Changes

==Carbon isotope ratios==

==Carbon isotope ratios==

[[file:oiloil-and-oilsource-rock-correlations_fig8-3.png|thumb|{{figure number|1}}From Bordenave and Burwood;<ref name=ch08r2>Bordenave, M., L., Burwood, R., 1990, [[Source rock]] distribution and [[maturation]] in the Zagros orogenic belt: provenance of the Asmari and Bangestan reservoir oil accumulations: Organic Geochemistry, vol. 16, p. 369–387., 10., 1016/0146-6380(90)90055-5</ref> reprinted with permission from Elsevier.]]

[[file:oiloil-and-oilsource-rock-correlations_fig8-3.png|300px|thumb|{{figure number|1}}From Bordenave and Burwood;<ref name=ch08r2>Bordenave, M., L., Burwood, R., 1990, [[Source rock]] distribution and [[maturation]] in the Zagros orogenic belt: provenance of the Asmari and Bangestan reservoir oil accumulations: Organic Geochemistry, vol. 16, p. 369–387., 10., 1016/0146-6380(90)90055-5</ref> reprinted with permission from Elsevier.]]

Carbon isotope ratios are commonly measured on whole oils, kerogens, and whole extracts (bitumens) from rocks. In many cases they are also measured on the C₁₅₊ saturate and aromatic fractions and are often displayed on a Sofer.<ref name=ch08r50>Sofer, Z., 1984, [http://archives.datapages.com/data/bulletns/1984-85/data/pg/0068/0001/0000/0031.htm Stable carbon isotope compositions of crude oils: application to source depositional environments and petroleum alteration]: AAPG Bulletin, vol. 68, p. 31–49.</ref> diagram (e.g., the figure on the right, below). Less commonly, carbon isotope ratios are measured on the distillate and/or chromatographic fractions. For oil-[[source rock]] correlations, isotope ratios can also be measured on kerogen. Results of isotope analyses are often presented in a socalled Galimov diagram (left, below). Carbon isotope ratios can be characteristic of geologic age and environment.<ref name=ch08r4>Chung, H., M., Rooney, M., A., Toon, M., B., Claypool, G., E., 1992, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0076/0007/0000/1000.htm Carbon isotopic composition of marine crude oils]: AAPG Bulletin, vol. 76, p. 1000–1007.</ref><ref name=ch08r5>Chung, H., M., Rooney, M., A., Toon, M., B., Claypool, G., E., Rooney, M., A., Squires, R., M., 1994, [http://archives.datapages.com/data/bulletns/1994-96/data/pg/0078/0003/0350/0396.htm Source characteristics of marine oils as indicated by carbon isotopic ratios of volatile hydrocarbons]: AAPG Bulletin, vol. 78, p. 396–408.</ref>

Carbon isotope ratios are commonly measured on whole oils, kerogens, and whole extracts (bitumens) from rocks. In many cases they are also measured on the C₁₅₊ saturate and aromatic fractions and are often displayed on a Sofer.<ref name=ch08r50>Sofer, Z., 1984, [http://archives.datapages.com/data/bulletns/1984-85/data/pg/0068/0001/0000/0031.htm Stable carbon isotope compositions of crude oils: application to source depositional environments and petroleum alteration]: AAPG Bulletin, vol. 68, p. 31–49.</ref> diagram (e.g., the figure on the right, below). Less commonly, carbon isotope ratios are measured on the distillate and/or chromatographic fractions. For oil-[[source rock]] correlations, isotope ratios can also be measured on kerogen. Results of isotope analyses are often presented in a socalled Galimov diagram (left, below). Carbon isotope ratios can be characteristic of geologic age and environment.<ref name=ch08r4>Chung, H., M., Rooney, M., A., Toon, M., B., Claypool, G., E., 1992, [http://archives.datapages.com/data/bulletns/1992-93/data/pg/0076/0007/0000/1000.htm Carbon isotopic composition of marine crude oils]: AAPG Bulletin, vol. 76, p. 1000–1007.</ref><ref name=ch08r5>Chung, H., M., Rooney, M., A., Toon, M., B., Claypool, G., E., Rooney, M., A., Squires, R., M., 1994, [http://archives.datapages.com/data/bulletns/1994-96/data/pg/0078/0003/0350/0396.htm Source characteristics of marine oils as indicated by carbon isotopic ratios of volatile hydrocarbons]: AAPG Bulletin, vol. 78, p. 396–408.</ref>

==Compound-specific isotope analysis==

==Compound-specific isotope analysis==

[[file:oiloil-and-oilsource-rock-correlations_fig8-4.png|thumb|{{figure number|2}}. Copyright: Unocal.]]

[[file:oiloil-and-oilsource-rock-correlations_fig8-4.png|300px|thumb|{{figure number|2}}. Copyright: Unocal.]]

Over the last decade, much interest has developed in compound-specific isotope analysis, in which carbon isotope ratios are measured for numerous individual compounds in a sample and then plotted to give a fingerprint.

Over the last decade, much interest has developed in compound-specific isotope analysis, in which carbon isotope ratios are measured for numerous individual compounds in a sample and then plotted to give a fingerprint.