14 Observations on the Origin of Stratification. 
the lines formed by differences in the quality of the component 
particles is beautifully marked on almost every slab, yet the di 
visions into layers are not coincident, and there is not a tendency — 
to divide along the lines of arrangement. 
At some points in the valley of the Connecticut where the — 
sandstones remain unaltered in any great degree by heat or dislo- 
cation, the stratification produced by these several causes may bi 
clearly seen and studied. On the western edge of this deposit, 
opposite Springfield, we have rocks composed of layers which 
would at once be referred to the production of tides or inunda-_ 
tions by the most inexperienced observer. ‘The strata here vary 
from the fraction of an inch to an inch in thickness; they are 
also covered with mud-cracks, and the various markings which 
are usually found upon a shore or beach. In other portions of _ 
the valley we have strata divisions, occasioned by the lines which 
separate materials differing either in quality or nature; as the — 
shales from the sandstones, the conglomerates from the fine sand- 
stones, or the highly bituminous shales from those less bitumin- 
ous. And then upon the extreme eastern edge of this sandstone 
deposit we find strata, the leaves of which measure from one to 
two, and some instances three feet in thickness, some layers em-_ 
bracing in themselves matter ranging from a coarse conglomerate — 
to the finest sand; and yet none of this collection of materials, 
within the limits of the particular layers in which they are in- 
-cluded, exhibits the slightest tendency to. break or divide in any 
one direction more than another. bs 
_ The observations here stated, Iam happy to find have beet 
also noticed to some extent by others conversant with the subject 
of stratification. Sawdust subjected to the filtering action 0 
water, has been observed by Prof. Agassiz to assume a regular — 
stratified appearance. The same has also been noticed by. Dr. 
Hayes of Boston, in the vats in which clay used for the manu: — 
facture of alum is washed. Dr. Emmons of Albany has referred — 
me to an instance of a clay bed in which the strata of one por- — 
tion are distorted and inclined, apparently from a force acting lat- — 
erally or from below, but which force evidently could not have — 
so acted from the perfectly regular and undisturbed condition of 
the surrounding clay strata; the inclinations must, therefore, ac- 
cording to Dr. Emmons, be referred to a peculiarity of deposition — 
ora subsequent division at an angle on consolidation. I have — 
also noticed regular stratification in the dried deposit of a le 
- . a : . 
in the streets, where no apparent change in the character of the — 
materials deposited could be noticed, and where there was cet 
cases of what are now considered disturbed and tilted strata, are 
in none other than their normal condition. 
