Paleozoic strata of Mississippi
We start our journey in the Paleozoic Era, when multi-cellular life was starting to diversify, filling niches in ocean environments and eventually moving on to land.
In Mississippi, we see only a very small portion of this time frame outcropping at the surface. Rocks in the most northeastern part of the state are from the Devonian Period (385-359 million years ago).
During the Devonian, sea levels were high and this area was covered with water.
Carboniferous-aged lignite coal deposits can be found in Choctaw County. Coal forms in warm, plant-rich, swampy areas. When the plants die, they are buried in oxygen-poor water where they accumulate and decay very slowly, turning them to peat. The peat is compressed and buried over time to create lignite. Lignite is the least dense type of coal containing only about 65% organic material and producing approximately 17 megajoules of energy per kilogram. Compare this to anthracite coal, which has 95% organic material and produces up to 33 megajoules of energy per kilogram and you can see why lignite is not the preferred energy producer. (eia.gov)
