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Peak Cenozoic warmth enabled deep-sea sand deposition

February 8, 2023

The early Eocene (~ 56–48 million years ago) was marked by peak Cenozoic warmth and sea levels, high CO2, and largely ice-free conditions. This time has been described as a period of increased continental erosion and silicate weathering. However, these conclusions are based largely on geochemical investigation of marine mudstones and carbonates or study of intermontane Laramide basin settings. Here, we evaluate the marine coarse siliciclastic response to early Paleogene hothouse climatic and oceanographic conditions. We compile an inventory of documented sand-rich (turbidite) deep-marine depositional systems, recording 59 instances of early Eocene turbidite systems along nearly all continental margins despite globally-elevated sea levels. Sand-rich systems were widespread on active margins (42 instances), but also on passive margins (17 instances). Along passive margins, 13 of 17 early Eocene systems are associated with known Eocene-age fluvial systems, consistent with a fluvial clastic response to Paleogene warming. We suggest that deep-marine sedimentary basins preserve clastic records of early Eocene climatic extremes. We also suggest that in addition to control by eustasy and tectonism, climate-driven increases in sediment supply (e.g., drainage integration, global rainfall, denudation) may significantly contribute to the global distribution and volume of coarse-grained deep-marine deposition despite high sea level.

Publication Year 2023
Title Peak Cenozoic warmth enabled deep-sea sand deposition
DOI 10.1038/s41598-022-27138-2
Authors Zachary FM Burton, Tim McHargue, Christopher H. Kremer, Richard B Bloch, Jared T. Gooley, Chayawan Jailka, Jake Harrington, Stephan A. Graham
Publication Type Article
Publication Subtype Journal Article
Series Title Scientific Reports
Index ID 70240482
Record Source USGS Publications Warehouse
USGS Organization Alaska Science Center Geology Minerals; Geology, Energy & Minerals Science Center