshoe-shaped nannolith composite line-age (Amaurolithus ndash Nicklithus ndash Ceratolithus) marks

J Backman et al234

the Base of this biozone by the genus Amaurolithusevolving from Triquetrorhabdulus rugosus (Raffi et al1998) The appearance of Amaurolithus primus isclosely followed by Amaurolithus delicatus The inter-val of absence of R pseudoumbilicus ends within thisbiozone (Ta R pseudoumbilicus biohorizon in Fig 2)

Name Zone CNM18 ndash Nicklithus amplificus TotalRange ZoneDefinition Biostratigraphic interval characterised bythe total range of the nominate taxon N amplificusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 682 Mandash598 Ma (Fig 2 Table 2)Duration 083 million yearsRemarks This zone corresponds to an interval in theupper part of Zone NN11 of Martini (1971) and to themiddle part of Subzone CN9b of Okada and Bukry(1980)Remarks on assemblages The short range of N am-plificus bracketing Chron C3An shows isochronyamong tropical locations (Krijgsman et al 1999)Amaurolithus primus A delicatus and related transi-tional forms characterise the nannofossil assemblagesof this biozone

Name Zone CNM19 ndash Discoaster quinqueramus TopZoneDefinition Biostratigraphic interval between the Topof N amplificus and the Top of the nominate taxonD quinqueramusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 598 Mandash553 Ma (Fig 2 Table 2)Duration 045 million yearsRemarks This zone corresponds to the uppermostparts of Zone NN11 of Martini (1971) and SubzoneCN9b of Okada and Bukry (1980) respectivelyRemarks on assemblages Discoaster quinqueramusis a major component of the Discoaster assemblages inthe uppermost Miocene interval where it gradually re-places D berggrenii Transitional forms between thetwo species are frequent in this biozone together withD pentaradiatus D surculus D variabilis and verylarge ( 30 μm) specimens of D brouweri

Name Zone CNM20 ndash Triquetrorhabdulus rugosusPartial Range ZoneDefinition Partial range of the nominate taxon be-tween the Top of D quinqueramus and the Base ofC acutus

Reference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 553 Mandash536 Ma (Fig 2 Table 2)Duration 017 million yearsRemarks This zone corresponds to the lowermostpart of Zone NN12 of Martini (1971) and to SubzoneCN10a of Okada and Bukry (1980)Remarks on assemblages Horseshoe-shaped nanno-liths of the genus Ceratolithus evolve within this bios-tratigraphic interval branching from T rugosus (Raffiet al 1998) Different species of the Ceratolithus line-age characterise the nannofossil assemblages in thelower Pliocene interval

5 Biozone definitions in thePliocenendashPleistocenendashRecentinterval

The definitions of the CNPL biozones are summa-rized in Table 3 Age estimates of zonal boundarymarkers and additional biohorizons in the Pliocene-Pleistocene interval are summarized in Table 4 Theaverage error of age estimates for the 27 Pliocene-Pleistocene biohorizons is 0007 million years asdeduced from Table 4 (depth uncertainty divided bysedimentation rate) An overview of the CNPL zona-tion in a chronostratigraphic context and compari-son with Okada and Bukryrsquos (1980) and Martinirsquos(1971) Pliocene-Pleistocene zonations is shown inFigure 9

Name Zone CNPL1 ndash Ceratolithus acutus TaxonRange ZoneDefinition Biostratigraphic interval characterised bythe total range of the nominate taxon C acutusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 536 Mandash505 Ma (Fig 9 Table 4)Duration 031 million yearsRemarks This zone corresponds approximately tothe upper part of Zone NN12 of Martini (1971) whoused the appearance of Ceratolithus rugosus to defineBase NN12 This zone corresponds to Subzone CN10bof Okada and Bukry (1980) although Bukry (1978)used four taxa to define the subzonal boundaries whichwere subsequently employed by Okada and Bukry(1980) its base by the appearance of C acutus and thedisappearance of Triquetrorhabdulus rugosus and itstop by the disappearance of C acutus and the appear-


ance of C rugosus These two pairs of bioevents areseparated in time by 30 ka (top Subzone CN10b) and130 ka (base Subzone CN10b) (Table 2) respectiv elyThe MiocenendashPliocene boundary at 5332 Ma (Lou -rens et al 2004) falls shortly (28 ka) after the onset ofZone CNPL1Remarks on assemblages Within this biozone thepeculiar species Ceratolithus atlanticus and Cerato -lithus larrymayeri (Raffi et al 1998) occur concomi-

tantly with the disappearance of T rugosus in a shortdistinct interval that precedes the appearance of Cera-tolithus rugosus

Name Zone CNPL2 ndash Sphenolitus neoabies PartialRange ZoneDefinition Partial range of the nominate taxon be-tween the Top of C acutus and the Base of commonDiscoaster asymmetricus

J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55

B Emiliania huxleyi (029)

T Pseudoemiliania lacunosa (043)

T Calcidiscus macintyrei (160)

Ta Gephyrocapsa

T Discoaster brouweri (193)

T Discoaster pentaradiatus (239)

T Discoaster surculus (253)

T Discoaster tamalis (276)

T Reticulof pseudoumbilicus (382)

T Sphenolithus spp (361)

TCeratolithus acutus (504)


TTriquetrorhabdulus rugosus (523)


Tc Reticulofenestra asanoi (091)

Bc Reticulofenestra asanoi (114)

T Gephyrocapsa

B Gephyrocapsa

Bc Discoaster triradiatus (216)

B Ceratolithus larrymayeri (533)

B Gephyrocapsa

Bc Discoaster asymmetricus (404)

T Amaurolithus primus (458)

CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19

B Ceratolithus rugosus (508)C acutus TRZ

D pentaradiatusTZ

Okada amp Martini

CALCAREOUS NANNOFOSSIL ZONES BIOHORIZON

Dasymmetricus R pseudoumbilicus CRZ

D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ

T rugosus PRZDquinqueramus TZ

CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r

T Helicosphaera sellii


GPTS

Bc Emiliania huxleyi

PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b

B Pseudoemiliania lacunosa

B Helicosphaera sellii

Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa

Fig 9 Pliocene and Pleistocene biozones and biohorizons plotted versus ldquostandardrdquo zonations (Okada and Bukry 1980Martini 1971) and the Geomagnetic Polarity Time Scale (GPTS Lourens et al 2004) Abbreviations are explained in thetext Middle and late Pleistocene stages are not yet formally defined Bc Emiliania huxleyi is time transgressive (Thiersteinet al 1977) and marked with an interval rather than a line


Table 3 Biohorizons used for definitions of Pliocene and Pleistocene biozones

Table 4 Age estimates of biohorizons Biohorizons defining biozone boundaries are marked in bold mcd ndash meters com-posite depth Acronyms used for depth and age columns are VG90 ndash Vergnaud Grazzini et al 1990 LR05 ndash Lisiec-ki and Raymo 2005 RAY89 ndash Raymo et al 1989 SC97 ndash Shackleton and Crowhurst 1997

