220 CONTENTS. 



Pane. 



Chapter IX. — The Purgatory conglomerate 364 



Coarse conglomerate overlying the Aquidneck shale series 364 



Sakonnet sandstones within the Aquidneck shales, in transition to the coarse con- 

 glomerate 365 



Coarse conglomerate forming the latest Carboniferous rocks in the southern part 



of the Narragansett Basin 365 



Purgatory conglomerate as a typical exposure 365 



Identity of the Purgatory and Sakonnet River western shore coarse conglomerate. . . 366 



Possible syncline between the two western Paradise ridges of conglomerate 366 



Hanging Rock ridge possibly the eastern side of an anticlinal fold 367 



Dips immediately east of Hanging Rock ridge 367 



Interpretation adopted 367 



Southward pitch of the great Paradise-Hanging Rock syncline 368 



Southward pitch of the Sakonnet River syncline 369 



Western coarse conglomerate exposures 369 



Possible syncline immediately west of Miantonomy Hill 369 



Possibility of two horizons of conglomerate at Miantonomy Hill 370 



Interpretation adopted 371 



Geological position of the Newport Cliff section 371 



Portsmouth synclinal conglomerate 373 



Conglomerates of Warwick Neck and Swansea 373 



Thickness of the coarse conglomerate 373 



Fossil localities 374 



Chapter X. — The arkoses and basal conglomerates 375 



Natiek arkoso 375 



From Natiek to Cranston 375 



Base of the Carboniferous south of Natiek 376 



Probable relations between the various granites and pegmatites and the Carbon- 

 iferous beds 376 



Tiverton arkose 378 



From Steep Brook to Nannaquacket Pond 378 



South of Nannaquacket Pond 379 



Equivalence of the Tiverton arkoses to those near Natiek 379 



Sachuest arkose 379 



Conanicut arkose 380 



Rose Island and Coasters Harbor Island arkose 380 



Chapter XI. — The pre-Carboniferous rocks of the southwestern portion of the Narragansett 



Basin 381 



Little Compton and Newport Neck shales 383 



Quartzites of Natiek 383 



Chapter XII. — The Cambrian strata of the Attleboro district 386 



Cambrian brook localities 388 



Localities 1 and 2, southwest of North Attleboro 388 



Valley of locality 3 392 



Locality 4, northeast of Diamond Hill 333 



Maps and sections 394 



