226 GEOLOGY OF THE NAERAGANSETT BASIN. 



Chapter III is devoted to a discussion of the exposures on the western 

 side of the bay. Directly west of Dutch Island lies Saunderstown. The 

 shore exposures south of this locality show lithologically all the features of 

 the Carboniferous of Dutch Island and northwestern Conanicut, so that, 

 although fossils are not found, the geological position of the beds is fairly 

 certain. Southward, however, metamorphism becomes more pronounced, 

 the Carboniferous exposures are no longer so continuous, they are separated 

 by large pegmatite intrusions, and finally appear only as rare inclusions 

 in the pegmatitic granites of Boston Neck and Narragansett Pier. The 

 gradual character of these changes prepares the student for the conclusion 

 that even these southern rocks and the Tower Hill exposures are Carbon- 

 iferous. From this region northward the Carboniferous age of the rocks 

 must be conceded. 



In Chapter IV the exposures between Providence River and Taunton 

 River, on the northern side of the bay, are taken up. 



Following the eastern shore of the bay southward, it is conveniently 

 possible, first, to describe all that is accurately known of the Carboniferous 

 formation on this shore, and then to discuss the probably pre-Carboniferous 

 rocks of Little Compton. This is done in Chapter V. 



In the same way, beginning with the basal arkoses at Sachuest Neck, 

 it is possible to describe all the more evident structures of Aquidneck 

 Island before the more doubtful regions near Miantonomy Hill, and then 

 those toward Newport Neck. This is done in Chapter VI. 



It has been the writer's aim so to arrange the materials as to proceed 

 from the better known to the less evident facts and structures. 



The conclusions founded on these observations form the basis of the 

 second part of this report, including Chapters VII to XI, and have been 

 placed toward the close. They are necessarily of a more argumentative 

 character, and the attempt has been made to bring out more sharply the 

 inferences deduced from the facts by removing from this part of the report 

 all unnecessary references to the more minute details of the geological 

 features presented by the individual exposures. It is this part of the report 

 which must necessarily be subject to revision, and which nevertheless is 

 the more important, since it gives the results of the work. No one has had 

 more occasion to regret the scantiness of continuous exposures in an east- 

 west direction in this area, across the strike, than the writer, for this has 

 left his efforts in the field often of little avail. 