1 Numbers in brackets refer to Marine Isotope Stage (MIS) boundaries

Reference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 505 Mandash404 Ma (Fig 9 Table 4)Duration 101 million yearsRemarks Taxonomic ambiguities of the Amau-rolithus ndash Ceratolithus lineage during the early 1970s(Gartner 1969 Gartner and Bukry 1975) in combina-tion with low abundances of the critical biohorizonsmake the lower Pliocene zonations of Martini (1971)and Bukry (1973a) problematic Martini used BaseDiscoaster asymmetricus and Top ldquoCeratolithus tri-corniculatusrdquo for subdivision of the NN13NN14 andNN14NN15 zonal boundaries respectively Bukryused two biohorizons for subdivision of SubzoneCN10cCN11a (Top ldquoCeratolithus primusrdquo Top ldquoCer-atolithus tricorniculatusrdquo) and the ldquoBeginning ofacmerdquo of D asymmetricus for subdivision of SubzonesCN11aCN11b without quantifying the ldquoacmerdquo con-cept The appearance interval of D asymmetricus aswell as the disapperance intervals of A primus andA tricorniculatus are characterised by low and discon-tinuous occurrences As a consequence these bio-horizons are still poorly calibrated to independentchronologies Taken together these factors make themless suitable for zonal boundary definitions We haveinvestigated the abundance behavior of D asymmetri-cus at ODP Site 926 (Fig 10) and suggest that the lev-el where D asymmetricus increases to 10 relativeto its ancestor taxon D brouweri represents a suitablecriterion for defining the Base of common (Bc)D asymmetricus This occurs at 404 Ma

Name Zone CNPL3 ndash Discoaster asymmetricusReticulofenestra pseudoumbilicus Concurrent RangeZoneDefinition Concurrent range of the nominate taxa be-tween the Base of common D asymmetricus and theTop of R pseudoumbilicusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 404 Mandash381 Ma (Fig 9 Table 4)Duration 023 million yearsRemarks This zone encompasses Zones NN14 andNN15 of Martini (1971) and Subzone CN11b of Oka-da and Bukry (1980) The Top of R pseudoumbilicusshows synchrony across the low latitude AtlanticOcean (Gibbs et al 2005)Remarks on assemblages In the upper part of thisbiostratigraphic interval the first small and rare spec-imens of Pseudoemiliania lacunosa begin to occur andrare specimens of Discoaster tamalis begin to occur

more consistently The last representative of the genusAmaurolithus A delicatus disappears within this bio-zone Its disappearance horizon may be blurred for rea-sons pointed out by Raffi and Flores (1995) ldquoMisiden-tification occurs in samples that contain nannofossilswith calcite overgrowth and when specimens of differ-ent Amaurolithus and Ceratolithus species possess in-tergrade morphologic features This is the case in mostof the lower Pliocene sequences recovered during Leg138 Ceratolithid species are irregularly distributed andare not easily differentiated because of the presence ofovergrowth and intergrade morphotypesrdquo

Name Zone CNPL4 ndash Discoaster tamalis Top ZoneDefinition Biostratigraphic interval between the Topof R pseudoumbilicus and the Top of the nominate tax-on D tamalisReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 381 Mandash276 Ma (Fig 9 Table 4)Duration 105 million yearsRemarks This zone corresponds to part of ZoneNN16 of Martini (1971) and to Subzone CN12a ofOkada and Bukry (1980) Raffi and Flores (1995table 2) proposed an identical age estimate (276 Ma)for the disappearance of D tamalis from the low lati-tude eastern Pacific Ocean whereas Shackleton et al

J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926

Proportion of D asymmetricus relative to D brouweri ()

CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus

Fig 10 Increase in relative abundance of D asymmetricusrelative to its ancestor species D brouweri The 10 limit isused to define the Bc D asymmetricus biohorizon and theCNPL2CNPL3 biozone boundary The T R pseudoumbili-cus biohorizon defines the CNPL3CNPL4 biozone bound-ary

(1995 tables 4 7) indicated ages ranging from301 Ma (Site 846) to 270 Ma (Site 848) and a ldquobestestimaterdquo of 278 MaRemarks on assemblages The genus Sphenolithusrepresented by the species S abies and S neoabiesdisappears about 02 million years after the onset ofthis biozone

Name Zone CNPL5 ndash Discoaster pentaradiatus TopZoneDefinition Biostratigraphic interval between the Topof D tamalis and the Top of the nominate taxonD pentaradiatusReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 276 Mandash239 Ma (Fig 9 Table 4)Duration 037 million yearsRemarks This zone includes the uppermost part ofZone NN16 and Zone NN17 of Martini (1971) andSubzones CN12b and CN12c of Okada and Bukry(1980) Zone NN17 was established from findings ofrare discoasters in five samples from two core sectionscharacterised by severe drilling disturbance (WintererRiedel et al 1971 p 143) at DSDP Site 62 (Martini1971 Martini and Worsley 1971)Remarks on assemblages The disappearance ofD surculus occurs within the biozone According toBukry (1973a) ldquoThe disappearance of D surculus typ-ically precedes D pentaradiatus but the interval isshort and D surculus survives diagenetic changes andreworking better than D pentaradiatus Therefore forpractical application their disappearances are consid-ered similarrdquo Subsequently when Bukry (1975) es-tablished the D surculus Subzone the interval be-tween the successive disappearances of D tamalis andD surculus he remarked however that ldquoSampling in-terval sedimentation rate and degree of reworkingmay determine whether this brief subzonal interval canbe identifiedrdquo The biostratigraphic distance betweenthe successive disappearances of D surculus andD pentaradiatus (D pentaradiatus Subzone ndash CN12c)is even briefer and Bukry (1975 p 678) did not dis-tinguish the D pentaradiatus Subzone in the investi-gated DSDP Leg 32 sites Our experience is similar toBukryrsquos in that this short biostratigraphic interval of-ten is difficult to distinguish consistently and at somelocations the two taxa seem to disappear simultane-ously Here we hence do not employ Top D surculusfor definition of a zonal boundary

Name Zone CNPL6 ndash Discoaster brouweri Top Zone

Definition Biostratigraphic interval between the Topof D pentaradiatus and the Top of the nominate taxonD brouweriReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 239 Mandash193 Ma (Fig 9 Table 4)Duration 046 million yearsRemarks This zone corresponds to Zone NN18 ofMartini (1971) and to Subzone CN12d of Okada andBukry (1980)Remarks on assemblages The three-rayed morpho-type of D brouweri D triradiatus shows a propor-tional increase relative to D brouweri at about023 million years prior to their mutual disappearanceand extinction of the genus Discoaster at 193 Ma(Backman and Shackleton 1983) shortly after the on-set of Subchron C2n (Olduvai) at 1945 Ma The genusDiscoaster thus existed for about 57 million yearsconsidering the evolutionary appearance of the firstdiscoaster species D mohleri at ca 5893 Ma (Agni-ni et al 2007) Continuous occurrences of small( 4 μm) specimens of the genus Gephyrocapsa arerecorded in the upper part of Zone CNPL6

Name Zone CNPL7 ndash Calcidiscus macintyrei PartialRange ZoneDefinition Partial range of the nominate taxon be-tween the Top of D brouweri and the Base of Gephy-rocapsa ( 4 μm)Reference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 193 Mandash171 Ma (Fig 9 Table 4)Duration 022 million yearsRemarks This zone corresponds to the lowermostpart of Zone NN19 of Martini (1971) Bukry (1973a)employed the successive appearances of Gephyrocap-sa caribbeanica and G oceanica to subdivide the in-terval between Top Discoaster brouweri and TopPseudoemiliania lacunosa Okada and Bukry (1980)codified the three resulting subzones as CN13aCN13b and CN14a A consequence of our differenttaxonomic approach with respect to the use of gephy-rocapsids in Pleistocene biostratigraphy (see remarksunder Zone CNPL8) compared to Bukryrsquos use ofmembers of this genus is that Subzones CN13aCN13b and CN14a are not compatible with the four-fold subdivision we use for the identical biostrati-graphic interval from Zone CNPL7 through ZoneCNPL10 There is hence no precise correspondencebetween the two zonal systems despite the use ofgephyrocapsids in both cases


