10,323
edits
Changes
Jump to navigation
Jump to search
Line 36:
Line 36: + + + − The figures below are typical m/z 191 mass chromatograms for group I (top) and group IV (bottom) oils from the Brazilian continental margin, showing the differences in terpane distributions. A marine carbonate depositional setting for the source of group IV oils is reflected in the high abundance of tricyclic and tetracyclic terpanes, in the high C<sub>33</sub> homohopane concentration, and in the low wax content.+ − − [[file:oiloil-and-oilsource-rock-correlations_fig8-50.png|thumb|{{figure number|8-50}}From Mello et al.<ref name=ch08r30 />); reprinted with permission from Marine and Petroleum Geology.]]
Oil correlation case history: Brazilian offshore basins (view source)
Revision as of 21:13, 13 February 2014
, 21:13, 13 February 2014→Group I and group IV oils contrasted
==Group I and group IV oils contrasted==
==Group I and group IV oils contrasted==
[[file:oiloil-and-oilsource-rock-correlations_fig8-50.png|thumb|{{figure number|3}}From Mello et al.<ref name=ch08r30 />); reprinted with permission from Marine and Petroleum Geology.]]
In contrast to group I oil, group IV oils contain significantly higher levels of sulfur, higher vanadium-nickel, less negative δ<sup>13</sup>C ratios, and lower wax contents (see Figure 8-49). Sterane concentrations are high, as are concentrations of ''n''-propylcholestanes. In addition, tricyclic and tetracyclic terpanes are present in relatively higher concentration in group IV oils, and the homohopane distribution is irregular, with high C<sub>33</sub>.
In contrast to group I oil, group IV oils contain significantly higher levels of sulfur, higher vanadium-nickel, less negative δ<sup>13</sup>C ratios, and lower wax contents (see Figure 8-49). Sterane concentrations are high, as are concentrations of ''n''-propylcholestanes. In addition, tricyclic and tetracyclic terpanes are present in relatively higher concentration in group IV oils, and the homohopane distribution is irregular, with high C<sub>33</sub>.
[[:file:oiloil-and-oilsource-rock-correlations_fig8-50.png|Figure 3]] illustrates typical m/z 191 mass chromatograms for group I (top) and group IV (bottom) oils from the Brazilian continental margin, showing the differences in terpane distributions. A marine carbonate depositional setting for the source of group IV oils is reflected in the high abundance of tricyclic and tetracyclic terpanes, in the high C<sub>33</sub> homohopane concentration, and in the low wax content.
==Geological conclusions==
==Geological conclusions==