26 Geology and Mineralogy of a part of Massachusetts, &c. 
On the bank of the Hoosick in the south part of Pownal, 
Vt. is a considerable bed of 
PUDDINGSTONE AND SANDSTONE. 
This seems to be an alluvial formation... The road from 
Williamstown to Pownal, at what is commonly called the 
dug-way, passes at the foot and over a part of the bed. It 
lies close to the Hoosick, in large rocks on the side of a 
hill, and forms the south front of the hill from the river to 
an elevation of more than one hundred feet. The masses 
seem to be not attached to the rocks about it, for one has 
moved down the hill. The bank of the river is gray gran- 
ular limestone. Passing another small bed of the pudding- 
stone a few rods north, we come upon argillite. ‘he 
puddingstone lies, therefore, upon limestone or limestone 
and argillite. It isa very singular deposite. ft is com- 
posed of rounded masses, sometimes four inches in diame- 
ter, and grains of quartz, limestone, siliceous slate, argillite 
and chlorite, cemented by a whitish argillaceous and sili- 
ceous cement. Sometimes, it is wholly composed of 
grains, and becomes sandstone, much resembling some 
arse gritstones. Half a mile south, in a bank o 
fine sand, similar sandstone is found in strata, from half an 
inch to two or three inches thick. Both kinds of this stone 
are slowly disintegrated on exposure to the weather. Inthe 
large masses the cement is so strong, that the fracture will 
pass through any of the aggregated minerals. 
~The formation of this stone is not easily accounted for, 
even on the supposition that the valley was once the bed of 
a large lake. The quantity of rolled minerals in this pud- 
dingstone, similar to those now washed along in some of 
the streams, and the quantity of rolled quartz in the plain 
for a mile south of this rock, favour such a supposition, 
But in what manner they should be collected chiefly on the 
northern banks and on the side towards which the stream 
now runs, and how the materials of the puddingstone should 
be collected in such quantity at this one place, is a point of 
very difficult solution. 
iy Sasa cen a 