Remarks on assemblages An increase in abundanceof small ( 4 μm) Gephyrocapsa specimens andH sellii characterise this biostratigraphic interval

Name Zone CNPL8 ndash Gephyrocapsa ( 55 μm)Gephyrocapsa ( 4 μm) Concurrent Range ZoneDefinition Biostratigraphic interval between the Baseof the nominate taxon Gephyrocapsa ( 4 μm) and theTop of Gephyrocapsa ( 55 μm)Reference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 171 Mandash125 Ma (Fig 9 Table 4)Duration 046 million yearsRemarks This zone corresponds to an interval in thelower part of Zone NN19 of Martini (1971) The useof a taxon or rather morphotype in this case that ap-pears within the biozone for definition of its top (TopGephyrocapsa 55 μm) differs from the strict con-cept of a Concurrent Range Zone by Wade et al (2011)Remarks on assemblages The rapid morphologicevolution of the genus Gephyrocapsa during the Pleis-tocene provides a series of biohorizons useful for im-proving the biostratigraphic resolution of the previouszonations of Martini (1971) and Okada and Bukry(1980) For reasons discussed by Raffi et al (1993)we have adopted an informal taxonomic subdivision ofGephyrocapsa based on placolith length This ap-proach has proven successful in terms of biostrati-graphic usefulness in many regions including thewestern and eastern Pacific Ocean the Caribbean Seathe Mediterranean and the North Atlantic It followsthat our zonal boundary definitions are not based onpresenceabsence of single taxa but may include sev-eral gephyrocapsid taxa For example specimensranging from 40 μm to 55 μm in placolith length in-clude both Gephyrocapsa caribbeanica and Gephyro-capsa oceanica Specimens 55 μm include Gephy-rocapsa lumina as well as G oceanica sensu Bukry(1973b p 678) Calcidiscus macintyrei disappears inthe lower part of the biozone just prior to the appear-ance of Gephyrocapsa spp 55 μm The group ofgephyrocapsid placoliths being 40 through 55 μm inlength is often referred to as ldquomedium sizedrdquo in the lit-erature Here it is referred to as Gephyrocapsa spp 4 μm

Name Zone CNPL9 ndash Small Gephyrocapsa PartialRange ZoneDefinition Partial range of the nominate taxon be-tween the Top of Gephyrocapsa ( 55 μm) and the re-entrance of Gephyrocapsa ( 4 μm)

Reference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 125 Mandash106 Ma (Fig 9 Table 4)Duration 019 million yearsRemarks This zone corresponds to an interval with-in Zone NN19 of Martini (1971)Remarks on assemblages The interval of almost totalabsence of what we refer to as medium-sized (40ndash55 μm) and large ( 55 μm) Gephyrocapsa speci-mens (Rio 1982 Raffi et al 1993) delineates the so-called ldquoSmall Gephyrocapsa Zonerdquo of Gartnerrsquos (1977)Pleistocene zonation This interval of absence has beenobserved in different oceanic basins (Gartner 1977 Rio1982 Raffi et al 1993 Wei 1993) and is characterisedby a dominance of small Gephyrocapsa specimens andP lacunosa in nannofossil assemblages In the mid-lat-itude North Atlantic Helicosphaera sellii disappearsshortly after the onset of Zone CNPL9 Reticulofenes-tra asanoi appears in the upper part of this biozone

Name Zone CNPL10 ndash Gephyrocapsa ( 4 μm)Pseudoemiliania lacunosa Concurrent Range ZoneDefinition Concurrent range of the nominate taxa be-tween the Top absence of Gephyrocapsa ( 4 μm) andthe Top of P lacunosaReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 106 Mandash043 Ma (Fig 9 Table 4)Duration 063 million yearsRemarks This zone corresponds to the upper part ofZone NN19 of Martini (1971)Remarks on assemblages The Gephyrocapsa speci-mens that re-enter the stratigraphic record followingthe interval of near-total dominance of gephyrocapsids 4 μm are mostly medium-sized (40ndash55 μm)whereas larger forms ( 55 μm) occur sporadicallyThe 4 μm specimens that reaches prominence againfollowing the absence interval (Zone CNPL9) amongthe gephyrocapsid assemblages contain common toabundant Gephyrocapsa parallela (Hay and Beaudry1973) with its characteristic wide central opening andits bridge nearly aligned with the elliptical placolithrsquosshort axis Gephyrocapsa omega (Bukry 1973b) is ajunior synonym of G parallela The medium-sizedReticulofenestra asanoi decrease in abundance prior toits extinction in the lower part of the biozone Largespecimens of P lacunosa characterise its uppermostdistribution range

Name Zone CNPL11 ndash Ceratolithus cristatus PartialRange Zone

J Backman et al240

Definition Partial range of the nominate taxon be-tween the Top of P lacunosa and the RecentReference section ODP Site 926 (western tropicalAtlantic Ocean)Estimated age 043 Mandash000 Ma (Fig 9 Table 4)Duration 043 million yearsRemarks This zone includes Zones NN20 and NN21of Martini (1971) and Subzone CN14b and ZoneCN15 of Okada and Bukry (1980)Remarks on assemblages Emiliania huxleyi appearswithin this biostratigraphic interval and increases inproportion relative to gephyrocapsids in the upper partof the biozone (Thierstein et al 1977) Subsequentstudies have confirmed the diachrony in this abun-dance cross-over initially pointed out by Thierstein etal (1977) spanning most of the latest glacial cycle(Jordan et al 1996 Findley and Flores 2000 Villa-neuva et al 2002 Baumann and Freitag 2004)

6 Summary

The Miocene through Pleistocene biozonation pre-sented here represents a basic biostratigraphic frame-work for relative dating of marine sediments using cal-careous nannofossils This new biozonation is an up-dated synthesis that relies on what Erlend Martini re-ferred to as a ldquoStandard [ ] zonationrdquo and the low-latitude zonation provided by David Bukry Our bio-zonation however includes several of the biohorizonsthey used for zonal boundary definitions that haveproven to be reliable besides several new biohorizonsWe take into account the biostratigraphic data that wehave produced over nearly three decades from chieflylow and middle latitudes in all three major oceanbasins and the Mediterranean Sea region derived byapplying semi-quantitative methods on high resolutionsampling sets from core material retrieved by theOcean Drilling Program Previously unpublished bios-tratigraphic data showing the abundance behaviour ofsome of the marker species are presented

Age estimates for all biohorizons are presentedwith calibration references for all individual biohori-zons In the Miocene through Pleistocene interval theindependent age control is chiefly provided by astro-nomically tuned cyclostratigraphies

Thirty-one (31) biozones are established that spanthe past 23 million years implying an average durationof about 074 million years for the biozones The spanof duration of indidvidual biozones however variesfrom 015 to 220 million years Pliocene-Pleistocene

zones have an average duration of 048 million yearswhereas the average duration of Miocene biozones is089 million years The longest biozone the Discoast-er signus Concurrent Range Zone encompasses ca50 (220 million years) of the middle Miocene

