Novel biologic marker parameters are applied to problems of geochemical correlation of crude oils and source rocks in the area of Prudhoe Bay field, northern Alaska. The molecular structures used for fingerprinting the shale extracts, the kerogen pyrolyzates, and the crude oils are steranes, terpanes, and monoaromatized steranes. The major sources of the principal oil accumulations are shown to be the Shublik (Triassic), Kingak (Jurassic), and the deep post-Neocomian shales. In two of the three (Kingak and Shublik), the indigenous nature of the bitumen was proven by pyrolysis and quantitative biomarker data. Possible source rocks based on geologic reasoning and bulk geochemical data include the deep Kayak (Mississippian) shale, the shallow post-Neocomian, the Neocomian, a d the Upper Cretaceous shales. However, all of these are shown by biologic marker techniques not to have generated the petroleum accumulations studied. Of the nine oils investigated, one (Kingak) rises from a single source (Kingak shale). The others have very similar source fingerprints using 10 different molecular and several bulk

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parameters in combination. These results are achieved by using a new quantitative approach based on concentrations and ratios of specific biomarkers by integration of mass chromatograms. The assessment of all parameters in combination results in a well-documented, internally consistent picture permitting the above conclusions. In addition, these biomarker data permit in hindsight a reasonable interpretation of the wide range of carbon isotope data. All results are consistent with the geologic setting. The approach adds a new dimension in assisting the petroleum explorationist toward paleoreconstruction.

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