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. Richmond Basin Geological Diagram

Extent

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 The James River is a river in Virginia that begins in the Appalachian Mountains and flows from the confluence of the Cowpasture and Jackson Rivers in Botetourt County U.S. Geological Survey. National Hydrography Dataset high-resolution flowli ...

, with the southern point at the Appomattox River.

Richmond Basin geology

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 The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

. When Richmond rift opened and filled with swamps from water in the Pamunkey River, sediment filled in over the swamps and the

sedimentary Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...

pressure converted organic plant material into

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...

. This weight is less pressure than coal deposits produced when the continents were pushing together and raising up mountains. Semi-anthracite and anthracite are often formed by such

tectonic Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...

squeezing when continents push together. The Richmond Basin has

Bituminous coal Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the coal seam, ...

, formed by the sedimentary weight only. The coal deposits were on a thin

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

and

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

layer over the

granite Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...

bedrock. Oolite or small round grains of

calcium carbonate Calcium carbonate is a chemical compound with the chemical formula . It is a common substance found in Rock (geology), rocks as the minerals calcite and aragonite, most notably in chalk and limestone, eggshells, gastropod shells, shellfish skel ...

was over the coal. Some coke with and without sulphur was with the coal. To the northwest of the basin is the ''Goochland Terrane'', and between them is the Boscobel complex.David B. Spears, Nick H. Evans, Patrick C. Finnerty, and Katherine E. Lang, 2022. ''The Goochland Terrane Revisited – Insights from Recent Mapping, Geophysics, and Geochronology''. The 52nd Annual Virginia Geological Field Conference, November 11 - 12, 2022. (Fieldtrip guidebook)

Richmond Basin mining

The Richmond Basin is located near

Midlothian, Virginia Midlothian ( ) is an Unincorporated area#United States, unincorporated area and census-designated place in Chesterfield County, Virginia, U.S. Settled as a coal town, Midlothian village experienced suburbanization effects and is now part of t ...

, in Chesterfield County, Virginia. It was mined in the early 18th century. Coal was carried on the Chesterfield Railroad in gravity and mule-pulled carts to Manchester, Richmond, Virginia and

Richmond, Virginia Richmond ( ) is the List of capitals in the United States, capital city of the Commonwealth (U.S. state), U.S. commonwealth of Virginia. Incorporated in 1742, Richmond has been an independent city (United States), independent city since 1871. ...

. Wood burning trains, such as the Clover Hill Railroad then the Brighthope Railway transported the coal found at Clover Hill in later years. The coal from Midlothian, Virginia was mainly used in Richmond, Virginia and

Petersburg, Virginia Petersburg is an independent city (United States), independent city in the Commonwealth (U.S. state), Commonwealth of Virginia in the United States. As of the 2020 United States census, 2020 census, the population was 33,458 with a majority bla ...

. The Clover Hill Pits in Winterpock, Virginia were sold as far away as

New York City New York, often called New York City (NYC), is the most populous city in the United States, located at the southern tip of New York State on one of the world's largest natural harbors. The city comprises five boroughs, each coextensive w ...

from the 1840s to the 1890s. The supply was not as great and as cheap to mine as the Pocahontas coalfield, however and mining the Richmond Basin was ended around 1890. Richmond and Petersburg grew economically because of manufacturing supported by the

and Appomattox River waterpower, more than from coal brought out of Midlothian and Clover Hill."

References

{{Reflist Geography of Richmond, Virginia Geology of Virginia Mining in Virginia Rift basins Sedimentary basins of North America