SANDSTONES EAST OF SAKONNET EIVER. 359 



found five-eighths of a mile north of South Swansea Station. Shaly sand- 

 stones occur west of Lees River north of the railroad. At Braytons Point 

 very coaly shales and some sandstones are exposed. Northeastward, on 

 Sewammock Neck, sandstone is found. The exposures east of Taunton 

 River include the arkoses resting upon pre-Carboniferous granites, both of 

 which will be discussed later. 



The section included between the coarse conglomerate of Swansea vil- 

 lage and the arkoses of Steep Brook or Fall River must correspond in some 

 measure to the Aquidneck shales and possibly to more or less of the Kings- 

 town saiidstones as described from the main area of the basin toward the 

 southwest. If the section from Swansea village to Steep Brook be consid- 

 ered as simple in geological structure, tolerably free from local folding 

 or marked changes of dip, a supposition by no means certain, fair esti- 

 mates might be made as to its thickness. If the strata be supposed to be 

 inclined toward the northwest at an average angle of 45°, a thickness of 

 10,600 feet would have approximate value, while at an inclination of 60° 

 the thickness of section might equal 13,800 feet. The thickness of the 

 Kingstown sandstones was placed above at 11,500 feet, and that of the 

 Aquidneck shales at 3,000 to 3,500 feet, making a total thickness of 14,500 

 to 15,000 feet for the corresponding strata farther southwest. Unfortunately 

 all these estimates are based on data either not strictly reliable or even not 

 fairly satisfactory, especially since in the regions where the estimates are 

 made there are areas where exposures are few, but these estimates are at 

 least the best at present available. While it is impossible to distinguish an 

 upper Aquidneck shale from a lower sandstone series between Swansea 

 village and Steep Brook, yet the existence of abundant shales in the upper 

 part of this section should -be distinctly recognized as an approach to the 

 lithological distinctions in existence farther southwestward. 



SAKONNET SANDSTONES ON THE EAST SIDE OF THE RIVER. 



That the upper part of the Aquidneck shales, that portion immediately 

 underlying the coarse conglomerate series, loses its shaly character and 

 assumes more of a sandstone nature eastward has already been noted in 

 speaking of the exposures north of Black Point and at Taggarts Ferry, on 

 the southeastern shore of Aquidneck Island. On the eastern side of the 

 Sakonnet River, east of Aquidneck Island, the rocks underlying the coarse 



