448 WARREN AXD POWERS DIAMOND HILL-CUMBERLAND DISTRICT 



consist of quartzite, felsite (probably Joes Bock type), and fine and 

 coarse granite of the biotite type. Half a mile south of West Wrentham 

 the conglomerate pebbles consist almost wholly of Joes Eock felsite. At 

 Arnolds Mills, near the stream called Abbotts Run, is an exposure of 

 coarse conglomerate b'ing above fine reddish conglomerate. The former 

 consists largely of pebbles of Hoppin Hill granite exposed just east of 

 the Area mapped, some of which are 10 inches long and 6 inches in diam- 

 eter: also there are quartzite. vein quartz, greenish schist, Joes Rock 

 felsite and quartz porphyn", and red sandstone pebbles of an average 

 length of 4 or 5 inches : all are well rounded. 



Along the road through Sheldonville there are several exposures of 

 fine conglomerates, red shales, purple fine-grained sandstones, and red 

 sandstones. These sediments are much finer-grained than those farther 

 to the south. In an outcrop just north of the Sheldonville road, at the 

 western end of the village, there is a cast of a Carboniferous tree-trunk 

 8 inches wide and 1% feet long. 



The Pawtucket formation outcrops just south of the area shown on the 

 map. It consists largely of saiidstones and shales with some conglom- 

 erates. In one outcrop 10 feet in width nine alternate bands of sand- 

 stones and shales were exposed, the former varying in composition from 

 an arkose to a fine quartz conglomerate. One coarse conglomerate wa^ 

 found lyo miles southeast of Hunting Hill in which some of the pebbles 

 are 16 inches long. The prevailing strike of these beds is north 38 de- 

 grees east and the dip is TO degrees south. 



The age of the Narragansett series has been considered to be Potts- 

 ville- Allegheny (Pennsylvanian) because of the e>'idence furnished by 

 plant remains. Besides these plant impressions, insect remains and a 

 number of impressions of amphibian footprints have been found. Re- 

 cently Mr. W. P. Havnes^* has found impressions of the carapaces of the 

 bivalve Crustacea Estheria sp. and Leaia tncarinaia, M. & W., associated 

 with the leaves of Cordaites and Calamites in the Pawtucket formation 

 at Central Falls (5 miles southeast of Arnolds Mills). These fossils in- 

 dicate a Conemaugh age, but are not good horizon markers. 



BELLiyOHAM SERIES 



In the northwestern part of the area shown on the accompanving map 

 a series of lustrous green schists and sheared conglomerates are exposed 

 in a few outcrops. These rocks occur in greater abundance north of this 

 area, in Bellingham, where there are some amygdaloids.*' This series 



" W. p. Haynes : Science, n. s.. vol. xxxvll. 1913. pp. 191-192. 



" This Information waa kindly furnished by Mr. Laurence La Forge, of Washington. D. C 



