of Saugerties, in Ulster County, is reached, when it takes a westward drift, being interrupted on the east by the older limestone formations, and on the north by the quartzose and. conglomerate or pudding-stone formations of the Catskills, the latter of which undoubtedly rests on a foundation of bluestone, as it again makes its appearance on the westward side of the range. In the town of Saugerties the gray color of the stone disappears, and the formation takes on the deep-blue tinge whence it gets its name. Here also the belt begins to widen, and when the broad plateau at the foot of the Catskills, covered by the adjoining towns of Kingston,
Fig. 2.—An Ulster County Monolith Size. twenty by twenty-four feet; nine inches thick.
Woodstock, Olive, Marbletown, Hurley, and Shandaken, is reached, the quarries are distributed over a range of country at least fifty miles broad. Here the stone varies but little in color, touching only the shades from medium to dark blue. The presence of ferric oxides is found in all the quarries, but only in the seams on the surface of the slabs, which have a rusty color from the oxidation. The stone produced in Ulster County has always commanded the largest prices, it being the best quality produced in the entire belt.
Leaving Ulster County, the bluestone belt crosses the Catskills, takes in a corner of Delaware and Orange Counties, and then
