Changes

==Group I oils, freshwater lacustrine setting==

==Group I oils, freshwater lacustrine setting==

[[file:oiloil-and-oilsource-rock-correlations_fig8-49.png|thumb|{{figure number|2}}From Mello et al.<ref name=ch08r30 />); reprinted with permission from Marine and Petroleum Geology.]]

[[file:oiloil-and-oilsource-rock-correlations_fig8-49.png|thumb|{{figure number|2}}From Mello et al.<ref name=ch08r30 />; reprinted with permission from Marine and Petroleum Geology.]]

For illustrative purposes, we discuss here differences in the characteristics of group I and group IV oils.<ref name=ch08r30 /> The group I oils are very low in sulfur (13C values more negative than –28.0 ‰. Concentrations of diasteranes, steranes, 4-methylsteranes, and gammacerane are low; ''n''-propylcholestanes (C₃₀ steranes) are absent. A distinctive odd-carbon ''n''-alkane dominance and a waxy appearance to the [[gas chromatogram]] of these oils is evident. These and other features suggest a freshwater lacustrine depositional setting.

For illustrative purposes, we discuss here differences in the characteristics of group I and group IV oils.<ref name=ch08r30 /> The group I oils are very low in sulfur (13C values more negative than –28.0 ‰. Concentrations of diasteranes, steranes, 4-methylsteranes, and gammacerane are low; ''n''-propylcholestanes (C₃₀ steranes) are absent. A distinctive odd-carbon ''n''-alkane dominance and a waxy appearance to the [[gas chromatogram]] of these oils is evident. These and other features suggest a freshwater lacustrine depositional setting.