PROVENANCE AND SEDIMENT DISPERSAL IN THE MISSISSIPPIAN-PENNSYLVANIAN GREATER BLACK WARRIOR BASIN
U-Pb ages of detrital zircons from the middle and upper Parkwood, the lower Pottsville, and the upper Pottsville all have dominant peaks at 1070–1010 Ma, consistent with Grenville-age crust; with some exceptions, the samples have only a few younger and older grains. Although most of the samples have narrow peaks between 1250 and 950 Ma, the lower Parkwood sample has a broader peak between 1500 and 950 Ma, and the upper Parkwood sample has a secondary peak at 1400 Ma, indicating pre-Grenville sources. Unlike all others, the lower Parkwood sample has a strong secondary peak at 700–500, suggesting derivation from an accreted Gondwanan terrane; the upper Parkwood has a subdued peak at 520 Ma. The southeastern lower Pottsville sample is similar to the other samples, but the northwestern lower Pottsville sample has two exceptional peaks at 1635 and at 435 Ma. The upper Pottsville sample from the polymictic conglomerate has secondary peaks at 2715 Ma and at 335 Ma. The variations between samples indicate variations in details of provenance through time and variations in local dispersal systems.