The occasion of this study was an attempt to determine the relations of the Wyoming Red beds to the underlying granite in the Front range of the Rocky mountains in northern Colorado. The southern half of the Boulder and the northern part of the Denver quadrangles represent the area of investigation.
It was evident from the nature of the variations in thickness of the sandstones that the sediments were laid down on a submerging land surface of considerable relief. It was also apparent that the details of this relief were totally unlike the forms produced by stream erosion. The rocks immediately below the contact surface are as free from weathering as those which lie hundreds of feet lower. It is therefore evident that during the progress of the submergence of the granite land surface, shore erosion by the advancing waters has removed a . . .