THE MINING AND QUARRY INDUSTRY I9QI12 87 
The Rylestone quarries. The Rylestone quarries, which were 
closed at the time of the writer’s visit, lie a mile or so south of 
the main belt on a separate lead. They are situated on the side of 
a low hill and are not worked below the surface. The marble is a 
coarse medium to light stone, in which the blue and white are 
equally mixed. It lacks the uniformity of texture exhibited by 
the marble elsewhere and is subject to considerable loss in quarry- 
ing by reason of vugs that are apt to be disclosed in the midst of 
an otherwise sound block. These vugs range from very minute 
cavities lined with crystallized minerals to those a foot or two in 
length. Calcite, marcasite and brown tourmaline are the more 
common minerals found in them. 
The quarry face is about 100 feet long at the base and 50 feet 
high. In the last operations, the stone has been quarried away by 
blasting. The product was sawed in a mill nearby equipped with 
eight gangs. 
There are a number of quarry openings on the main belt which 
have been idle for some time, such as the Callahan quarry on the 
northeast end, the Sullivan quarry, near the St Lawrence quarries, 
and the quarry of the former Whitney Marble Co., on the south- 
west, near the property of the Northern New York Marble 
Company. 
Southeastern New York. Crystalline limestone is found in the 
Highlands and the bordering metamorphosed area to the north and 
south. It is specially prominent on the east side of the Hudson, 
‘where it underlies many of the north-south stream valleys of West- 
chester, Putnam and eastern Dutchess counties. It is associated 
with schists, quartzites and thinly bedded gneisses, the whole series 
of interfolded metamorphosed sediments bearing much resemblance 
to the Grenville series of the Adirondacks. There is some doubt, 
however, as to the stratigraphic position that should be assigned 
to the limestone, if indeed it is to be regarded as an essentially 
continuous formation throughout the area. 
In Westchester county the limestone is coarsely crystalline, white 
and usually dolomitic, but varying considerably in its magnesia 
content. The name “ Inwood” limestone was first applied to it by 
F. J. H. Merrill, who later advocated the view of the general 
equivalence of the limestones in this section with those of western 
New England and withdrew that name in favor of the prior term 
“Stockbridge dolomite.” 
In the northern section in eastern Dutchess county, the lime- 
