Elsevier

Cretaceous Research

Volume 114, October 2020, 104508
Cretaceous Research

Macrofauna and biostratigraphy of the Rollrock Section, northern Ellesmere Island, Canadian Arctic Islands – a comprehensive high latitude archive of the Jurassic–Cretaceous transition

https://doi.org/10.1016/j.cretres.2020.104508Get rights and content

Abstract

The Rollrock Section in the Sverdrup Basin of Arctic Canada is one of the northernmost outcrops where the Jurassic-Cretaceous transition is accessible. The over 500 m thick sedimentary succession exposes the Oxfordian to Valanginian Ringnes and Deer Bay formations. Macrofauna from 15 discrete horizons includes ammonites, Buchia bivalves and belemnites. These fossils improve the biostratigraphy of the Tithonian and Berriasian in the Sverdrup Basin, provide correlation to the remainder of the Boreal Realm and set reliable calibration points. The occurrence of Buchia rugosa in the Ringnes Formation moves the upper formation boundary from the top of the Kimmeridgian into the lower Tithonian. Dorsoplanites maximus and D. sachsi document the middle Tithonian Dorsoplanites maximus Zone in Arctic Canada for the first time. The late Tithonian to early Berriasian Buchia terebratuloides is considered to be the best approximate indicator of the Jurassic-Cretaceous transition in the Rollrock Section. The middle early Berriasian Praetollia maynci and the late early Berriasian Borealites fedorovi tie the respective horizons to the successive Chetaites sibiricus and Hectoroceras kochi zones. Two species of the belemnite Arctoteuthis, collected from an interval with common glendonites, suggest a Valanginian age for the upper Deer Bay Formation. The dearth of Late Jurassic to earliest Cretaceous macrofossils in the Sverdrup Basin is inferred to be predominantly a function of diagenetic carbonate loss. Abundant dropstones and glendonites in the middle Tithonian to middle Valanginian interval suggest cold climatic conditions, and make the Rollrock Section a prime candidate for studying the Arctic environmental perturbations of this time.

Introduction

The Jurassic–Cretaceous transition interval (Tithonian to Valanginian) is widely known as a phase of environmental perturbation and associated biotic turnover (see Tennant et al., 2017 for a summary). However, the magnitudes of extinction, recovery and ecosystem change remain poorly known (e.g. Hallam, 1986, Tennant et al., 2017). Notable is a global eustatic sea-level drop of 40–50 m close to the system boundary (latest Tithonian), followed by a second drop of similar magnitude during the latest Berriasian to mid Valanginian, resulting in the lowest sea-level of the entire Cretaceous Period (Haq, 2014). Both sea-level drops were associated with significant cold intervals, but whether the low temperatures corresponded to phases of polar glaciation is still a matter of debate (e.g. Price, 1999, Price et al., 2013, Haq, 2014, O'Brien et al., 2017, Vickers et al., 2019).

Logically, one would turn to high latitude records when searching for evidence of cold snaps and ice caps, or more generally for an archive of pronounced climate fluctuations. The Mesozoic sedimentary succession of the Sverdrup Basin in Arctic Canada is one of the best candidates for investigating these topics (Kemper, 1987, Galloway et al., 2020). Today, only the Wandel Sea Basin in northern Greenland has exposures of the Jurassic–Cretaceous boundary interval that lie at a higher latitude (e.g. Håkansson et al., 1981). However, the palaeo-latitude of the Sverdrup Basin during the Jurassic-Cretaceous transition was lower than today, but still Arctic to sub-Arctic, approximately between 60° and 70° N (van Hinsbergen et al., 2015). Moreover, cold climatic conditions during the deposition of the Tithonian to Valanginian Deer Bay Formation of the Sverdrup Basin are suggested by the occurrence of glendonites (Kemper and Schmitz, 1975, Kemper and Schmitz, 1981; Grasby et al., 2017) and abundant dropstones (Embry, 1991).

