1883.] 199 [Dale. 



which can be definitely assigned to a geological period upon 

 paleontological grounds is No. 4, the quartz and clay aggregate 

 of Sachuest Pt., in the upper part of which characteristic fossils 

 of the lower Millstone Grit occur, which fact, therefore, also 

 determines the Carboniferous age of the overlying rocks as far as 

 8, and including the anthracite beds which overlie the entire series. 

 The conglomerate II, as pointed out by Prof. W. B. Rogers, 

 is made up largely of fragments of a rock which may be as old as 

 the Primordial. A thinly stratified sandstone or, if in a metamor- 

 phic region, quartzite with a little mica and Lingulae, if not entirely 

 eroded,must still represent the ancient source of this Carboniferous 

 conglomerate. Perhaps it may be looked for successfully among 

 rocks which are now regarded as of Archeean Age. The exact 

 source of the boulder of conglomerate containing the fossil plant 

 stems could not be determined ; whether from a stratum of con- 

 glomerate overlying the anthracite beds or from an intervening 

 or underlying one is uncertain. It was, however, quartzite and 

 resembled in character the boulders which strew a large part of 

 the Island. The occurrence implies that while conglomerate was 

 being deposited, vegetation was present at no very great distance. 

 The discoveries of Messrs. Crosby and Barton in the Massachusetts 

 extension of the Narraganset Carboniferous basin * point, though 

 less strongly, to a similar conclusion, and any theories as to the 

 glacial origin of the conglomerate must be made to conform to 

 these facts. 



Physio graphical : Professor Shaler has dwelt upon the physi- 

 ography of the Island and attributes its peculiar features to pre- 

 glacial, subaerial erosion followed by glacial erosion. We can 

 certainly observe in this portion of the Island the effects of two 

 causes : 1st, a system of anticlinals trending $T. 20 E., and 2d, 

 glacial erosion running almost BP.-61 The peculiar features of 

 Paradise are due to two folds of conglomerate, the one faulted 

 and the other ruptured (compare General Section and Section B.) 

 together with the forcing up of highly inclined strata of horn- 

 blende and mica schist, whose alternations, affording different 

 amounts of resistance to erosion, resulted in a series of ridges 

 and glens parallel with the strike. The angle at which the ice 



1 Op. cit. 



