lithostratigraphy of the miocene sedimentary sequences in strymon basin, northern greece

Доклади на Българската академия на наукитеComptes rendus de l’Academie bulgare des Sciences

Tome 63, No 8, 2010

GEOLOGIE

Stratigraphie

LITHOSTRATIGRAPHY OF THE MIOCENESEDIMENTARY SEQUENCES IN STRYMON

BASIN, NORTHERN GREECE

Christo Pimpirev, Ioannis Beratis∗

(Submitted by Academician T. Nikolov on April 26, 2010)

Abstract

The Miocene sedimentary sequences in Strymon basin, Northern Greeceare divided into the Lefkonas, Dafni, Houmnikon and Kriopigi Formations.The Lefkonas Formation is a new formal lithostratigraphic unit and consists ofcoarse poorly sorted terrigenous rocks as breccias, breccia-conglomerates, con-glomerates in thick and very thick massive beds probably older than Maeotianage. The Dafni Formation is represented mostly of thin, medium and thick bed-ded biogenic limestones and is of Maeotian age. The Houmnikon Formation isdominated of interbedded thin to medium sandstones, silty clays, argillites anderosive-based, gravel and pebbly conglomerates. Lenses and seams of lignitesoccur in different levels. Limestone beds, up to 1.5 m thick are common in theupper parts of the succession. The age of the formation is proved as Pontian.The Kriopigi Formation is a new formal lithostratigraphic unit and is depositedin a monotonous clayey-limy-silty sedimentation with Pontian age. The sedi-mentological character of the Lefkonas Formation supports its alluvial fan andfluvial origin. The Dafni Formation represents shallow marine deposits indi-cated the first Miocene transgression in the Strymon basin. The sedimentationof the Houmnikon Formation is realized in small deltas, low salinity lagoons,lakes and rivers in the upper part of the succession. The Kriopigi Formationsediments are deposited in lacustrine environments.

Key words: Miocene sequences, Maeotian, Pontian, Strymon basin,lithostratigraphy

Introduction. The Strymon basin occupies the northern part of Greecewhere Miocene sedimentary sequences are generally accessible and well exposed.

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During our field work 22 sedimentological sections were measured (Fig. 1). TheMiocene sediments in the region were first studied by Wurm [1], and Osswald [2],and divided into four horizons: first with Sarmatian age; second (marine) withMaeotian?-Pontian age; third (lacustrine) with Pontian age and fourth (marine)with Pliocene age. Freyberg [3,4], distinguished two series: lower with flu-vial and lacustrine sediments and upper with marine origin. Gramman andKockel [5], were first that made detailed stratigraphic and paleogeographic stud-ies of the sediments in the Strymon basin and divided five lithostratigrapfic units:basal lacustrine beds; marine Dafni beds (Maeotian); brackish Houmnikon beds(Pontian); lacustrine Terpni beds (Upper Pliocene) and second marine beds (Cal-abrian). Karistineos [6] introduced two lithostratigraphic units: Lefkon Group(fluvio-lacustrine) and Georgios Group (marine-brackish). Kojumdgieva [7] ina correlation scheme mentioned several informal units in the sediments from Ser-res basin: Metochi + Lefkon Formation, Ano Formation including Dafni andHoumnikon beds and upper Spilia Formation with Maeotian to Pontian age.Syrides [8,9] for the Miocene sediments in Strymon basin used Lefkon Groupof Karistineos [6] for the basal fluvial-lacustrine rocks and Dafni beds (marine)and Houmnikon beds (brackish) of Gramman and Kockel [5] for the Maeotian andPontian sediments. Popov and Nevesskaya [10] in their geological map mentionedseveral lithostratigraphic units with Neogene age in Serres basin: Lefkon series,Dafni Formation, Houmnikon Formation and Spilia Formation. Zagorchev etal. [11] in their correlation scheme for Mediterranean and Paratethys Neogenesubdivided the sediments in Serres graben into Lefkon Formation, Dafni beds,Houmnikon beds and Spilia Formation. In all papers mentioned above the pro-posed lithostratigraphic units were introduced without the requirements of theInternational Code of stratigraphic nomenclature and are informal. In this paper,the lithostratigraphy of sedimentary sequences in Strymon basin is revised andformally defined for the first time, and possible origin for the different rock groupsis suggested. This study will enable workers to arrive at a common stratigraphyand nomenclature and are an essential prerequisite to a fuller understanding ofthe origin and evolution of the Miocene deposition in Strymon basin.

