Connecticut River Valley. 229 
same powerful currents, perhaps aided, possibly produced, by fluc- 
tuations caused by the renewed energy of subterranean fires, dis- 
turbed, softened, and displaced the previously arranged beds of fine 
red clay, dislocated and intermingled the upper sandstone strata, and 
rolled and kneaded into the mass various pebbles and fragments, until 
the whole subsided into their present state of confused mixture. Sim- 
ilar combinations have been noticed in numerous places, over an ex~ 
tent of forty miles, from Hadley falls to Hartford, and below. 
3. Laminated clay-beds.—As soon as the commotion which produ- 
ced the mixture of No. 2. had ceased, it is manifest that an extensive 
surface, consisting chiefly of clay and other fine materials, must have 
been left exposed to the action of water; if in hills above the sur- 
face, to the washing of rains and streams; if below the surface, to 
the agitations of the lake itself. In this manner, chiefly during pe- 
riodical, or at least violent storms, successive portions of fine mate- 
rials would again become suspended and diffused, and finally subside 
in the manner already described, forming clay-beds, of thin layers 
often repeated, provided cement were wanting to unite them into 
rocky strata. Accordingly No. 3 consists of clay-beds, composed 
of layers, generally about half an‘inch thick, with sand at bottom, 
and the finest clay and deepest color at top, and between, a mix- 
ture of sand and clay, proceeding upward by insensible gradation 
from the slightest color, and heaviest materials, to the darkest and 
finest at top. This arrangement is invariable, in every layer. The 
greatest elevation of clay-beds along Enfield falls, is about fifty feet 
above the present surface of the river. They rest upon and termi- 
nate in the sides, and never overspread the tops of the higher red clay 
hills of No. 2. Hence it is probable that during the period of the 
deposition of No. 3. the waters of the lake, or of the river, if it 
were then reduced to a river, were not more than fifty feet higher - 
than its present surface; otherwise the layers of clay would have 
extended farther up the sides of No. 2. The clay-beds which were 
cut through in forming the canal were of various thickness, con- 
taining sometimes twenty, sometimes sixty layers, the latter when 
the formation commenced at a greater depth than the former. . Be- 
tween Enfield falls and Hartford, the clay-beds rarely attain the 
height of fifty feet, above low tide. An instrumental level carried 
twelve miles, from the foot of Enfield falls to Hartford, at a height 
of thirty feet above low water in the river, touched the margin of 
nearly thirty brick yards, scattered along the route. Probably the 
Vou. XXII.-—No. 2. 30 ote 
