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Organic compounds: environmental indicators (view source)
Revision as of 15:05, 18 March 2014
, 15:05, 18 March 2014→Cx and Cz triterpanes
==C<sub>x</sub> and C<sub>z</sub> triterpanes==
==C<sub>x</sub> and C<sub>z</sub> triterpanes==
[[file:oiloil-and-oilsource-rock-correlations_fig8-31.png|thumb|{{figure number|9}}m/z 191 mass chromatograms of three oils from the Cooper/Eromanga basin of Australia. From Philp and Gilbert;<ref name=ch08r42 /> reprinted with permission from Elsevier.]]
[[file:oiloil-and-oilsource-rock-correlations_fig8-31.png|left|thumb|{{figure number|9}}m/z 191 mass chromatograms of three oils from the Cooper/Eromanga basin of Australia. From Philp and Gilbert;<ref name=ch08r42 /> reprinted with permission from Elsevier.]]
Two triterpanes, often called “C<sub>z</sub>” and “C<sub>x</sub>,” are also empirically associated with terrestrial organic matter, but their origin is unknown. They can be seen in [[:file:oiloil-and-oilsource-rock-correlations_fig8-26.png|Figure 4]]. C<sub>z</sub> has also been called compound X<ref name=ch08r42>Philp, R., P., Gilbert, T., D., 1986, Biomarker distributions in oils predominantly derived from terrigenous source material, in Leythaeuser, D., Rullkötter, J., eds., Advances in Organic Geochemistry 1985: New York, Elsevier, p. 73–84.</ref> and has been shown to be a diahopane (e.g., <ref name=ch08r39 />). C<sub>x</sub> is probably a neohopane. They often co-occur with other terrestrial markers, such as high C<sub>29</sub> steranes, oleanane, and bicadinanes, but they can also occur alone.
Two triterpanes, often called “C<sub>z</sub>” and “C<sub>x</sub>,” are also empirically associated with terrestrial organic matter, but their origin is unknown. They can be seen in [[:file:oiloil-and-oilsource-rock-correlations_fig8-26.png|Figure 4]]. C<sub>z</sub> has also been called compound X<ref name=ch08r42>Philp, R., P., Gilbert, T., D., 1986, Biomarker distributions in oils predominantly derived from terrigenous source material, in Leythaeuser, D., Rullkötter, J., eds., Advances in Organic Geochemistry 1985: New York, Elsevier, p. 73–84.</ref> and has been shown to be a diahopane (e.g., <ref name=ch08r39 />). C<sub>x</sub> is probably a neohopane. They often co-occur with other terrestrial markers, such as high C<sub>29</sub> steranes, oleanane, and bicadinanes, but they can also occur alone.