Tài liệu STRATIGRAPHY AND AMMONITE FAUNA OF THE VOLGIAN AND BERRIASIAN ROCKS OF EAST GREENLAND ppt

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Tài liệu STRATIGRAPHY AND AMMONITE FAUNA OF THE VOLGIAN AND BERRIASIAN ROCKS OF EAST GREENLAND ppt

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MEDDELELSEK OM GRUNLAND U1)GIVKE hF ICOMMISSIONEN FOR VIDENSKAHELIGE UNDERSBGELSRH I GR0NLAND BD. 154 . NR. 4 DE IIANSKE EKSPEDITIONER TIL DSTGRONLAND 1947-58 UNDER LEDELSE AF LAUGE KOCH STRATIGRAPHY AND AMMONITE FAUNA OF THE VOLGIAN AND BERRIASIAN ROCKS OF EAST GREENLAND BY IIESMOND T. DONOVAN WITH 3 FIGURES IN THF: TEXT AND 9 Pl.A'CICS K0HENHAVN C. A. REITZELS FORLAG BIANCO LUNOS BOCTHYKKERl A/S 1964 COKTENTS PBYC I'rrface 5 .ibstract 6 I . Introduction 7 IT . Thr localities and t. hcir stratigraphy 8 1 . Milne Land 8 2 . Soutll-western Jorrlesun Land Y 3 . Northenr Wollastun Forland 9 4 . Weslern Kuhn O 1.1 5 . East. crn Kuhn M 13 6 . The ammonite sequence 13 111 . Correlation Ih 1 . Russia I4 2 . England 16 3 . Conclllsions 18 I\. . Systematic paloeontology 19 1 Referrrlces tu litrruture 32 I'KEFACE ilrlng the summer of 1957, as a member of 1,nucc KOCH'S Expedi- tion to East. Grrcrrland of that year, I was able to visit most of the D ' localities which are of importance for working out the latcst Jurassic anrl earliest Cretaceous succession. The exceptions were soulh-wcstern Jame- son Land, and castern Kuhn f3, which 1 was not able to reach. As a result I have been ablc to review the rocks of this ago and bring ilp to date their correlation, and this is the object of this paper. I was accompanied by Mr. A. WYTTETRACII as field assistant, and wish to thank him for his help. In Milne Land I also had the advantage of the company of Dr. J. H. CALLOMON. 1 am indebted to Dr. LAUGK I<oc~r and his secretary, Miss IXGRID BSCK, for discussion and for assi- stance with publication. I have had useful discussions on correlation with Dr. R. CASI:Y of the Geological Survcy. Dr. hf. K. HOWARTH of tbc British MUSBIIIIL (Natural History) has kindly supplied photographs ol arr~monites from the Spilsby Sandstone. The olher photographs illustrating the papcrwere taken by Mr. E. W. SJ~AVILL at Bristol University. Bristol, July 1962. Abstract The localilirs al n-l~ich Lalr dnrlwsic and Lux~rr~nost Cretaceous rocks ha\-r liven rnnnrl in nast Grwnland arc rcrirlrcd and some of tl~rrn redescribed T~P higllest .lnrassic fauna is characterized I]>- the ammonite I,augrite.s, and is proba- bly to he correlated~vitl~ the Lox\-er Volpian of Russia. There is no positive evidence for the presence of UliperVolgian. Tl~r rarlirsl Crelaceous fauna has thc am~nonites Tollia, Srrrite.7 and Hertorocerns artrl vo~rrspurl<lr I,, llle Ryazanian of S~zo~nv or Lu\vrr Valanginiatl or olhrr R~~ssian nt~tho~,s. ailll In ilrr Rrrriasian of ~rcstcrn authors. Corrclaiion with thc English scquencc is also disrrrssecl. The palaeor~tology of the im~~nonite genera Laupeites, Suril~s ancl Tollia is Lreoled s~slr~n;rliiallq Tl~ree new sprcirs or Lnrrgrires uri. named, dcscrih~d and ligurrcl. Among the numerous illesozoic am~no~lile faunas collected by LAUGE 1Zoc~'s ~hree-year anil Two-Year Expeditions to East Greenland and described by the late Dr. I,. F. SPATI] (see nol-ovx, 1957, PI). 1C-10) were several helonging to littleknowrr horizons near tl~e top oI the Jnrassic system anrl (,he base of the Cretaceous. Describing some of them SPATH (1946, 1947, 1952) gave much attention to problems of dating and corrc- lation, arrd t,o ll~e sequence of faunas rrcar thc Jurassir Crel,a(:eous boundary. At one time (1947, 11. 