Trenton Prong

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The Trenton Prong is a physiographic subprovince of the Piedmont Uplands section of the Piedmont province of the Appalachian Mountains. The prong consists of crystalline metamorphic rock.

Geologic province A spatial entity with common geologic or geomorphic attributes

A geologic or geomorphic province is a spatial entity with common geologic or geomorphic attributes. A province may include a single dominant structural element such as a basin or a fold belt, or a number of contiguous related elements. Adjoining provinces may be similar in structure but be considered separate due to differing histories.

Piedmont (United States) plateau region located in the eastern United States

The Piedmont is a plateau region located in the Eastern United States. It sits between the Atlantic coastal plain and the main Appalachian Mountains, stretching from New Jersey in the north to central Alabama in the south. The Piedmont Province is a physiographic province of the larger Appalachian division which consists of the Gettysburg-Newark Lowlands, the Piedmont Upland and the Piedmont Lowlands sections.

Appalachian Mountains mountain range in the eastern United States and Canada

The Appalachian Mountains, often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They once reached elevations similar to those of the Alps and the Rocky Mountains before experiencing natural erosion. The Appalachian chain is a barrier to east–west travel, as it forms a series of alternating ridgelines and valleys oriented in opposition to most highways and railroads running east–west.

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Location

The Trenton Prong stretches from near Norristown, Pennsylvania, through northern Philadelphia and southern Bucks County, reaching its northern terminus in West Windsor Township, New Jersey. [1] The prong underlies much of the City of Trenton, and forms a series of rapids known as the Falls of the Delaware River.

Norristown, Pennsylvania Place in Pennsylvania, United States

Norristown is a borough in and the county seat of Montgomery County, Pennsylvania, United States. Located along the Schuylkill River approximately six miles from the Philadelphia city limits, Norristown has a population of 34,324 as of the 2010 U.S. Census. It is the fourth most populous municipality in the county and second most populous borough in Pennsylvania.

Pennsylvania State of the United States of America

Pennsylvania, officially the Commonwealth of Pennsylvania, is a state located in the northeastern and Mid-Atlantic regions of the United States. The Appalachian Mountains run through its middle. The Commonwealth is bordered by Delaware to the southeast, Maryland to the south, West Virginia to the southwest, Ohio to the west, Lake Erie and the Canadian province of Ontario to the northwest, New York to the north, and New Jersey to the east.

Philadelphia Largest city in Pennsylvania, United States

Philadelphia, sometimes known colloquially as Philly, is the largest city in the U.S. state and Commonwealth of Pennsylvania, and the sixth-most populous U.S. city, with a 2017 census-estimated population of 1,580,863. Since 1854, the city has been coterminous with Philadelphia County, the most populous county in Pennsylvania and the urban core of the eighth-largest U.S. metropolitan statistical area, with over 6 million residents as of 2017. Philadelphia is also the economic and cultural anchor of the greater Delaware Valley, located along the lower Delaware and Schuylkill Rivers, within the Northeast megalopolis. The Delaware Valley's population of 7.2 million ranks it as the eighth-largest combined statistical area in the United States.

Geology

The Trenton Prong is part of the Precambrian basement which is discontinuously exposed in the north-central Appalachians. The rocks that make up the prong are mostly Ediacaran and Cambrian aged rocks, that includes the Wissahickon Formation. [2] Other rocks present include metabasalt, gabbro, gneiss, migmatite and granofels. The prong is heavily eroded, presenting as low, gently rolling hills. [3]

The Precambrian is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the Phanerozoic eon, which is named after Cambria, the Latinised name for Wales, where rocks from this age were first studied. The Precambrian accounts for 88% of the Earth's geologic time.

The Ediacaran Period, spans 94 million years from the end of the Cryogenian Period 635 million years ago (Mya), to the beginning of the Cambrian Period 541 Mya. It marks the end of the Proterozoic Eon, and the beginning of the Phanerozoic Eon. It is named after the Ediacara Hills of South Australia.

The Cambrian Period was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 55.6 million years from the end of the preceding Ediacaran Period 541 million years ago (mya) to the beginning of the Ordovician Period 485.4 mya. Its subdivisions, and its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name of Wales, where Britain's Cambrian rocks are best exposed. The Cambrian is unique in its unusually high proportion of lagerstätte sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambrian biology surpasses that of some later periods.

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Passaic Formation

The Passaic Formation is a mapped bedrock unit in Pennsylvania, New Jersey, and New York. It was previously known as the Brunswick Formation since it was first described in the vicinity of New Brunswick, New Jersey. It is now named for the city of Passaic, New Jersey, which is near where its type section was described by paleontologist Paul E. Olsen.

New Jersey is a very geologically and geographically diverse region in the United States' Middle Atlantic region, offering variety from the Appalachian Mountains and the Highlands in the state's northwest, to the Atlantic Coastal Plain region that encompasses both the Pine Barrens and the Jersey Shore. The state's geological features have impacted the course of settlement, development, commerce and industry over the past four centuries.

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Belt Supergroup

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Ramapo Fault

The Ramapo Fault zone is a system of faults between the northern Appalachian Mountains and Piedmont areas to the east. Spanning more than 185 miles (298 km) in New York, New Jersey, and Pennsylvania, it is perhaps the best known fault zone in the Mid-Atlantic region, and some small earthquakes have been known to occur in its vicinity. Recently, public knowledge about the fault has increased, especially after the 1970s, when the fault's proximity to the Indian Point nuclear plant in New York was noted.

Geology of North America regional geology of North America

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The Mansfield Natural Gas Field is located west of Mansfield, Ohio, within the Appalachian foreland basin. The field is 1.5 miles long by 1.4 miles wide and is in a general oval shape, stretching northward. This field, although small, is an analog for many of the natural gas fields that occur within the Appalachian Basin. It was first discovered by the Pan American Petroleum and Transport Company in the early 1930's. It is part of the Utica – Lower Paleozoic system, which is estimated to make up 15 to 20 percent of the total hydrocarbon abundance of the Appalachian Basin.

References

  1. The Geology of North America Vol. C-2: Precambrian: Conterminous U.S.; edited by John C. Reed, Jr., Marion E. Bickford, R.S. Houston, Paul Karl Link, D.W. Rankin, Paul K. Sims, W. Randall Van Schmus; The Geological Society of America, 1993; p 390
  2. Orndorff, R.C., et al., (1998). Bedrock Geologic Map of Central and Southern New Jersey. United States Geological Survey, Scale 1:100,000
  3. Regional and Economic Geography of Pennsylvania: Physiography, Part 1 Walter Sheldon Tower in The Bulletin of the Geographical Society of Philadelphia, Volume IV; 1906, p 19