chapter  9
Oil resources of the Middle East
Pages 25

Theories of origin of oil Petroleum would seem to have been formed by the decomposition of various types of marine life - chiefly plankton, but also algae and lowly animal organisms. A s the remains of these organisms collected on the floors of seas and estuaries, they were gradually covered by deposits of thick, fine sediment that excluded air and light. Under such conditions, the normal process of decay did not operate; instead, partial decompo­ sition, produced by certain bacteria that exist in anerobic conditions1 seems to have transformed the original organic material into globules of petroleum. It is also possible that chemical reactions involving mineral salts contained in the surrounding water and silt played some further part in the process of decomposition.2