Richmond Basin

Pangea divided and many small rifts split opened in the earth in addition to the large one that became the Atlantic Ocean.

When Richmond rift opened and filled with swamps from water in the Pamunkey River, sediment filled in over the swamps and the sedimentary pressure converted organic plant material into coal.

This weight is less pressure than coal deposits produced when the continents were pushing together and raising up mountains.

[1] The coal deposits were on a thin shale and sandstone layer over the granite bedrock.

The Clover Hill Pits in Winterpock, Virginia were sold as far away as New York City from the 1840s to the 1890s.