RHODE ISLAND GOAL MEASURES. 



165 



G/ac/aJ drift 



as regards both attitude and alteration. They not only lie in less disturbed 

 positions, but they preserve to a much greater degree their original clastic 

 texture, and fossils are of frequent occurrence in them. An account of the* 

 more typical exposures as they now exist follows: 



Leonards Corner quarries. — In tho southeastom triauglo formod by the roads, 

 at an elevation of about 100 feet above the sea, is an exposure of pebbly 

 sandstone on the site of a rock crusher. The strike here is about east-west 

 and the dip very gently to the south. An unidentifiable fossil tree, over 9 

 feet in length and from 6 to 8 inches in diameter, lies prostrate in the bed- 

 ding, with its major axis east-west. 



A half mile east of the outcrop just described, about 25 feet of the 

 coarse pebbly sandstone of the Carboniferous are exposed in Mr. John 

 McCormick's quarry. The beds are massive, essentially horizontal, with 

 traces of coaly shales and coal, the last 

 mostly marking the sites of single plants. 

 The following plants were found: 



Calamites suckovii, in large, well-pre- 

 served forms, showing inner markings. 

 One large specimen, somewhat flattened, 

 was preserved in a coat of wad, a replace- 

 ment of the cortical layer probably after I'IG.IS.-Sketohof zone of excessively jointed sand- 



•^ -^ -^ stones (SS), face of McCormicfc^s quarry. 



carbonate of lime. This stem lay nearly 



east-west, as did others in the same quarry, but the plants are disseminated 

 and occur at no particular level, indicating the occasional drifting in of 

 floating trees and the rapid accumulation of the sands and pebbles. 



Sigillariaf Long, slightly tapering, flattened stems, with longitudinal 

 stiiations, but without cross markings, occur in this section, usually pre- 

 served as internal casts in sandstone. They may be ill-preserved calamites. 



In the rubbish in the bottc m of the quarry, but evidently transported, 

 were fragments of shale with raindrop impressions. • 



The sandstone beds are traversed by a fault striking N. 44 '^ W., with 

 a hade of 10^ S,, and the well-marked slickensides have a uniform pitch on 

 the exposed wall of 55*^ NW. This dislocation can not be of any consider- 

 able extent, for the same sandstones lie on both sides of the plane of divi- 

 sion. Another set of divisional planes, in the form of very close-set joints, 

 striking N. 46^ E., divides the sandstone along a belt of variable width into 



