Late quaternary history of hydrography, oxygen depletion and organic carbon accumulation on the Oman Margin
- Univ. of British Columbia, Vancouver (Canada)
- Univ. of Edinburgh (United Kingdom)
Measurements of the sedimentary organic carbon and nitrogen contents and minor element concentrations are used along with stable isotope records obtained form planktonic and benthic foraminifera to interpret hydrographic history at mid-depth (600 m) on the central Oman Margin (ODP Site 724) over the past half million years. Both C. wuellerstorfi data and Iodine/C[sub org] ratio information indicate that the oxygen minimum on the margin has been continuously present over the period examined. Glacial-interglacial [delta][sup 18]O amplitudes recorded by benthic foraminifera are reduced when compared to the estimated mean ocean changes of [delta][sup 18]O[sub seawater]. This implies that Red Sea outflow waters (which are enriched in [sup 18]O and [sup 13]C) were replaced during glacial periods by intermediate waters still enriched in [sup 13]C but relatively depleted in [sup 18]O. Glacial-interglacial amplitudes of the planktonic [delta][sup 18]O record exceed those of the mean ocean [delta][sup 18]O[sub seawater] variation and imply decreased surface water temperatures at this site during glacial times. If this interpretation is correct, then the data suggest that increased upwelling occurred during glacials. This conclusion conflicts with previous findings that upwelling maxima in the western Arabian Sea correspond to maxima in the strength of the SW monsoon, which occur primarily during interglacials.
- OSTI ID:
- 6662048
- Report Number(s):
- CONF-9002174--
- Journal Information:
- EOS, Transactions, American Geophysical Union; (United States), Journal Name: EOS, Transactions, American Geophysical Union; (United States) Vol. 71:2; ISSN 0096-3941; ISSN EOSTAJ
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
540310* -- Environment
Aquatic-- Basic Studies-- (1990-)
ANIMALS
ARABIAN SEA
ASIA
CARBON
CENOZOIC ERA
CHEMICAL COMPOSITION
DEVELOPING COUNTRIES
ECOLOGICAL CONCENTRATION
ELEMENTS
FLUCTUATIONS
FORAMINIFERA
GEOLOGIC AGES
HYDROGEN COMPOUNDS
HYDROLOGY
INDIAN OCEAN
INVERTEBRATES
MICROORGANISMS
MIDDLE EAST
NITROGEN
NONMETALS
OMAN
OXYGEN
OXYGEN COMPOUNDS
PROTOZOA
QUATERNARY PERIOD
RED SEA
SARCODINA
SEAS
SEAWATER
SURFACE WATERS
TEMPERATURE MEASUREMENT
UPWELLING
VARIATIONS
WATER