Monahan, Kyle Matthew et al. (2010): Eocene fluctuations in the CCD & climate; evidence from carbonate & oxygen isotopes (ODP Site 1090)

Leg/Site/Hole:
ODP 177
ODP 177 1090
Identifier:
2011-086899
georefid

Creator:
Monahan, Kyle Matthew
Rensselaer Polytechnic Institute, Department of Earth and Environmental Sciences, Troy, NY, United States
author

Katz, Miriam E.
author

Cramer, Benjamin
author

Identification:
Eocene fluctuations in the CCD & climate; evidence from carbonate & oxygen isotopes (ODP Site 1090)
2010
In: Anonymous, Geological Society of America, 2010 annual meeting
Geological Society of America (GSA), Boulder, CO, United States
42
5
286
The transition from warm global climates in the early Paleogene to cool global climates by the early Oligocene was accompanied by a large-scale reorganization of deep-sea circulation patterns (Cramer et al. 2009), small transient Antarctic glaciations (e.g., Browning et al. 1996) and large fluctuations in the Calcite Compensation Depth (CCD) (e.g., Coxall et al. 2005; Lyle et al. 2005). Using CaCO (sub 3) and stable isotopic data from a central Pacific location, Lyle et al. (2005) proposed that the CCD changes reflected by changes in accumulation of calcium carbonate were linked to global cooling events, and possibly small glaciations in Antarctica. We build on the Pacific study by analyzing the mid- to late Eocene ( approximately 36 to 40 Ma) section from Ocean Drilling Program (ODP) Site 1090, located in the Atlantic sector of the Southern Ocean. At a paleodepth of approximately 2500-3000m, this site is well located to monitor changes in the CCD. We analyzed bulk sediments from Site 1090 for (1) %CaCO (sub 3) to document changes in the CCD in this region and (2) bulk sediment oxygen isotopes (d (super 18) O) as an indicator of cooling events and possible Antarctic glaciation from approximately 36-40 Ma. Our CaCO (sub 3) data at Site 1090 record substantial variability in carbonate content, indicating fluctuations in the CCD. There is good agreement between high %CaCO (sub 3) and high d (super 18) O, linking a deeper CCD to cooling and possible Antarctic ice sheet growth. Our results support the hypothesis proposed by Lyle et al. (2005).
English
Coverage:Geographic coordinates:
North:-42.5449
West:8.5359East: 8.5359
South:-42.5449

Stratigraphy; Antarctica; Atlantic Ocean; calcium carbonate; carbonate compensation depth; carbonates; Cenozoic; climate; Eocene; glaciation; isotope ratios; isotopes; Leg 177; marine sediments; O-18/O-16; ocean circulation; Ocean Drilling Program; ODP Site 1090; Oligocene; oxygen; Pacific Ocean; paleoclimatology; Paleogene; sediments; South Atlantic; Southern Ocean; stable isotopes; Tertiary;

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