Smithsonian Report. 1939. — Bassler 



Plate l 



1 . Terraced Slope on North Side of Harvard street. With Student Group 

 STUDYING Outcrop of Unconformity Between Pre-Cambrian Schists (S) 

 AND Sedimentary Potomac Formation (P). 



2. View of Above Before Terracing. Exhibiting the Uneven Eroded Sur- 

 face OF THE Old Schists (S). the Sand and Boulder beds of the Creta- 

 ceous Potomac Formation (P). and the Iron Ore. Limonite. Deposits at 

 the Base of the Same in Depressions on the Schist. 



