Geology. - " Cuba, Tlte Antilles and t!te Sout!tern Moluccas." By L. RUTT~:N.

(Communicated at the meeting of May 27, ] 922).

In 1865 E. SUESS elldeavoUI'ed to show in which way Norlh-, and Sonlh-America are connecled geologically I). Basing npon the then scallt geological literallll'e of t.he bOI'derlands, he partly adopted t.he conceptiolls of some few of Ihe oldel' explorers. He obsel'\'ed that the 1lI0unlain systems of Westel'll NOJ'th-Amel'Ïca do not direclly merge into those of Western Soulh-Amel'ica, bilt Ihat in South­Mexico and in Guatemala Ihe coastal ranges belld round, ramifying there in different chains, which eross transversely Ihe nal'l'OW Central Amel'ica, to proceed on their course in the Greater Antilles. All along the row of the Alllilies SUESS imagined 10 observe the traces of a large chain of folded-moulltains, which he conceived to extend along the North Coast of SOllth America, as far as the hOllndal'yof Venezuela and Colllmbia to merge Ihere into the Andes. So he considel's the Andes of South-America as a continuation of the mountains of Westem NOl'lh America, bnl looks upon the cUl'ving chain of mOlllltûins via the AntilIes as the connectillg link.

In the regioll of the AntilIes SUESS distinguished thl'ee zones: nn interiOl' zone of small islands all composed of young \'olcanic rocks with very yOllllg coaslal limestones alld allied forrnatiolls, extending from Grellada to Saba j a rniddle zone. in which in man)' places ol der, folded I'oeks emel'ge, bnilding np the Antillean-Cordillera proper, extending from Trillidarl via Barbados as far as Haiti, branching out thel'e in at least two chains, of which the sOlllhmost proceeds via Jamaica to Hondnl'as, while the most northel'll runs \'ia Cu ba to Yucatan; lastly an exteJ'ior zone, stretching from Bal'hnda via the Bahama Islands and Florida to Yncalan and which is supposed to be the remainder of the unfolded and disrupted "Vorland" of the Antillean Cordillera.

Ah'eady SUESS had pointed to the strildng analogy between the row of the Antilles and the Soulhern Moluccas, A few years later

I) E. SUESS, Das Antlitz der Erde. I. 1885.

17*

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this analogy was discus!led flIrther by WICHMANN 1) and MARTIN '). In the Soulhem Moluccas we also dislinguish an intel'iOl' curve of volcanic islands, an intennediate curve, consisting of the l"t~mains of folded moulltains, and farther to Ihe east the remaindel' of the almost undislurbed "Vorland".

In many points the hypothesis of SUESS has been corrobol'ated hy subsequent researches. K. SAPPER I) has demonstraled that the peculial' curvature and ramification of the tectonical units in NOI,thern Cent mi America, which SUESS only suspected, really exist. W . SIEVI<:RS 4) has p!'Oved it to be pI'obable that the eastel'll CJorde­rillas of Coillmbia split up in the North into different branches, then bend round to the Nort.h·ea~t aJld to the east, and can be tmced as fa I' as Tl'inidad with rather great distinctness. LACROtX i) fonnd in yOIlJlg volcanic !'Ocks of Marti.J1ique xenoliths of mica­schist, pl'oviJlg thereby that in the' subsoil of this islalld there still must exist old, metamol'phic sediments, HÖGBOM has pointed out Ihe l'emarkable analogy G) belween tlle eruptive rocks of the Virgin lsles and Ihose of the Andes of SOllth-America. In Ihe colleclions of the chemist RICHARD LUDWIG W, StEVERS has found a young eruptive rock from Alla Vela, a small island south of Haili, and has proved the possibilily thaI. this islet may be the continualion of the volcallic illtel'iOl' curve of the Lessel' Antilles '), FiJlally W. BERGT 8), who al'l'anged the above·named colleclions pelrograph­ically, has shown Ihe occnl'l"ence of old schists in Haiti. Laslly m: LA TORR~~ I) discovel'ed in Western Cuba a fauna of Malm­ammonites and M. SANCHEZ ROJG 10) established that Ihis fauna beal's a close resemblance 10 the jllrassic fanna of San Pedro del Gallo in Mexico, which has been treated in such a masterly way by BURCKHARDT 11).

