- 230 Connecticut River Valley. 
clay beds at Springfield, and indeed all between Enfield and Had- 
ley falls, belong to the same period of time, and the same elevation 
of the waters. Unless we suppose that immense quantities of clay 
belonging to this formation have subsequently been removed, the 
period of No. 3. was not of long duration. , Fifty or sixty years, 
perhaps less, would suffice to form the greatest number of overly- 
ing plates of clay which are known in the region about Enfield falls. 
The clay beds of different sections of the Connecticut river valley, as 
they belong to separate lakes, may have been formed at different pe- 
riods, and remote one from another. 
4. Loose Aggregations.—Over the surface of the slopes i hills, 
resting upon the clay beds of No. 3. and where these are wanting, upon 
the confused mixture of No. 2. lies a disarranged covering, compo- 
sed of earth, gravel, pebbles, and large and small fragments, embrac- 
ing fragments of primitive rocks, sandstone, and greenstone. It is 
perfectly manifest that these materials could not have occupied their 
present place, during the subsidence of the subjacent layers of clay. 
It is equally plain that no agencies now operating, either with or with- 
out the presence of a lake, could have collected these heavy materials 
and masses, and spread them over the tops and sides of the hills and 
slopes where they now lie. A vast amount of sand and gravel is 
spread over extensive portions of the lower valley, forming barrens 
or plains remote from the river. These seem to belong to the 
same period as the coarse covering along Enfield falls above des- 
cribed, (No. 4.) and must be distinguished from the terraces of 
plains previously mentioned. But one natural agent is adequate 
and adapted to collect and distribute the materials of No. 4, An 
overwhelming rush of waters, probably the deluge of the Scriptures, 
bore along with equal ease the sand, gravel, pebbles, and even 
larger fragments, which now overspread formations produced in a pre- 
vious state of tranquillity, filling the deeper cavities where are more 
remote plains and barrens, and levelling them like the strike of a 
measure of grain, but leaving a more shallow covering upon the 
hills whose rocky strata were elevated above the general surface. 
5. Soil.—A vegetable soil completes the formations, found in place, 
one above another, at Enfield falls. 
SUMMARY. Fi 
The principal states and changes which have been described, 
and of which incontestable proofs remain in the valley of the Con- 
necticut river, are, 
