Page:The American Cyclopædia (1879) Volume XII.djvu/316

 304: NEW JERSEY tween the gneissic rocks and the magnesian limestone. The latter, known as the Potsdam sandstone, crops out at Franklin and Vernon in Sussex co., and at Oxford Furnace and other points in Warren co. The third member in this system, ascending, is the Hudson river slate, which has an extensive outcrop in the Kittatinny valley, and forms the E. slope of the Blue or Kittatinny mountain. It shows nearly everywhere its tendency to cleavage, and it is quarried at the Delaware Water Gap and at Newton for roofing slate. Some of the thicker and more arenaceous beds are used for flagging stone. In the Blue mountain the gray con- glomerate, the equivalent of. the Oneida con- glomerate, has a wide and unbroken outcrop from the Delaware river to the New York line. Overlying it, and forming the western and lower slope of the Blue mountain, is the Me- dina sandstone ; the rocks are red sandstones and shales, and a few vegetable forms are oc- casionally seen in them. West of this, and occupying the narrow valley of the Delaware, are several formations or members of the Si- lurian and Devonian epochs. Southeast of the Highlands there is a wide belt of red shales and sandstones of the triassic pe- riod. This occupies a large part of Bergen, Passaic, Essex, Union, Somerset, Hunterdon, Middlesex, and Mercer counties, and is 30 m. wide on the Delaware river. The rocks are red argillaceous shales and sandstone, with a few limited outcrops of calcareous and silicious conglomerates on the N. W. border, near the azoic rocks. Within the limits of this forma- tion there are several long outcrops of trap rock lying between beds of shale and sandstone, forming the well known Palisades, First and Second mountains, Pickles mountain, Sourland mountain, Rocky hill, and others. Narrow dikes of trap are also known. The sandstone is extensively quarried for building at Pater- son, Little Falls, Newark, Trenton, Centre Bridge, and in other places. Fossil fish have been found in the rocks of this formation at Pompton, Boonton, and near Somerville. Fossil plants are more common. Copper ores and native copper are common in the altered sandstone near the junction of the trap rocks, occurring irregularly disseminated through the sandstone, and not in veins or beds. Several copper mines were early opened, but none of them are now in operation. The next forma- tion S. E. of the triassic rocks is the plastic clay series belonging to the cretaceous period. In this are the valuable beds of fire clay and pot- ter's clay which are so largely dug in the vicini- ty of Woodbridge and Amboy, and near Trenton. Fossil wood and leaf prints with a few cretace- ous shells are found in this series. This belt follows the Delaware from Trenton S. W. to Salem. The next geological formation on the southeast is the clay marl, occupying a nar- row belt entirely across the state. The beds are mainly astringent clays containing a small percentage of greensand. The next belt S. E. is that of the greensand marl beds, stretching from Sandy Hook to Salem. There are three beds, separated by beds of sand, dipping gently toward the southeast. They are characterized by the mineral glauconite or greensand which makes up most of their mass. (See GKEEN- SAND.) Generally there is some carbonate and some phosphate of lime in these beds, and hence the value of this marl as a fertilizer. Many fossils characterize these beds and help to fix their geological age. The S. E. portion of the state is supposed to belong to the tertiary age. There are beds of calcareous marl near Shiloh, Cumberland co., which are undoubtedly mio- cene, and are very full of shells. Beds of glass sand, which are extensively worked, occur along Maurice river near Millville, at Winslow, Jackson, and other places. The higher grounds in this part of the state are gravelly, and prob- ably belong to the modified drift. Bog ore is found in many places, generally under the peat or mud of wet meadows. The drift period is represented nearly everywhere throughout the state in the superficial beds of sand, gravel, and bowlders. These beds are thicker and the bowlders are larger in the northern than in the southern part of the state. The smoothed, polished, and striated rock surfaces so common on the harder rocks also represent this period. Alluvial beds are found in isolated patches, sometimes of great extent, as in the wet mea- dows along the Paulinskill, Pequest, and Pas- saic rivers. Peat bogs are also common, al- though they are not generally of great area. Under some of these, in the limestone districts of Sussex and Warren counties, there are beds of calcareous or shell marl a few feet thick. There are extensive tide meadows bordering the tide waters, from 5 to 10 ft. above low- water level, and still in process of formation. Along the Atlantic coast there is a long line of sand beach, which is geologically a long dune, constantly changing in location, extent, and form. These belong to the present or historic period. New Jersey offers numerous attractions to travellers, among which are the falls of the Passaic at Paterson; the passage of the Delaware through the Blue moun- tains, called the Delaware Water Gap; the well known bathing places of Cape May, Long Branch, Deal, Squan beach, Atlantic City, and Tuckerton ; Schooley's mountain in Morris co., with a mineral spring on its summit; Lake Hopatcong, Greenwood and Budd's lakes, and other points in the northern highlands. The climate varies much in different parts of the state. In the north, where the country is more elevated, it is much colder than toward the south, where the influence of the ocean and a low situation is felt. The annual mean temperature of the southern end of the state is between 53 and 54 ; that of the northern end from 48 to 50. The annual rainfall is about 44 inches ; annual mean barometer, 30. Fevers and ague prevail in the neighborhood of the marshes, but upon the seashore and in the