394 HOLLICK. 



base of which there is a uniform grade to the water's edge. On 

 the exposed southern shore however the shingle is rounded and 

 water-worn and in places is thrown up into extensive ridges, 

 beyond ordinaiy high-water mark, by wave action during storms, 

 often masking the base of the adjacent bluffs and causing an 

 abrupt line of demarkation betw^een the irregularly wave-tum- 

 bled, rounded beach shingle, and the steep face of the eroded 

 moraine, with its angular ice-transported fragments. It is along 

 this shore that erosion is proceeding most extensively, as may 

 be readily seen in the steep escarpments of the bluffs which face 

 it, and also in the rapid descent to deep water, as evidenced by 

 the location of the submarine contours. 



Inasmuch as these islands, considered as a whole, seemed to 

 bear every indication of being simply a partly submerged and 

 gradually disintegrating ridge in the morainal region south of 

 the New England shore line, it was recognized that theoretically 

 they ought to have the same general structure as the similar but 

 larger ridge to the south, represented by Long Island, Block 

 Island, Martha's Vineyard and Nantucket. In other words that 

 the superficial morainal material ought to be found resting upon 

 a superstructure of Cretaceous strata. A careful search was 

 therefore made for plastic clays and also for the ferruginous clay 

 concretions and hardened fragments, which are invariably found 

 under similar conditions in the islands mentioned. Such con- 

 cretions were finally found on Nonamessett, and by tracing them 

 up a bed of plastic clay, some of it highly lignitic, other portions 

 brightly colored in reds and yellows, was found at the base of a 

 bluff on the south shore, near the eastern end. No organic re- 

 mains, other than the lignite were found, but the lithologic iden- 

 tity of the concretions and plastic clays wdth those of Gay Head, 

 Block Island and Glen Cove was unmistakable. At no other 

 locality w^as any indication of either the clays or the concretions 

 discovered, although this is hardly to be wondered at consider- 

 ing the limited time given to the exploration.^ 



^ The only reference which I have seen in regard to the occurrence of Cretaceous 

 clays in the Elizabeth Islands is in a paper on " Glacial Brick Clays of Rhode Island 

 and Southeastern Massachusetts," by N. S. Shaler, J. B. Woodworth and C. F. 