Description of the lithostratigraphic units. Our detailed field data al-low to establish the volume, lateral distribution, field relationships and chronos-tratigraphic range of four lithostratigraphic units (formations) and to introduce aformal lithostratigraphic scheme. The formations are as follow from base to top:Lefkonas, Dafni, Houmnikon and Kriopigi.

Lefkonas Formation. Previous use and synonyms. The sediments ofthis lithostratigraphic unit were mentioned for the first time from Freyberg [3,4]as a transgressive succession of breccias, conglomerates, sandstones, clays andlignites with fluvial and lacustrine origin. Paraskevaidis [12] confirms this coarsegrained sediments in the lowermost parts of Neogene in the study area. Grammanand Kockel [5] describe these sediments as continental lacustrine beds of the

1178 Ch. Pimpirev, I. Beratis

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Compt. rend. Acad. bulg. Sci., 63, No 8, 2010 1179

basal series (Basalfolge). Brown et al. [13], for the first time named the basalfluvial-lacustrine sediments in Serres basin as Lefkon formation. Psilovikosand Syrides [14] divided these sediments in one lower formation. Karistineos [6]named these coarse rocks as Lefkon group. Kojumdgieva [7] in a correlationscheme for the Upper Miocene sediments in the Aegean basin mentioned LefkonFormation. Syrides [9] used the name Lefkon group after Karistineos [6] andbasalfolge after Gramman and Kockel [5]. Popov and Nevesskaya [10] describe thefirst Neogene litostratigraphic unit in Serres basin as Lefkon series. Zagorchevet al. [11] in correlation scheme mentioned Lefkon Formation in Serres grabenand Snel, Marunteanu and Meulenkamp [15], also used the name LefkonFormation for the basal conglomerates.

Name. The name of this lithostratigraphic unit comes from the town ofLefkonas, situated W-NW from the town of Serres.

Type section. A holostratotype section for Lefkonas formation is definedin the northeastern side of the Strymon basin, 2 km southwest of the town ofAllistrati (Figs 1, 2).

Lithological description and defining features. The lowest lithostrati-graphic unit on Strymon basin consists mostly of coarse poorly sorted terrigenousrocks as breccias, breccia-conglomerates, conglomerates in thick and very thickmassive beds. The lower contacts are common sharp-based (erosive) and chan-nelled. Normal and reverse gradation is observed. The clasts are of differentsizes from gravels and pebbles to blocks up to 1.3 m thick and varying composi-tion: marbles, granites, gneises and sandstones. Packets of alternating polymicticsandstones, sands and silty clays and argillites are presented in different levels.Marble olistolith block up to 20 m thick is mentioned in Perdikari section (Fig. 3,section 7).

Field relationships. The formation is widespread in the northern part ofStrymon basin, northeast and northwest of the towns of Lefkonas and Serres andsouthwest of the town of Allistrati (Figs 3, 4). The thickness is from 25 to 80 m.The base of the formation is not exposed and is overlain transgressively by themarine sediments of Dafni Formation.

Fossil content and stratigraphic range. No fossils have been found. Thestratigraphic position of the unit under the Maeotian Dafni Formation generallyfavouring an age older than Maeotian.

