82 7 Geology, &c. of the Connecticut. 
a deposite of a loamy sediment, The region in which 
sand occurs most abundantly, has just been mentioned. It 
is sometimes seen in alternating beds with gravel, clay and 
Joam. | 
5. Loamand mud. This is the most recent of our allu- 
vion, and depositions of it are frequently made. The Con- 
necticut indeed, seems, with some exceptions, to have 
nearly reached its maximum of depositions, rarely flowing 
over more than a small part of the alluvion along its banks. 
But its tributaries, such as the Farmington, Westfield, Deer- 
field, and Chickapee, still continue annually, and often 
semi-annually, to flood the adjacent meadows, and to leave 
there an additional soil, from half an inch to six inches 
deep, and though the agriculturalist has sometimes to la- 
ment the destruction of his crops by these inundations, yet 
without them his fields would soon become comparatively 
unproductive. i : 
The depth of the alluvion along the Connecticut has 
never been accurately measured ; Ac = should judge it 
sometimes to be as great as one hundred and fifty feet: 
but in general it is much less. It is not unfrequent to find 
ten or fifteen feet below the surface of the most recent of 
this alluvion, logs, stumps of trees, leaves, butternuts, wal- 
nuts, &c. in a partially decaying state, and sometimes we 
meet with skeletons of the aborigines of the country. But 
no aurock, mastodon, or megatherium, has yet been dis- 
covered to give an interest to this alluvial formation, —. 
_ Lhave found a difficulty in some instances in drawing the 
line between genuine post-deluvian depositions and geest. 
n some cases there appears to be a mixture. In other 
cases the rocks are entirely hid by the soil, and yet the 
predominant characteristic of the soil is derived from the 
rock underneath it, although there is a mixture of alluvion. 
The old red sandstone for instance, and the red slate of the 
coal formation, are very liable to decomposition, and thus 
a reddish soil is produced, so manifestly composed of the 
ruins of the rock, that one is able often to determine from 
the appearance of the soil at the distance of two or three 
miles the particular rock that lies beneath it. 1 have not, 
