148 GEOLOGY OF THE NAKRAGANSETT BASIN. 



THE PAWTUCKET AREA. 



Another small area south of the last, not more than a few yards in 

 width, is exposed in the gorge of the Blackstone River, in the southern 

 part of the city of Pawtucket. At this point the red slates are associated 

 with green slates, recalling a similar association of red and green slaty 

 beds at Pondville, in the Norfolk County Basin. Close folding appears 

 also to be, in this locality, the explanation of the relations which these 

 beds bear to the adjacent carbonaceous beds. This is the southernmost 

 exposure of the red rocks known to me in the basin. Southward and west- 

 ward in this latitude the red rocks disappear. At only one point on the 

 Little Compton shore do red rocks appear at the surface outside of the 

 areas named, and in this instance they are limited to a thin layer of red 

 hematite in the coal-bearing section. The deposition of the carbonaceous 

 series of the Coal Measures in this southern field preceded the incoming of 



Site of Site of 



A/.Att/eboro Pawtucket 



Fig. 13.— Diagram showing disappearance of Wamsutta group (Cw) in the Coal 

 Measures (Cc). 



the red material from the north, and continued without interruption south 

 of Pawtucket. 



RED BEDS IN ATTLEBORO, REHOBOTH, AND NORTON. 



These occurrences are fully considered elsewhere in this report. Rea- 

 sons will be advanced in the following chapters for regarding at least the 

 first two of these red beds as local deposits formed at different levels in 

 the Coal Measures. The last-named area contains red shales with calamites 

 in the drift a few rods south of the outcrop. 



NORFOLK COUNTY BASIN AREA. 



No detailed work was done in this basin during the present survey. 

 As a result of a reconnaissance, fossils were found at Canton Junction, con- 

 firming the views of Crosby and Barton as to the Carboniferous age of a 

 part of the strata. The rocks closely resemble the red and gray beds along 

 the northern margin of the main basin. Red beds largely predominate in 

 all the exposures. A characteristic basal section has already been described 

 at Pondville. The strata are almost everywhere inclined at very steep 



