Pre-rift sedimentation of the Lomonosov Ridge, Arctic Ocean at 84°N; a correlation to the complex geologic evolution of the conjugated Kara Sea

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doi: 10.1016/j.jog.2018.05.002
Author(s): Sauermilch, Isabel; Weigelt, Estella; Jokat, Wilfried
Author Affiliation(s): Primary:
Alfred Wegener Institute for Polar and Marine Research (AWI), Bremerhaven, Germany
Volume Title: Journal of Geodynamics
Source: Journal of Geodynamics, Vol.118, p.49-54. Publisher: Elsevier, Oxford, United Kingdom. ISSN: 0264-3707
Note: In English. 23 refs.; illus., incl. sects., geol. sketch maps
Summary: The Arctic Ocean region plays, and has played in the geological past, a key role for Earth's climate and oceanic circulation and their evolution. Studying the Lomonosov Ridge, a narrow submarine continental ridge in the central Arctic Ocean, is essential to answer fundamental questions related to the complex tectonic evolution of the Arctic basins, the glacial history, and the details of known paleoceanographic changes in the Cenozoic. In this study, we present a new seismic dataset that provides insights into the sedimentary structures along the ridge, their possible origin, age and formation. We compare the structure and stratigraphy of the deeper parts of the ridge between 83°N and 84°30'N to its conjugate, the Severnaya Zemlya Archipelago at the Eurasia margin. We propose that some sediment sequences directly underlying the prominent HARS (High Amplitude Reflector Sequence) formed well before the ridge separated from the Barents and Kara shelves and represent a prolongation of the North Kara Terrane, most likely part of the Neoproterozoic Timanide orogen. Towards Siberia along the Lomonosov Ridge, we interpret the HARS to be underlain by Upper Proterozoic-Lower Paleozoic metasedimentary material that is correlated to metamorphic complexes exposed on Bol'shevik Island. Northward, this unit descends and gives way to a foreland sedimentary basin complex of presumed Ordovician/Devonian age, which underwent strong deformation during the Triassic/Jurassic Novaya Zemlya orogeny. The transition zone between these units might mark a conjugate continuation of the Eurasian margin's Bol'shevik-Thrust Zone. A prominent erosional unconformity is observed over these strongly deformed foreland basins of the Eurasian and Lomonosov Ridge margins, and is conceivably related to vertical tectonics during breakup or a later basin-wide erosional event.
Year of Publication: 2018
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 20 Geophysics, Applied; Arctic Coring EXpedition; Arctic Ocean; Arctic region; Asia; Barents Sea; Basins; Cenozoic; Commonwealth of Independent States; Continental shelf; Eocene; Foreland basins; Geophysical methods; Geophysical profiles; Geophysical surveys; Integrated Ocean Drilling Program; Inversion tectonics; Kara Sea; Krasnoyarsk Russian Federation; Lomonosov Ridge; Lower Paleozoic; Marine environment; Metamorphic rocks; Metasedimentary rocks; Neoproterozoic; Paleogene; Paleozoic; Plate tectonics; Precambrian; Proterozoic; Rifting; Russian Arctic; Russian Federation; Sea-floor spreading; Sedimentation; Seismic methods; Seismic profiles; Severnaya Zemlya; Shelf environment; Surveys; Tectonics; Tertiary; Unconformities; Upper Precambrian; West Siberia
Coordinates: N750000 N850000 E1500000 E0800000
Record ID: 2019035314
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands