MEM. MUS. COMP, ZOOL. 



4-1-15' 



/0-3U 



GEOLOGY CAPE COD. PLATE 29 



4l'io' 



41" 1 5' 



EXPLANATION 



Swamps 

 (Chiefly above sea level) 



Beaches and dunes 

 (Sa-nd and gravel) 



Nantucket moraine 

 (Corrugated moraine, mainly of folded pre- 

 Wisconsin clay, sand, gravel, and glacial 

 till overlain by thin bouldery Wisconsin 



drift) 



&]Manhasset formation, Jacob sand, and 

 Gardiners clay, and older Pleistocene 

 deposits 

 (Sand, gravel, boulders and glacial till ex- 

 posed only in sea cliffs) 



>- 

 tr 

 < 

 ■z. 



<z 



LU 

 < 



a 



White clay and dark lignitic clay 

 (Exposed only in sea cliffs) 



J 



■J, 

 D 

 O 



LU 



:. 

 " 



Base from U. S. Geological Survey 

 topographic map of Block Island 

 quadrangle, reprinted from earlier 

 editions without revision 



70"35' WILLIAMS & HEINTZ CO..WAS H..D.C. 



Geology by i. B. Woodworth, 

 GEOLOGIC MAP OF BLOCK ISLAND, R.I. ". S. Geological Survey, 1915. 16 



Scale 6 



2^(50 



2 Miles 



2 iSIometjRr-s 



CGirtoixc inteiTval 20 feel; 

 J)atufTt is rn&ctrt s&cc leve-L 



