Paralic Coal Formation

a coal formation that originated in a body of water once linked with the open sea. The coal-bearing deposits contain marine interbeds or horizons with marine fauna. The frequent interstratification of marine, lagoon, and continental deposits with coal indicates that the coal deposits came from coastal peat bogs. In the USSR’s Donets Coal Basin, characterized by paralic coal formation, there are numerous marine interbeds. In other basins marine interbeds are found only in the lower regions (as in the Karaganda Coal Basin) or upper regions of the coal-bearing strata (as in Rio Grande do Sul in Brazil). Paralic basins are typical of the Carboniferous; they are found less frequently in later geological periods.