366 J. F. KEMP GRANITES OF ATLANTIC COAST 



Company and the New England Company. In tlie quarryman's classi- 

 fication there are minor varieties, such as blue and gray, but petrograph- 

 ically they are practically the same. Tiiis is the stone most distinctively 

 known as Westerly granite. It shows the characteristic shelly joints of 

 granites to a remarkable degree (see plate 36, figure 1). In the lull or 

 ridge north of the railway there are a number of other quarries, some of 

 which yield gray granite and some red. The red is much coarser than 

 the gray in crystallization, but is still finer than, the Stony Creek red 

 granite, to be later described. It is a rather light shade for a red granite. 



Bet\veen Niantic and Westerly are other small quarries, which yield 

 gray granites. To the west, in the town of Mystic, Connecticut, there 

 are various small openings, displaying gray granites, and on Masons 

 island, in Mj^stic harbor, a large ledge has been utilized for rough stone 

 for breakwaters. It is a gneiss, plentifully seamed with pegmatite and 

 -aplite dikes, but it shows some quite massive phases. In the town of 

 Groton, near New London, but east of the Thames, are exposures of 

 graj granite, somewhat coarser than the Westerly variety, but of the 

 same general character. Southwest of New London, in the town of 

 Waterford, there is another small quarry. The largest opening in this 

 immediate district is, however, the one on Millstone point, 5 miles west 

 of New London. A neck of rock juts out into the sound and consists 

 almost entirely of granite. The stone is a gray variety, darker than the 

 Westerly stone, but in other respects much like it. The gneisses are 

 visible in the walls of the pit and the contact is an irruptive one. The 

 exposures of granite are shown in plate 36, figure 2. 



Quarries for stone for governmen.t breakwaters have been opened near 

 South Lyme in gneiss. They have exposed most interesting pegmatites, 

 that have yielded some rare minerals. On the east bank of the Connect- 

 icut river, and just north of Lyme station, a coarsely cr\^stalline, pink, 

 porphyritic granite has been developed to some extent in former years. 

 It is a very beautiful stone when polished, but is now no longer worked. 

 Its microcline was studied as long ago as 1880 by Descloiseaux, who has 

 left a brief note on record about it, as is later noted. This granite borders 

 closely on the pegmatites. Passing westward across the Connecticut river, 

 gneisses appear in all the railway cuts until Sachems head, Leets island, 

 and Ston}'' creek are reached. At all of these localities quarries have 

 been opened, but those at Stony creek are the most extensive. The 

 characteristic Stony Creek stone is a coarsely cr3^stalline red variety, that 

 is chiefly obtained north of the station in two large works. One of the 

 •quarries is illustrated by i)late 37, figure 1. It is extremel}' massive. 

 South of the station the Brookljni quarry yields a gray stone, quite finely 

 crystalline, and unique among the granites of the region in that it con- 



