Changes

===Kerogen Type III===

===Kerogen Type III===

Kerogen type III contains sufficient hydrogen to be gas generative but not enough hydrogen to be oil prone. In its pure form, it is composed of vitrinite, a maceral formed from land plant wood. As with other intermediate kerogen types, however, various maceral mixtures or degradational processes can contribute to kerogen type III formation. Coal-forming environments represent several different kerogen types. Most coals form in paralic swamps and abandoned river channels. Vail et al. (in press) find that in regions where sediment supply is low, incised valleys contain these sediments as estuarine or coastal plain deposits.

[[Type III kerogen|Kerogen type III]] contains sufficient hydrogen to be gas generative but not enough hydrogen to be oil prone. In its pure form, it is composed of vitrinite, a maceral formed from land plant wood. As with other intermediate kerogen types, however, various maceral mixtures or degradational processes can contribute to kerogen type III formation. Coal-forming environments represent several different kerogen types. Most coals form in paralic swamps and abandoned river channels. Vail et al. (in press) find that in regions where sediment supply is low, incised valleys contain these sediments as estuarine or coastal plain deposits.

===Kerogen Type IV===

===Kerogen Type IV===