We employ a limited set of selected biohorizons inthe new biozonation in order to maintain stability tothe scheme and hence avoid introduction of subzonesMost of the new biozones however contains severaladditional biohorizons

Acknowledgements We acknowledge the importanceof past support and continued inspiration provided by thelate Nick Shackleton (1937ndash2006) This research used sam-ples provided by the Integrated Ocean Drilling Program(IODP) sponsored by the US National Science Foundation(NSF) and participating countries under management ofJoint Oceanographic Institutions (JOI) This research hasbeen made possible thanks to support from Stockholm Uni-versity and the Swedish Research Council (JB) by the Uni-versitagrave degli Studi ldquoG drsquoAnnunziordquo (IR) and the Universitagravedegli Studi di Padova (DR EF) Reviews by Sherwood WWise Jr and an anynomous reviewer are gratefully ac-knowledged

References

Agnini C Fornaciari E Raffi I Rio D Roumlhl U West-erhold T 2007 High-resolution nannofossil biochronol-ogy of middle Paleocene to early Eocene at ODP Site1262 Implications for calcareous nannoplankton evolu-tion Marine Micropaleontology 64 215ndash248 doi101016jmarmicro200705003

Agnini C Fornaciari E Giusberti L Grandesso P Lan-ci L Luciani V Muttoni G Paumllike H Rio D Spof-forth D J A Stefani C 2011 Integrated biomagne-tostratigraphy of the Alano section (NE Italy) A propos-al for defining the middlendashlate Eocene boundary GSABulletin 123 841ndash872 doi101130B301581

Backman J Shackleton N J 1983 Quantitative bio -chronology of Pliocene and Pleistocene calcareous nan-nofossils from the Atlantic Indian and Pacific oceansMarine Micropaleontology 8 141ndash170

Backman J Raffi I 1997 Calibration of Miocene nanno-fossil events to orbitally tuned cyclostratigraphies fromCeara Rise In Curry W B Shackleton N J RichterC Bralower T J et al Proceedings ODP Scientific Re-sults 154 (Ocean Drilling Program College Station TX)83ndash99 doi102973odpprocsr1541011997

Baumann K-H Freitag T 2004 Pleistocene fluctuationsin the northern Benguela Current system as revealed bycoccolith assemblages Marine Micropaleontology 52195ndash215


Berggren W A Kent D V van Couvering J A 1985Neogene geochronology and chronostratigraphy InSnel ling N J The chronology of the geological recordLondon Geological Society of London Memoir 10 211ndash260

Berggren W A Kent D V Swisher C C III AubryM-P 1995 A revised Cenozoic geochronology andchronostratigraphy In Berggren W A Kent D VAubry M-P Hardenbol J Geochronology time scalesand global stratigraphic correlation A unified temporalframework for an historical geology Spec Publ SocEcon Paleontol Mineral 54 29ndash212

Berggren W A Pearson P N 2006 Tropical and subtrop-ical planktonic foraminiferal zonation of the Eocene andOligocene In Pearson P N Olsson R K Huber B THemleben C Berggren W A (Eds) Cushman Founda-tion Special Publication 41 29ndash40

Bukry D 1971 Discoaster evolutionary trends Micropale-ontology 17 43ndash52

Bukry D 1973a Low-latitude coccolith biostratigraphiczonation In Edgar N T Saunders J B et al InitialReports DSDP 15 Washington (US Govt Printing Of-fice) 685ndash703 doi102973dsdpproc151161973

Bukry 1973b Coccolith stratigraphy eastern Equatorial Pa-cific Leg 16 Deep Sea Drilling Project In van AndelT H Heath G R et al Initial Reports DSDP 16 Wash-ington (US Govt Printing Office) 653ndash711 doi102973dsdpproc161261973

Bukry D 1975 Coccolith and silicoflagellate stratigraphynorthwestern Pacific Ocean Deep Sea Drilling ProjectLeg 32 In Larson R L Moberly R et al Initial Re-ports DSDP 32 Washington (US Govt Printing Office)677ndash701 doi102973dsdpproc321241975

Bukry D 1978 Biostratigraphy of Cenozoic marine sedi-ments by calcareous nannofossils Micropaleontology 2444ndash60

Bukry D Bramlette M N 1970 Coccolith age determi-nations Leg 3 Deep Sea Drilling Project In MaxwellA E et al Initial Reports DSDP 3 Washington (USGovt Printing Office) 589ndash611 doi102973dsdpproc31181970

Curry W B Shackleton N J Richter C et al 1995 Pro-ceedings ODP Initial Reports 154 (Ocean Drilling Pro-gram College Station TX) 1ndash1111 doi102973odpprocir1541995

Filewicz M V 1985 Calcareous nannofossil biostratigra-phy of the Middle America trench and slope Deep SeaDrilling Project Leg 84 In von Heune R Aubouin Jet al Initial Reports DSDP 84 Washington (US GovtPrinting Office) 339ndash361 doi102973dsdpproc841081985

Findlay C S Flores J A 2000 Subtropical front fluctua-tions south of Australia (45deg 09 S 146deg 17 E) for the last130 ka years based on calcareous nannoplankton MarineMicropaleontology 40 403ndash416

Flower B P Zachos J C Paul H 1997 Milankovitch-scale climate variability recorded near the OligoceneMiocene boundary In Curry W B Shackleton N J

Richter C et al Proceedings ODP Initial Reports 154(Ocean Drilling Program College Station TX) 433ndash439 doi102973odpprocsr1541411997

Fornaciari E 1996 Biocronologia a nannofossili calcareie stratigrafia ad eventi nel Miocene Italiano Unpub-lished Ph D Thesis Universitagrave degli studi di PadovaPadova

Fornaciari E Raffi I Rio D Villa G Backman J Olaf-sson G 1990 Quantitative distribution patterns of Oli -gocene and Miocene calcareous nannofossils from thewestern equatorial Indian Ocean) In Duncan R ABackman J Peterson L C et al Proceedings ODPScientific Results 115 (Ocean Drilling Program CollegeStation TX) 237ndash254 doi102973odpprocsr1151531990

Fornaciari E Backman J Rio D 1993 Quantitative dis-tribution patterns of selected lower to middle Miocenecalcareous nannofossils from the Ontong Java PlateauIn Berger W H Kroenke L W Janecek T R et alProceedings ODP Scientific Results 130 (Ocean DrillingProgram College Station TX) 245ndash258 doi102973odpprocsr1300091993

Fornaciari E Rio D 1996 Latest Oligocene to early mid-dle Miocene quantitative calcareous nannofossil bios-tratigraphy in the Mediterranean region Micropaleontol-ogy 42 1ndash36

Fornaciari E Di Stefano A Rio D Negri A 1996 Mid-dle Miocene quantitative calcareous nannofossil bios-tratigraphy in the Mediterranean region Micropaleontol-ogy 42 37ndash63

Fornaciari E Agnini C Catanzariti R Rio D BollaE M Valvasoni E 2010 Mid-latitude calcareous nan-nofossil biostratigraphy and biochronology across themiddle to late Eocene transition Stratigraphy 7 229ndash264

Gartner S 1969 Correlation of Neogene planktonicforaminifer and calcareous nannofossil zones Transac-tions of the Gulf Coast Association of Geological Soci-eties 19 585ndash599

