290 GEOLOGY OF THE NAKRAGANSETT BASIN. 



Point coaly shale comes in again. A quarter of a mile southward this has 

 evidently been violently squeezed in an east-west direction. 



South of McCurrys Point a small stream entering the bay from the 

 west exposes from the shore to a considerable distance up the hill westward 

 nothing but bluish-black shale of the type found so abundant on the west- 

 ern side of the island over the coal regions. These bluish-black shales 

 evidently overlie the coaly shales, sandstones, and fine conglomerates so 

 far described, and a small fault has probably thrown them a little eastward 

 near the point. The cleavage obscures the stratification. The cleavage 

 dips 15° to 20° W., and there seems to be a southward dip of perhaps no 

 more than 5°. Southward the shale becomes blacker and more coaly and 

 seems to be nearly horizontal. A quarter of a mile north of the mouth of 

 the creek traversing the Glen it contains impressions of fern leaves. The 

 coaly shale continues as far as the Glen. 



A mile south of Sandy Point, or a little over half a mile from the 

 southern extremity of the beach, dark-gray sandstone makes its appearance 

 again. Over it occurs, southward, coaly shale, apparently dipping eastward, 

 but this dip is of little moment, since southward there is abundant evidence 

 of violent crumpling and folding of the rock by a force acting in an east- 

 west direction. Southward more sandstone is seen sheared into a shale. 



The absence of clear indications of the bedding at this locality and as 

 far northward as McCurrys Point, and the violent crumpling at the last- 

 described locality as well as south of Sandy Point, afford serious difficulties 

 in attempting to determine the stratigraphic position of the coarse conglom- 

 erates in the southeastern part of Aquidneck. 



The great Aquidneck shale series exposed at the Glen and along the 

 shore is believed, however, to be overlain north of Black Point b}^ the 

 coaly Sakonnet sandstone with fine conglomerate, representing a section of 

 much smaller thickness, 110 feet being exposed at the point, and this in 

 turn is overlain by the coarse Purgatory conglomerate, whose maximum 

 thickness as exposed along the shore apparently does not exceed 380 feet. 



COARSE CONGLOMERATES AND UNDERLYING SANDSTONE SERIES 

 FROM BLACK POINT TO THE NORTH END OF SMITHS BEACH. 



About a quarter of a mile northwest of Black Point is a second promon- 

 tory. In a cove immediately toward the west of the latter is bluish sand- 



