336 GEOLOGY OF THE NABRAGANSETT BASIN. 



Probable thickness of the Kingstown sandstone series in Cranston and Warwick. The dips of tile 



rocks exposed in southwestern Cranston are rather low, usually varying 

 from nearly horizontal to 25° NE. and E. The miners report a steeper dip 

 in the mine on the east side of Sockanosset Hill, the reported inclination 

 being about 50° E.; but this, judging from surface exposures, seems to be 

 but a local increase of dip. 



On the eastern side of Warwick Neck, toward Rocky Point, the 

 sandstones forming the slopes of the hill dip about 45° E. The first 

 sandstones and shales met on the road to Rocky Point, and some of the 

 sandstone and conglomerate exposures at the point also, slope about 20° E. 

 Between Hills Grove and Norwood Station and Warwick Neck there are 

 no exposures. Under these circumstances it is not safe to make calcula- 

 tions as to total thickness of the series of strata underlying Warwick and 

 Cranston; but with an average inclination of 20° E., which is hardly war- 

 ranted, considering the often lower dips where the rocks are actually 

 exposed, the total thickness of the Carboniferous series from southwestern 

 Cranston to the conglomerates of Rocky Point would be about 11,200 

 feet. The actual exposures suggest that this estimated thickness is perhaps 

 extravagant, (See pp. 334, 337.) 



If a series of close synclines and anticlines be imagined along the 

 western margin of the southern part of the bay, extending northward into 

 Warwick and Cranston, the preceding estimate can hardly be said to have 

 any value whatever. In that portion of the field investigated by the writer, 

 limited to the Narragansett Bay quadrangle, there is no actual field evidence 

 of such folding, either north or south, although the great east-west extension 

 of the Kingstown area of exposure is suggestive of such folding. 



Warwick Neck exposures. — The lowest part of this thickness of 11,200 feet of 

 Carboniferous strata in Warwick and Cranston is equivalent to the Kings- 

 town series as exposed farther southward. Whether the Warwick Neck 

 exposures belong to the Kingstown series can not be determined by the 

 evidence secured in the area in question. Near the southern end of Warwick 

 Neck carbonaceous shales occur along the shore, the contortion suggesting 

 local folding. Black shales are found in the railway cut at the lower end of 

 the neck Heavy sandstone beds, some medium conglomerate layers, and 

 dark-blue shales are seen on the eastern side of the neck, with more bluish 

 shale on the east before reaching the conglomerate series of Rocky Point. 



