Richmond Basin

The Richmond Basin was one of the Eastern North America Rift Basins. It lies over Swift Creek Reservoir from Interstate 64 to the Appomattox River.

The Richmond Basin is a rift basin, making a north to south double pointed oval, with the eastern edge over the Swift Creek Reservoir, with the northern point at interstate 64, spanning the James River, with the southern point at the Appomattox River.

The Richmond Basin is 205 to 245 million years old. 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 created when the continents were pushing together and raising up mountains. Semi-anthracite and anthracite are often created by such tectonic squeezing when continents push together. The Richmond Basin has Bituminous coal, created by the sedimentary weight only.

The coal deposits were on a thin shale and sandstone layer over the granite bedrock. Oolite or small round grains of calcium carbonate was over the coal. Some coke with and without sulphur was with the coal.

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