Synchronizing early Eocene deep-sea and continental records; cyclostratigraphic age models for the Bighorn Basin Coring Project drill cores

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doi: 10.5194/cp-14-303-2018
Author(s): Westerhold, Thomas; Röhl, Ursula; Wilkens, Roy H.; Gingerich, Philip D.; Clyde, William C.; Wing, Scott L.; Bowen, Gabriel J.; Kraus, Mary J.
Author Affiliation(s): Primary:
University of Bremen, MARUM-Center for Marine Environmental Sciences, Bremen, Germany
Other:
University of Hawaii, United States
University of Michigan, United States
University of New Hampshire, United States
National Museum of Natural History, United States
University of Utah, United States
University of Colorado at Boulder, United States
Volume Title: Climate of the Past
Source: Climate of the Past, 14(3), p.303-319. Publisher: Copernicus, Katlenburg-Lindau, International. ISSN: 1814-9324
Note: In English. 57 refs.; illus., incl. 2 tables
Summary: A consistent chronostratigraphic framework is required to understand the effect of major paleoclimate perturbations on both marine and terrestrial ecosystems. Transient global warming events in the early Eocene, at 56-54 Ma, show the impact of large-scale carbon input into the ocean-atmosphere system. Here we provide the first timescale synchronization of continental and marine deposits spanning the Paleocene-Eocene Thermal Maximum (PETM) and the interval just prior to the Eocene Thermal Maximum 2 (ETM-2). Cyclic variations in geochemical data come from continental drill cores of the Bighorn Basin Coring Project (BBCP, Wyoming, USA) and from marine deep-sea drilling deposits retrieved by the Ocean Drilling Program (ODP). Both are dominated by eccentricity-modulated precession cycles used to construct a common cyclostratigraphic framework. Integration of age models results in a revised astrochronology for the PETM in deep-sea records that is now generally consistent with independent 3He age models. The duration of the PETM is estimated at ∼ 200 kyr for the carbon isotope excursion and ∼ 120 kyr for the associated pelagic clay layer. A common terrestrial and marine age model shows a concurrent major change in marine and terrestrial biota ∼ 200 kyr before ETM-2. In the Bighorn Basin, the change is referred to as Biohorizon B and represents a period of significant mammalian turnover and immigration, separating the upper Haplomylus-Ectocion Range Zone from the Bunophorus Interval Zone and approximating the Wa-4-Wa-5 land mammal zone boundary. In sediments from ODP Site 1262 (Walvis Ridge), major changes in the biota at this time are documented by the radiation of a second generation of apical spine-bearing sphenolith species (e.g., S. radians and S. editus), the emergence of T. orthostylus, and the marked decline of D. multiradiatus.
Year of Publication: 2018
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Age; Atlantic Ocean; Bighorn Basin; Biozones; Cenozoic; Chronostratigraphy; Color; Cores; Cyclostratigraphy; Deep-sea environment; Demerara Rise; Depth; Eccentricity; Eocene; Equatorial Atlantic; Gilmore Hill; Leg 113; Leg 207; Leg 208; Lower Eocene; Marine environment; Maud Rise; North Atlantic; Northwest Atlantic; ODP Site 1260; ODP Site 1262; ODP Site 1263; ODP Site 1265; ODP Site 1266; ODP Site 1267; ODP Site 690; Ocean Drilling Program; Outcrops; Paleocene-Eocene Thermal Maximum; Paleoclimatology; Paleogene; Polecat Bench; Precession; Reflectance; South Atlantic; Southern Ocean; Spectra; Statistical analysis; Terrestrial environment; Tertiary; Time series analysis; United States; Walvis Ridge; Weddell Sea; West Atlantic; Wyoming; X-ray fluorescence spectra
Coordinates: S290000 S270000 E0030000 E0013000
S704954 S614837 E0030559 W0432706
S650938 S650937 E0011218 E0011218
Record ID: 2018052279
Copyright Information: GeoRef, Copyright 2018 American Geosciences Institute. Reference includes data from Copernicus Gesellschaft, Katlenburg-Lindau, Germany