472 Haivkins — Notes on the Geology ol Rhode Island. 



Along the western side of the southern Harris lime- 

 stone quarry there is exposed a block of fine-grained 

 granite containing sharply defined inclusions of green 

 schist and of crystalline limestone, within a few inches of 

 each other. Neither of the included fragments seems 

 different from the adjacent large exposures of similar 

 rocks. The granite surrounding them may be an aplitic 

 phase, and later in age than the main granitic intrusion, 

 but its presence certainly suggests that the limestone as 

 well as the green schist may be pre-granite in age. 



Throughout the western and northwestern portions of 

 the State, where granites greatly modified by assimila- 

 tion of basic rocks are repeatedly found in contact with 

 the latter, only one small limestone deposit was found, 

 the rather insignificant one at South Foster mentioned 

 above. Apparently the granite was able to assimilate all 

 of the lime which it derived from the partial assimilation 

 of the gabbros throughout this area, possibly because of 

 more deep-seated intrusion than in the area farther east, 



Whether sedimentary or metamorphic in origin, the 

 limestone of Rhode Island has without doubt been second- 

 arily segregated by solution during metamorphism, 

 contact or regional. If it be attributed to contact action, 

 the solutions may have been rising to points above, 

 toward the top of the batholithic dome. The present 

 attitude of the beds at least is highly inclined. Subse- 

 quent shearing has also helped in the formation of the 

 present lens-shaped bodies (Emerson and Perry, op. 

 cit, 16). 



The sincere thanks of the author are due to Professor 

 C. W. Brown of Brown University for his many helpful 

 suggestions and guidance during the course of this inves- 

 tigation ; to Professor Charles Palache of Harvard Uni- 

 versity for aid in the crystallographic study of _ the 

 minerals here described, and to all others who in various 

 ways have contributed something to the work. 



Houston, Texas. 



December, 1917. 



