Further evaluation of long-chain alkenones as indicators of paleoceanographic conditions

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(88)90132-9· OSTI ID:5180398

Prahl, F G; Muehlhausen, L A; Zahnle, D L ^[1]

---

1. Oregon State Univ., Corvallis (USA)

Cultures of the marine coccolithophorid, Emiliania huxleyi, were grown in the laboratory at five temperatures (8{degree}, 10{degree}, 15{degree}, 20{degree}, 25{degree}) and monitored by capillary gas chromatography for their long-chain, unsaturated lipid compositions. Systematic changes in the degree of unsaturation and in the overall carbon chain length distribution of the alkenones and in the proportion of fatty acid esters relative to alkenones are noted as a function of growth temperature. The authors present temperature calibrations of this biomarker series measured in a variety of sediments accumulating beneath warm ({ge}25{degree}C) and cold ({le}12{degree}C) surface waters in the tropical and temperate North Pacific Ocean, respectively. The comparisons demonstrate (1) this series of biomarkers is deposited in these oceanic sediments with minimal evidence of alteration to its original composition and (2) the strain of E. Huxleyi used in this laboratory calibration is representative of the average marine phytoplankton supplying this novel series of biomarkers to contemporary sediments in these two environments and a wide variety of other oceanic environments. The long-chain alkenones constitute a major component (8.0 {plus minus} 2.9%) of the total organic carbon content of living cells of E. huxleyi. The high cellular abundance of these compounds appears to be relatively constant and independent of the growth temperature of the plant. These biomarkers provide a well-designed and useful geochemical tool for assessing variations not only in surface water temperatures but potentially also in the productivity of an important group of marine phytoplankton in oceans of the recent and distant past.

• OSTI ID: 5180398
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 52:9; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AQUATIC ORGANISMS
BIOLOGICAL MARKERS
CARBOXYLIC ACIDS
CHEMICAL COMPOSITION
CHEMISTRY
CHROMATOGRAPHY
DIAGENESIS
GAS CHROMATOGRAPHY
GEOCHEMISTRY
INTERFACES
KETONES
LIPIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PACIFIC OCEAN
PHYTOPLANKTON
PLANKTON
SEAS
SEDIMENT-WATER INTERFACES
SEDIMENTS
SEPARATION PROCESSES
STRUCTURAL CHEMICAL ANALYSIS
SURFACE WATERS
TEMPERATURE EFFECTS