ia 
Lead Mines, &c. of Hampshire County, Mass. 269 
the quartz not only pantnies a variety of minerals ; but when 
the gangue itself is often ate of barytes 
Note A. The geest of this region may be properly divid- 
ed into three varieties, First, that which is found in the 
neighborhood of granite, and may be properly called the 
hard-pan formation, and seems to owe its origin to the i 
sion, disintegration and decomposition of granite, and of so 
other primitive rocks, his variety is usually cateas on 
granite hills and waaay wae affording a shallow covering to 
the rocks beneath. As we descend a hill or mountain, this 
covering grows thicker st thicker, until we reach the plain 
or valley below ; here it is frequently of great thickness, even 
of 50 or 100 fect or more. Torrents, coming from elevated 
regions, carry more or less of this covering down the stream, 
and deposit it on the banks of the stream in lowlands. This 
together with leaves, sticks, rotten wood and decayed vege- 
tables, forms alluvion. This variety of geest has imbedded 
in it vast quantities of blocks and boulders of granite, and 
some other primitive rocks. These blocks and boulders are’ 
often seen lying about upon the surface of the ground, and 
are exposed also to view, by excavating the earth and when 
torrents carry away ‘the earth in which they are. imbedded. 
This earth is frequently’cut through and carried away down 
to the rock formation, Jeaving these blocks and boulders be- 
hind, in the bed of the stream. The soil which this variety 
constitutes, is covered with a few inches of vegetable mould, 
and is fertile, but not adapted to tillage. It is stiff and hard, 
retaining much moisture ; and affords excellent pasture. The 
timber growing upon this soil is maple, mountain ash, h, 
pee red ash, hemlock, spruce, apuly< chesnut or Eboliern 
Se is called the second variety. — 
The second variety also contributes its shee i forma- 
tion of alluvion, whenever circumstances are Ee conatic but 
it is’seen at a lower level than the first, and aoe mica 
slate, nae ay limestone, greenstone This ty 
as no grani e boulders in it, thou ugh it contains eb 
blocks and eit of the rocks with which it is associated 
some of which are of an enormous size. It affords a mellow 
soil, well adapted for tillage, and the growth of grain. Grass 
grows well from this soil, whenever there is moisture suffi- 
cient, but it is much exposed to suffer by drought, The tim-. 
