Oxygen isotope compositions of sinistral Neogloboquadrina pachyderma tests in surface sediments: North Atlantic Ocean

Journal Article · Tue Feb 01 00:00:00 EST 1994 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(94)90383-2· OSTI ID:7161150

Wu, G; Hillaire-Marcel, C ^[1]

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1. Universite de Quebec a Montreal (Canada)

Neogloboquadrina pachyderma (Left-coiled) is a planktonic foraminifer indicator species for polar waters. It is present in both the glacial and interglacial sediments of the high-latitude oceans, and therefore is frequently used as a signal-carrier for constructing late Pleistocene-Holocene planktonic [delta][sup 18]O records. In this study the [delta][sup 18]O compositions of N. pachyderma (L) tests from deep-sea surface sediments are compared with surface water [delta][sup 18]O values and summer sea surface temperatures (SST) in the North Atlantic Ocean, the Norwegian-Greenland Sea, and the Labrador Sea. The authors document that for a temperature range of 2-8[degrees]C, the planktonic [delta][sup 18]O values follow paleotemperature equations with an offset of less than 0.4%, and that above 8[degrees]C the planktonic [delta][sup 18]O compositions become almost independent of SST and remain nearly constant. This pattern suggests that N. pachyderma (L) precipitates its shell nearly at isotopic equilibrium with surface waters colder than 8[degrees]C, and that in warmer surface waters N. pachyderma (L) changes its habitat depth or its growth season to secrete its shell at an ambient temperature around 7-9[degrees]C.

• OSTI ID: 7161150
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 58:4; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ATLANTIC OCEAN
PALEOTEMPERATURE
FORAMINIFERA
SHELLS
ISOTOPE RATIO
OXYGEN 18
ANIMALS
EVEN-EVEN NUCLEI
INVERTEBRATES
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
NUCLEI
OXYGEN ISOTOPES
PROTOZOA
SARCODINA
SEAS
STABLE ISOTOPES
SURFACE WATERS
540310* - Environment
Aquatic- Basic Studies- (1990-)