The Newark Basin is a

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand ...

-filled rift basin located mainly in 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 Delawa ...

but also stretching into south-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, ...

and southern

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

. It is part of the system of Eastern North America Rift Basins.

Geology

Approximately 220 million years ago, during the late

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest per ...

Period, the

supercontinent In geology, a supercontinent is the assembly of most or all of Earth's continental blocks or cratons to form a single large landmass. However, some geologists use a different definition, "a grouping of formerly dispersed continents", which leav ...

Pangaea Pangaea or Pangea () was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from the earlier continental units of Gondwana, Euramerica and Siberia during the Carboniferous approximately 335 million y ...

began to break apart. The focus of the rifting began somewhere between where present-day eastern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

and north-western

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

were joined. As in all rifting environments,

graben In geology, a graben () is a depressed block of the crust of a planet or moon, bordered by parallel normal faults. Etymology ''Graben'' is a loan word from German, meaning 'ditch' or 'trench'. The word was first used in the geologic conte ...

s formed. Many of these grabens were created, but for some of them, extension stopped before full rifting occurred. Where only partial rifting occurred,

basins Basin may refer to: Geography and geology * Depression (geology) ** Back-arc basin, a submarine feature associated with island arcs and subduction zones ** Debris basin, designed to prevent damage from debris flow ** Drainage basin (hydrology), a ...

formed, analogous to the present-day

Basin and Range Province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...

in western United States. By definition, a basin is any area that collects sediments. These "aborted rifts" (rifts that are tectonically inactive and no longer collecting sediments) extend from

North Carolina North Carolina () is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. The state is the List of U.S. states and territories by area, 28th largest and List of states and territories of the United ...

Newfoundland Newfoundland and Labrador (; french: Terre-Neuve-et-Labrador; frequently abbreviated as NL) is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region ...

. Along certain basins, rifting was not partial. Where full rifting occurred, the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

was created. It is important to note that along these rifts, magmatic activity never stopped, as shown by the ongoing eruption of lava along the

Mid-Atlantic Ridge The Mid-Atlantic Ridge is a mid-ocean ridge (a divergent or constructive plate boundary) located along the floor of the Atlantic Ocean, and part of the longest mountain range in the world. In the North Atlantic, the ridge separates the North A ...

. The Newark Basin is one in a series of these failed rifts. It is a half-graben filled over time by characteristic

red bed Red beds (or redbeds) are sedimentary rocks, typically consisting of sandstone, siltstone, and shale, that are predominantly red in color due to the presence of ferric oxides. Frequently, these red-colored sedimentary strata locally contain t ...

sediments, sediments eroded from the uplifted footwalls of the border faults that were deposited within the basin; they are red due to their abundance in oxidized iron oxide minerals. The border fault is the Ramapo Fault on the western boundary of the basin; this is where the hanging wall of the graben slid down to its current position. Estimates to the depth of accumulated sediments on the western side of the basin, and therefore the depth of the hanging wall, are in the area of 11,000 feet. The beds dip roughly 15 degrees to the west throughout the basin. Though the north-eastern end of the basin is well-defined (it ends at 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 Ne ...

), the south-western "end" is not an end at all, but merely a narrowing where the graben then re-opens into the

Gettysburg Basin Gettysburg may refer to: Events * Gettysburg Campaign, a series of American Civil War military engagements in the Main Eastern Theater. ** Battle of Gettysburg, July 1–3 military engagements during the 1863 Gettysburg Campaign ** Retreat from G ...

. A significant geological feature within the Newark Basin is the Palisades Sill. During rifting events, magmatism is common due to

decompression melting Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma ...

. The Palisades Sill is a result of this process. Image:Break-up of Pangaea.JPG, A USGS cartoon showing the break-up of Pangaea and the origin of the Newark Basin Image:Newark Basin Cross Section.jpg, USGS cross-section of the Newark Basin

References

Sources
"The Newark Basin"
on the

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

website
"Mesozoic Basins"
on the USGS website {{Geology of the Newark Basin Geology of New Jersey Geology of Pennsylvania Geology of New York (state) Aulacogens Sedimentary basins of North America

Geology

See also

References