The Coal Measures are found in Allegany and Garrett counties, Maryland, situated in the western part of the State, where they underlie a large part of the region between the Alleghany front and the West Virginia-Maryland State line. The strata occupy three major structural troughs whose axes trend northeast-southwest, parallel to the trend of the mountains. The most westerly trough is called the Lower Youghiogheny, or Friendsville, basin. The middle basin is divided into two parts by a transverse minor anticline, thus forming the Upper Youghiogheny basin on the southwest and the Castleman basin on the northeast. The eastern trough is cut into two parts by the Potomac River, which turns across it at Piedmont, the southern extension of the basin being known as the Upper Potomac basin and the northeastern as the Georges Creek basin. The relations of these basins are shown in the accompanying map.
The investigation of . . .