Gartner S 1971 Calcareous nannofossils from the JOIDESBlake Plateau cores and revision of Paleogene nannofos-sil zonation Tulane Stud Geol 8 101ndash121

Gartner S 1977 Calcareous nannofossil biostratigraphyand revised zonation of the Pleistocene Marine Micropa-leontology 2 1ndash25

Gartner S 1992 Miocene nannofossil chronology in theNorth Atlantic DSDP Site 608 Marine Micropaleontol-ogy 18 307ndash331

Gartner S Bukry D 1975 Morphology and phylogeny ofthe coccolithophycean family Ceratolithaceae Journal ofResearch of the US Geological Survey 3 451ndash465

Gibbs S J Young J R Bralower T J Shackleton N J2005 Nannofossil evolutionary events in the mid-Pliocene an assessment of the degree of synchrony in theextinctions of Reticulofenestra pseudoumbilicus andSphenolithus abies Palaeogeography Palaeoclimatol-ogy Palaeoecology 217 155ndash172 doi101016jpal -aeo200411005

J Backman et al242

Haq B U 1973 Evolutionary trends in the Cenozoic coc-colithophore genus Helicopontosphaera Micropaleontol-ogy 19 32ndash52

Hay W W Mohler H Roth P H Schmidt R RBoudreaux J E 1967 Calcareous nannoplankton zona-tion of the Cenozoic of the Gulf Coast and CaribbeanndashAntillean area and transoceanic correlation Transactionsof the Gulf Coast Association of Geological Societies 17428ndash480

Hay W W Beaudry F M 1973 Calcareous nannofossils ndashLeg 15 Deep Sea Drilling Project In Edgar N T Saun-ders J B et al Initial Reports DSDP 15 Washington(US Govt Printing Office) 625ndash683 doi102973dsdpproc151151973

Hilgen F J Abdul Aziz H Krijgsman W Raffi I Tur-co E 2003 Integrated stratigraphy and astronomicaltuning of the Serravallian and lower Tortonian at Montedei Corvi (middle upper Miocene northern Italy) Palaeo-geograpy Palaeoclimatology Palaeoecology 199 299ndash264 doi101016S0031-0182(03)00505-4

Jordan R W Shao M Eglinton G Weaver P P E 1996Coccolith and alkenone stratigraphy at a NW Africa up-welling site (ODP658C) over the last 130000 years InMoguilevsky A Whatley R (Eds) Microfossils andoceanic environments University of Wales AberystwythPress 111ndash130

Krijgsman W Hilgen F Raffi I Sierro F Wilson D1999 Chronology causes and progression of the Messin-ian salinity crisis Nature 400 652ndash655

Lisiecki L E Raymo M E 2005 A PliondashPleistocenestack of 57 globally distributed benthic d180 records Pa-leoceanography 20 PA1003 doi1010292004PA001071

Lourens L J Hilgen F J Shackleton N J Laskar JWilson D 2004 The Neogene Period In GradsteinF M Ogg J G Smith A G (Eds) A Geological TimeScale 2004 Cambridge University Press Cambridge409ndash440

Martini E 1969 Nannoplankt aus dem Latdorf (locus typi-cus) und weltweite Parallelisierungen im oberen Eozaumlnund unteren Oligozaumln Senckenberg Lethaea 50 117ndash159

Martini E 1970 Standard Palaeogene calcareous nanno-plankton zonation Nature 226 560ndash561

Martini E 1971 Standard Tertiary and Quaternary cal-careous nannoplankton zonation In Farinacci A (Ed)Proceedings 2nd International Conference PlanktonicMicrofossils Roma Rome (Ed Tecnosci) 2 739ndash785

Martini E Worsley E 1970 Standard Neogene calcareousnannoplankton zonation Nature 225 289ndash290

Martini E Worsley T 1971 Tertiary calcareous nanno-plankton from the western Equatorial Pacific In Winter-er E L Riedel W R et al Initial Reports DSDP 7Washington (US Govt Printing Office) 1471ndash1507doi102973dsdpproc71291971

Moshkovitz S Ehrlich A 1980 Distribution of the cal-careous nannofossils in the Neogene sequence of the Jaf-fa-1 Borehole Central Coastal Plain Geological SurveyIsrael Report PD180 1ndash25

Okada H Bukry D 1980 Supplementary modificationand introduction of code numbers to the low-latitude coc-colith biostratigraphic zonation (Bukry 1973 1975) Ma-rine Micropaleontology 5 321ndash325

Perch-Nielsen K 1985 Cenozoic calcareous nannofossilsIn Bolli H M Saunders J B Perch-Nielsen K(Eds) Plankton Stratigraphy Cambridge UniversityPress Cambridge 427ndash554

Paumllike H Moore T Backman J Raffi I Lanci LPareacutes J M Janecek T 2005 Integrated stratigraphiccorrelation and improved composite depth scales forODP Sites 1218 and 1219 In Wilson P A Lyle MFirth J V et al Proceedings ODP Scientific Results199 (Ocean Drilling Program College Station TX) 1ndash42 doi102973odpprocsr1992132005

Paumllike H Norris R D Herrle J O Wilson P A CoxallH K Lear C H Shackleton N J Tripati A K WadeB S 2006 The heartbeat of the Oligocene climate systemScience 314 1894ndash1898 doi101126science1133822

Paumllike H et al 2007 Ceara Rise OligocenendashMioceneODP926B Stable Isotope Data IGBP PAGESWorldData Center for Paleoclimatology Data Contribution Se-ries 2007-017 NOAANCDC Paleoclimatology Pro-gram Boulder CO USA

Raffi I 1999 Precision and accuracy of nannofossil bios-tratigraphic correlation Philosophical Transactions of theRoyal Society of London Series A MathematicalPhysics and Science 357 1975ndash1993

Raffi I 2002 Revision of the early-middle Pleistocene cal-careous nannofossil biochronology (175ndash085 Ma) Ma-rine Micropaleontology 45 25ndash55

Raffi I Backman J Rio D Shackleton N J 1993 Plio-Pleistocene nannofossil biostratigraphy and calibration tooxygen isotope stratigraphies from Deep Sea DrillingProject Site 607 and Ocean Drilling Program Site 677Paleoceanography 8 387ndash408

Raffi I Flores J A 1995 Pleistocene through Miocenecalcareous nannofossils from Eastern Equatorial PacificOcean (Leg 138) In Pisias N G Mayer L A JanecekT R Palmer-Julson A van Andel T H et al Proceed-ings ODP Scientific Results 138 (Ocean Drilling Pro-gram College Station TX) 233ndash286 doi102973odpprocsr1381121995

Raffi I Rio D drsquoAtri A Fornaciari E Rocchetti S1995 Quantitative distribution patterns and biomagne-tostratigraphy of middle and late Miocene calcareousnannofossils from equatorial Indian and Pacific oceans(Legs 115 130 and 138) In Pisias N G Mayer L AJanecek T R Palmer-Julson A van Andel T H et alProceedings ODP Scientific Results 138 (Ocean DrillingProgram College Station TX) 479ndash502 doi102973odpprocsr1381251995

Raffi I Backman J Rio D 1998 Evolutionary trends ofcalcareous nannofossils in the late Neogene Marine Mi-cropaleontology 35 17ndash41

Raffi I Backman J Fornaciari E Paumllike H Rio DLourens L Hilgen F 2006 A review of calcareous nannofossil astrobiochronology encompassing the past


