The rocks underlying the Black Moshannon Creek drainage basin are primarily shale, sandstone, and coal. Three major rock formations are present in Black Moshannon State Park, all from the Carboniferous period. These sedimentary rocks formed in or near shallow seas roughly 300to 350million years ago. The Mississippian Burgoon Formation is composed of buff-colored sandstone and conglomerate. The late Mississippian Mauch Chunk Formation is formed with grayish-red shale, siltstone, sandstone, and conglomerate. The third is the early Pennsylvanian Pottsville Formation, which is a gray conglomerate that may contain sandstone, siltstone, and shale, as well as anthracite coal.