8.) Ire had hopes that discoveries in East Greenland might roake an important contribution to the problem of defining the Jurassi1:-C~.etaceolls boundary and working out thc stm- I,igraphy of thc beds immediately above and bclow. Thcsr: hopes have not been i~~lfilled, and it is now cl<.ar, as will he shorn, that there is a gap in t,he ammonite sequrxlr~e known from East Greenland as compared with Europe and Russia. Since I attempted to summarisc tho question from inadequate knowledge in 1957 (p. 142), I havc been able t,o visil most of the 1or:;rlilies and collect fossils. Thcsc fossils are described and illu- stratrtl in this paper, arul arrompanied by a review of stratigraphy arrd <:orrelation. In ad,lit:ion to my own collcctiuris, I have stu(lied material collected at the Nirsen in Wollaston Forlanrl 11y A. J. STAXDRING and E. ITT. RORERTS in 1952, and 11y F. PERREYOLID and 0. KOY in 1956. 11. THE LOCA1,ITIES AND THEIR S1'H.ATIGRAPHY Rocks of lalest Jurassic and Berriasian age arp krtown from five places in East Greenland, namely 1) Milne Land: 2) soutll-western Jamc- son Land; 3) northern Wollaston Forland; 4) I\-?;tern ICnhn B and 5) eastern Kohn 0. These will he reviewed in turn. 1. Milne Land The sequence at Hartz Fjeld in castern Milne Land \\-as re-'xamined by Dr. J. H. CILT.OMOX and the wriber in 1957. The i'<~llnn-ins sequence was noted in part of thc Harzfjald Sandstone (for general succession in Milne Land sco UONOVAX 1957, p. 41; CALLOMON, ICltil. p. 264): m. 7. Whil,ish sands with indctcrminale hivalves sandstone, ovrrlying glnuc-~~nitic sand- g~o~nlar~diea (SPATH), and Iussil \t~ooil c. I 20 4. Kust,y weal,I~wring glauconitic, miraceor~s sandstonr: fr.durnent,ary 3 impression of a large Laageiles, and t,wo whorl fra~m~-nl~ of the N e sarne genus. Impressinns ul bivalvcs and gastrupod~. c. 1 3. Wl~itishsands 10 2. Glal~conitic sand cappad hy hruwn-weatherod saridstonc witl~ ammoniles: ?Lnug~ites and sharp-ribbed perisphinrl ill. e. 3 2 1. Whitish sands 75 Hrarhiopnd bed forming top of Glauconitic Series. The Lingula-Bank of ALDINGER (1935, p. 67) was not identified, but is almost certainly either 11cd 2 or 4; from it, SPATH (1935, p. 82) described Laugcifes groenlandicus. Also from the IIartafjzld Sandstone ahovc the Lingula-Bank, SPATH described and figured two new ammonite species (1936, pp. 85-87) which hc assigned to Crnspedites, although there seems no rcason to pnt them in this genns (see below, p. 25). The suggestion is now made that t1lese sirtall, ill-preserved ammonilcs may helong to the genus Tollia. For the division into Lower and Upper IIartzfjalrl Sandstone, see page 15. 1V Stratigraphy and Ammonite Fauna of East Greenland 9 2. South-western Jameson Land A suc~cession here was observed by MAYNC and puhlished by SPATH (1947, p. 49). The only fossiliferous beds are the Hectoroceras Beds which occur in the middle of a scries of barren strata. Apart from the genus IIectoroceras, the only ammonites are some poorly preserved "peri- sphinctids" all identified by SPATH as Snbcraspedites, Their slratigraphical relationship to Nectoroceras is not c,lmr. At locality 318 the two kinds of ammonite are said to have been found in association (SPATH, 1947, pp. 50, 53). Some of the "Suhcraspedites" from here (SPATII, op. cit. 1'1. 1, fig. 6, pl. 4, figs. 11-13) could he Tollia of the group rer:ordcd by SPATH from Milne 1,and as Subcraspedite.