On the othel' hand Su~ss's theory has not been llniversallyaccepted

I) G. E. A. WICHMANN, Samml. Geol. Reichsmus. 11, 1887, p. 198 sqq, 2) K. MARTIN, Tijdschr. Kon, Ned. Aardr. Gen. VII, 1890, p. 260 sqq. ') K. SAPPER, Pete.m, Geogr, Mitt. Erg. Hef te 127, 1899, 151, 1905; Report

81h Int. Geogr. Oongr., held in the Uno Stales, 1904. ') W. SrEvERs, Peterm. Geogr. Milt, 1896, p. 125 -] 29, 6) A. LÄcRorx, La Montagne Pelée et ses éruptions, 1904. 8) A. HÖGBOM, Bull. Geol. Inst. Upsala, VI, 1905. 7) W. SIEVERS, Zeitschr. Ges. für Erdkunde Berlin, 33, 18\18. 8) W. BERGT, Abhandl. Gesellschaft Isis. Dresden. 1897, p. 61-6'. 9) C. DE LA TORRE, O.R. Congrès Intern. Géol. Xl, Stockholm, 1910, p. 1021-· 1022.

10) M, SANCHEZ-ROIG, Boletin especial de la Secrelarla de agl"icuItura, comercio y lrabajo, Habana, 1920.

11) C. BURCKHARDT, Bolet. Instit. Geologico Mexico, 29, 1912,

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in America. The investigations of Americans have negalived ..al hel' than snbslanlialed SUESS'S conceptioJls in some respects. J. W. SPENCEI\ 1), for illstance, callle 10 the cOllclnsion, chiefly aftel' the sludy of chal'ls and mOl'phological speculations in conneclion wilh them, Ihal Ihe Anfilles wel'e not the remains of all' old eordillera. This researcher maintained that Ihe whole t..act of the Caribbean Sea, fhe Anlilles and Ihe Gnlf of Mexico cOllstilntect an ancient continellial l'egioJl, which e\'el' since Ihe Miocene had execuled the most slupendous verlical flllct.uatiolls of an amplitude of mally Ihonsands of meters. R. T. Hn.L '), ho we vel', who visiled many of Ihe Ant.illes, is by no mealls inelined 10 considel' most of Ihese islands as olhel' Ihan Irlle oceanic fOl'mations and refuses to believe that thel'e is any connection bef ween tlle lIorlhern Antilles alld Harbado!>-Tl'inidad, Ihe laf ter being by him assigned to the South-AlIlel'Ïea mainland. In his avel'sion to the assumplioll of old-sedimenlel'y COl'es in the Anfilles east of Westem Cnba he even goes the lellgth of qllesfioning Ihe resnlts of BERG1' (I.c .) who had established Ihe OCCU1'l'ence of old sehists in Haiti 011 Ihe basis of simple petrographic \Vork.

Neithel' wel~e the long-continlled explorations of T. W. VAUGHAN I), who has contributed so largely to the knowledge of the geology of Centl'al America in modern lime, based upon Ihe ideas of SUESS, which, as shown above, were ofsuch pregnant significanee for lIlariy a EUl'opean explorf31'.

Pal·ticulal'ly the island of (1nbu., whel'e since Ihe Spallish-Amel'Ïcan wal' a numbel' of Amel'ican explol'ershave heen wOl'king, seemed to have many features not belonging to the ol.hel· Antilles. The Spanish lIIining-engineel' SUTERAIN alr'eady had lIlistaken a gronp of sharply folded rocks from the environs of Habana, where fossils had never been found for crelaceolls sediments 4) and the lateI' American i) explorers adhel'ed to th is view Ol' cOlltellded it only

1) J. W. SPENCER, Geol. Mal\azine (4), I, 1894, p. 448-451; Bull. Geol. Soc, Amel'ica VI, 1895, p, 103-140; Transactions Canad. InsliL, V, lR98, p. 359-368, and many olher publications.

') R, T. HILL, Bull Museum. Comp. Zoology, Harvard Coll., 34, 1899, p. 225 sqq.: Bull . Geol. Soc. America, X VI, 1905, p. 243-~88, and many other publications.

I) T. WAYLAND VAUGHAN, Bulletin U.S. National Museum, Washington, 103, 1919; Contributions to the geology and paleontology of the West Indies, pub\. by the Carnegie lnst. of Washington, 1919, in which older publicatious are cited in extenso.

