The geology of Orange County is as varied as its topography. Along the eastern feet of the Shawangunk Mountains are Heidelberg limestones, gray and Medina sandstones, shales and grits, and the mountain rocks are mostly sandstones, shales and grits. The grits extend along the top of the range through the county and are from 60 to 150 feet thick. Heidelberg limestone extends from the Mamakating valley to the Delaware River. Grit and red rocks are on the west side of Greenwood Lake, and grit of various colors extends from Round Hill to Woodcock Mountain, and is also found in the southwest base of the Schunnemunk range and in Pine Hill. Grawacke is the rock on the southeast side of the Bellvale range in Warwick, and is found in the town of Blooming Grove in the Schunnemunk range. The Hudson River group occupies a large part of the surface of the county, and consists of slates, shales, grits, limestones, breccias and conglomerates. It extends from the Hudson River through Warwick to the Jersey line, and from the Hudson at Cornwall Landing to four miles above Newburgh. It is stratified with grawacke and grawacke slate. It forms the surface rock of the most of Goshen and Blooming Grove, and parts of Cornwall, New Windsor, Newburgh, Montgomery, Hamptonburgh, Crawford, Wallkill, Mt. Hope and Minisink. Dark Utica slate is found on the banks of the Hudson near Newburgh. Trenton limestone appears in Hamptonburgh near Mount Lookout, and this mountain is composed of Black River limestone, which is also found on Big Island in the Drowned Lands and in Minisink. There is a bed of blue limestone about a mile wide extending from the Hudson at Hampton southeasterly through Newburgh into New Windsor. It is also found in the towns of Cornwall, Blooming Grove, Warwick, Monroe and Goshen. Oolitic limestone is on Big Island, near New Milford, and on Pochunck Neck.
Slate rocks of the Taconic system are above Newburgh, and its limestone between the Highlands and Grove Pond Mountain. Its white limestone appears in Warwick, where it is in narrow ridges separated by other rocks. It is also found along the shore of the Drowned Lands at Amity, and near Fort Montgomery in the Highlands, from which it may be traced by way of Little Pond across the Ramapo. In some localities it is so white as to be translucent. Many different minerals are found in it.
The primary rocks of the county consist of gneiss, hornblende, granite, sienite, limestone, serpentine, angite and trappeau. They extend over parts of several towns, and several mountains and hills are composed of them. Granite is found at the foot of Butter Hill, sienite at Butter Hill and on the east side of Bare Mountain at West Point, gneiss along the Highlands, mica and slate north of Fort Montgomery, angite rock between West Point and Round Pond and at several points in Monroe, greenstone trap at Tuxedo Pond, granular limestone at Cro'-nest and Butter Hill. Quartz rock and hornblende are all along the Highlands and in Monroe and Warwick. Crystalline serpentine is in the white limestone in Warwick, serpolite at Amity, yellow garnet at Edenville, soapstone in Monroe. Large sheets of mica are found southwest of the Forshee iron mine in Monroe, and in this mine, which embraces an entire hill, are red garnet, brown tremoline, carbonate of copper, serpentine, cocolite and umber. In the O'Neil mine, half a mile northeast of the Forshee mine, are crystallized magnetic ore, magnetic and copper pyrites, carbonate of copper, serpentine, amianthus, asbestos, brown and rhombic spars, angite, cocolite, feldspar and mica.
There are beds of arsenical and titanium ores in Warwick and a bed of hemolite ore near Canterbury village. Magnetic oxide of iron abounds in the primitive rocks of the Highlands, and at West Point is associated with hornblende. Beds of lead have been opened at Edenville and in the towns of Mt. Hope and Deer Park, and zinc and copper ores have been found in small quantities. The Sterling iron bed in Monroe, which was opened in 1781, extends over about thirty acres, and has produced so strong an ore that it has been much used in the manufacture of cannon. There are a number of other iron mines. Searches for the traditional silver, gold, lead and tin mines have been without satisfactory results.
Many evidences of glacial action in Orange County include masses of boulders scattered in places throughout the county. These are mostly of granite and gneiss, and there is occasionally one of grawacke. The eastern slope of the Shawangunk Mountains gives evidence of the passage there of an enormous glacier, which ground the rocks into the rich soil that has been cultivated there for 200 years. Some of the county's drift deposits are valuable for casting, brick and pottery making, lithographic stones and glass.
The soil of the semicircular plateau from the Highlands of the Hudson to the Dans Kamer is mostly a mixture of gravel, sand and clay, which form a warm and fertile loam. That of the wide Wallkill valley is alluvium mixed with clay, sand and gravel and is easily worked and richly productive. So is the soil brought down from the hills in the town of Deer Park. The lands on the islands of the Drowned Lands are among the richest in the county. The alluvium of the Otterkill is a sandy and gravelly loam. In other sections of the county there is an alternating variety of soils, rich, medium and poor.
[CHAPTER V.]
EARLY GOVERNMENT
Until after the conquest of New York by the English in 1664 Holland methods of government, with a local government for each town, prevailed. The next year the English introduced courts and sheriffs. In 1682 Thomas Dongan was appointed governor, with directions to organize a council of not more than ten "eminent inhabitants," and issue writs for the election by freeholders of a general assembly, the members of which should consult with the governor and his council as to what laws were necessary for the good government of the province. The first meeting of the first general assembly was in New York in 1683, and it passed fourteen acts, which were assented to by the governor and his council. One of them established twelve counties, as follows: New York, Kings, Queens, Suffolk, Richmond, Westchester, Albany, Ulster, Dutchess, Orange, Duke's and Cornwall.