Provenance and paleoenvironment of organic matter within the Fika sediments in Chad (Bornu) Basin, northeastern Nigeria: An integrated organic geochemical and palynofacies approach

Organic matter provenance and depositional environment of marine-to-continental mudstones and coals in eastern Ordos Basin, China—Evidence from molecular geochemistry and petrology

“…Because 17α,21β(H)-hopanes are more thermally stable than 17β,21α(H)-moretanes, C 30 moretane/C 30 hopane ratios decrease from 0.8 in immature bitumen to values of <0.15 (typically <0.06) in mature source rocks (Seifert et al, 1979;Mackenzie et al, 1980a;Seifert and Moldowan, 1980;Adegoke et al, 2017). However, the C 30 moretane/C 30 hopane ratios of our samples (0.14-0.26) are slightly higher than 0.15, which is inconsistent with their J o u r n a l P r e -p r o o f thermal maturity.…”

“…A lot of organic geochemical studies on marine shales have been done, but transitional source rocks are inadequately studied. Many marine shales, especially shallow marine shales, have been found to contain humic organic matter, generally with a lower concentration than the aquatic organic matter (Milliken et al, 2013;Mathia et al, 2016;Adegoke et al, 2017;Petersen et al, 2017;Borrego et al, 2018). The organic matter input of transitional source rocks is more complex.…”