4) P. SALTERAIN, Holetin Mapa geologico de Espafla, VII, 1880. 6) R. T. HILL, Amer. Journalof Science, (3), 48, 1894, p. 196- 212. Bull. Mus

Compar. Zoology Harvard Univ. Geo\. Series IJ, ] 895, p. ~43 - 288; B. WILLIS, Index to the slratigraphy of Norlh America, US. Geo\. Survey, Professo Papers, 71, 1912.

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reservedly 1), However, the petrographic habitus of this would-be cretaceous formation, made up of white limestones, of soft, white marls and of loose ealcareou8 sandstones, is quite different from all the cI'etaceous rocks known fl;om the other Antilies, Centl'al Amel'ica and Nol'thern South-America, sothat Cuba seemed to be isolated from the rest in this respect. Another pecllliarity of Cuba seemed to be th at on the whole the tel'fial'y is not very thick and only feebly folded: HILI. ') says that the tel,tiary is merely a thin ,'eneel' ovel'­lying the oldel' formations sothat its thickness does not excel 1000 feet, and HAYl<:s-V AUGHAN-SPENCER have reprodnced pl'ofiles of the island in which everywhel'e a very feebly folded tertiary formation is marked '). If this is correct, Cuba ditfers vel'y ffillCh fl'om the other Antilles, fOl' in Haiti 4), Babados as weil as in Trinidad ') there are vel'y thick and intensely folded tertiary deposits, as may be expected in a young mountain-range, such as SUESS asserts the Ahtilles to be composed of,

A two months' stay in Cuba, in the mOllths of March and August of the past year, put me in a posHion to explain this seeming con­tradiction and to detect sOlne striking resemblances between Cuba and the other Antilles.

First of all Ihe so-called cretaceolls deposils in Ihe environs of Habana were explored . They can readily be examined in numerous exposures along roads and railway enls in and near the capital. They are eomposed of white soft, sometimes nodular, fine-grained mal'ls; of light-coloul'ed, YOllngish looking, Ol'ganogenetic Iimestones, whieh are seldom ,'el'y pure, most often however contain some volcanic tlltf-matel'ial; of true submarine tutfs; while sometimes also peculiar tine-gmined limestolle-breccias occur in the formation. In IlUmerouS spots I found in the Iirnestones and in the sllhmarine tutfs micl'O·organisms, which conld be determined in mieroscopical sections. It now appeared that besides a TIIlmber of Foraminifera, insignificant fOl' the age of the f?rmation, and beeides Lithothamnia,

! ) :

1) C, W. HA YES, T. W. VAUGHAN and A. C. SPENCER, Geology of Cuba, 1901 reprinted in HH8 by the Dirección de Montes y Minas at Habana.

i) R. T. HILL, l.c.

S) C. W. HAYE8, T. W. VAUGHAN and A. C, SPENCER, I.c,

4) L. TIPPENHAUER, Peterm. Geogl'. Mitteilungen, 1899, p. 25-29, 153-155, 201-204;11901, p. 121-127, 169-178, 193-199; 1909, p. 49-57. W. F, JONES, ,Tournal of Geology, 26, 1918, p. 728-758.

5) I. B. HARRISON and A. J. JUKES BROWN, The geology of Barbados, lR90, and other publications. G. W ALL and J. SA WKINS, Report on the geology of Tri· nidad, Memoirs Geol. Survey, London, 1860.

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also smal! Nummulinae alld Ol'!hophl'agminae OCCUI' iu various local­ities and Nummlllinae and Lepidocyclinae in otll6r places, I en'connt­ered in variolls tuffish Iimestones between Ardai and AI'l'oyo Naranjo small Nummnlites and Ol,thoplll'agminae, while in limes, sOllth-east of Regla, to the sOllth of the bay of Habana and to the nOl,th of Gllanabacoa, besides N.ummulites also small Lepidocyclinae wel'e found, which also OCCIll' in the railway-cnt, north-east of Palatino (Ihe finding-places al'e marked on the accompanying map). I) This "OldeJ' Habanaformation" is intensely folded, with dominant W -E. strike,and rapidly altemating steep dips, so that no positive opinioll can be formed about the thickness of the whole complex of layers with its few well-continuous sections. This thickness howevel' is sure to be vel'y considerable. lt is evident that this f01'01ation, which contains Nummulites and Orbitoides, and which, in conCUl'l'ence with SAJ.TEHAIN (\. c.) was generally mistaken fOl' cretaceous, is of a distinctly mOl'e modern type, being nothing else but the well­developed and intensely folded eogene, which we recognize with the same tectonic ano partly al80 with the same petrographic features in so many IocaIit,ies of the Antilles. The OCCUl'l'en('.e of Ol,thophrag­mina implies that part of this intensely folded formation is decidedly eocene. We wiII endeavour to ascertain whether pel'haps subseqllent parts of the Tertial'y are l'epresented in thi~ complex.

