No. 50.] 425 
of the small streams ; and approaches the surface over the greater part of 
this neighbourhood. 
The grey or ash colored marls just described, are succeeded by blu- 
ish, slaty and drab colored impure limestone, which embrace large beds 
of gypsum. These occur mostly in the north part of Leroy and Stafford . 
Gypsum is also found in the western part of Elba, near the junction of 
the Pine-hill road, with the Batavia and Lockport turnpike ; which is 
the most northern point that I have found it, in the county. At this 
place some 30 or 40 tons were quarried ; but the masses being small, 
and about eight feet below the surface, requiring the removal of all the 
superincumbent earth and stone ; the work proved unprofitable and was 
abandoned. That which was quarried still lies on the ground. 
In the vicinity of this quarry, and for some distance west, there are 
sufficient indications of gypsum in the peculiar irregularity of the sur- 
face ; being raised into little mounds, which give the appearance of 
heaps of earth deposited on the level soil. The thin bluish or drab 
limestone, is also found near the surface, and often ploughed up in the 
fields. 
In the north part of Leroy plaster is obtained in large quantities, on 
lots 118, 144 and 132. The quarries in the first are of white gypsum, 
and free from seams and intermixture of clay ; it is covered with a blu- 
ish kind of limestone with shaly seams, and splitting into laminae J or 
•J an inch thick. In the others, the gypsum is cla}^ colored with seams 
of clay ; this when exposed crumbles rapidly ; the rock above is a drab 
limestone, resembling in general appearance the hydraulic limestone. 
In this I found some few fossil shells of a species of Pterinea. Some 
parts of the rock are filled with small round pores the size of a must- 
ard seed ; such are also seen in the soft limestone, a few feet below the 
hydraulic or drab limestone. 
The masses are all more or less spherical ; the surrounding rocks 
being raised in the centre, presenting a fractured convex surface, dip- 
ping on every side of the mass. 
The quarries last mentioned, belong to Messrs. Bannister, Collins and 
Clifford ; the white gypsum to Mr. Hughes and Mr. Cash. The plas- 
ter is sold at the bed for fifty cents per ton ; when ground, from $3 .00 
[Assembly, No. 50.] 
54 