Dafni Formation. Previous use and synonyms. Freyberg [3,4], de-scribes a marine succession with corals and other marine fossils from the UpperMiocene in Serres graben. Gramman and Kockel [5], first named this marine sedi-ments Dafni beds (Dafni-Schihten). Karistineos [6] includes the marine sedimentsfrom Serres basin in Georgios Group. Kojumdgieva [7] in her correlation schemefor the Upper Miocene sediments in Aegean basin mentioned Dafni beds of Gram-man and Kockel [5]. Syrides [9], described the deposition of Dafni beds as a resultof the first marine transgression in Strymon basin. Popov and Nevesskaya [10], in


Fig. 2. Sedimentological section “Alistrati” – type section of the Lefkonas Formation


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their geological map of Serres basin mentioned Dafni formation and Zagorchev etal. [11], in correlation chart included Dafni beds.

Name. The name of this lithostratigraphic unit comes from the village ofDafni, situated in the southern board of Strymon basin.

Type section. A stratotype section for the Dafni Formation is defined onthe southern side of Strymon basin and was figured and described by Grammanand Kockel [5] (section 4).

Lithological description and defining features. The deposits consistmostly of thin, medium and thick bedded biogenic limestones. Some individ-ual beds are massive. Dome-like bioherms seldom occurs. The limestones aresubordinately intercalated with thin to medium beds of polymictic sands, limysandstones and silty clays.

Field relationships. The formation is widespread in the southern andnorthern side of Strymon basin. In the northern part it is traced from AnoChristos village to the towns of Lefkonas and Seres (Fig. 3). In the southernside it is traced in west-east direction in the areas of the villages Kastri, Dafniand Kato Kerdylia (Fig. 5). The maximum thickness is 50 m. The base of theformation is sharp and transgressive with the continental sediments of Lefkonasformation and passes gradationally upward through the brackish sediments ofHoumnikon formation.

Fossil content and stratigraphic range. The range of the formationis constrained as Maeotian Stage based on fossil bivalves: Anomia ephippium,Lutraria (Lutraria) lutraria, Pecten (Oppenheimopecten) cf. aduncus, Anadara(Anadara) sp., (Anadara (Anadara) sp., Chama gryphoides gryphoides, Cardita(Cardita) caluculata, found in the sediments in the northern part of the basin,and: Pecten (Oppenheimopecten) cf. aduncus, Callista cf. chione, Crassostreagryphoides, Cerastoderma arcella mithridatis, Abra tellinoides found in southernside.

Houmnikon Formation. Previous uses and synonyms. The rocks ofthis formation were previously referred from Gramman and Kockel [5], to Choum-nikon beds (Choumnikon-Schihten) with brackish origin. Brown et al. [13] andKaristineos [6] included the marine sediments of Dafni beds and the brackish rocksof Houmnikon beds in the Georgios Group. Kojumdgieva [7] in her correlationscheme for the Upper Miocene sediments in Aegean basin mentioned Houmnikonbeds of Gramman and Kockel [5]. Syrides [8] described six new fossiliferous find-ings from Houmnikon beds that indicated Pontian age. Syrides [9] include thebrackish Houmnikon beds in the end of the first upper Miocene marine cyclein Strymon basin. Popov and Nevesskaya [10] in their geological map of Serresbasin mentioned Dafni formation and Zagorchev et al. [11] in one correlation chartincluded Dafni beds.

Name. The name of this lithostratigraphic unit comes from the village ofHoumnikon, situated in the southern side of Strymon basin.


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Type section. A stratotype section for the Houmnikon Formation is definedon the southern side of Strymon basin, 1 km west of the village of Humnikon andwas figured and described by Gramman and Kockel [5] (section 2).

Lithological description and defining features. The deposit consistsmostly of interbedded thin to medium sandstones and silty clays and argillites.Uncommon, erosive-based, gravel and pebbly conglomerates also present, up to afew metres thick lenses and seams of lignites occurs in different levels. Limestonebeds, up to 1.5 m thick are common in the upper parts of the succession. Thesediments are locally rich in unvaried fossil fauna of Bivalvia and Gastropodawith brackish origin.

Field relationships. The formation is widespread in the southern andnorthern side of Strymon basin in the vicinities of villages Terma, Kerdylia (south-ern part), and villages Lefkothea, Kato Christos, Ano Christos, Lefkonas and townof Serres (northern part) (Figs 3, 5). The maximum thickness of the sedimentsare 175 m in Perdikari section. The base of the formation is gradational withthe marine deposits of Dafni Formation and the top is sharp with the marls ofKriopigi Formation.

