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GRIMSLEY. | History and Distribution. Ds, 
Gypsum is found in Thuringia, Saxony, Norway, at Mont 
Marte near Paris, Austria, Bohemia, Italy, Egypt, Arabia, Per- 
sia, and many other places in the old world. In this country 
it occurs in small quantities in most of the states of the Union, 
and it is of economic importance in many of these. Wherever 
this mineral is found, it has attracted attention, and we now 
have good descriptions of the extent, origin, and uses of gyp- 
sum in the leading producing states of the union. 
Gypsum in New York.® 
The gypsum deposits of New York state occur in the Salina 
or Onondaga formation of the Upper Silurian period, and 
occur in regular beds, which plainly show it was originally 
deposited from water. Mr. Clarke states in his report that no 
evidence of gypsum is found east of Madison county, and that 
towards this eastern limit the gypsum is of a much darker and 
more earthy type, probably due to presence of carbonaceous 
matter. ‘The dark variety lies near the surface, while whiter 
gypsum at west is generally heavily capped with rock, and has 
less thickness than the other. 
The largest quarries belong to the Cayuga Plaster Company, 
of Union Springs. The beds have been worked for fifty years 
and about fifty tons of rock are quarried per day. The gypsum 
is covered with earth and underlaid with limestone. The beds 
are exceptionally regular and persistent and surface inequalities 
do not appear to influence the gypsum except in thickness. 
The plaster is shipped to other parts of the state and adjoining 
states and used as fertilizer. The color of the rock is gray with 
plates of selenite more or less intermingled, and large crystals 
are sometimes found. Weathering action disintegrates the gyp- 
sum, breaking it into dirt and small pieces which are not used 
at the mill. The rock has a maximum thickness of 40 feet 
while the average is about 8 feet of top rock and 8 feet of bot- 
tom rock. Other mills are located tothe west. At Garbuttsville, 
in Monroe county, the Caledonia White Land Plaster is made 
3. Condensed from New York Reports: Bull. State Museum, Vol. 3, No. 11, by Wm. C. Clarke, 
pp. 70-84, 1893. Same, Vol. 3, No. 15, by F. J. H. Merrill, Ph. D., p. 550, 1895. ia 
