KmOSTOWN^ SERIES m ORAI^rSTON AND WARWICK. 335 



along the road 1 and 2 miles north of Wickford. If the escarpment 

 west of the railroad from Wickford Jmiction to East Greenwich, Coweset, 

 Apponang, Natick, and northward, marks the western boundary of the 

 Carboniferous basin, south as well as north of East Grreenwich, the 

 equivalents of the Saunderstown sandstones must He immediately east of 

 that escarpment in Cranston and Warwick, and would be expected to show 

 a considerable thickness and some lithological resemblance to the exposures 

 southward. As a matter of fact, however, the exposures in Warwick are 

 altogether insufficient to aiford the basis for a judgment on this point. In 

 southwestern Cranston, north of Natick and Pontiac, sandstones occur 

 dipping at a low angle to the eastward, except along the Carboniferous 

 margin. Beginning, however, near the State almshouse and extending 

 thence northward along the east side of the hill occupied in part by the 

 Reform School is a series of black shales, becoming in places very coaly. 

 These coaly shales are the conspicuous feature of the Carboniferous section 

 in western Cranston, and appear in the mines east of the Sockanosset 

 Reservoir and on the east side of Rocky Hill. Beneath the coal-bearing 

 shales at Sockanosset Hill are others of dark-blue or black color, often 

 ottrelitic, which are exposed in the vicinity of Sockanosset Reservoir and 

 near Wayland Station. Associated with these shales are sandstones, but 

 these more northern sandstones are usually bluish gray, or more or less 

 carbonaceous and medium grained, and, although not very different from 

 the sandstones farther southward, do not closely resemble them 



While, therefore, it seems beyond question that the rocks of western 

 Warwick and Cranston form the northern extension of the Kingstown series, 

 they present somewhat different lithological features, the shales being much 

 more coaly, and at one horizon containing workable coal; moreover, the 

 sandstones are finer grained and apparently less quartzitic and less suggestive 

 of arkose. Still, while the more carbonaceous character of the shale north- 

 ward is recognized, the abundance of dark-blue shales, certainly containing 

 carbonaceous material, along the shore southward from Barbers Height 

 to the Bonnet should not be forgotten. The more northern exposures, in 

 Cranston, will therefore be regarded as simply a more carbonaceous phase 

 of the Saunderstown series, while they evidently correspond also to the 

 lowest part of the lower part of the Tenmile River beds or the Pawtucket 

 shales of Mr. Woodworth. 



