268 
GEOLOGY OF THE THIRD DISTRICT. 
Rising and going west from the primary which skirts Black river, the first range of rock is 
the Black river limestone , forming a terrace coextensive with the county. It is its most 
valuable rock for building, and for lime, of which there are two kinds, the common and the 
water-lime. The upper layers of the terrace are those which are intermediate to the Trenton 
and the Birdseye limestone ; those below belong to the latter rock, and are the most valuable 
for building, and burning for lime, being more solid and pure. The part used for water-lime is 
under the layers which are usually quarried, and where seen, was a yellowish color, and some¬ 
what dull as to reflection of light. It was noticed only at the following localities : First, 
near the mouth of Sugar river, at the quarries; then to the east of Collinsville ; and near 
Lowville. It is no doubt coextensive with the cliff or terrace. The test of a water-lime, for 
all practical purposes, is very simple. When the stone is calcined or burnt, it must not slake ; 
and when ground and made into mortar, it must set and harden under water. It may be well 
to remark, that generally less heat is required to burn this kind of limestone for the purpose 
required, than to make ordinary lime. 
The Trenton limestone is the next rock in succession, rising upon the Black river limestone, 
and showing a thickness of three hundred feet at its north end, but appearing to be less at its 
south end. Its greatest known thickness is in this county. It ranges like the lower limestone 
along the river, curving north, exposing a surface from two to four miles broad ; in some 
parts rising rapidly from the lower terrace, in others by a gentle slope. From its great thick¬ 
ness, it exhibits many fine water-falls yet unknown to fame, the greatest of which is near 
Copenhagen ; and another is on Deer river, falling two hundred and seventy feet perpendicular 
depth from towards the upper part of the rock. 
The Trenton limestone underlies the villages of Collinsville, Martinsburgh, Lowville, Den¬ 
mark and Copenhagen. It varies considerably in quality : in some places, greyish and crystal¬ 
line ; in others, more generally dark-colored, the separations of shale thick, and the limestone 
frequently assuming an accretionary character from admixture of shale. It is a metalliferous 
rock, galena having been found in it at three places, but not in profitable quantity as yet. The 
first place where seen going north, is near Ives’ mill, on the road from Shelden’s to Collinsville, 
some particles being found in the quarry at the creek ; but it is more abundant at Lowville, 
associated with other ores which were worked as silver. It is in considerable quantity at 
Martinsburgh, but in veins too narrow to be worked with advantage under the existing state 
of things. The rock appears near the surface at the highest point to the northwest of the 
village. The veins are very numerous, and occupy the vertical east and west joints of the 
rock ; continuous as to direction, both vertically and according to their east and west points, 
but often interrupted for want of continuity in the joints. The ore is accompanied by blende, 
and by what appears to be calamine, in which the galena often presents a beautiful feathery 
form of crystallization. The stony materials are white crystalline carbonate of lime. The 
joints are from zero to eight or more inches in diameter, ranging in parallels but a few feet 
from each other ; their character is unknown beyond a few feet from the surface, the greatest 
depth attained being but fifty feet, and the thickness of the rock at that place, as previously 
mentioned, being about five times that depth. 
