Oil shale
Biological Process
Synonym
Kerogen shale
Required Geological Setting
Neogene and Quaternary sediments, Paleogene and older sediments
Occurrence
Sedimentary rocks containing kerogen composed of hydrocarbons with minor organic sulphur and nitrogen compounds. The host of most oil shale is shale. Oil shale contains solid kerogen whereas oil sands contains asphalt originated from petroleum. Kerogen is formed in the diagenetic process under 300 degree from organic materials such as algae, plants, and aquatic lives. Oil shale is usually associated with coal deposits. Oil shale burns as it is, although calorific value is smaller than coal. Heating higher than 300 degree without oxygen, inflammable gas and liquid are released. These inflammable gas and liquid may be used as alternative materials of inflammable natural gas and petroleum.