Temporal and geographical distribution of fossil organic carbon

6 Temporal and geographical distribution of fossil organic carbon 

Major coal deposits coincided with periods following regression, which is consistent with the most suitable conditions for deposition—a steady increase in accommodation space—being predominantly found in lowland coastal swamps (Section 3.4.2a). Two main episodes of coal formation can be distinguished the first during the Carboniferous—Permian and a second smaller episode spanning the Jurassic to early Tertiary. The majority of coals formed in the earlier episode are now bituminous coals or anthracites, whereas those from the Tertiary are mainly brown coals. 

Middle East, Libya, North Central America 

North Sea, Middle East, Mexico, Siberia, Australia, Central Asia 

Sahara, Volga-Ural, Canada, West Texas 

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