If the fossils, occllrring in the "Older Habana-formation", had been fOllnd in Europe Ol' Asia, there would be no doubt whatevel' about the OCCll\"l'ence also of oligocene and maybe even of old­miocene rocks in thi8 complex, as in Europe as weil as in Asia Lepidocyclinae al'e charactel'istic of the oligocene and the oldel' mioeene (Stampian to Burdigalian). Howevel', in America Lepidocy­clinae have been found also in unmistakably eocene deposits, ') so that theil' OCCLllTenCe in the vicinity of Habana is in itself no evidente at all. Now, the American species in positively eocene rocks (south­easterll pad of the U nited Stat~s),{tl'e all large species, except one (L. flöridana Cushmann witha diameter of 4--8 mm.). In San Bal'tholomew (L. antillea Cushmann with 5 lOm.) and in tlle zone of the Panama·canal CL. Macdonaldi with 5-7 mm.) thera occnr, it is trne, some smallel' species in l'ock~, taken to be eocene, but the age of these deposits is not so weil established as that of the

I) It is a pity thai the names in the map are rather illegible but with the aid of a reading·glass it will be possible to recognize most of them.

t) J. CUSHMANN, U. S. Geological Survey, Professional Paper, 125 D, 1920. T, W, VAUGHAN, Proceedings ~'irsl Pan Pacific Conference, Honolnlu, 1921,

p. 754-755.

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formations of the South-east of the United Stales. Now, in the Habana rocks, descl'ibed above, large Lepidoèyclinae are absolutely lacking; they contain only dwal'f-species which - as experience in Asia and EIII'ope has taught us - are more or less indicative of yonngel' formatioJls, so that. part of the "Oldel' Habanaformation" must very Iikely still be referred 10 the Oligocene. And this is not all. In Ihe city of Habana and west of it the Older Hahanaformation is ovel'lain by rocks of quite similar pelrographic habitus, bul Ihey are mllch less distIlrbed. These rocks of the "Younger Habana­formation" (ol'ganogenetic limestones, white and yeHow marIs, sub­madne tntfs) fMm namely a monocline, whose cor~ still exhibita steep dips - up to 40° and higher -. The younger portions of Ihis formation, however, which in its totality is dipping towards the se a, ure much less steep. In the suburb of Vedado Ihe marls of this formation are ovel·lll.in by coral-Iimeslones which are also dipping down towards Ihe sea. The rocks ofthis "Younger Habanaformation", which are so beantifully exposed in the marIpils of Puenles Grandes and of Cienaga and at Ihe CastiHo del Principe, are lying uncon­for'mably - as the accompanying map indicates - on the rocks of Ihe "Older HabalJaformation": w hile the strike of the older rocks is E.-W" that of Ihe younger is about N.E.-N.N.E. The facts, however, that in the deeper parts of Ihe yOllnger formatioJl the layers are vel'y sharply inclined, and that there is a remarkable petro­gl'aphic similarity belween the two formations tend 10 show that the stl'atigl'aphical gaping between Ihe two formations is only very inconsiderable; nay, in all probability, the llnconfOl'mity is only "tectonic", is ol'iginaled during the folding, and tho two formations succeed each other most Iikely wilhout a significant stratigra­phical gap.

Now, M. SANCHII.Z ROlG 1) has fOl' several years been collecting fossils from Ihe marl pits of CieJlaga. It is especially the teeth of Selachii that were encountered here. They point to a miocene age,_ while the more sOllthem limestones of Vedado belong evento the Pliocene.

The foregoing no doubt justities Ihe conclusioJl that Ihe rocks of Ihe "Older Habana forlllation" belong partIy to the eocone, partly to tho oligocene, Ihat the tertiary orogenetic movements in this pad of Cuba began towards the close of the Oligocene, aQd that they continued even in the Plioeene.

So while in the North the layers of the "Older Habanaformation" are overlain unconfol'Inably by miopliocene rocks, which have slill

I) M. S.ANCHEZ ROIG, Boletin de Minas, Habana, N0. 6, 1920.

