The Reading Prong is a

physiographic Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere, ...

subprovince of the

New England Uplands The topography of the New England Uplands section is that of a maturely-dissected plateau with narrow valleys, and the entire area is greatly modified by glaciation. It is the most widespread of the geomorphic sections in the New England Province, e ...

section of the

New England province The New England province is a physiographic province of the larger Appalachian division of eastern North America. The province consists of the Seaboard Lowland, New England Upland, White Mountain, Green Mountain, and Taconic sections. Geology ...

of the

Appalachian Highlands The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. They ...

. The prong consists of

mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually highe ...

s made up of crystalline

metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...

Location

The Reading Prong stretches from near Reading, Pennsylvania, through the

Lehigh Valley The Lehigh Valley (), known colloquially as The Valley, is a geographic region formed by the Lehigh River in Lehigh County and Northampton County in eastern Pennsylvania. It is a component valley of the Great Appalachian Valley bound to the no ...

in eastern

Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

northern

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

and into southern New York. It reaches its northern terminus in

Connecticut Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its capita ...

. In Pennsylvania, the Reading Prong is referred to as South Mountain while in New Jersey and New York the mountains of the subprovince are referred to as the New York – New Jersey Highlands. Near the

Hudson Valley The Hudson Valley (also known as the Hudson River Valley) comprises the valley of the Hudson River and its adjacent communities in the U.S. state of New York. The region stretches from the Capital District including Albany and Troy south to ...

, the term

Hudson Highlands The Hudson Highlands are mountains on both sides of the Hudson River in New York state lying primarily in Putnam County on its east bank and Orange County on its west. They continue somewhat to the south in Westchester County and Rockland Count ...

is often used. The portion of the prong that enters Connecticut is known as the Housatonic Highlands.

Relation to other divisions of the New England Uplands

There are two subsections of the New England Uplands in addition to the Reading Prong. A prong of the same rock belt extends from the Hudson Highlands south to

New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the Un ...

along the

Hudson River The Hudson River is a river that flows from north to south primarily through eastern New York. It originates in the Adirondack Mountains of Upstate New York and flows southward through the Hudson Valley to the New York Harbor between N ...

. This region is often referred to as the

Manhattan Prong The Manhattan Prong of the New England Uplands is a smaller belt of ancient rock in southern New York (including Manhattan, the Bronx, and segments of Brooklyn and Staten Island), parts of Westchester County, and upland portions of southwestern Co ...

. The Staten Island Serpentinite is also a southward extension of the New England Uplands.

Geology

The Reading Prong is part of the Precambrian basement which is discontinuously exposed in the north-central Appalachians. The rocks that make up the prong consist of diverse

gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures a ...

es. The New England Province and the Blue Ridge province share many geological similarities, and some experts consider the Reading Prong merely a continuation of the

Blue Ridge Mountains The Blue Ridge Mountains are a Physiographic regions of the world, physiographic province of the larger Appalachian Mountains range. The mountain range is located in the Eastern United States, and extends 550 miles southwest from southern Pennsy ...

, which reach their northern terminus at South Mountain near Harrisburg, Pennsylvania. In the gap between the Blue Ridge and the Reading Province, the two mountainous regions descend into the Appalachian

Piedmont it, Piemontese , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , demographics1_title2 ...

. Together, the Blue Ridge province and the New England province are often referred to as the Crystalline Appalachians. Rocks of the Reading Prong are characterized by elevated concentrations of

uranium Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...

, the decay of which produces gaseous

radon Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colourless, odourless, tasteless noble gas. It occurs naturally in minute quantities as an intermediate step in the normal radioactive decay chains through ...

, a potentially hazardous source of indoor contamination in structures constructed on the prong.Critical Geologic Features-Allamuchy Township
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Mountains of the Reading Prong

Housatonic Highlands (north to south)

East Hudson Highlands (north to south)

* Sour Mountain * Beacon Mountain *

Scofield Ridge Scofield may refer to: People * Barbara Scofield (born 1926), American tennis player * Bryant T. Scofield (1823–1881), American lawyer and politician * C. I. Scofield (1843–1921), American theologian and author of the Scofield Reference Bibl ...

* North Sugarloaf *

Breakneck Ridge Breakneck Ridge is a mountain along the Hudson River between Beacon and Cold Spring, New York, straddling the boundary between Dutchess and Putnam counties. Its distinctive rocky cliffs are visible for a long distance when approached from the ...

* Bull Hill, aka Mt. Taurus * South Redoubt and North Redoubt * Sugarloaf Hill * White Rock * Canada Hill * Anthony's Nose

West Hudson Highlands (north to south)

* Storm King Mountain *

Crow's Nest A crow's nest is a structure in the upper part of the main mast of a ship or a structure that is used as a lookout point. On ships, this position ensured the widest field of view for lookouts to spot approaching hazards, other ships, or land b ...

* Popolopen Torne * Bear Mountain * West Mountain * Bald Mountain *

Dunderberg Mountain Dunderberg Mountain is a mountain on the west bank of the Hudson River at the southern end of the Hudson Highlands. It lies just above Jones Point, New York, within Bear Mountain State Park and the town of Stony Point in Rockland County, New Yo ...

New Jersey Highlands (north to south)

* Pochuck Mountain * Maple Hill * Wawayanda Mountain * Sterling Hill * Hamburg Mountain * Sparta Mountain *

Lookout Mountain Lookout Mountain is a mountain ridge located at the northwest corner of the U.S. state of Georgia, the northeast corner of Alabama, and along the southeastern Tennessee state line in Chattanooga. Lookout Mountain was the scene of the 18th-cen ...

* Allamuchy Mountain * Hackettstown Mountain * Danville Mountain * Watnong Mountain * High Rock Mountain * Jenny Jump Mountain * Mount Mohepinoke *

Baldpate Mountain Baldpate Mountain is a peak in the New York–New Jersey Highlands of the Reading Prong of Upper Pohatcong Mountain in Warren County, New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United State ...

* County House Mountain * Mount No More * Scotts Mountain * Oxford Mountain * Marble Mountain * Upper Pohatcong Mountain * Pohatcong Mountain * Silver Hill * Musconetcong Mountain

Reading Prong of Pennsylvania (north to south)

* Chestnut Hill * Morgan Hill * Hexenkopf Hill * Christines Hill * Pektor Hill * Focht Hill * Kirchberg * Swoveberg * Kohlberg * Lehigh Mountain * Saucon Hill * Applebutter Hill * South Mountain

References

{{Mountains of Pennsylvania Geology of Pennsylvania Appalachian Mountains Geology of New Jersey Geology of New York (state)