In which geologic setting were most of the world's coal reserves deposited?
A) Precambrian fluvial and shallow marine systems
B) shallow epicontinental seas with abundant carbonate-producing organisms
C) tropical and subtropical fluvial and shallow marine systems where swamps could occur
D) in sedimentary basins along passive continental margins

Question

Quizplus · Accepted Answer

Coal reserves are primarily derived from the remnants of ancient swamps and wetlands. The tropical and subtropical fluvial and shallow marine systems of the past provided the ideal conditions for the formation of these swamps, where large amounts of plant material accumulated and eventually turned into coal.

In Which Geologic Setting Were Most of the World's Coal