~. An arnmonite figured from locality 305 (Pl. 4, fig. 1) could be a Laugeiles not very different from L. intermedins sp. nov. SPATH regarded his "Suhcra.~pedites" as occurring in general bclow Iiectoroceras, but the field evidence for this is not very clear. At Auc~ellaelv, about 38 km west-north-west of Kap Stewart, a loose block yielded ammonites which were figured by SPATH (1936) as Pecti- natitrs? In t,hc present paper (p. 21) thcsc are referred to Langeites jamesoni sp. nov. The formation from whirh the block was derived has not been discovered. 3. Northern Wollaston Forland Tbe important loralily here is the mountain namcd the Niesen by tho Swiss members of LAUCE I<ocH's 1936-38 expedition, marked as a 688 m summit on t.he Geodetic Institute 1 :250.000 map. A resumt. of earlier knowledge of the succession was made by Do~ov~n. (1957, p. 62 R: fig. 13). Since that account was written, the mountain has again been visitcd, by Messrs F. I'ERRESOUD and 0. ROY in 1956, and hy the present writer in 1957. These visits render t,he curlier accounts oul of date. A rcviscd geological sketch-map of tho area is given in figure 1. VISCHER anti \l,\ync, whose map was p~ihlished by lioc~ (1950, pl. 6) mapped two serlimenlary scries, the Rigi Series of supposed I!pper Jurassic age, and the Niesen Reds (Valanginian in the key to KOCH'S pl. 6) placed in the lowest Cretaceons, divided into Lower Niesen Rods (Berriasian) and Upper Niesen Beds (Valanginian). The Kigi Series was named after the monntain Rigi (summit 484 m on Ccodetic Institute map, 7 km. south-west of the Nicsen) where a thick series of cong- lon~cratcs and sandstones outcrops. A careful examination by the pre- sent writer ol the conntry between the Niesen and the Kigi, both on the ground and from the air, showed beyond doubt that the Kigi Series Upper Niesen Beds Fig 1. Geologicill sketiii I!I,BI> "I parls of Wollnst,on Forland and Kuhn D, Easl, Greenland. Scale: 1 :2511,111111. I3ased on t,he mapping hy V1scnr.n and MAYNC, publish- ed by R,II:H (1950, pl. 61, modified by the writer's own observations. Suprrficial denosits o~rritted. and the Lowcr Niesen Beds are one and the same formation; the promi- nent conglomernle hands can be followed through from the outcrop of t,he Lower Niesen Beds to that of the "Rigi Series" without a break, dipping steadily westwards at a few degrees. OJI ac~ount, of the westerly dip the lowest beds at the Niesen are 1v Stratigraphy and am mil nit,^ Fauna ol East Greanlarld 11 exposed at the eastern end of the coastal flank of the mountain. 'rey, pcl~bly sands hegin to he exposed at 27 m altitude, and pass up into "handed beds" which r:unsist of ycllow sand altcrnating with grey or blac,k shaly sand and shale, the yellow sand layers being c. Z rrn thick. In this series at altitude 90 m were collected some poor ammonite im- pressions which arc idcnl,ified as lArrrrgeitee ?pnrons sp. nov. The handed beds contir~uc 1111 LO 115 m, and are s~~cceeded by whitish sands with hands of sandsl,one which form crags. At an altitude of 235 m MAYNC (19'19, p. 96) found the ammonil.es which were descrihcd lty S~ATFI (1952) ;is thc rrcw gcrrus Praetollia, here placed in Tollia (p. 27). This fossil bed has not heen 1.e-lo11nd hy l;rt,cr visitors to the mountain. Thirteen metres higher MAYNC found a specimen of Hreloroceras which u7as figured by SPATXI (1947, pl. 3, fig. 2; \vrongly localised, corrected SPATII 1952, p. 13). ST~NDRINCT in 1952 collected Hectorocerns s~t. juv. from an outcrop at 285 rn, and from a loose bloc,k ncarhy larger examples of