in the vicinity Great Barrington, Mass. 269 
many layers solidified together ; the bedding stops short off in 
ignorant of the facts would suppose were all rence 
boulders, ay they are -— at least the hard knots of the 
rotted sand rock. 
These ‘aivenicess in the quartzite serve to explain much that 
is my serious in its apparent distribution. It does not answer 
the pu of strict science to set down the plains along the 
valleys as all limestone areas; for the soil of these plains may 
test on soft beds either of the quartzite formation, or of the 
Mica schist; and we cannot infer from dn outcrop of hard 
quartzite only a few yards in breadth that the concealed stra- 
tum below to whith it belongs has no greater breadt 
Again, following the direction of the bedding, seis are some- 
times changes from quartzite to mica schist or gneiss. is is 
Proved by the fact t at the’étrata-of the sme north-and-south 
range, or in the direction of the strike, are mainly quartzite in 
one Mg and in another, two or oe miles we! are Seid 
Berke 
Those 1 facts at the first thought seem strange. But we take 
ed 
little note heath unaltered ses rocks of the change pepe 
the beddin ie unger f purely siliceous sand to a 
impure con a ff an existing seashore, from the sands of 
4 sand-flat to Sie: ee of the shallow hoveor but a few rods 
