JEFFERSON COUNTY. 
401 
Loraine Shales. 
In the general description of the rocks of the Second district, I proposed to change the 
name of this rock, substituting Loraine for Pulaski shales; and though the latter had been 
used in the annual reports, and there are objections to a change of name when it can be avoided, 
or when no sufficient reason exists, still in this case it appeared to me that a change was 
required ; for if the principle for local names is good, it is evident that the locality from which 
the name is to be derived should be one where the most important characters of the rock are 
best displayed. It was upon this ground that I proposed to substitute Loraine for Pulaski; 
the whole mass, with all the relations of the inferior and superior rocks, being exposed either 
ffi the gulfs of Loraine, or in the adjacent country. If, therefore, a complete and satisfactory 
knowledge is wished of this rock, it is -necessary to visit Loraine. At Pulaski, the upper 
part of the rock only is exposed; but the deeper beds, those which give to the mass its 
mineral characters, are not exposed at this place. There seemed, therefore, sufficient reasons 
for the change proposed. 
In this mass, we find a great diversity of materials. In this county they are composed of, 
1. Thin even-bedded sandstone; grey internally, but becoming brownish or brown by weathering. 
2. A shaly sandstone, weathering as in the preceding. 
3. Fine grained, fragile slate, mostly argillaceous, and invariably exfoliating on being moistened or wet after having been 
dried. 
4. Strata composed of calcareous matter and shale, varying from one to ten inches thick. They are mostly a mass of 
fossils, and become brown by weathering. 
5. A stratum of compact, fine-grained limestone, intermixed with carbonate or oxide of iron. This is from six to ten 
inches thick; and though it appears an unimportant part, yet it extends over a wide surface, and occupies a definite 
position. It resembles the ironstone of the coal measures, and sometimes furnishes a mass in that curious form called 
cone in cone. 
The whole mass is characterized by alternating beds of shale and slate, with a great pre¬ 
ponderance of the former. From the utica slate, for two or three hundred feet, thin grey 
shaly sandstone predominates. In this part, a few fossils were found : one orthoceratite, a stro- 
phomena and pterinea. The strata consist usually of thin laminae bent or curved among them¬ 
selves, partly in consequence of each individual layer thickening and thinning out, giving the 
strata a waved appearance when worn. When used as a flagging stone, these layers present 
this peculiar appearance. 
The change in mineral character from the utica slate is gradual, the slaty or argillaceous 
strata are replaced slowly by those which are siliceous ; and though the steps of this change 
may not in all cases be equal, yet we find in the end that the argillaceous matter disappears ; 
as when the grey sandstone is formed, this substance is only found in small insulated masses, 
but rarely in sufficient amount to form a continuous stratum. 
The boundaries of the loraine shales are well defined on their northern outcrop. 
From near Mannsville, the line of outcrop runs northeast, passing two and a half miles east 
of Adams to Whitesville and Tylerville, whence, in two or three miles, it takes an easterly 
direction, and passes from Jefferson to Lewis county. 
Geol. 2d Dist. 51 
