Herbert, Timothy D. and Schuffert, Jeffrey D. (2000): Alkenone unsaturation estimates of sea-surface temperatures at Site 1002 over a full glacial cycle

ODP 165
ODP 165 1002


Herbert, Timothy D.
Brown University, Department of Geological Sciences, Providence, RI, United States

Schuffert, Jeffrey D.
University of Rhode Island, United States

Alkenone unsaturation estimates of sea-surface temperatures at Site 1002 over a full glacial cycle
In: Leckie, R. Mark, Sigurdsson, Haraldur, Acton, Gary D., Abrams, Lewis J., Bralower, Timothy J., Carey, Steven N., Chaisson, William P., Cotillon, Pierre, Cunningham, Andrew D., D'Hondt, Steven L., Droxler, Andre W., Galbrun, Bruno, Gonzalez, Juan, Haug, Gerald H., Kameo, Koji, King, John W., Lind, Ida L., Louvel, Veronique, Lyons, Timothy W., Murray, Richard W., Mutti, Maria, Myers, Greg, Pearce, Richard B., Pearson, D. Graham, Peterson, Larry C., Roehl, Ursula, Garman, Phyllis (editor), Proceedings of the Ocean Drilling Program, scientific results, Caribbean Ocean history and the Cretaceous/Tertiary boundary event; covering Leg 165 of the cruises of the drilling vessel JOIDES Resolution, Miami, Florida, to San Juan Puerto Rico, sites 998-1002, 19 December 1995-17 February 1996
Texas A & M University, Ocean Drilling Program, College Station, TX, United States
We determined alkenone concentrations (mu g/g dry sediment) and unsaturation indices (U (super k') (sub 37) ) on 280 samples from Ocean Drilling Program Hole 1002C over the last full glacial cycle (marine oxygen isotope Stages [MIS] 1-6). Alkenone concentrations vary dramatically in relation to glacial-interglacial cycles, with high concentrations typical of interglacial stages, high sea level, inferred high surface productivity, and bottom-water anoxia. Our reconstruction of low productivity during the last glacial maximum is consistent with previous reports of a sharp decline in the foraminiferal species Neogloboquadrina dutertrei, an upwelling index. Alkenone paleotemperatures show little cooling at both the last glacial maximum and MIS 6. Variations of as much as 4 degrees C occurred during the earlier part of MIS 3 and MIS 4 as well as the latter part of MIS 5. The absence of cooling during glacial maxima determined from alkenone paleothermometry is consistent with faunal reconstructions for the western Caribbean but requires that much of the oxygen isotopic record of the planktonic foraminifer Globigerinoides ruber be influenced by salinity variations rather than temperature.
Coverage:Geographic coordinates:
West:-65.1011East: -65.1011

Quaternary geology; alkenones; Atlantic Ocean; biostratigraphy; Caribbean Sea; Cenozoic; climate change; cores; Foraminifera; glacial environment; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides ruber; Invertebrata; ketones; Leg 165; microfossils; Neogloboquadrina; Neogloboquadrina dutertrei; North Atlantic; Ocean Drilling Program; ODP Site 1002; organic compounds; paleo-oceanography; paleoclimatology; paleosalinity; productivity; Protista; Quaternary; Rotaliina; salinity; sea-surface temperature;