The Skunnemunk Conglomerate (also spelled Schunemunk) is a mapped bedrock unit in
New Jersey
New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...
and
New York
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* New York (state), a state in the northeastern United States
* New York City, the most populous city in the United States, located in the state of New York
New York may also refer to:
Places United Kingdom
* ...
from the
Middle Devonian
In the geological timescale, the Middle Devonian epoch (from 393.3 ± 1.2 million years ago to 382.7 ± 1.6 million years ago) occurred during the Devonian period, after the end of the Emsian age.
The Middle Devonian epoch is subdivided into two ...
period
Period may refer to:
Common uses
* Period (punctuation)
* Era, a length or span of time
*Menstruation, commonly referred to as a "period"
Arts, entertainment, and media
* Period (music), a concept in musical composition
* Periodic sentence (o ...
.
It forms the resistant ridge of
Schunemunk Mountain in New York and
Bearfort Mountain in New Jersey.
Description
The Skunnemunk is a Middle
Devonian
The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...
, grayish-purple to grayish-red, thin to very thick-bedded, locally
cross–bedded,
conglomerate and
sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
containing clasts of white vein
quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...
, red and green
quartzite
Quartzite is a hard, non- foliated metamorphic rock that was originally pure quartz sandstone.Essentials of Geology, 3rd Edition, Stephen Marshak, p 182 Sandstone is converted into quartzite through heating and pressure usually related to tecton ...
and sandstone, red and gray
chert
Chert () is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO2). Chert is characteristically of biological origin, but may also occur inorganically as a prec ...
, and red
shale
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...
.
[ It is a classic Puddingstone. Pieces of the conglomerate are easy to recognize and have been found in glacial deposits throughout the lower ]Hudson Valley
The Hudson Valley or Hudson River Valley comprises the valley of the Hudson River and its adjacent communities in the U.S. state of New York (state), New York. The region stretches from the Capital District (New York), Capital District includi ...
region.[
]
References
{{NewYork-geologic-formation-stub
Conglomerate formations of the United States
Geologic formations of New Jersey
Geologic formations of New York (state)
Sandstone formations of the United States