Smithsonian Report. 1939. — Bassler 



Plate 5 



1 . Outcrop of Jointed Granite Blocks Exhibiting Formation of Boulders 

 (b) by spheroidal weathering and the accumulation of a talus slope (t). 



2. Old Quarry Along Tilden Street (Near Connecticut Avenue). Illus- 

 trating Weathering of the Hard Jointed Granite (G) Into Subsoil (SS» 

 AND Then soil (S). 



