Changes

Other minor components present in gas chromatograms can be used for correlations, even when compound identities are not known. However, one should always treat unidentified compounds with caution, since they may represent contaminants, or their concentrations may be affected by maturity or alteration effects.

Other minor components present in gas chromatograms can be used for correlations, even when compound identities are not known. However, one should always treat unidentified compounds with caution, since they may represent contaminants, or their concentrations may be affected by maturity or alteration effects.

[[:file:oiloil-and-oilsource-rock-correlations_fig8-12.png|Figure 8]] shows gas chromatograms of two oils from Texas and Oklahoma. Full-scale chromatograms on the left show the oils are not degraded, a condition necessary for this type of correlation. The shaded areas indicate the regions expanded on the right. Based on the many similarities in the expanded-scale chromatograms and on other geo-chemical similarities, it was concluded that these two oils were derived from the same Lower Paleozoic source facies.

[[:file:oiloil-and-oilsource-rock-correlations_fig8-12.png|Figure 8]] shows gas chromatograms of two oils from Texas and Oklahoma. Full-scale chromatograms on the left show the oils are not [http://www.oiltracers.com/services/exploration-geochemistry/oil-biodegradation.aspx degraded], a condition necessary for this type of correlation. The shaded areas indicate the regions expanded on the right. Based on the many similarities in the expanded-scale chromatograms and on other geochemical similarities, it was concluded that these two oils were derived from the same lower Paleozoic source facies.

==Star diagrams==

==Star diagrams==