In order to investigate palaeoecology and palaeoclimate in detail, a robust stratigraphy is first needed for the study interval. In 2015, we thus logged and sampled a more than 500 m thick, continuously exposed succession of Upper Jurassic to Lower Cretaceous mudstones, cropping out on the northern flank of the Rollrock River Valley, northern Ellesmere Island. This outcrop extends laterally over more than five kilometres (Fig. 1, Fig. 2) and exposes the mudstone-dominated Ringnes and Deer Bay formations, grading into sandstones of the Isachsen Formation at the top. Based on its macrofossil content, the Rollrock Section was regarded as the biostratigraphically most important Jurassic–Cretaceous transition section of the Canadian Arctic by Jeletzky (1984). Furthermore, the succession contains glendonites in several horizons and abundant dropstones over a large interval, and thus is likely to provide a direct record of Late Jurassic to Early Cretaceous Arctic cooling.

Discovered and briefly described by Wilson (1976), the Rollrock Section was logged and sampled by A. F. Embry and N. S. Ioannides in 1977 (personal communication A. F. Embry, 2017). Their results are expressed in the 1:250,000 scale geological map of the area, issued by the Geological Survey of Canada (Map no. 1886A, Tanquary Fiord; Mayr and Trettin, 1996), and the macrofossils they collected were published by Jeletzky (1984). However, no detailed account of the succession is available, and the collected palynology data were never published.

Herein, we present a comprehensive log and brief sedimentological description of the succession exposed in the Rollrock Section, along with a lithostratigraphic framework. We further provide systematic descriptions of the macrofauna, together with an updated ammonite and bivalve biostratigraphy, which correlates the Jurassic-Cretaceous boundary succession of the Sverdrup Basin with the entire Boreal Realm.

Section snippets

The Sverdrup Basin

The Sverdrup Basin is located in the Queen Elizabeth Islands, Nunavut and the Northwest Territories, and covers an area of approximately 300,000 km2 (e.g. Embry and Beauchamp, 2008, Pugh et al., 2014, Fig. 1). Basin development commenced in the Mississippian on Neoproterozoic to Devonian strata, and terminated with the onset of the Eurekan Orogeny in the latest Cretaceous (e.g. Hadlari et al., 2016).

The Sverdrup Basin is filled with up to 13 km of Carboniferous to Eocene sedimentary strata,

Material and methods

The Rollrock Section was logged and sampled during five days in July 2015. The strata dip gently (17° on average) towards northwest (dip direction is 321° on average), which is approximately perpendicular to the slope. A telescopic walking pole, calibrated to 1.5 m length, was used for measuring thickness. We chose one of the easternmost ridges for logging, since it provided relatively easy access and had less scree cover in its lowest part (base near 81.61172°N, −75.58489°W; top near

Sedimentology

The lower 230 m of the Rollrock Section expose a succession of dark, thinly bedded or laminated clayey siltstones and mudstones, with rare intercalations of siltstone or fine-grained sandstone (Fig. 6). From 190 m upward, several horizons of sideritic concretions occur, some of which have yielded bivalves, a lobster and fossilised wood. Above 230 m, a 20 m thick interval of siltstones and fine-grained sandstones follows. At 251 m, the change back to mudstone sedimentation is sharp and sudden.

Lithostratigraphy

The Ringnes Formation has its type section on central Amund Ringnes Island, and was defined as a succession of dark grey to black, very silty to slightly sandy shale with abundant, randomly distributed, giant, up to 5 m long, ellipsoidal, yellowish weathering, sideritic mudstone concretions (Balkwill et al., 1977, Balkwill, 1983). These characteristic concretions served to distinguish the unit from the McConnell Island Formation below and the Deer Bay Formation above. Sparse macrofossils

Systematic palaeontology

  • All fossils from the Rollrock Section are part of the Nunavut Collections of the Canadian Museum of Nature, Ottawa, Canada, and stored under registration numbers with the prefixes NUIF (for invertebrate fossils) and NUPB (for plant remains). Numbers NUIF 2979–3019, NUIF 3030–3046, NUIF 3061–3064, NUIF 3134–3140, NUIF 3158, NUIF 3165–3167 and NUPB 571, 572 and 575 are assigned to fossils from the Rollrock Section. Registration numbers for individual specimens are provided in the material

Biostratigraphy

As a result of the dearth of macrofossils in the Upper Jurassic to Lower Cretaceous interval in the Sverdrup Basin, biostratigraphic correlation with the remainder of the Boreal Realm is relatively poorly constrained. Dinoflagellate cysts and foraminifera offer only limited insight. This is because the intra-basin zonation schemes developed by Davies (1983) and Wall (1983), respectively, have not been correlated to other parts of the Arctic, and the precision of the ages determinable from these