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co-operated in Ihe crl181al movements, in the Soulh near Arroyo Nan'anjo Iimestones are overlying the "Older Habanaformation", which are perfectly horizon lal alld can be "'aeed southwal'd as far as Guim, invariahly in hOl'izonlal position. Neal' Arroyo Narranjo t.hese Iimestones, which in their habitus diffel' gl'eatly from the rocks of the "Oldel' Hahanafol'lnarion", are coaslal limestones; fal'ther 10 the south also Globigel'ina limestones OCCUI'. As a maltel' of fact these limeslones, which have had no share in fhe lalesl ol'ogenetic movements, must be of mOl'e recent date than the mio­pliocene rocks of the "Yollnger Habanaformation" and belong con­sequently to the Youngest Pliocene or Pleistocene. These Iimestones, which the Geological survey:map of NOl'lh-America 1) still mal·ks as Old Tertiary, have lent support to the opinion that the Cuban Tertiary is only feebI)' folded, and that Ihe Terliary const.itules only a thin varnish ove..tying Ihe older formations.

This does away wilh the seeming conlJ'asts helween Cuba and lhe othel' Antilles and replaces the island in lhe homogeneous range of the Antillean Cordillel'a.

In an exclll'sion 10 San Diego de los HaÏlos, about 100 k.m. 10

the west of the capital I encolllltel'ed also here a well-developed and intensely folded eogene fOl'malion; 10 Ihe Nort.h of this smalI town mcsozoic Iimestones emerge, but farther to the south inlensely folded rocks (stl'Ïke E.-W .) are exposed every w here - especially submarine tuffs - eontaining Lilhothamnia, Nummulites and Ol'lho­phl'agminae. fHobigel'ina marls also OCCUI'.

The Petrographic composition of the Cuban Tel'tial'y is intel'esling also in other respecis. Fil'st of all, in tlle Older as well as in Ihe Youngel' HabanafOl'malion limeslolles occur Ihat, being examined microscopically, appeal' 10 contain much yOIlJlg \'olcanic malerial, nay in many cases, even change into true calcite-poor, submal'Îne iuffs. Shal'p angulal' splinters of plagioclase and qual'tz are numerous. Likewise nnmel'oua gl'ains present themselves, of a substance con­t.aining plagioclase microliles, gmnllles of ore and glass, which are 10 be considel'ed as ground-mass fl'agmenls of an andesitic or dacitic rock. Similal' eogene, submarine Inffs were also recognized in the Tel'lÏary of San Diego. Mllch ,'olcanic malerial also OCC\ll'S in mio­pliocene deposils of a shallow sea (co'ralligene limestones, mal'ls, calcal'eous sandstones and finely granular conglomerates), which are excellently exposed in the YlIHlUrl cleft near Matanzas, about 75 k.m, east of Habana. On the contl'ary volcanic matel'ial seems to be lacking enlil'ely ilJ the verj' yOllng, hOl'izonlally disposed Iimestones

1) B. WILLIS, l.c.

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fonnd near Anoyo Naranjo, Rincón, San Antonio de 108 Bauos and Guira. In olie of the younger pOl·tions of the Yumllrl cleft-pl'ofile feldspars wel'e so ntlmerous that they could readily be examined in the pulverized rock. All Ihe splintel's th at were examined, had a higher refractive index than canada balsam, so t.hat there il:l a complete lack of ortho(')ase and albite. Among 20 splinters examined 13 had a higher, 7 an equal Ol' alowel' refractive index than eugenol (1 . 546), so the latter belong to oligoclase. Neal'ly all the splintel's have alowel' refl'llctive index than nitrobenzol (1,556), so t.hat amollg the lal'ger feldspar splinters, which al'e of course fl'agment.s of phenocrysts from the dacitic-andesitic rocks, from which also the g!'Ound-mass originates, no plagioclases occur that are mOl'e basic than andesine 1). The etrusive rocks supplyillg the material for submarine tutrs, must th en have been a highly acid, potassium­pOOI' dacite i.e., a rock in all points of the type of the "Pacific Rock".

