The Ammonite Zones of the Boreal Volgian (Upper Jurassic) in East Greenland
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ARCTIC GEOLOGY AND GEOPHYSICS THE AMMONITE ZONES OF THE BOREAL VOLGIAN (UPPER JURASSIC) IN EAST GREENLAND by JOHN H. CALLOMON AND TOVE BIRKELUND Reprint from Arctic Geology and Geophysics Edited by A. F. Embry and H. R. Balkwill Canadian Society of Petroleum Geologists Memoir 8 December, 1982 THE AMMONITE ZONES OF THE BOREAL VOLGIAN (UPPER JURASSIC) IN EAST GREENLAND JOHN H. CALLOMON' AND TOVE BiRKELUND2 ABSTRACT Detailed collecting in the Upper Jurassic of Milne Land, form the biostratigraphic basis for a new Boreal provincial central East Greenland, has established a succession of 24 standard scale of nine zones. Correlations with Britain, ammonite faunas spanning the Lower and much of the Mid- Siberia and the Russian Platform are discussed: there has dle Volgian, up to a non-sequence extending into the been great progress in the last 30 years, but many problems Valanginian of the Lower Cretaceous. For the chronostrati- remain. Six new ammonite species of the family Dorso- graphic classification of the seven Lower Volgian faunas planitidae are described: three of Dorsoplanites, two of the standard zonation of Britain is used unchanged. The 17 Pavlovia and one of Epipallasiceras. faunas of the Middle Volgian are regionally distinct and INTRODUCTION Most would agree that chronostratigraphy forms the basis One of the finest Upper Jurassic successions in the world of historical geology. Its successes in the Mesozoic are well is now known to be the one preserved in a small relict on known, particularly in the Jurassic, deriving as they do in crystalline basement in Milne Land, central East Greenland large measure from the fortunate circumstance that the prin- (71°N 26°W) (Figure 1). The first collections of the abun- cipal guide-fossils, the ammonites, make possible a particu- dant and beautifully-preserved faunas were brought back by larly rich and detailed biostratigraphy. Faunal provincialism Rosenkrantz f 1929) during Koch's first expeditions of 1926 however sets limits to what can be achieved in world-wide - 1927, and made famous in two monographs by Spam correlation by direct methods. In practice, therefore, work (1935, 1936). The outline of the stratigraphy was worked proceeds in each faunal province independently, and final out by Aldinger(1935). interprovincial synthesis is achieved by correlation in re- These works continue to form a solid basis for our mod- gions of overlap. It is in this field that many unresolved ern descriptions, but what was lacking was the close con- problems remain, including some in the Jurassic. nection between fauna and horizon that is needed to define a Historically one of the oldest of these problems to be standard of reference. Subsequent expeditions in 1957-1958, recognized lies in the Upper Jurassic and Lower Cretaceous, 1970 and 1977 filled the gaps. Some 2000 ammonites were and despite the efforts of a century (and the wishful persua- collected bed by bed from over 50 carefully-recorded sec- sions of committees and codes of stratigraphical nomencla- tions (Figure 1), and a succession of 47 Jurassic ammonite ture) a threefold system of chronostratigraphical classifica- faunas could be characterised, terminating in a major non- tion continues to be in use today for the Upper Jurassic, sequence. Of these, faunas 1-19 were described on a based on three parallel major units, or stages: previous occasion (Callomon and Birkelund, 1980) and range Portlandian (Brongniart, 1829 - d'Orbigny, 1850), for from Middle Jurassic to the lowest part of the Kimmeridgian. Britain, northern and western France, northern Germany, Faunas 20 - 30 cover the rest of the Kimmeridgian (lower Norwegian-Danish Basin. Kimmeridgian in the English sense) and lower Volgian (middle, or lower upper Kimmeridgian sensu anglico}. They Tithonian (Oppel, 1865), for southern Germany, south- are so similar to those of Britain that the same zonal classi- ern France, and almost the whole of the circum-Tethyan fication may be used (Cope, 1967, 1980), and only a brief Jurassic south of the Alpine fold-belt, up to and including summary is needed here. California. Faunas 31-47 span almost the whole of the middle Volgian (Nikitin, 1881), for the Russian Platform north- Volgian (upper upper Kimmeridgian sensu anglico and lower ern Siberia, and, by extension through the new discover- Portlandian). The similarities with Britain now become so ies of more recent time, over the whole of the circum- slight, however, that the same zonal classification (Cope, Arctic shelf-deposits known today, including the Barents 1978, 1980) cannot be used. Such similarities as exist are shelf and northern Canada. now equally strong with the successions of northern Russia Attempts at finer stratigraphical subdivision, to the level and Siberia, although these, in turn, are so far known only of zones, have necessarily to be even more restricted in broad outlines. The main purpose of the present paper is geographically, reflecting the existence within the broad therefore to present a first description of the Milne Land faunal realms outlined above of numerous lesser faunal prov- succession, lying as it does in an area in which those defin- inces. ing the Volgian and Kimmeridgian/Portlandian classifica- 1 University College London, Gower Street, London WC1, U.K. * Institut for historisk Gcologi og Palaeontokigi, 0ster Voldgade 10. 