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Line 19: − The figure below is a gas chromatogram of a high-wax oil of terrestrial origin with an odd-carbon preference in the wax region and a high pristane-phytane ratio typical of coaly or certain nearshore aquatic environments. Significant input of terrigenous organic matter is indicated by a bimodal ''n''-alkane distribution (a second mode in the wax region, from ''n''-C<sub>23</sub> to ''n''-C<sub>31</sub>), a pristane-phytane ratio greater than 2.0, and a strong odd-carbon ''n''-alkane dominance from ''n''-C<sub>25</sub> to ''n''-C<sub>31</sub>. These features are characteristic of deltaic or lacustrine-sourced oils (in this case, from Indonesia). − + + + − The figure below is a gas chromatogram of an extremely waxy oil from the Paradox basin, Utah. It was sourced from a marine anoxic evaporitic carbonate. Here the waxes, which are not derived from terrestrial plants, show an even-carbon preference, and the pristane-phytane ratio is very low ( − + + + − The figure below shows a gas chromatogram of a low-wax oil derived from typical marine algae. Pristane-phytane ratios for such oils tend to be slightly above 1.0. This Alaskan oil was derived from a source rock containing predominantly marine algal organic matter. − + + + − The figure below is a gas chromatogram of saturates from an Ordovician-sourced oil from the Illinois basin. It shows a low-wax oil derived primarily from the primitive organism ''Gloeocapsamorpha prisca''. Samples derived from ''G. prisca'' show strong odd-carbon preferences up to ''n''-C<sub>19</sub>, and have very low concentrations of both pristane and phytane.<ref name=ch08r44>Reed, J., D., Illich, H., A., Horsfield, B., 1986, Biochemical evolutionary significance of Ordovician oils and their sources: Organic Geochemistry, vol. 10, p. 347–358., 10., 1016/0146-6380(86)90035-5</ref><ref name=ch08r28>Longman, M., W., Palmer, S., E., 1987, Organic geochemistry of mid-continent middle and late Ordovician oils: AAPG Bulletin, vol. 71, p. 938–950.</ref><ref name=ch08r18>Hatch, J., R., Risatti, J., B., King, J., D., 1990, Geochemistry of Illinois basin oils and hydrocarbon source rocks, in Leighton, M., W., Kolata, D., R., Oltz, D., F., Eidel, J., J., eds., Interior cratonic basins: AAPG Memoir 51, p. 403–423.</ref><ref name=ch08r17>Guthrie, J., M., Pratt, L., M., 1995, Geochemical character and origin of oils in Ordovician reservoir rock, Illinois and Indiana: AAPG Bulletin, vol. 79, p. 1631–1649.</ref> − + + +
Gas chromatography: data obtained (view source)
Revision as of 14:33, 4 February 2014
, 14:33, 4 February 2014→Examples
==Examples==
==Examples==
===Example: oil of terrestrial origin===
===Example: oil of terrestrial origin===
[[file:oiloil-and-oilsource-rock-correlations_fig8-5.png|thumb|{{figure number|8-5}}From Robinson;<ref name=ch08r46>Robinson, K., M., 1987, An overview of [[[[source rock]]s]] and oils in Indonesia: Proceedings, Indonesian Petroleum Association 16th Annual Convention, p. 97–122.</ref> reprinted with permission from the Indonesian Petroleum Association.]]
[[file:oiloil-and-oilsource-rock-correlations_fig8-5.png|left|thumb|{{figure number|1}}From Robinson;<ref name=ch08r46>Robinson, K., M., 1987, An overview of [[[[source rock]]s]] and oils in Indonesia: Proceedings, Indonesian Petroleum Association 16th Annual Convention, p. 97–122.</ref> reprinted with permission from the Indonesian Petroleum Association.]]
