(Table 1) Organic carbon and hydrogen index data for sediment samples from ODP Site 105-645 ...
The extractable organic matter in Holocene to early Miocene deep-sea sediments from Site 645 (ODP Leg 105) in Baffin Bay contains almost exclusively biological markers of terrigenous origin. Pentacyclic triterpenoids of the alpha-(ursene) and beta-amyrin (oleanene) type often occur as the most abund...
Main Authors: | , |
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Format: | Dataset |
Language: | English |
Published: |
PANGAEA
1988
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Subjects: | |
Online Access: | https://dx.doi.org/10.1594/pangaea.707415 https://doi.pangaea.de/10.1594/PANGAEA.707415 |
Summary: | The extractable organic matter in Holocene to early Miocene deep-sea sediments from Site 645 (ODP Leg 105) in Baffin Bay contains almost exclusively biological markers of terrigenous origin. Pentacyclic triterpenoids of the alpha-(ursene) and beta-amyrin (oleanene) type often occur as the most abundant compounds in the aliphatic hydrocarbon, ketone and alcohol fractions of the sediment extract.A specific diagenetic reaction involves the conversion of taraxer-14-ene into olean-12-ene in the upper 700 metres of the sedimentary sequence. The taraxerene-to-oleanene conversion is complete before the onset of isomerisation of diasterenes at C-20. In the sediment as well as in laboratory simulation experiments, olean-12-ene further isomerises to olean-13(18)-ene and olean-18-ene, the latter of which may be the direct precursor of 18beta(H)- and 18alpha(H)-oleanane found in sediments containing more mature organic matter and in crude oils. The subsurface interconversion of these triterpenoid skeletons indicate that ... : Supplement to: ten Haven, H Lo; Rullkötter, Jürgen (1988): The diagenetic fate of taraxer-14-ene and oleanene isomers. Geochimica et Cosmochimica Acta, 52(10), 2543-2548 ... |
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