NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Diploptene: an indicator of terrigenous organic carbon in Washington coastal sedimentsThe pentacyclic triterpene 17 beta(H),21 beta(H)-hop-22(29)-ene (diploptene) occurs in sediments throughout the Columbia River drainage basin and off the southern coast of Washington state in concentrations comparable to long-chain plantwax n-alkanes. The same relationship is evident for diploptene and long-chain n-alkanes in soils from the Willamette Valley. Microorganisms indigenous to soils and soil erosion are indicated as the biological source and physical process, respectively, for diploptene in coastal sediments. Similarity between the stable carbon isotopic composition (delta 13CPDB) of diploptene isolated from soil in the Willamette Valley (-31.2 +/- 0.3%) and from sediments deposited throughout the Washington coastal environment (-31.2 +/- 0.5%) supports this argument. Values of delta for diploptene in river sediments are variable and 8-17% lighter, indicating that an additional biological source such as methane-oxidizing bacteria makes a significant contribution to the diploptene record in river sediments. Selective biodegradation resulting from a difference in the physicochemical association within eroded particles can explain the absence of the more-13C-depleted form of diploptene in Washington coastal sediments, but this mechanism remains unproven.
Document ID
20040090303
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
Authors
Prahl, F. G.
(College of Oceanography, Oregon State University Corvallis 97331-5503)
Hayes, J. M.
Date Acquired
August 21, 2013
Publication Date
January 1, 1992
Publication Information
Publication: Limnology and oceanography
Volume: 37
Issue: 6
ISSN: 0024-3590
Subject Category
Exobiology
Funding Number(s)
CONTRACT_GRANT: OCE87-16244
CONTRACT_GRANT: 89-15720
CONTRACT_GRANT: NAGW-1940
Distribution Limits
Public
Copyright
Other
Keywords
Non-NASA Center
NASA Discipline Number 52-30
NASA Program Exobiology
NASA Discipline Exobiology

Available Downloads

There are no available downloads for this record.
No Preview Available