the genus which appear closely similar in preser~~ation to l\Ia~?ic's cxamplc figured hy SPATH. It seems likely that hoth RIAYEC'S and S~I~AN~RTSG'S finds wcrc frorrl thc same horizon. At 305 rrr on Lhe north-easl.ern spur. of Llle Niesen tl~c prcscrrt writcr discoverer1 ammonites in a horizon of brown-weathering, calcarco~~s "doggers" in sands. Ammonites identical in preservation and matrix, and clearly frorrr the same Iossil ld, were i:ollevt,ed lty S.I.ANI)IIIYG at localities rei:orrlerl as 020 and 322 m. The 11iffel.enre in altibllrle is douhtlcss duc either to the dip of the rocks or to inaccnracy of the altimeters nsed. The fauna here comprised species of Snrifes and small ammonites which may br t,hc inrrcr whorls of Tollia pnyeri. Bitween 360 and 370 m, on the same flank of the moontain, the writer found similar doggers and platy-weathering sandstones, which contained occasional exarnples of Surifes and abundant Tollia. An example of the lat,t,cr gcrlus frorrt this level was figured by SPATII (1952, pl. 4, fig. 8) as Tollia pnyeri (TOULI), bill does not exa~:lly agree will1 thal, species (see page 30). Ammonites indistinguishable from Tollia ("Praetollian) moynci were also fourtd at the horizon. At 41 4 m t,he writcr lollnll, near the r1ort.h-cast,em flank of t,hc moun- tain, nodllles wibh lypical Valanginian Poly~~tyd,itrs.Valnrlginian ammoni- I,es have been found by all collectors at various higher levels, and Lqtico- ceros occurs at the sumrr~it (SP\.I.II, 1946, p. 6; confirmed by later c,ollecting). 4. Western Kuhn 0 The country behind "Haakonshytta", a ruined trappers' hut, is dissected 11y slrenm valleys I5 Lo 00 m deep. Thesc \,alleys show a number of sections through conglomerates, sands and sandstones, and <., x.v .::::-z; ,.> Sond &sandstone . , . . . . oooo Doggerr - - - Bonded rhole 8 rand ~ - @ Fossil locality 50m Altitude 0 500m - Fig. 2. Rkebcll map of the country north and easl, 01 'Haalionshyti,a', western Kuhn 0. Scale: 1 : 18.000 approx. dark grey shales which arc often banded with thin laminae of yellow sand. Ono interpretation ol lhe exposures has heen published hy MAYXC (1947, pp. 2836; 1949, pp. 27-32). In summarising it I have already (1957, p. 51)) expressed doubt as to f.he regular cyclic sedimentation which MAYNC finds. Having seen the exposures since writing my 1'357 paper, 1 can only repeat that I can not accept tho existence of Maunc's four cycles. Thcre is certainly alternation of lithology, and prohahly rapid lateral variation, but further than this I am not prepared to go. The dip of the rocks exposed in the 17all~g sides is often vcry nearly [...]... dne to the fact t h a t the higher zoncs of the Lower Volgian had not then been separated I n the central par1 of the Soviet Arctic 1,aageitcs ;~lsoocxurs a t t h c top of the Lower 1958, o Volgian ( O ~ ~ ; C I I K I N p 574) At:r:or~lingL 1,r:rrov and DRUSHCHITZ (1!358, p 90) T,augcitr.s occnrs both in the npper part of the Lower Volgian recorded Perisphinctes and the lower part of the Upper Volgian. ..1v Stratigraphy and Anr~noniteFauna of East Greenland 13 the same as the gradient of the stream, and for this reason i t was found impossible t o correlate or place in stratigraphical order the isolated exposures which were recorded A sketch map of the area, showing the outcrops observed and the locality numbers referred to in the palaeontological part of this paper, is given in figure 2 The commonest... 