er —e See 
Geology, &¢c. of the Connecticut. 13 
Granitic veins are very numerous in many parts of the 
map, especially in the region of the South Hampton granite. 
In width they vary from a mere line to 30, and perhaps 
even 40 feet. But I have not observed any that exceed 
this breadth. They traverse mica slate, hornblende slate, 
limestone of a peculiar character, sienite, gneiss and gran- 
ite. ‘Those Pid traverse the latter rock differ from it cae 
in being of a finer, or a coarser grain, Yet they are as re- 
ally veins as those zones of granite traversing other rocks. 
Examples of these are frequertt—as near the South Hamp- 
ton lead mine. 
In these veins all tHe i ingredients of granite are usually 
present, but in variable proportion. Ihave seen some that 
aes nearly or quite graphic granite: But usually the mica 
superabundance, especially in the narrower ones, and 
on it is of adelicate straw or light green colour, as in Go- 
shen and Conway. The eee is sometimes of an ele- 
owe ver veins peoretiit divide aa ubdivide ke the 
a tree, some of the branches being smaller and some larger. 
These branches rarely go off from the main stock at right 
angles, but generally oblique. At one place you will yeas a 
vein retaining its width for several feet, or even rods, w 
mathematical exactness—at another, its width will sii 
increase or decrease; and I have seen, in some instances, a 
sudden reduction of two or three inches, by which a.shoul- 
der was, poagpenae 6 The course. vot igi m6 ere veins is 
cael siesta: or mass of the rock, except in ihe 
sienite. Some of the veins feaversidy sienite, (between 
Belchertown and Ludlow for example,) are so numerous 
and their intersections so many, that they form what the 
Germans call a stock worke, except that they are not metal- 
ic. By these cross veins the surface of the rock is some- 
times divided into prem et ee or thomboids: and 
sometimes it is tesselated.. 
