OFAPTEE VI, 



AQUIDNECK, OR THE ISLAND OF RHODE ISLAND, WITH THE 



ISLANDS OF NEWPORT HARBOR. 



ARKOSE AKD PBE-CARBOKIFEROFS BOCKS ON SACHIJEST IN^ECK. 



ARKOSE 



At the promontory almost lialf a mile south of Flint Point, gTeenish 

 shaly rocks are exposed along the immediate shore, but farther out the 

 promontory is composed of arkose. Interbedded layers of coaly shale show 

 that the arkose occurs in the form of a low anticline, whose axis pitches 

 northward at a low angle and trends parallel to the general coast line, about 

 N. 20^ E. It is evidently a great block of grit which once lay above the 

 level of the green shale series, but was dropped by faulting down to its 

 present position in the green shale area. 



Along 'the shore the green shales occur as far northward as a point a 

 quarter of a mile south of Flint Point. Here they change from their former 

 trend of N. 20^ E., dip 60^ W., to N. 45 "" E., dip 35'' W. A short distance 

 north the arkose series comes in with a similar strike and a nearly vertical 

 or steep western dip. The strike changes rapidly to N.-S, dip 45° to 

 60^ W., and continues as far as the cpartz- veined promontory southeast 

 of FKnt Point. Between this and FUnt Point hiterbedded coaly shales 

 show that the arkose series dips about 70° W. West of the point the dip 

 becomes almost vertical, then 70° to 60° E., then 75° E., 60° E,, 35° E., 

 and 80° E., the exposures of the arkose series -terminating on the shore 

 about 600 feet southwest of the point. A closer examination of the line 

 of exposure between this more western point and Flint Point shows that 

 the arkose is here several times closely folded, the western sides of the 

 folds being sometimes a little overturned, in consequence of which there 

 appears to be a fairly general steep eastward dip. Coaly shale layers 

 are frequently interbedded with the arkoses, the latter, however, predomi- 

 nating. These coaly shale layers are very numerous elsewhere in the series, 



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