Hydrocarbon Potential of a Hoh Turbidite Sequence (Miocene), Western Olympic Peninsula, Washington: ABSTRACT

Abstract

The type section of S.L. Glover's Browns Point formation, a turbidite sequence within the Hoh rock assemblage, was examined for its hydrocarbon potential. In addition, the turbidite facies are matched to the organic facies throughout the entire vertical section (4000 ft) to correlate kerogen distribution, type, and maturation level with organic and turbidite facies. Outer and middle fan turbidite facies association were analyzed for organic facies lateral continuity. Distribution of organic concentrations and organic carbon types suggests terrestrial input are dominant. Thermal alteration indexes (TAI) and vitrinite reflectance data (R/sub 0/) demonstrate a marginally mature thermal alteration level (R/sub 0/ = 0.5-0.6). Visual inspection of kerogen displays a mixed to structured kerogen with Type III/IV to Type IV kerogen predominant. A gas source with marginal oil potential is inferred. However, individual turbidite facies display a significant relationship to the amount, type, and maturation level of organic matter present within each facies and facies association. Hydrocarbon exploration in the Browns Point sequence demonstrates how frontier basin analysis can be expedited through proper field identification of facies and subsequent geochemical examination of the amount, type, and maturation level of the organic matter present in each facies. These processes can help the explorationistmore » develop sedimentological, environmental, and structural reconstructions of the basin.« less