Publikationsdatum:
2018-07-15
Beschreibung:
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.
Repository-Name:
EPIC Alfred Wegener Institut
Materialart:
Article
,
isiRev
Permalink