1t should be observed that the fl'agments of the ground-mass occurring in the tlltrs, very of ten ha"e a diameter of 1 mmo It is not out of the bounns of P9ssibility of course, that similar volcanic matel'ial could have reached Cuba dul'ing an eruption of rather remote volcanoes, if at the time of the eruption a violent storm had ueen blowing in the direction of the island, The coarseness of the fragments, however, together with the very high frequency of volcanic material in formations extending from the eocene into the pliocene in localities neal'ly 200 k.m. apart, indicate that this material has not "come ovel'" nndel' "peculial'" circumstanees f!'Om far-away . volcanic centra, These snbmarine volcanic tutrs that are so widely ditrused both stt'atigraphically and geographically, must be regarded as e\'idence that in the Tertiary the volcanic activity iJl the Antillean region extended over a Inueh large I' al'ea than at present and that it did not settle down before the close of the Tertial'y, This fact , also lends to strengthen our view that the Antilles are geologically . homogeneousJ

lt is likewise deserving of note, that no remains whatever are to be fOllnd of the volcanoes that must have existed as late as the latter half of the Tertiary in the neighbourhood of Cuba. This proves thai al ready since the beginning of the Tertiary Cuba must have been subject to violentdistlll'bances, where denudat.ion destl'oyed rapidly what had been built up by volcanic and orogenetic processes.

1) The refractive indices of the fluids used in the Utrecht geological institute for the determination of the refractive indices of mineraIs, have been verified only a short time ago by Prof. SCHOORL for which we tender our thanks,

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Pl'esently we shall see that other faets also corroborate this hypothesis. In the vieinity of Habana a deeply weathered sel'pentine-massif

(sse sketehmap) has long (SALTERAIN I. c. and othel's) been known. In two localities - south of Guanabaeoa and due south of the bay of Habana - qual'tzarnphibole diol'iles are found as a dyke. These moderately acidic plagioclase rocks fOl'eibly I'eminded me of the granulal' cl'ystalline rocks of the "Pacific type", described by HÖGBOl\f (Ic.) and del'ived from the Vil'gin Isles. The felspal's of this quartz­alllphibolediorite all had a I'efraclive index higher than canada balsam, bnt tlle refractive index of most of Ihem was lowel' t.han that of qual'lz, to which they often are contiguous in the micro­scopicaI sections. COllseql1ently they belong 10 the acid portions of the plagioclase series. [ndeed the facl Ihat this rock is pOOl' in polassil1m and comparatively I'ich in siliC'ic acid (much quarlz and many acid ie plagioclases) reminds us fOl'cibly of many "Andes-I'ocks". Also by the OCCUlTence of gl'anulal' rocks of this type Cuba is united to the American continent on the one side and on Ihe other to the Virgin Isles.

When pel'using the literature concerning the Antilles we are impressed with an otller incongl'lIity between Cuba and the olhel' Antilles. AIl'eady long ago yonng Radiolaria-bearing deposits became known in Barbados (HARRISON and JllKES BRowN, I. c.) which many geologists re gard as true deepsea-deposits. R. T. HIJ.J. also descl'Ïbed tertiary Radiolal'ia-deposils in the east of Cuba (Bal'acoa). However, whel'eas in Barbados the Hadiolal'ia deposils overlie unconformably the older tertiary - which de\'eloped there as a telTigenic deposit­and ha\'e only been subject there to fanlting and not to folding, tlle Radiolaria deposÎts of Baracoa have a steep dip, so Ihat there seemed to exist a stratigraphical incongl'uity between these deposits in the two islands.Jn the neighbourhood of Habana I encountered Radiolaria-beal'ing rocks in two levels of the Tel'tiary . In the first place while marls in the "Oldel' Habanaformalion" lIeal' Ceno, with a dip of 75° sonthward. They are enlirely filled up with Ra,diolaria I hat belong for t.he major pal't to the Spllmellal'ia, fol' a small part howevel' also to the Nasselaria (fig. 1). Secondly, in the most recent pal't of the "Younger Habanaformation", i. a. in the mal'lpits of La Cienaga, white Glohigel'ina marl s occur which contain a not inconsiderable amount of Radiolaria. Now it is very weil possible Ihat the Radiolaria-marls of CelTo are the equivalent of those of Bal'aeoa in East-Cuba, whereas the Radiolaria-bearing Globigerina marIs of La Cienaga are stratigraphically more like the deposits in Barbados. Also the contrast which apparently exists in

272

this respect betweell Cllba and some of Ihe other Antilles finds an explanation in Ihe above.

