MARYLAND GEOLOGICAL SURVEY 



CAMBRIAN AND ORDOVICIAN, PLATE XXIII 



FlG. I. VIEW OF MARTINSBURG SHALE TOPOGRAPHY, LOOKING NORTHEAST FROM A POINT 

 ONE-HALF MILE SOUTH OF WILSON, MARYLAND. CONOCOCHEAGUE CREEK IS SEEN IN THE 

 FOREGROUND AND THE NATIONAL HIGHWAY IN THE MIDDLE. 



inc. 2. VALLEY OF MARTINSBURG SHALE (BLAIR VALLEY, MARYLAND) VIEWED FROM ROAD, 

 JUST WEST OF UNION BETHEL CHURCH. THE MOUNTAINS ON BOTH SIDES ARE FORMED OF 

 THE JUNIATA AND TUSCARORA FORMATIONS. 



