Connecticut River Valley. 221 
Dip.—The position of the secondary strata is rarely horizontal. 
The dip is more generally 10° or 12° to the east or north east, but 
is not uniform in direction or quantity. At Hatfield, the strata are 
seen dipping to the north west or west, and at Montague falls, they 
stand almost perpendicularly, forming an angle of 75° and 80° with 
the horizon. 
Causes of the secondary formation.—Are natural causes and agents 
adequate to account for the formation of the secondary rocks, inclu- 
ding the accumulation of the materials—their arrangement in parallel 
layers, and of the layers in similar plates—the distribution of coarse 
ingredients around the margin, and of fine near the center of the 
basin—the pervading color—and the cement which has converted an 
aggregation of previously dissevered substances into solid strata? 
plates and_layers.—Every kind and combination of mineral 
substances, found in the component parts of the secondary formation, 
may also be found in the primitive strata. The disruption of the 
primitive crust, and the process by which pebbles, gravel, sand, clay, 
and every species and mixture of fine earth were probably produced, 
have already been described. ‘The sandstone rock was doubtless the 
first formation which took place, after the disruption of the primitive, 
and the alluvial meadows are the latest. 1en the primitive strata 
were broken up, a vast amount of fragments and of rocky surface 
was exposed to the power of disintegrating agents, heat, cold, and 
moisture ; and the decomposition, and consequent production of fine 
earth, were proportionally rapid. At the commencement of the 
secondary formation, the whole surface of the valley would supply 
materials, which would be accumulated in its deeper and more cen- 
tral parts. When the new formation had spread to its ultimate 
limits, the materials of subsequent layers were supplied from the 
uncovered surfaces of the primitive, above, and at the sides of the 
secondary. In the course of time, floods and currents would accu- 
roulate an amount of materials equal to the whole contents of the 
secondary basin. ‘To distribute those materials in their existing po- 
sitions and order—to arrange successive plates into layers, and by 
successive layers to raise the surface to its final elevation—and to 
diffuse the coloring matter and cement, would require the presence 
of a lake or bay, at least coextensive with the secondary formation. 
Such a lake or bay must have extended from New Haven to the north- 
ern boundary of Massachusetts. 
Vou. XXIL— 29 
