Changes

[[File:KerogenTypeFig2.png|thumb|350px|{{figure number|2}}Modified Van Krevelen diagram for organic facies A through D. (After Jones.<ref>Jones, R. W., 1987, Organic Facies, in J. Brooks and D. H. Welte, eds., Advances in Petroleum Geochemistry, v. 2, Academic Press, London, p. 1-90.</ref>)]]

[[File:KerogenTypeFig2.png|thumb|350px|{{figure number|2}}Modified Van Krevelen diagram for organic facies A through D. (After Jones.<ref>Jones, R. W., 1987, Organic Facies, in J. Brooks and D. H. Welte, eds., Advances in Petroleum Geochemistry, v. 2, Academic Press, London, p. 1-90.</ref>)]]

Pioneers of pyrolysis found that some minerals inhibit hydrocarbon expulsion during whole-rock pyrolysis and not during kerogen pyrolysis.<ref name=Esptl1980 /><ref name=Hrsfld1980 /><ref name=Dmbcki1983 /> The effect of different matrix constituents<ref name=Esptl1980 /><ref name=Hrsfld1980 /><ref name=Dmbcki1983 /><ref name=Ktz1983 /> varies from strongest to weakest: illite > Ca-bentonite > kaolinite > Na-bentonite > calcium carbonate > gypsum.<ref name=Esptl1980 /> Variations in the mineral matrix effect related to organic richness occur in whole-rock samples with TOC values less than 10%.<ref name=Esptl1980 /><ref name=Hrsfld1980 /><ref name=Dmbcki1983 />

Pioneers of pyrolysis found that some minerals inhibit hydrocarbon expulsion during whole-rock pyrolysis and not during kerogen pyrolysis.<ref name=Esptl1980 /><ref name=Hrsfld1980 /><ref name=Dmbcki1983 /> The effect of different matrix constituents<ref name=Esptl1980 /><ref name=Hrsfld1980 /><ref name=Dmbcki1983 /><ref name=Ktz1983 /> varies from strongest to weakest: illite > Ca-bentonite > kaolinite > Na-bentonite > calcium carbonate > [[gypsum]].<ref name=Esptl1980 /> Variations in the mineral matrix effect related to organic richness occur in whole-rock samples with TOC values less than 10%.<ref name=Esptl1980 /><ref name=Hrsfld1980 /><ref name=Dmbcki1983 />

Geological thermal maturation processes differ from those of Rock-Eval pyrolysis. Whole-rock Rock-Eval samples are heated rapidly in an anhydrous environment. Geological burial processes cause clays to undergo physical and chemical alteration usually preceding the slow and systematic thermal conversion (generation) of kerogen to petroleum. These changes occur in hydrous environments, which probably reduce the reactive capabilities of clays, usually before significant hydrocarbon generation has occurred. Nevertheless, some degree of mineral matrix effect probably does persist under geological conditions.

Geological thermal maturation processes differ from those of Rock-Eval pyrolysis. Whole-rock Rock-Eval samples are heated rapidly in an anhydrous environment. Geological burial processes cause clays to undergo physical and chemical alteration usually preceding the slow and systematic thermal conversion (generation) of kerogen to petroleum. These changes occur in hydrous environments, which probably reduce the reactive capabilities of clays, usually before significant hydrocarbon generation has occurred. Nevertheless, some degree of mineral matrix effect probably does persist under geological conditions.