Washington Rock on the first ridge, looking south

The Watchung Mountains are a group of three long low ridges of volcanic origin, between 400 ft. Washington Rock State Park is a 52-acre scenic State park on top the first Watchung Mountain in Green Brook Township, New Jersey. Plate tectonics and hotspots Divergent plate boundaries At the (122 m) and 500 ft. (152 m) high, lying parallel to each other in northern New Jersey in the United States. New Jersey ( is a state in the Mid-Atlantic and Northeastern regions of the United States. The United States of America —commonly referred to as the The ridges, known as Orange or First Watchung Mountain (the southeastern ridge) and Preakness or Second Watchung Mountain (the northwestern ridge), stretch for approximately 40 miles (64 km) from Somerville (in Somerset County) in the southwest to Paterson (in Passaic County) in the northeast. Somerville is a borough in Somerset County, New Jersey, United States. Somerset County is a County located in the US state of New Jersey. Passaic County is a County located in the US state of New Jersey. The discontinuous ridge formed by Long Hill, Riker Hill, Hook Mountain and Packanack Mountain is sometimes referred to as Third Watchung Mountain and lies on the northwestern side of Second Watchung.

Trees in the Watchung Reservation between the first and second ridges

Collectively, the three ridges demarcate a geologic barrier on the western edge of the plains west of the Hudson River. The Watchung Reservation is the largest Park in Union County, New Jersey, United States The Hudson River, called Muh-he-kun-ne-tuk, the Great Mohegan by the Iroquois, or as the Lenape Native Americans called it in Unami The highest point in the Watchungs is High Mountain in Wayne, which stands at 879ft (268m) above sea level. Wayne is a Township in Passaic County, New Jersey, United States, located less than 15 miles from midtown Manhattan. Other notable summits are Garret Mountain in Paterson and the Hilltop in Verona, Cedar Grove, and North Caldwell. Verona is a township in Essex County, New Jersey, United States. Cedar Grove Township is a Township in north central Essex County, New Jersey, United States. North Caldwell is a borough in northwestern Essex County, New Jersey, United States, and a suburb of New York City. All along the Watchungs there are county reservations, one of which in Union County is called the Watchung Reservation. Union County is a County located in the US state of New Jersey. The Watchung Reservation is the largest Park in Union County, New Jersey, United States

A section of the Hilltop in Verona — the site that used to contain a sanatorium for tuberculosis sufferers — is the highest point in Essex County; the county hospital was built there because the high elevation provided clean, mountain air away from the cities to the east, that is beneficial for people with TB. Verona is a township in Essex County, New Jersey, United States. A sanatorium (also sanitorium, sanitarium) is a medical facility for long-term illness typically Tuberculosis. Tuberculosis (abbreviated as TB for tubercle bacillus or T u' b' erculosis Bacillus --> is a common Essex County is a County located in the northeastern part of the U

Since the 1970s, the area has seen extensive suburban growth, but before the construction of the interstate highway system, the Watchungs actually held back urbanization. South San Jose (cropjpg||thumb|A suburban development in San Jose California. The Dwight D Eisenhower National System of Interstate and Defense Highways, commonly called the Interstate Highway System (or simply the Interstate System)

Washington Valley in Bridgewater between the first and second ridge

During the Revolutionary War, General George Washington used the protection of the Watchung mountains to erect the first and second Middlebrook encampment. Bridgewater Township is a township in Somerset County, New Jersey, United States. In this article the inhabitants of the thirteen colonies that supported the American Revolution are primarily referred to as "Americans" with occasional references to "Patriots" George Washington (February 22 1732 December 14 1799 served as the first President of the United States of America (1789&ndash1797 and led the See also New Jersey during the American Revolution The Middlebrook encampment refers to the seasonal encampment of the Continental Army during the American This position on the high ground also allowed him to monitor the area between Perth Amboy and New Brunswick and to identify and disturb British movements between New York City and Philadelphia. Perth Amboy is a city in Middlesex County, New Jersey, United States. New Brunswick, also known as "the Healthcare City" or "Hub City" is a city and the County seat of Middlesex County The City of New York Philadelphia (ˌfɪləˈdɛlfiə ^[1]

Geology

The Newark Basin contains Traprocks, which are mineral-rich mafic volcanic rocks. Trap rock is a form of Plutonic Igneous rock that tends to form polygonal vertical fractures most typically hexagonal but also four to eight sided Mafic is an adjective describing a Silicate mineral or rock that is rich in magnesium and iron the term was derived by contracting "magnesium" and "ferric" Their resistance to erosion (relative to the surrounding sandstone and shale) produce elevated regions above the surrounding terrain. Sandstone is a Sedimentary rock composed mainly of Sand -size Mineral or rock grains. Shale (also called mudstone) is a fine-grained Sedimentary rock whose original constituents were Clay minerals or Muds It is characterized by The volcanic rocks of the Watchung Mountains were formed as mafic volcanic material extruded on the surface as surface flows aprroximately 185 million years ago. Most of the Watchung Mountains are examples of extrusive igneous rocks, displaying characteristic columnar jointing and stacked lava flows. Igneous rocks (etymology from Latin ignis, fire are rocks formed by solidification of cooled Magma (molten rock It has been proposed that the basalts of the Watchung Mountains are extrusive eruptions of the same magma that created the Palisades Sill several miles to the east. Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock. Magma (Plurals magmas and magmata) is molten rock that sometimes forms beneath the surface of the Earth (or any other Terrestrial planet The Palisades Sill is a Triassic, 200 Ma Diabase Intrusion. It extends through portions of New York and New Jersey

The mountains have historically been the site of extensive quarrying of volcanic basalt. Basalt (bəˈsɔːlt ˈbeisɔːlt ˈbæsɔːlt is a common Extrusive Volcanic rock.

References

External links

• Geology of the Newark Basin and Connecticut River Basin
• U.S. Geological Survey - South Mountain Reservation