Kerogen definition

Durand B. (1980) Sedimentary organic matter and kerogen definition and quantitative importance of kerogen. In Kerogen Insoluble Organic Matter from Sedimentary Rocks (ed. B. Durand). Technip, Paris, pp. 13-34. 

It is apparent that, at temperatures of at least 800°F and, at most, 1000°F, a definite fraction of the kerogen can be removed and will be removed if enough time in a hydrogen atmosphere is allowed. Further-... 

We should caution that the above concept of the genetic relationship between kerogens and asphaltenes differs from the more historic view that asphaltenes are condensation and/or alteration products of hydrocarbons and resins. Certainly, in some petroleum processing treatments and probably at higher maturation levels in nature, various reactions do form new products with asphaltene solubility characteristics. These new condensation products may be regarded as altered asphaltenes and intermediates in the coke or pyrobitumen formation process (62-64)- Contamination of original asphaltenes by subsequently formed or altered products, of course, will result in a less definitive correlation between an asphaltene and its source kerogen. 

Although the preceding observations seem to indicate definite mineral matter influences on kerogen decomposition, extrapolation of the results to actual oil shale processing is tenuous because a physical mixture of kerogen and mineral matter, such as was used in most of the previous work, is not likely to reproduce the exact forms of physical structure or chemical bonding that exist in indigenous oil shale ... 

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