25 million years Quaternary Science Reviews 25 3113ndash3137 doi101016jquascirev200607007

Raymo M E Ruddiman W F Backman J ClementB M Martinson D G 1989 Late Pliocene variation innorthern hemisphere ice sheets and North Atlantic deepcirculation Paleoceanography 4 413ndash446

Rio D 1974 Remarks on late Pliocene ndash early Pleistocenecalcareous nannofossil stratigraphy in Italy LʻAteneoParmense Acta Naturalia 10 409ndash449

Rio D 1982 The fossil distribution of coccolithophoregenus Gephyrocapsa Kamptner and related PliondashPleis-tocene chronostratigraphic problems In Prell W LGardner J V et al Initial Reports DSDP 68 Washing-ton (US Govt Printing Office) 325ndash343 doi102973dsdpproc681091982

Rio D Sprovieri R Raffi I 1984 Calcareous planktonstratigraphy and biochronology of the PliocenendashlowerPleistocene succession of the Capo Rossello area SicilyMarine Micropaleontology 9 135ndash180

Rio D Raffi I Villa G 1990a PliocenendashPleistocene cal-careous nannofossil distribution patterns in the westernMediterranean In Kastens K A Mascle J et al Pro-ceedings ODP Scientific Results 107 (Ocean DrillingProgram College Station TX) 513ndash533 doi102973odpprocsr1071641990

Rio D Fornaciari E Raffi I 1990b Late Oligocenethrough early Pleistoene calcareous nannofossils fromwestern equatorial Indian Ocean (Leg 115) In DuncanR A Backman J Peterson L C et al ProceedingsODP Scientific Results 115 (Ocean Drilling ProgramCollege Station TX) 175ndash235 doi102973odpprocsr1151521990

Roth P H Baumann P Bertolino V 1971 Late EocenendashOligocene calcareous nannoplankton from central andnorthern Italy In Farinacci A (Ed) Proceedings 2nd In-ternational Conference Planktonic Microfossils RomaRome (Ed Tecnosci) 2 1069ndash1097

Schneider D A 1995 Paleomagnetism of some Leg 138sediments Detailing Miocene magnetostratigraphy InPisias N G Mayer L A Janecek T R Palmer-JulsonA van Andel T H et al Proceedings ODP ScientificResults 138 (Ocean Drilling Program College StationTX) 69ndash72 doi102973odpprocsr1381051995

Shackleton N J Baldauf J Flores J A Iwai M MooreT C Raffi I Vincent E 1995 Biostratigraphic sum-mary for Leg 138 In Pisias N G Mayer L A JanecekT R Palmer-Julson A van Andel T H et al Proceed-ings ODP Scientific Results 138 (Ocean Drilling Pro-gram College Station TX) 517ndash536 doi102973odpprocsr1381271995

Shackleton N J Crowhurst S 1997 Sediment fluxesbased on an orbitally tuned time scale 5 Ma to 14 Ma Site926 In Curry W B Shackleton N J Richter CBralower T J et al Proceedings ODP Scientific Re-

sults 154 (Ocean Drilling Program College Station TX)69ndash82 doi102973odpprocsr1541021997

Shackleton N J Hall M A Raffi I Tauxe L Zachos J2000 Astronomical calibration age for the Oligocene-Miocene boundary Geology 28 447ndash450 doi1011300091-7613(2000)28447ACAFTO20CO2

Takayama T 1993 Notes on Neogene calcareous nanno-fossil biostratigraphy of the Ontong Java Plateau and sizevariations of Reticulofenestra coccoliths In BergerW H Kroenke L W Mayer L A et al ProceedingsODP Scientific Results 130 (Ocean Drilling ProgramCollege Station TX) 179ndash229 doi102973odpprocsr1300201993

Theodoridis S 1984 Calcareous nannofossil biozonation ofthe Miocene and revision of the helicoliths and discoast-ers Utrecht Micropaleontological Bulletins 32 1ndash271

Thierstein H R Geitzenauer K R Molfino B Shackle-ton N J 1977 Global synchroneity of late Quaternarycoccolith datum levels validation by oxygen isotopesGeology 5 400ndash404

Vergnaud Grazzini C Saliegravege J F Urrutiaguer M J Ian-nace A 1990 Oxygen and carbon isotope stratigraphyof ODP Hole 653A and Site 654 The PliocenendashPleis-tocene glacial history recorded in the Tyrrhenian Basin(west Mediterranean) In Kastens K A Mascle J etal Proceedings ODP Scientific Results 107 (OceanDrilling Program College Station TX) 361ndash386doi102973odpprocsr1071531990

Villaneuva J Flores J A Grimalt J O 2002 A detailedcomparison of the Ukrsquo37 and coccolith records over thepast 290 kyears implications to the alkenone paleotem-perature method Organic Geochemistry 33 897ndash905

Wade B S Pearson P N Berggren W A Paumllike H2011 Review and revision of Cenozoic tropical plank-tonic foraminiferal biostratigraphy and calibration to the geomagnetic polarity and astronomical time scaleEarth-Science Reviews 104 111ndash142 doi101016jearscirev20100900

Wei W 1993 Calibration of upper Pliocene-lower Pleis-tocene nannofossil events with oxygen isotope stratigra-phy Paleoceanography 8 85ndash99

Winterer E L Riedel W R et al 1971 Initial ReportsDSDP 7 Washington (US Govt Printing Office) 1ndash1757 doi102973dsdpproc71971

Young J 1990 Size variation of Neogene Reticulofenestracoccoliths in Indian Ocean DSDP cores Journal of Mi-cropalaeontology 9 71ndash86

Zachos J C Kroon D Blum P et al 2004 ProceedingsODP Initital Reports 208 College Station TX (OceanDrilling Program) doi102973odpprocir2082004

Manuscript received March 28 2012 rev version accept-ed June 4 2012

J Backman et al244

1 Introduction

About 40 years ago a series of calcareous nannofossilbiostratigraphic zonations was established for variousparts of the Cenozoic stratigraphic column (Hay et al1967 Gartner 1969 1971 Bukry and Bramlette 1970Martini 1969 1970 Martini and Worsley 1970) Thesewere all based on the study of marine land sectionsandor rotary cored Deep Sea Drilling Project sedi-ments a drilling technique characterised by low re-covery and disturbed cores (JOIDES Journal June1979 wwwodplegacyorg) Biozonations for the en-tire Cenozoic were developed by Martini (1971) andBukry (1973 1975 1978) Martini introduced 25 Pa-leogene and 21 Neogene zones (NPNN zones)whereas Okada and Bukry (1980) codified Bukryrsquos19 Paleogene and 15 Neogene zones (CPCN zones)In addition Okada and Bukry (1980) also codified20 Paleogene and 24 Neogene subzones These twozonal systems are still widely used in spite of Bukryrsquos(1973a) insightful comment that ldquo the continuing re-covery of deep-ocean sediment sections by the DVGlomar Challenger at various latitudes will providethe material needed to thoroughly evaluate the strati-graphic and geographic ranges of coccolith speciesThis will permit more consistent zonationrdquo Bukryrsquoszonation was ldquonot intended to be exhaustive but sim-ply illustrates the basis of a low-latitude open-oceancoccolith zonationrdquo He thus aimed to establish a gen-eral framework for relative dating of open ocean sedi-ments rather than producing the highest possible reso-lution This spirit is adopted here together with thegeneral aim to produce a ldquomore consistent zonationrdquo

