Marine biotic response of the northern Atlantic Ocean during gradual and abrupt warming events from the late Paleocene to the early-middle Eocene

Author(s): Keller, Allison L.; Kirtland Turner, Sandra; Penman, Donald; Sexton, Philip F.; Norris, Richard D.; Paytan, Adina
Author Affiliation(s): Primary:
University of California at Riverside, Department of Earth Sciences, Riverside, CA, United States
Other:
Yale University, United States
Open University, United Kingdom
Scripps Institution of Oceanography, United States
University of California at Santa Cruz, United States
Volume Title: Geological Society of America, 2017 annual meeting & exposition
Source: Abstracts with Programs - Geological Society of America, 49(6); Geological Society of America, 2017 annual meeting & exposition, Seattle, WA, Oct. 22-25, 2017. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592 CODEN: GAAPBC
Note: In English
Summary: The latest Paleocene to the early-middle Eocene (∼58 to 48 Ma) was climatically dynamic, experiencing elevated global temperatures and atmospheric carbon dioxide (CO2) levels across both gradual and geologically brief episodes. Transient warming events known as 'hyperthermals' punctuated the long-term warming trend, typically lasting <200 kyr in duration. These are characteristically associated with negative carbon isotope excursions and dissolution of deep-sea carbonates, suggesting an association with massive changes to the exogenic carbon reservoir. Hyperthermals thus likely indicate the release and/or redistribution of large quantities of isotopically light (13C-depleted) carbon to the atmosphere and oceans. Throughout this time, hyperthermals vary in magnitude, making them effective case studies for future climate change driven by anthropogenic CO2 emissions. The marine biological pump describes the fixation of carbon in surface waters through primary production and its transport to the deep-sea. Biogenic barium (Babio) has been widely applied as a proxy for the strength of the biological pump, since barite is formed during the degradation of sinking organic matter. Understanding connections between the marine biological pump and climatic perturbations of varying magnitude and duration will provide context for predicting the behavior of the biological pump in the future. Here we present new bulk and benthic stable isotopic carbon (δ13C) and oxygen (δ18O) records from the Integrated Ocean Drilling Program (IODP) Site U1409, recovered offshore Newfoundland. We compare these records with Ocean Drilling Program (ODP) Site 1258 (Demerara Rise, Equatorial Atlantic) and ODP Site 1262 (Walvis Ridge, South Atlantic) to discriminate probable global climatic events. Additionally, we present an X-Ray Fluorescence (XRF) derived barium/iron (Ba/Fe) record and select, preliminary barite measurements from Site U1409 to evaluate trends in export production coincident with hyperthermals and long-term trends in climate. Our new records suggest that the Early Eocene was a time of high export production in this region and that transient increases in export coincided with short-lived warming events.
Year of Publication: 2017
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Atlantic Ocean; Ba/Fe; Barium; C-13/C-12; Carbon; Cenozoic; Climate change; Demerara Rise; Eocene; Equatorial Atlantic; Expedition 342; IODP Site U1409; Integrated Ocean Drilling Program; Iron; Isotope ratios; Isotopes; Leg 207; Leg 208; Marine environment; Metals; North Atlantic; Northwest Atlantic; O-18/O-16; ODP Site 1258; ODP Site 1262; Ocean Drilling Program; Oxygen; Paleocene; Paleoclimatology; Paleoecology; Paleoenvironment; Paleogene; Productivity; South Atlantic; Stable isotopes; Tertiary; Upper Paleocene; Walvis Ridge; West Atlantic
Coordinates: S271100 S271100 E0013500 E0013400
N092600 N092600 W0544400 W0544400
N411744 N411745 W0491359 W0491400
Record ID: 2018064535
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States