Fossil content and stratigraphic range. The range of the formationis constrained as Pontian Stage based on fossil bivalves: Limnocardium (Eux-inicardium) subodessae, Chama gryphoides gryphoides, Dreissena (Modiolodreis-sena) simplex, Parvivenus widhalmi, Congeria (Andrusoviconcha) navicula var.,Dreissena (Dreissena) tenuissima tenuissima, Pseudocatilus pseudocatilus, Eupa-torina litoralis, Abra sp. indet., Plagiodacna arcaeformis, Congeria (Rhombocon-geria) cf. subrhomboidea, Congeria ex. gr. Balatonica, Dreissena sp., Dreissenarostiformis corniculata, Paradacna abichi abichiformis, Abra tellinoides. Gas-tropods: Diodora graeca, Nassarius (Hinia) sp., Melanopsis impressa, Cerithiellasp. (aff. Dertobicarinata), Valvata sp., Theodoxus ex. gr. Balatonica, Melanopsissp. indet., Theodoxus sp. indet., and Bacillariophyceae: Aulacoseira.

Kriopigi Formation. Previous uses and synonyms. The Kriopigi For-mation is introduced for the first time in this study and the presence of marlysedimentation in Strymon basin is not mentioned in the previous papers.

Name. The name of this lithostratigraphic unit comes from the village ofKriopigi, situated in the northern side of Strymon basin.

Type section. A holostratotype section for Kriopigi Formation begins 800 mnorthwest of Lefkothea village towards Palia Lefkothea village in the northern sideof the Strymon basin (Fig. 6).

Lithological description and defining features. The rocks of KriopigiFormation consists of silty clays, limy siltstones and marls deposited in onemonotonous clayey-limy-silty sedimentation.

Field relationships. The formation crops out in the northern side of Stry-mon basin, in the vicinities of the villages of Palia Lefkothea and Kriopigi (Fig. 4)


Fig. 6. Sedimentological Section “Palia-Lefkothea” type section of the Kri-opigi Formation

7 Compt. rend. Acad. bulg. Sci., 63, No 8, 2010 1187

and in the southern side between the villages of Kormista, Iliokomi and Amfipoli(Fig. 5). The maximum thickness is 220 m measured in section Palia Lefkothea(Fig. 6). The base of the formation is sharp with the sediments of HoumnikonFormation (section Kriopigi) and is overlain with erosive contact with possiblyQuaternary deposits.

Fossil content and stratigraphic range. The only diatom fossil of thefloral genus Aulacoseira found in Sections Kriopigi, Palia Lefkothea, Kormistaand Amfipoli referred the sediments of the formation to Pontian Stage.

Description of selected sections. The holostratotype sections of the twonewly introduced formal lithostratigraphic units: Lefkonas and Kriopigi Forma-tions are described below.

Section “Allistrati”The section is situated in the northeastern side of the Strymon basin, 2 km

southwest of the western entrance of the town of Allistrati. The sediments ofLefkonas Formation are presented. The stratigraphic position under the MaeotianDafni Formation generally favouring an age older than Maeotian.

Cover: Quaternary sedimentsLefkonas Formation (holostratotype)(3–1)3. (35 m)The deposit consist almost entirely of polymictic unsorted pebble, cobble to

boulder conglomerates and breccia-conglomerates. The clasts are predominantlysupported in a sandy-gravel matrix, but parts of the sequence are clast-supportedwith normal and reverse gradation. The clasts are predominantly of marbles(90%) and sandstones and gneises (10%). The outcrop appears predominantlymassive, but erosive and abrupt bed surfaces are sometimes preserved. Somemetric fine to medium grained sandstones is included.