Among us a paper by Rio (1974) was the first in astill ongoing effort (Fornaciari et al 2010 Agnini et al2011) to generate biostratigraphic data using Cenozoiccalcareous nannofossils Many biostratigraphic stud-ies of Cenozoic calcareous nannofossils present data inthe form of range charts characterised by qualitativeestimates of relative abundances of taxa in widelyspaced samples As discussed by Backman and Raffi(1997) it is difficult to judge the quality of individualbiohorizons from qualitative presence-absence listingsin range charts Inspired by the work of Thierstein etal (1977) we developed methods to acquire censusdata (Backman and Shackleton 1983 Rio et al 1990aRaffi 1999) By combining census data with shortsample distances we aimed to improve both the strati-graphic precision and resolution by which calcareousnannofossil biohorizons were determined Census datahave the advantage that they permit independent as-

sess ments of the abundance behaviour and distributionof taxa and hence the quality of the biohorizons Wehave subsequently generated much data showingabundance variations of biostratigraphically importantcalcareous nannofossil taxa from marine sediments ofCenozoic age representing different low and middlelatitude paleoenvironmental settings

We here synthesise Miocene through Pleistocenedata in order to a establish a basic biostratigraphicframework for relative dating of marine sediments using calcareous nannofossils This synthesis clearlyrelies on the pioneering contributions by Erlend Mar-tini and David Bukry as many of the biohorizons theyused for zonal boundary definitions have proven toprovide consistent results Several of their zonalboundary defining biohorizons however have provenless practical and explains the need for a revised bio-zonation Our approach has been to employ a limitedset of selected biohorizons in order to establish a rela-tively coarse and stable framework taking into accountthe biostratigraphic data that we have produced overnearly three decades consistently using semi-quanti-tative methods and short sample distances In additionwe here present some previously unpublished bios-tratigraphic data

A secondary purpose has been to provide age esti-mates for all biohorizons Age estimates of individualbiohorizons are presented with their calibration refer-ences In the Miocene through Pleistocene interval theindependent age control is provided primarily by as-tronomically tuned cyclostratigraphies

2 Biozones defining biohorizonsand a revised biozone codesystem

A biostratigraphic unit or biozone is a body of stratathat are defined on the basis of its unique content se-quential distribution absence or combinations there-of of fossils Here we use selected calcareous nanno-fossil biohorizons to establish a revised biozonationfor the Miocene through Pleistocene interval

The major advantage of using a logically organisedzonal scheme e g Zone CN5 is relatively older thanZone CN6 etc is its ease of use compared to learningand remember the names of the many taxa providingindividual biohorizons and biozone boundary defini-tions In our view biozones in a zonal scheme shouldrepresent a relatively coarse and stable framework us-

J Backman et al222







tratig

raph

y

younger

older

Biohorizon 2

Biohorizon 1

AA B A B A B A B C



Zone - CRZ















J Backman et al224










J Backman et al226


CNM6

CNM5

D hamatus TRZ


A primus BZ

D signus CRZ

this study

60

70

80

90

100

110

120

130

140

150

160

170

180

190

240

200

210

220

230











B Catinaster















CNM11

CNM4

CNM7

CNM8

CNM9

CNM12

CNM13






CNM1

CNM2

CNM3

CNM18

CNM17

CNM16

CNM15

CNM14

CNM19

NN2CN1c

CN1b

CN2

CN3

CN4

NN3

NN4

NN6

NN7

NN8

CN5a

NN9

NN10

NN11

NN5

CN5b

CN6

CN8b

CN8a

CN7

CN9b

CN9a

S conicus PRZ


C3An


T rugosus PRZ

D quinqueramus TZ

N amplificus TRZ

D berggrenii BZ

D bellus BZ


C coalitus BZ

S heteromorphusBZ

CNM10

Dvariabilis PRZ

C exilis PRZ

D kugleri TRZ

S belemnos BZ

H carteri PRZ

H carteri PRZ

B Discoaster bellus


C6Cn

C3Ar

C4n

C4Ar

C3Br

C4An

C4r

C5r

C5n

C5Ar

C5An


C5ACn

C5ADn

C5BnC5ADr

C5ACr

C5Br

C5Cn

C5Dn

C5En

C5Cr

C5Dr

C6n

C6r

C6AAr

C6Ar

C6Bn

C6An

C6Br

C6Cr

C5Er

C3n

C3rNN12CN10b

GPTS Epoch


CN1a


MIO

CE

NE

OLI

GO

-

late

mid

dle

early

late




CN10a


NP25





CNM20

C premacintyrei TZ



coalitus (1079)

calyculus (965)


Mes

sini

an

Zancl

Torto

nian

Ser

aval

lian

Lang

hian

Bur

diga

lian

Aqu

itani

anC

hatt-

ian

CE

NE

Age (Ma)

Oligocene biozone









J Backman et al228



above)









C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n


200 400 600 800 1000

80

85

90

95

100



CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one




J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244







tratig

raph

y

younger

older

Biohorizon 2

Biohorizon 1

AA B A B A B A B C



Zone - CRZ















J Backman et al224










J Backman et al226


CNM6

CNM5

D hamatus TRZ


A primus BZ

D signus CRZ

this study

60

70

80

90

100

110

120

130

140

150

160

170

180

190

240

200

210

220

230











B Catinaster















CNM11

CNM4

CNM7

CNM8

CNM9

CNM12

CNM13






CNM1

CNM2

CNM3

CNM18

CNM17

CNM16

CNM15

CNM14

CNM19

NN2CN1c

CN1b

CN2

CN3

CN4

NN3

NN4

NN6

NN7

NN8

CN5a

NN9

NN10

NN11

NN5

CN5b

CN6

CN8b

CN8a

CN7

CN9b

CN9a

S conicus PRZ


C3An


T rugosus PRZ

D quinqueramus TZ

N amplificus TRZ

D berggrenii BZ

D bellus BZ


C coalitus BZ

S heteromorphusBZ

CNM10

Dvariabilis PRZ

C exilis PRZ

D kugleri TRZ

S belemnos BZ

H carteri PRZ

H carteri PRZ

B Discoaster bellus


C6Cn

C3Ar

C4n

C4Ar

C3Br

C4An

C4r

C5r

C5n

C5Ar

C5An


C5ACn

C5ADn

C5BnC5ADr

C5ACr

C5Br

C5Cn

C5Dn

C5En

C5Cr

C5Dr

C6n

C6r

C6AAr

C6Ar

C6Bn

C6An

C6Br

C6Cr

C5Er

C3n

C3rNN12CN10b

GPTS Epoch


CN1a


MIO

CE

NE

OLI

GO

-

late

mid

dle

early

late




CN10a


NP25





CNM20

C premacintyrei TZ



coalitus (1079)

calyculus (965)


Mes

sini

an

Zancl

Torto

nian

Ser

aval

lian

Lang

hian

Bur

diga

lian

Aqu

itani

anC

hatt-

ian

CE

NE

Age (Ma)

Oligocene biozone









J Backman et al228



above)









