Various oil shales and asphaltic deposits are essentially original sediments which have subsequently undergone more or less decay and distillation.
"The Economic Aspect of Geology"
C. K. Leith
Oil and gas are distillates from these oil shales and asphaltic deposits, and also from other organic sediments such as carbonaceous limestones.
"The Economic Aspect of Geology"
C. K. Leith
Large amounts of asphaltic and bituminous rock, used mainly in paving, are normally produced in Alsace, France, and in Italy.
"The Economic Aspect of Geology"
C. K. Leith