19) The obvious placing of the Laugeites Rods at about the boundary between Lower and IJpper Volgiari of Russia, on the basis of Laugeires, now falls into line with recent work in England On the hasis of independent evidence, namely thc recognition of autochthonous Portlandian and Volgian ammonites, CASEY has revised the dating of t h e Spilshy Sandstone the basement bed or whic,h he regards as the. .. notes on the Cretaceous ammonite faunas of East Grcanlantl Medd om Gronl Bd 132, Nr 4 - 1947: Additional ohservatiuns on the invertebrates (chiefly ammonites) of the Jurilssic ant1 Crelaceoms 111 Easl Gremland I The FIecrorocemr fauna of S W Jameson Land Mcdd om Gronl Bd 132, Nr 3 - 1952: Additional observations un the invertebrates (chiefly ammonites) of thc Jurassic and Crrtaceuus ul East Greenland 11... Subcraspedilec rcplace one another gcographically Lastly, the East Greenland succession throws light on the date of the Sandringham Sands, Norfolk, England, in which the amrrionitc IIectoroceras was recently recorded (CASEY, 1961) for the first time outside East Greenland They turn out t o be equivalent, in part, t o the I ) Presumablr SPATH assumed this as a rrsult of his pending of t h e fossil evidence... succession in ILhe Volpr Basin of Kussia The Upper Volgian is not proved in East Greenland, and the lowest Cretaceous horizon is identified as the Spasskensis Zone The lowest Cret.aoeoiis beds in East Greenland Iall in t h o Rcrriasian Stage, but the succession does not throw any light on the correlation of the base of the Rcrriasian, as dcfincd in sout,h-castcrn France, with the Volgn Rasirr stapcs IV... as the equivalent of thc npper part of t h e Portland Beds of southern England If, with ARKELL (1946, pp 24-28), we place the Portland Beds in the upper part of the Lower Volgian, they, the Laugeitcs Beds and t.he basement bed of t h e Spilsby Sandstone are not very different in age Their exact relationship is more difficult t o decide Tho pavloviids Rcds, though they s~lggosta Portlandian datc, would... equation of their up11cr and lower limits is not suggested 2 England Tho correlation given above is different from that of SPATR(1952, p 20) The reason for t h e diffcrenre is that SPATXI regarded S~~hcrnspedites as an early Cretaceous ammonite He did so, presumably, because 1v Stratigraphy and Ammonite Fauna of East Greenland 17 the formation from which Subcraspedites was dexribed, the Spilsby Sandstone of. .. Present-day Rnssian arltl~ors place the hase of the C~.etaceous helow tht! Kjasanensis Zone Sornc foreign authors, including SPATH (1047, p 54; A H K I C L L , p 493) correlate the Njasanensis Zone with 1956, the earliest Berriasellid urr~mordtefauna at Lhe top of the Tithonian, and hence put the base of the Crrtaceous above it The base of the Berriasian SLayo coincides with the hasc of t h e Cretaceous in regions,... material is desirable t,o settle t,he question The material frorn Milne Land consists solely of impressions of the umbilical portions of ammonites which agree with the figure of T bideveza, and also of T tolli A cast made from the hest of the impressions is shown in plat,o 6, figure 4 For the distinction between T hidevera and T groen,landica, see under the latter species Material: two impressions . UNDER LEDELSE AF LAUGE KOCH STRATIGRAPHY AND AMMONITE FAUNA OF THE VOLGIAN AND BERRIASIAN ROCKS OF EAST GREENLAND BY IIESMOND T. DONOVAN WITH. 17all~g sides is often vcry nearly 1v Stratigraphy and Anr~nonite Fauna of East Greenland 13 the same as the gradient of the stream, and for this

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