Unknown
PANGAEA
In:
Supplement to: Zahn, Rainer; Pedersen, Thomas F (1991): Late Pleistocene evolution of surface and mid-depth hydrography at the Oman margin: planktonic and benthic isotope records at Site 724. In: Prell, WL; Niitsuma, N; et al. (eds.), Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 117, 291-308, https://doi.org/10.2973/odp.proc.sr.117.162.1991
Publication Date:
2024-01-09
Description:
Stable isotope records of coexisting benthic foraminifers Uvigerina spp. and Cibicidoides spp. and planktonic G. ruber (white variety) from Site 724 are used to study the late Pleistocene evolution of surface and intermediate water hydrography (593 m water depth) at the Oman Margin. Glacial-interglacial d18O amplitudes recorded by the benthic foraminifers are reduced when compared to the estimated mean ocean changes of d18Oseawater . Epibenthic d13C remains at its modern level or is increased during glacial times. This implies that Red Sea outflow waters which are enriched in d18Oseawater and d13C (Sum CO2) have been replaced during glacial periods by intermediate waters still positive in d13C (Sum CO2) but more negative in d18Oseawater. Glacial-interglacial amplitudes of the planktonic d18O record exceed those of the mean ocean d18Oseawater variation and imply decreased surface water temperatures (SST) during glacial times. Throughout most of the records these cooling events correlate with enhanced rates of carbon accumulation. However, both negative (colder) SST and positive Corg accumulation rate anomalies do not correlate with potential physical upwelling maxima as inferred from the orbital monsoon index. This is in conflict with the established hypothesis that upwelling in the estern Arabia Sea should be strongest during maxima of the southwest monsoon.
Keywords:
117-724C; Arabian Sea; DRILL; Drilling/drill rig; Joides Resolution; Leg117; Ocean Drilling Program; ODP
Type:
Dataset
Format:
application/zip, 2 datasets
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