2. (1.5 m)Cobble to boulder conglomerates with reverse gradation with erosive lower

bed surfaces1. (3.2 m)Coarse-grained yellowish massive sandstonesBase: not exposed

Section “Palia Lefkothea”The section begins at about 800 m northwest of Lefkothea village along the

road towards Palia Lefkothea and Mandili villages. The deposits are includedin Kriopigi Formation and the chronostratigraphic is referred as Pontian stagebased on diathom fossil flora of genus Aulacoseira found in Sections Kriopigi,Palia Lefkothea, Kormista and Amfipoli.

Cover: quaternary breccio-conglomeratesKriopigi Formation (holostratotype)(2–1)2. (5 m)


Grey, massive siltstones with scattered (20%) pebble clasts of marbles1. (220 m)This thick deposit consists of monotonous mixed silty-clayey-limy sedimen-

tary sequence with thin (1–3 cm) beds of fine-grained parallel bedded sandstones.In the upper part of the succession medium bedded (up to 40 cm) fine-grainedsandstones occur. The sandstones are generally poorly sorted, structureless anderosive-based

Base: Not exposed, but in Section Kriopigi is presented by fine-grainedyellow-grey sands and sandstones of Houmnikon Formation

Interpretation and conclusions. The Miocene sedimentary sequences inStrymon basin are formally subdivided into four formations in ascending order:Lefkonas Formation, Dafni Formation, Houmnikon Formation and Kriopigi For-mation. The Lefkonas Formation is possibly older than Maeotian age. DafniFormation chronostratigraphic range is in the frame of the Maeotian Stage. Theage of Houmnikon Formation is proved as Pontian with abundant fossil findingof bivalves and gastropods and the same age is proposed for Kriopigi Formationbased on diatom fossil flora.

The sedimentological character of the Lefkonas Formation given above sup-ports its alluvial fan and fluvial origin. The Dafni Formation represents shallowmarine deposits indicated the first Miocene transgression in the Strymon basin.The sedimentation of the Houmnikon Formation is more complex. The brackishpalaeoenvironments are realized in small deltas, low salinity lagoons, lakes andrivers in the upper part of the succession. The Kriopigi Formation sediments aredeposited in lacustrine environments.

REFERENCES

[1] Wurm A. Die Kriegsschauplatze 1914–1918, geologisch dargestellt, 1925, No 13,71–84.

[2] Oswald K. Griech. Nat. Druckerei, 1938, No 31, 98.[3] Freyberg Von. B. N. Jb. Monatshefte Abt. B, 1948, 71–75.[4] Freyberg Von. B. Sedimentary Geology, 1951, No 38, 393–420.[5] Gramman F., F. Kockel. Geol. Jb., 1969, No 87, 445–484.[6] Karistineos N. Doctoral Thesis, 1984, No 10, 230.[7] Kojumdgieva E. Geol. Balc., 17, 1987, 3–14.[8] Syrides G. Rom. J. Stratigraphy, 78, 1998, 171–180.[9] Syrides G. Geol. Soc. of Greece, Spes. Publ., 9, 2000, 217–225.

[10] Popov S., L. Nevesskaya. Stratigraphy and Geolog. Correl., 8, 2000, No 2, 97–107.

[11] Zagortcev I. et al. Geol. Carp. Spec. iss., Proc. of the XVIIth Congr. Carp.-Balc.Geol. Assoc., 2002, 53–58.

[12] Paraskevaidis I. I G E Y, II, 1952, 181–248.


[13] Brown A. et al. VII Colloq. on the Geol. of the Aegean Reg., 1977, No 2, 615–622.[14] Psilovikos A., G. Syrides. Clausth. Geol. Abhandl., 44, 1983, 55–87.[15] Snel E., M. Marunteanu, J. E. Meulenkamp. Palaeography, Palaeoclimatol-

ogy, Palaeoecology, 238, 2006, 125–150.

St. Kliment Ohridski Sofia University15, Tsar Osvoboditel Blvd

1504 Sofia, Bulgariae-mail: [email protected]

∗Directorate of Secondary Education of Drama1, Ist July

661 00 Drama, Greecee-mail: [email protected]


lithostratigraphy of the miocene sedimentary sequences in strymon basin, northern greece

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