HISTORICAL NOTES ON THE MICA-GRANITES. 3 13 



from Southampton through WilUamsburg "the Southampton granite," and 

 considers it "an original fundamental deposit of this rock." He says: 



1 would here sugge.st whether the mica-slate of this region that contains beds 

 of granite may not be a newer formation reposing immediately upon that granitic 

 nucleus which probably forms the basis rock in New England. And wherever this 

 mica-slate and upper granite is worn away or there is a projection in the nucleus the 

 basis rock may appear. 



He describes further the Amherst-Leverett range of granite, extending 

 it to the mouth of Millers River. The granite veins abundantly cutting 

 across all the other rocks of the region are discussed and figured. These, 

 as, for example, the main body of the great Chesterfield tourmaline-bearing 

 vein, "are doubtless contemporaneous — that is, such as were consolidated 

 at the same time with the rocks they traverse" — a curious idea, based, I 

 presume, on the fact that the Chesterfield dike is interbedded in its schists 

 with appai'ent conformity. 



Graphic granite in Deerfield and Goshen, porphyritic granite in a 

 range five or six miles long in Chester (which is a mistake for Middlefield), 

 on authority of Dr. Emmons, and "pseudomorphous granite" are described. 

 The latter is a coarse pegmatite, in which thin blades of biotite of the size 

 and shape of the blade of a dinner-knife penetrate the rock in every 

 direction and meet at every angle, but never intersect. 



In 1824 Dewey correctly locates the great Middlefield porphyritic 

 gi-anite vein, doubtless on the authority of Emmons, and the latter 

 describes and figures luany veins in Chester. 



In 1827 Nash notes that often in ascending a mountain mica-slate foims 

 the base, granite the apex, and that the great masses of granite are wholly 

 destitute of minerals, and only the veins in mica-slate contain these. 



In 1833 President Hitchcock gives a very complete and very clear 

 description of granite, restricting it to the variety without hornblende, illus- 

 trating its complex relations to the mica-slate by forty-eight figures, enumer- 

 ating the minerals contained in it, and giving a long argument in favor of its 

 eruptivity. He says: "Upon the whole, the granite lies i-emarkably low 

 in respect to other rocks, and one can not avoid the inference when he 

 examines its situation, in almost all cases, that the abrasion of the stratified 

 rocks may have brought the granite to light." 



In 1835, and again in 1841, he publishes the same description with 



