Abstract
The facies problems of the Eocene formations ranging from Wilcox to Cockfield are discussed and illustrated by cross sections through the Cheneyville, Eola, Ville Platte, and Mamou fields. The structural type, the different producing formations and the reservoir characteristics of these fields are briefly described. Petroleum accumulation in these structures appears to be controlled by the presence of several marine shale bodies, which act as effective seals and cause the present distribution of petroleum in sand reservoirs underlying them. A possible relationship between oil types and sedimentary facies seems to be indicated, heavier hydrocarbons being found updip in the shallow-water sand facies, lighter hydrocarbons in the downdip, more marine shale facies of a producing formation.