C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n


200 400 600 800 1000

80

85

90

95

100



CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one




J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244











J Backman et al224










J Backman et al226


CNM6

CNM5

D hamatus TRZ


A primus BZ

D signus CRZ

this study

60

70

80

90

100

110

120

130

140

150

160

170

180

190

240

200

210

220

230











B Catinaster















CNM11

CNM4

CNM7

CNM8

CNM9

CNM12

CNM13






CNM1

CNM2

CNM3

CNM18

CNM17

CNM16

CNM15

CNM14

CNM19

NN2CN1c

CN1b

CN2

CN3

CN4

NN3

NN4

NN6

NN7

NN8

CN5a

NN9

NN10

NN11

NN5

CN5b

CN6

CN8b

CN8a

CN7

CN9b

CN9a

S conicus PRZ


C3An


T rugosus PRZ

D quinqueramus TZ

N amplificus TRZ

D berggrenii BZ

D bellus BZ


C coalitus BZ

S heteromorphusBZ

CNM10

Dvariabilis PRZ

C exilis PRZ

D kugleri TRZ

S belemnos BZ

H carteri PRZ

H carteri PRZ

B Discoaster bellus


C6Cn

C3Ar

C4n

C4Ar

C3Br

C4An

C4r

C5r

C5n

C5Ar

C5An


C5ACn

C5ADn

C5BnC5ADr

C5ACr

C5Br

C5Cn

C5Dn

C5En

C5Cr

C5Dr

C6n

C6r

C6AAr

C6Ar

C6Bn

C6An

C6Br

C6Cr

C5Er

C3n

C3rNN12CN10b

GPTS Epoch


CN1a


MIO

CE

NE

OLI

GO

-

late

mid

dle

early

late




CN10a


NP25





CNM20

C premacintyrei TZ



coalitus (1079)

calyculus (965)


Mes

sini

an

Zancl

Torto

nian

Ser

aval

lian

Lang

hian

Bur

diga

lian

Aqu

itani

anC

hatt-

ian

CE

NE

Age (Ma)

Oligocene biozone









J Backman et al228



above)









C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n


200 400 600 800 1000

80

85

90

95

100



CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one




J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244









J Backman et al226


CNM6

CNM5

D hamatus TRZ


A primus BZ

D signus CRZ

this study

60

70

80

90

100

110

120

130

140

150

160

170

180

190

240

200

210

220

230











B Catinaster















CNM11

CNM4

CNM7

CNM8

CNM9

CNM12

CNM13






CNM1

CNM2

CNM3

CNM18

CNM17

CNM16

CNM15

CNM14

CNM19

NN2CN1c

CN1b

CN2

CN3

CN4

NN3

NN4

NN6

NN7

NN8

CN5a

NN9

NN10

NN11

NN5

CN5b

CN6

CN8b

CN8a

CN7

CN9b

CN9a

S conicus PRZ


C3An


T rugosus PRZ

D quinqueramus TZ

N amplificus TRZ

D berggrenii BZ

D bellus BZ


C coalitus BZ

S heteromorphusBZ

CNM10

Dvariabilis PRZ

C exilis PRZ

D kugleri TRZ

S belemnos BZ

H carteri PRZ

H carteri PRZ

B Discoaster bellus


C6Cn

C3Ar

C4n

C4Ar

C3Br

C4An

C4r

C5r

C5n

C5Ar

C5An


C5ACn

C5ADn

C5BnC5ADr

C5ACr

C5Br

C5Cn

C5Dn

C5En

C5Cr

C5Dr

C6n

C6r

C6AAr

C6Ar

C6Bn

C6An

C6Br

C6Cr

C5Er

C3n

C3rNN12CN10b

GPTS Epoch


CN1a


MIO

CE

NE

OLI

GO

-

late

mid

dle

early

late




CN10a


NP25





CNM20

C premacintyrei TZ



coalitus (1079)

calyculus (965)


Mes

sini

an

Zancl

Torto

nian

Ser

aval

lian

Lang

hian

Bur

diga

lian

Aqu

itani

anC

hatt-

ian

CE

NE

Age (Ma)

Oligocene biozone









J Backman et al228



above)









C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n


200 400 600 800 1000

80

85

90

95

100



CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one




J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244








J Backman et al228



above)









C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n


200 400 600 800 1000

80

85

90

95

100



CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one




J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244









C6C

n2n

C6C

n3n

20 40 60 80

90

95

100

C6C

n1n

CN

M1

CN

M2

Chron

MioceneOligocene

Olig

ocen

e bi

ozon

e

0

Dep

th (r

mcd

) in

OD

P S

ite 1

218

C6B

n2n


200 400 600 800 1000

80

85

90

95

100



CN

M1

CN

M2

C6B

n2n

CN

M3 C6AAr1n

C6AAr2n

C6B1n

C6C3n

C6C1n

C6C2n

Chron

Miocene

Olig

ocen

e

Oligocene

0 D

epth

(rm

cd) i

n O

DP

Hol

e 12

18A

bioz

one




J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244



J Backman et al230

250

300

350

400

450

500

5500 20 40 60 80 100


Dep

th (m

cd) i

n O

DP

Hol

e 92

6B


400

410

420

430

440

4500 20 40 60 80 100

CN

M3

CN

M4






316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244





316

318

320

322

324

3260 5 10 15

0 20 40 60 80



Dep

th (m

bsf)


Core boundary

0 5 10 15

0 50 100 150 200



CN

M5

CN

M5

CN

M6

CN

M6

NO DATA

abc

defb

c

de

f

a






J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244





J Backman et al232

CN

M6

CN

M7

3945

3950

3955

3960

3965

3970

3975

Dep

th (m

cd) i

n O

DP

Site

925




276

277

278

279

280

281

2820 2 4 6 8 10 12 14

Dep

th (m

cd) i

n O

DP

Site

926


CN

M8

CN

M9

275
















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244















J Backman et al234













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244













J Backman et al236

00

05

10

15

20

25

30

35

40

45

50

55




Ta Gephyrocapsa













T Gephyrocapsa

B Gephyrocapsa



B Gephyrocapsa



CNPL1

CNPL2

CNPL3

CNPL4

CNPL5

CNPL6

CNPL7

CNPL8

CNPL9

CNPL10

CNPL11

CNM20CNM19


D pentaradiatusTZ

Okada amp Martini



D tamalis TZ

Gephyrocapsa

S neoabies PRZ

GephyrocapsaePRZ

Gephyrocapsa

P lacunosa CRZ

C cristatus PRZ

D brouweri TZ

C macintyrei PRZ


CN15 NN21

CN10aCN9b

NN20

NN19

NN18

NN17

NN16

NN13

NN12

NN11

NN15 +NN14

C1n

C1r

C2n

C2r

C2An

C2Ar

C3n

C3r



GPTS


PLI

OC

EN

EP

LEIS

TOC

EN

Ee

amp

tete

te

MIO

-

CN10b

CN10c

CN11a

CN11b

CN12a

CN12b

CN12c

CN12d

CN13a

CN13b

CN14a

CN14b



Stage1971

Pia

cenz

ian

Mes

s-in

ian

Age (Ma)

CE

NE

Gephyrocapsa










J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244









J Backman et al238

105

110

115

120

125

130

135

1400 20 40 60 80 100

Dep

th (m

cd) i

n O

DP

Site

926


CN

PL2

CN

PL3

CN

P4

T R pseudoumbilicus

Bc D asymmetricus














J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244













J Backman et al240


6 Summary







References

































J Backman et al242




















































J Backman et al244


6 Summary







References

































J Backman et al242




















































J Backman et al244



























J Backman et al242




















































J Backman et al244




















































J Backman et al244

biozonation and biochronology of miocene through pleistocene

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