BALTIMORE GNEISS 



331 



probably represents a detached portion of this larger mass lying a little 

 to the south. 



The second occurrence* of Baltimore gneiss is found in an anticlinal 

 dome, 15 miles long and 5 miles broad, lying on either side of the North- 



Figure 1. — Distribution of Formations in Maryland Piedmont and contiguous Areas. 



ern Central railroad 10 miles south of the Mason and Dixon line and 20 

 miles north of Baltimore. 



* Detailed maps of the region north of Baltimore accompany the following paper by the author 

 and Mr Miller. 



