Weems (1980)'s interpretation The Doswell Formation was originally described by
USGS paleontologist Robert E. Weems in 1980. He used it to refer to the entire Triassic geological sequence preserved at the Taylorsville basin, overlying the much older
Carboniferous "Petersburg granite" which predated the basin, and underlying much younger
Cretaceous and
Cenozoic gravel. Weems subdivided the formation into several "members". The oldest of these (middle
Carnian in age) was the
Stagg Creek Member, a
fluvial (river) deposit of
sandstone and
conglomerate. Weems originally described this layer as lacking fossils, although later studies argued otherwise. Overlying the Stagg Creek Member was what Weems called the
Falling Creek Member (late middle Carian). As sediments began to slow down the rivers of the Stagg Creek Member,
lacustrine (lake) deposits began to form. Rivers still managed to flow into the now dominant lakes from different directions, depositing a diverse assortment of sediments. This allowed the Falling Creek Member to contain a variety of rock types, including sandstone,
shale,
siltstone, and occasionally even
coal. In addition, it is the most fossiliferous part of the Taylorsville basin, containing the fossils of not only fish and invertebrates, but also reptiles such as the heavily armored
Doswellia. The Falling Creek Formation was more thoroughly deconstructed. Weems, Tanner, & Lucas found that this formation was basically identical to the
Vinita Member (or "Vinita beds") of the Richmond basin. As the Vinita member was named approximately 70 years earlier than the Falling Creek Formation, it was considered to take priority in naming. The Poor Farm and Deer Creek members of the Falling Creek Formation were also abandoned due to being poorly defined by LeTourneau. These authors not only found the Doswell Formation to extend to the Richmond basin, but also to several other Triassic basins in Eastern Pennsylvania. For example, the "Irishtown beds" at the base of the
Gettysburg basin were found to be a young layer of the Doswell Formation (the
Irishtown Member) due to
conchostracan dating. Lastly, an unusually old section of the
Stockton Formation was also found to be a young part of the Doswell Formation (as the
Lahaska Creek Member) due to preserving fossils of
Calamops, a
temnospondyl amphibian which lived at the same time as the Doswell Formation. ==Paleobiota==