Indications of the homogelleily of Ihe row of Antilles ean also be found in the older formalions of Cuba. As slaled previously, of late years Malm-ammonites have been found Ileal' Vii'iales, in Ihe most westel'Jl part of Cllba. These U pper-j lIrassic layeJ's, w hieh dip away to the NOl'th at a I'alhel' small gl'adient, al'e overlain by thick, old-Iooking gl'ey limeslones wilh inlermediate layers of sandstolles, which, therefore, are probably to be referred 10 Ihe Cretaceous system. In one place I fo.,nd in these limeslones small nests of red chert; IIndel' Ihe microscope this I'ed eIJerl appeal'ed 10 be a true Radioinrite, \'el'y much like the Radiolarites so widely diffused in the mesozoic rocks of Ihe southel'Tl Molueclln-cordillere (tig. 2). The geologiral institute at Ulrecht possesses a number of I'oeks from t.he islands of Curaçao, Bonaire and Aruba, collected by DI'. 1. BOI.D1NGH. Among the rocks fl'om Bonaire and Cllraçao it was nol difficult to recognize Radiolariles - probably mesozoic - bearing close resem­blance to those from Cuba. 1) This is 1101 all. In the cOl'al-limeslones of Ihe Yumurl-cleft near Matanzas coarse claslic material wasr'ound; boulders to a maximum of 7 mmo in diamelel'. Four of them were gl'Ound, of which two appeared to be red radiolarites like those f'ound to thel north of ViÏlales, while in our days mesozoic sediments are lackillg in this pal'l of the island.

Jt is evident, therefore, that sueh a peculiar sediment as t.he mesozoic, red radiolal'ite is found at the extremities of the Anlillean regioIl: in the most westenl part of Cuba and in Bonaire and Curaçao. l'his, no dOllbt, warrants the assumption Ihat the Antillean region is one conlinllous whoIe, parts of which, in spite of their different appearance, have many features in common, that point to an historical homogeneity.

From the occurrence of mllch voleanic material in the whole terlial'y of Cuba, in the neighbollrhood of which no volcanoes exist any more, we may conclude that the island must have been subject to great geological distllrbances in recent times: A similar conclusion may be deduced from the great abundance of bOlllders of cretaceolls Radiolal'ites in the miopliocene of the Yllfllllrl-eleft, as these boulders

I) K. MARTIN, Bericht über eine Reise nach Niederl. West Indien, lI, 1888, p. 28 and 73 and J. H. KLOos, Samml. Geol. Reichs-Museums, Leiden 11, I, 1887, already demonstrated the occurrence of Radiolaria-bearinK rocks in Guraçao and Bonaire. From their descriptions it is not evident, however, th at we have to do here with typical Radiolarites, which at lh at time did not receive so 'much aUention (rom geologists as nowadays.

273

point to a powerful post-eocl'etareous mOllntain-building by which the deep-seated Radiolal'ia-deposits wel'e uplifted beyond the sea­level, while in the Tel'tiary the mounlains were entirely oenuded again,

In the foregoing Radiolaria-bearing deposits have been described from three levels of tlle series of sediments of Cuba: a fourth level call still be added, Between Baeul'anao and tlle boring-field which is located to the 1I0rth of this village, green sediments were obsel'ved in the eentre of the serp~lItine-al'ea , These sedimellts al'e distinctly seen to dip away below Ille set'pentine, Under the microscope they appeal'ed to be in pal't voleanie luffs, in pal't remal'kable radioIa­rites, whirh consist ehiefly of skolelons of Radiolal'ia, but also cOlltain spieulae of sponges, wllile the silieie acid of the Radio­laria as weil as of tlle sponges spiculae is still pel'feclly amorpholls (fig. 3). These siliceolls sedimellts are elosely C'ollnected with the volcanie tllffs; not only do the Radiolaria-Iayers and the tuifs possess equal dip alld equal strike, bul sometimes the siliceous sedi­ments contain splilltel's of plagioclase, and in one of the micro­scopieal seetions the tuif even passes illto the siliceous sediment. These Radiolarites of Bacuranao certainly belong 1.0 an older level than the tertiary Radiolarites, as the fOl'mer dip away below the serpentine, whel'eas the whole tertial'y is lIIore recent than lhe serpelltine, whose water-WOl'11 fragmellts al'e found here and there in the tel,tiary limestolles and calcal'eous salldstolles, They belong mOl'eover to anothel' level than the red Radiolarites of Vifiales and Matanzas, for lhe thiek limestones beariJlg Ihe red Radiolarites of ViIiales al'e not found near Bacuranao. The siliceous sedim~nts are clo~ely relaled to the Cllban sel'pelltines.

