Ind., Va. Potomac - Point of Lectum. In the hills Creek Cement this same crookling occurs the middle once or less throughout 350 foot of beds. Then there are occasional gaps throughout the rest of the hills Creek but the tendency in these thin beds is to be more and more than horizontal. The Tondroy - Keuper contact is as sharp as can be. On one side are the overlying laminated beds almost without joints, and on the other thinly bedded slate with joints. This difference however need not be explained as due to a new sea invasion over the Tondroy land but maybe due to a deeping of the sea 25 to originally about 100 feet deeper in Keuper time. Hardly seems probable that the All of the higher Keuper and the rest of the lower Devonian is cut out by a steep contorted fold. Tondroy | hills Creek. Keuper Clinton Bedding Left Potomac for Cumberland at 6:20 P.M. Looking at the Allegheny Front from Potomac one sees the three marked Folley's river levels, or terraces. Top of Allegheny Plaiton Potomac river level