[[:file:oiloil-and-oilsource-rock-correlations_fig8-5.png|Figure 1]] is a gas chromatogram of a high-wax oil of terrestrial origin with an odd-carbon preference in the wax region and a high pristane-phytane ratio typical of coaly or certain nearshore aquatic environments. Significant input of terrigenous organic matter is indicated by a bimodal ''n''-alkane distribution (a second mode in the wax region, from ''n''-C<sub>23</sub> to ''n''-C<sub>31</sub>), a pristane-phytane ratio greater than 2.0, and a strong odd-carbon ''n''-alkane dominance from ''n''-C<sub>25</sub> to ''n''-C<sub>31</sub>. These features are characteristic of deltaic or lacustrine-sourced oils (in this case, from Indonesia).
===Example: oil of marine origin===
===Example: oil of marine origin===
[[file:oiloil-and-oilsource-rock-correlations_fig8-6.png|thumb|{{figure number|8-6}}. Copyright: Unocal.]]
[[file:oiloil-and-oilsource-rock-correlations_fig8-6.png|thumb|{{figure number|2}}. Copyright: Unocal.]]
[[:file:oiloil-and-oilsource-rock-correlations_fig8-6.png|Figure 2]] is a gas chromatogram of an extremely waxy oil from the Paradox basin, Utah. It was sourced from a marine anoxic evaporitic carbonate. Here the waxes, which are not derived from terrestrial plants, show an even-carbon preference, and the pristane-phytane ratio is very low
===Example: oil of marine algal origin===
===Example: oil of marine algal origin===
[[file:oiloil-and-oilsource-rock-correlations_fig8-7.png|thumb|{{figure number|8-7}}. Copyright: Unocal.]]
[[file:oiloil-and-oilsource-rock-correlations_fig8-7.png|left|thumb|{{figure number|3}}. Copyright: Unocal.]]
[[:file:oiloil-and-oilsource-rock-correlations_fig8-7.png|Figure 3]] shows a gas chromatogram of a low-wax oil derived from typical marine algae. Pristane-phytane ratios for such oils tend to be slightly above 1.0. This Alaskan oil was derived from a source rock containing predominantly marine algal organic matter.
===Example: Oil derived from ''G. prisca''===
===Example: Oil derived from ''G. prisca''===
[[file:oiloil-and-oilsource-rock-correlations_fig8-8.png|thumb|{{figure number|8-8}}From Hatch et al.<ref name=ch08r18 />); reprinted with permission from AAPG.]]
[[file:oiloil-and-oilsource-rock-correlations_fig8-8.png|thumb|{{figure number|4}}From Hatch et al.<ref name=ch08r18 />); reprinted with permission from AAPG.]]
[[:file:oiloil-and-oilsource-rock-correlations_fig8-8.png|figure 4]] is a gas chromatogram of saturates from an Ordovician-sourced oil from the Illinois basin. It shows a low-wax oil derived primarily from the primitive organism ''Gloeocapsamorpha prisca''. Samples derived from ''G. prisca'' show strong odd-carbon preferences up to ''n''-C<sub>19</sub>, and have very low concentrations of both pristane and phytane.<ref name=ch08r44>Reed, J., D., Illich, H., A., Horsfield, B., 1986, Biochemical evolutionary significance of Ordovician oils and their sources: Organic Geochemistry, vol. 10, p. 347–358., 10., 1016/0146-6380(86)90035-5</ref><ref name=ch08r28>Longman, M., W., Palmer, S., E., 1987, Organic geochemistry of mid-continent middle and late Ordovician oils: AAPG Bulletin, vol. 71, p. 938–950.</ref><ref name=ch08r18>Hatch, J., R., Risatti, J., B., King, J., D., 1990, Geochemistry of Illinois basin oils and hydrocarbon source rocks, in Leighton, M., W., Kolata, D., R., Oltz, D., F., Eidel, J., J., eds., Interior cratonic basins: AAPG Memoir 51, p. 403–423.</ref><ref name=ch08r17>Guthrie, J., M., Pratt, L., M., 1995, Geochemical character and origin of oils in Ordovician reservoir rock, Illinois and Indiana: AAPG Bulletin, vol. 79, p. 1631–1649.</ref>
==G. prisca==
==G. prisca==