Mississippian source rock maturation and richness, eastern Nevada
Using vitrinite reflectance values and palynomorph thermal alteration indices, areas of optimum and overmature Mississippian source rocks of eastern Nevada have been identified. Thermal maturation data show a northwestern trend of the oil-generation window through eastern Nevada. The oil-generating area is bounded on the northeast by increasingly higher values that indicate an area of overmaturation. This area of overmaturation is probably due to thick overlying Pennsylvanian and Permian Oquirrh basin sediments in northwestern Utah. Overmaturation in northeastern Nevada is probably due to massive intrusives. Mississippian sediments in central Nevada are not exposed west of a line that extends from western Pine Valley in north-central Nevada through the eastern edge of the Diamond Mountains in central Nevada to the Atomic Test Site. The data strongly suggest a thrust fault on the western border of the oil window that is part of this north-south trend. Total organic content (TOC) data averaged over this same Mississippian interval show a similar northwestern trend. Average TOC content, excluding some samples of coal that were analyzed, exceed 5% in some cases. Select individual samples exceed 13%. These data can guide explorationists away from overmature and lean areas and toward optimum maturation and organically rich areas. In addition, extrapolation of known trends can lead to exploration in areas of unknown maturation and source rock richness. Recognition of anomalous data leads to interpretations such as the unmapped thrust fault in the Diamond Mountains.
- Research Organization:
- Nevada Scout, Reno
- OSTI ID:
- 6962587
- Report Number(s):
- CONF-8609129-
- Journal Information:
- Am. Assoc. Pet. Geol., Bull.; (United States), Journal Name: Am. Assoc. Pet. Geol., Bull.; (United States) Vol. 70:8; ISSN AAPGB
- Country of Publication:
- United States
- Language:
- English
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