| [[file:oiloil-and-oilsource-rock-correlations_fig8-11.png|300px|left|thumb|{{figure number|7}}Gas chromatograms of two extracts of immature source rock candidates in southern California (Monterey Formation, Santa Maria basin). From Curiale et al.;<ref name=ch08r13>Curiale, J., A., Cameron, D., Davis, D., V., 1985, Biological marker distribution and significance in oils and rocks of the Monterey Formation, California: Geochimica et Cosmochimica Acta, vol. 49, p. 271–288., 10., 1016/0016-7037(85)90210-8</ref> reprinted with permission from Elsevier.]] | | [[file:oiloil-and-oilsource-rock-correlations_fig8-11.png|300px|left|thumb|{{figure number|7}}Gas chromatograms of two extracts of immature source rock candidates in southern California (Monterey Formation, Santa Maria basin). From Curiale et al.;<ref name=ch08r13>Curiale, J., A., Cameron, D., Davis, D., V., 1985, Biological marker distribution and significance in oils and rocks of the Monterey Formation, California: Geochimica et Cosmochimica Acta, vol. 49, p. 271–288., 10., 1016/0016-7037(85)90210-8</ref> reprinted with permission from Elsevier.]] |
− | An unusual biomarker is 28, 30-bisnorhopane, which can be extremely abundant in those few samples where it is present. [[:file:oiloil-and-oilsource-rock-correlations_fig8-11.png|Figure 7]] shows gas chromatograms of two extracts of immature source rock candidates in southern California (Monterey Formation, Santa Maria basin). They contain bisnorhopane as well as a series of monoaromatic steroid hydrocarbons. These two biomarker types, together with the low pristane–phytane ratios shown here, are characteristic of Monterey oils. These distinctive characteristics provide a fairly confident correlation to Monterey oils, despite the very low maturity of the source rocks. | + | An unusual biomarker is 28, 30-bisnorhopane, which can be extremely abundant in those few samples where it is present. [[:file:oiloil-and-oilsource-rock-correlations_fig8-11.png|Figure 7]] shows gas chromatograms of two extracts of immature [[source rock]] candidates in southern California ([[Monterey Formation]], [[Santa Maria Basin]]). They contain bisnorhopane as well as a series of monoaromatic steroid hydrocarbons. These two biomarker types, together with the low [[pristane–phytane ratio]]s shown here, are characteristic of Monterey oils. These distinctive characteristics provide a fairly confident correlation to Monterey oils, despite the very low [[maturity]] of the source rocks. |