Conclusions

The Rollrock Section on northern Ellesmere Island provides the most comprehensive outcrop record of the Jurassic-Cretaceous transition interval in the Sverdrup Basin of the Canadian Arctic, and is globally one of the northernmost exposures of such rocks. More than 500 m of a continuously exposed mudstone-dominated succession are almost evenly split into the lower, Oxfordian to lower Tithonian Ringnes Formation and the overlying, lower Tithonian to middle Valanginian Deer Bay Formation, grading

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

Working in the Arctic would not be possible without manifold support. Our sincere thanks go to the following people in Canada who helped to make our research a success: Sylvie LeBlanc (Department of Culture and Heritage, Iglooik, Canada); Jane Chisholm (Parks Canada, Iqaluit, Canada); John Innis (Universal Helicopters); the rangers of Parks Canada at Quttinirpaaq National Park (Ellesmere Island, Canada); the Polar Continental Shelf Programme team at Resolute (Cornwallis Island, Canada);

References (149)

  • S.A.J. Pocock

    The Jurassic-Cretaceous boundary in northern Canada

    Review of Palaeobotany and Palynology

    (1967)
  • L. Agassiz

    Études critiques sur les mollusques fossils. Monographie des Myes

    (1842)
  • F. Anderson

    Knoxville Series in the California Mesozoic

    The Geological Society of America Bulletin

    (1945)
  • W.J. Arkell

    A classification of the Jurassic ammonites

    Journal of Paleontology

    (1950)
  • H.R. Balkwill

    Geology of Amund Ringnes, Cornwall and Haig-Thomas islands, District of Franklin

    Geological Survey of Canada, Memoir

    (1983)
  • H.R. Balkwill et al.

    Ringnes Formation (Upper Jurassic), Sverdrup Basin, Canadian Arctic Archipelago

    Bulletin of Canadian Petroleum Geology

    (1977)
  • K. Beurlen

    Beiträge zur Stammesgeschichte der Muscheln

    Sitzungberichte der Mathematisch-Naturwissenschaftlichen Abteilung der Bayerischen Akademie der Wissenschaften zu München

    (1944)
  • V.J. Bodylevsky

    Novye pozdnejurskie belemnity Severnoj Sibiri [New Late Jurassic belemnites of Northern Siberia]

  • W.W. Brideaux et al.

    Upper Jurassic - Lower Cretaceous dinoflagellate assemblages from Arctic Canada

    Geological Survey of Canada, Bulletin

    (1976)
  • L. von Buch

    Über einige neue Versteinerungen aus Moskau

    Neues Jahrbuch für Mineralogie, Geognosie, Geologie und Petrefaktenkunde

    (1844)
  • R. Casey

    The ammonite succession at the Jurassic-Cretaceous boundary in eastern England

  • R. Casey et al.

    Sopostavlenie pogranichny otlozhenij Jury i mela Anglii, Russkoj Platformy, Priopoljarnogo Urala i Sibiri [Correlation of the Jurassic/Cretaceous boundary beds of England, Russian Platform, Subpolar Urals and Siberia

    Izvestija Akademii Nauk SSSR, Serija Geologicheskaja

    (1977)
  • T.P. Chamney

    Foraminifera useful for determining the Jurassic-Cretaceous boundary in Arctic America

    Geological Survey of Canada, Paper

    (1968)
  • T.P. Chamney

    New species of Foraminifera, Cretaceous-Jurassic boundary, Arctic America

    Geological Survey of Canada, Bulletin

    (1971)
  • M. Chierici et al.

