Biomarkers in Tertiary mélange, western Olympic Peninsula, Washington, U.S.A.

Chemical Geology
By: , and 



Middle Eocene to middle Miocene mélange and broken formations are exposed in the coastal outcrops along the west side of the Olympic Peninsula, Washington. A petroleum geochemical assessment of these geologic units has included the investigation of biomarker compounds. A comparison was made of biomarkers in an oil sample from a middle Miocene reservoir penetrated in the Medina No. 1 well with biomarkers in extracts from two samples of middle Eocene Ozette mélange (one sample having a strong petroliferous odor, and the other sample lacking this characteristic odor). Distribution patterns of n-alkanes, tricyclic terpanes, pentacyclic triterpanes, steranes, and diasteranes are remarkably similar in the oil and rock extracts. Biomarker maturity parameters indicate higher maturity in the oil relative to the extracts. The presence of 17α(H)-23,28-bisnorlupane, 18α(H)- and 18β(H)-oleanane, and de-A-lupane and an odd-carbon-number dominance of the n-alkanes in the oil and extracts seems to tie the hydrocarbons to a common source that has a significant terrigenous component.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Biomarkers in Tertiary mélange, western Olympic Peninsula, Washington, U.S.A.
Series title Chemical Geology
DOI 10.1016/0009-2541(91)90066-Z
Volume 93
Issue 1-2
Year Published 1991
Language English
Publisher Elsevier
Description 10 p.
First page 101
Last page 110
Online Only (Y/N) N
Additional Online Files (Y/N) N