Now it is vel'y remarkable that in Cuba sueh extreme deposits as Radiolal'Ïtes appeal' in four diffel'ellt levels. Even when not assuming that Radiolal'ites are trlle deepsea deposits, we must be convinced that the fonnatioll of these ealeiullI-free Ol' calcium-pool' siliceous sediments requires conditions thai do not exist in the shallow epi-eontinelltal seas. At all evenls the occul'l'ence of these deposits in al least fom' level s of the island of Cuba justifies Ihe conclusioll, t.hat the area in whieh lhe island is 1I0W silualed, was in the latter hRlf of the Mesozoicum Rn ext.remely l'estless I'egion, wheJ'e now deposits of a shallow epi(~Olllinental sea (sandstones in lhe Chalk, Nummulites and Orbitoide-beal'ing limestolles in the Tertial'Y), then again suel! peculiat' sediments as Radiolarites 1) conld be formed.

1) One more fact may be adduced to confirm the conception that at least one level of the Radiolaria -hearing deposits in Cuba is formed, if not in a true deep-

274

There are, indeed, two more arguments for the cOJlclusion that Cnba has ever been a vel'Y inconstant region, at least since the Tertiary.

In the Ol1tset we reminded the reader that already SUESS, WICHMANN and MARTIN' had pointed out the analogy bet ween the Antilles and the sOllthel'Jl Moluccas, which analogy is brol1ght ont in a similar al'rangemellt of the tectonic elements. Two poillts have been discussed above to emphasize this analogy. In the th'st place the occurrence of Red Radiolarites, so ver.}' typical of the Mesozoicum of the Moluccas, in the two extremities of the Anti1les. In the second place the conception that in the Jatter geological periods the Antillean l'egion was so extremely restless. It is known, indeed also of the sOllthel'll Moluccas, th at theÎl' l'egion was very changeable, and was characterized by gl'eat instability in the I'elations of land and sea: also there the formation and the denudation of mountains took place in sueh rapid suecession, that it is difficult to disentangle the develop­ment of the geological histol'y . We may add even olie more detai I in comparing the instability of the Antillean region with that of the southel'll Molllccas. 111 the Antilies it sf.rllck us that in one and the same island Radiolal'ia-deposits occurat least in four different levels. Why, also of the island of Rotti, near Timor, BROUWER has described 1) Radiolal'ia-bearing deposits in three totally dilfel'ent levels: U ppet' Trias, Malm and Tertiary .

Ut1'echt, May 1922,

sea, anyhow in a sea of considerable depth. In the white marls of La Cienaga, where many Globigerina and also numerous Radiolaria occur SalJchez-Roig (J.c,) has found numerous leeth of Selachii. A large numher of these teeth (though by far not all) display the peculiarity that only the enamel of the teeth is len, while the dentin has completely disappeared. This state of preservation is exclusively characteristic of Selachii·teeth that al:e encountered in the deepest sea and in deepsea deposits.

Cf. MOLENGRAAFF and BEAUFORT, Proceedings XXIX, 1921, p. 677-692. 1) H. A. BROUWER, De Nederlandsche Timor Expeditie, UI. 1921. Geologische

onderzoekingen op het eiland Rotti . ------

DESCRIPTION OF THE PLATES.

Fig. l. White Radiolariamarl. Older Habanaformation. X 26. Fig. 2. Red Radiolarite. Viilales. X 26. Fig. 3. Silicious rock with Radiolaria and Sponge-spiculae. Bacuranao. X 26. Fig. 4. Geological Sketch map and transverse profile of the vicinity of Habana.

- . - . - Railways. ABC-CD Line of Profile. S. Serpentine. D. Quartzhornblendediorite. A . Petroleum Rigs.

L. RUTTEN : "Cuba, The Aotilles aod the Southero Moluccas".

Fig. I. X 26.

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--, , ~' , -­c .... \. ...... - ', ; .-

,~ ,.,.....:." , .. ~

v" I:,:" ...... I I i

.- I

I ,

, , I

!­,t,

I

I I

" , , , '. , 1+

Fig. 4.

Fig. 2. X 26.

--- - ------

-----

Fig. 3. X 26.

Proceedings Royal Acad. Amsterdam. Vol. XXV.