1350 Copenhagen K, Denmark 349 350 J. H. CALLOMON and T. BIRKELUND Fig. 1. Map of the Jurassic and Cretaceous deposits in Milne Land, giving place-names and the localities of the principal sections that have been measured and collected (nos, 1 - 52). Outcrops of crystallines indicated. tions intermingle. The faunal succession is summarized in SUMMARY OF LITHOSTRATIGRAPHY Table 1. The faunas are there grouped into a scheme of 9 The lithostratigraphy of the Mesozoic of Milne Land is standard zones which it is hoped will be a standard of refer- summarised in Table 2. The succession is divided into three ence for the region and find application in areas further formations of which the lowest, the Charcot Bugt Forma- afield, including the Barents Shelf and northern North America. tion, was described previously and is omitted. Some of the Correlations between this scheme and those of other regions members into which the formations are divided were also are briefly discussed at the end. Full description of the new defined elsewhere (Birkelund etal., in prep.), but are largely results is a major task and will take time. Most of the critical recognisable in terms of previously-described units also shown ammonites have however already been described in consid- in Table 2. erable detail by Spath, so that in many cases reference to his FAUNAL SUCCESSION work should suffice. Only a handful of new species are needed for the present purposes, and to avoid nomina nuda The notes that follow contain numerous citations of and brief descriptions are appended. references to the names of ammonite species founded by VOLGIAN AMMONITES, EASTERN GREENLAND 351 FAUNAS ZONES AND SUBZONES 48 Tollia groenlandica Tollia klimovskiensis VALANG. 47 Laugeites groenlandicus Laugeites groenlandicus 46 Crendonites anguinus Crendonites anguinus 45 Pavlovia aff. subgorei 44 Dorsoplanites intermissus n.sp. 43 Pavlovia groenlandica Epipallasiceras pseudapertum 42 Epipallasicems pseudapertum 41 Epipallasicems acutifurcatum n.sp. 40 Epipallasicems rotundiforme 39 Dorsoplanites gracilis S Dorsoplanites gracilis 38 Dorsoplanites antiquus 37 Dorsoplanites liostracus n.sp. Dorsoplanites liostracus 36 Dorsoplanites gracilis ft 35 Pavlovia variocostata n.sp. Pavlovia communis 34 Pavlovia communis 33 Pavlovia rugosa Pavlovia rugosa 32 Pavlovia iatriensis Pavlovia iatriensis 31 Dorsoplanites primus n.sp. Dorsoplanites primus 30 Paravirgatites sp.5 P. paravirgatus 29 Paravirgatites sp. ^4 28 Pectinatites eastlecottensis pectinatus P. eastlecottensis R 27 Pectinatites groenlandicus 26 Pectinatites cf. abbreviatus Pectinatites hudlestoni LOWE 25 Sphinctoceras spp. Pectinatites wheatleyensis 24 Pectinatites elegans Pectinatites elegans 23 Aulacostephanus cf. kirghizensis Aulacostephanus au tissiodorensis 22 Amoeboceras elegans 2 1 Hoplocardioceras decipiens Aulacostephanus eudoxus N 20 Amoeboceras kochi 1 9 Xenostephanus borealis A ulacostephanoides mutabilis 18 Rasenia aff.evotuta 1 7 Rasenia cymodoce Rasenia cymodoce 16 ? Pachypictonia sp. 1 5 Rasenia inconstans KIMMERIDGIA 14 Pictonia cf. normandiana Pictonia baylei Table 1. The succession of ammonite faunas in Milne Land and their zonal classification. 352 J. H, CALLOMON and T. BIRKELUND FORMATIONAL UNITS Aldinger, 1935 DESCRIPTIONS Spath, 1935,36 Sandstones, non-marine -1 00m Pinnadal Mb Hartz fjaeld Shales, lagoonal, Hauterivian -30 m (n) Sandstone d Sandstones with marine Tollia beds, n L. Valanginian, fauna 48 -180 m Fjel Hennig Ryg Mb - ooo z Lingula Bed Sandstones with Lingula Bed, Hart Formatio (n) M. Volgian, fauna 47 ~30 m Glauconitic Fine micaceous shales, Astartedal Mb - oooo- non-glauconitic, (n) M, Volgian, fauna 46 0-25 m Series Glauconitic shales and sandstones, Pernaryggen Mb many shell-beds, M. Volgian (n) faunas 3745 15-6 Om Pallasiceras Fine micaceous shales, variably Krebsedal Mb Beds - OOO/3 glauconitic in upper part, with Pectinatites layers of concretions, (n) Beds L.-M. Volgian, faunas 25-36 -200 m ? n Laminated black shales, Grakloft Mb Oil Kimmeridgian-L. Volgian, faunas 20-24 160m Formatio Shales e (n) Bioturbated dark shales, Lesli - ooo V p Cardioceraskloft Mb Amoebites 30m Ka (CB) - OOO<5 L. Kimmeridgian,