    Calcium carbonate saturation in the surface water of the Arctic Ocean: undersaturation in freshwater influenced shelves

    Biogeosciences

    (2009)
  • L.R. Cox

    Lower Cretaceous Gastropoda, Lamellibranchia and Annelida from Alexander Island (Falkland Islands Dependencies)

    Scientific Reports of the British Antarctic Survey, Falkland Islands Dependencies Survey

    (1953)
  • G. Cuvier

    Second mémoire sur l’organisation et les rapports des animaux à sang blanc, dans lequel on traite de la structure des mollusques et de leur division en ordre, lu à la société d’Histoire Naturelle de Paris, le 11 Prairial an troisième [30 May 1795]

    Magazin Encyclopédique, ou Journal des Sciences, des Lettres et des Arts

    (1795)
  • E.H. Davies

    The dinoflagellate Oppel-zonation of the Jurassic-Lower Cretaceous sequence in the Sverdrup Basin, Arctic Canada

    Geological Survey of Canada, Bulletin

    (1983)
  • E.H. Davies

    Dinoflagellate cyst occurrences of the Jurassic-Lower Cretaceous sequence in the Sverdrup Basin, Arctic Canada

    Geological Survey of Canada, Open File

    (1985)
  • G. Dörhöfer

    Distribution and stratigraphic utility of Oxfordian to Valanginian miospores in Europe and North America

    American Association of Stratigraphic Palynologists Contributions Series

    (1979)
  • P. Doyle et al.

    The Jurassic and Cretaceous belemnites of Kong Karls Land, Svalbard

    Norsk Polarinstitutt Skrifter

    (1988)
  • O.S. Dzyuba

    Systematics and phylogeny of the boreal family Cylindroteuthidae: Problems solved and unsolved

  • O.S. Dzyuba

    Subfamily classification within the Cylindroteuthididae (Belemnitida)

    News of Palaeontology and Stratigraphy

    (2011)
  • O.S. Dzyuba

    Belemnites and biostratigraphy of the Jurassic–Cretaceous boundary deposits of northern East Siberia: new data on the Nordvik Peninsula

    Stratigraphy and Geological Correlation

    (2012)
  • A.F. Embry

    The Wilkie Point Group (Lower-Upper Jurassic) Sverdrup Basin, Arctic Islands

    Geological Survey of Canada, Paper

    (1984)
  • A.F. Embry

    Stratigraphic subdivision of the Isachsen and Christopher formations (Lower Cretaceous), Arctic Islands

    Geological Survey of Canada, Paper

    (1985)
  • A.F. Embry

    Stratigraphic subdivision of the Awingak Formation (Upper Jurassic) and revision of the Hiccles Cove Formation (Middle Jurassic), Sverdrup Basin, Arctic Islands

    Geological Survey of Canada, Paper

    (1986)
  • A.F. Embry

    Mesozoic history of the Arctic Islands

  • A.F. Embry

    Triassic history of the Tanquary High in NE Sverdrup Basin, Canadian Arctic Archipelago

  • G. Fischer von Waldheim

    Oryctographie du gouvernement de Moscou. Auguste Semen

    Moscou, I–XVII

    (1837)
  • H. Frebold

    The Jurassic faunas of the Canadian Arctic. Middle and Upper Jurassic ammonites

    Geological Survey of Canada, Bulletin

    (1961)
  • H. Frebold

    Illustrations of Canadian Fossils, Jurassic of western and Arctic Canada

    Geological Survey of Canada, Paper

    (1964)
  • H. Frebold

    The Jurassic faunas of the Canadian Arctic. Lower Jurassic ammonites, biostratigraphy and correlations

    Geological Survey of Canada, Bulletin

    (1975)
  • J.M. Galloway et al.

    Finding the VOICE: organic carbon isotope chemostratigraphy of Late Jurassic – Early Cretaceous Arctic Canada

    Geological Magazine

    (2020)
  • F.M. Gradstein et al.

    The geologic time scale 2012

    (2012)
  • S.E. Grasby et al.

    Lower Cretaceous cold snaps led to widespread glendonite occurrences in the Sverdrup Basin, Canadian High Arctic

    GSA Bulletin

    (2017)
  • J.E. Gray

    A revision of the arrangement of the families of bivalve shells (Conchifera)

    Annals and Magazine of Natural History, series 2

    (1854)
  • M. Grey et al.

    Variation in evolutionary patterns across the geographic range of a fossil bivalve

    Science

    (2008)
  • M. Grey et al.

    Morphological variability in time and space: an example of patterns with buchiid bivalves (Bivalvia, Buchiidae)

    Palaeontology

    (2010)
  • E. Håkansson et al.

    Jurassic – Cretaceous boundary strata of the extreme Artic (Peary Land, North Greenland)

    Bulletin of the Geological Society of Denmark

    (1981)
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