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Midcontinent Rift System. The Midcontinent Rift System (MRS) or Keweenawan Rift is a 2,000 km (1,200 mi) long geological rift in the center of the North American continent and south-central part of the North American Plate. It formed when the continent's core, the North American craton, began to split apart during the Mesoproterozoic era of the ...
The Point Pleasant Formation is the oldest rock unit exposed at the surface in Ohio and formed during the Late Ordovician, outcropping along the Ohio River near Cincinnati. The formation records a transition from shallow-water limestone reef formation to a deeper water environment, marked by overlying shale and limestone, which form the ...
Magnetic potential map of the Reelfoot Rift. The New Madrid Seismic Zone (NMSZ), sometimes called the New Madrid Fault Line, is a major seismic zone and a prolific source of intraplate earthquakes (earthquakes within a tectonic plate) in the Southern and Midwestern United States, stretching to the southwest from New Madrid, Missouri.
A rift zone is a feature of some volcanoes, especially shield volcanoes, in which a set of linear cracks (or rifts) develops in a volcanic edifice, typically forming into two or three well-defined regions along the flanks of the vent. [1] Believed to be primarily caused by internal and gravitational stresses generated by magma emplacement ...
Gulf of Suez Rift showing main extensional faults. In geology, a rift is a linear zone where the lithosphere is being pulled apart [1][2] and is an example of extensional tectonics. [3] Typical rift features are a central linear downfaulted depression, called a graben, or more commonly a half-graben with normal faulting and rift-flank uplifts ...
North American Plate. The North American Plate is a tectonic plate containing most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of 76 million km 2 (29 million sq mi), it is the Earth's second largest tectonic plate, behind the Pacific Plate (which borders the plate to the west).
Þingvallavatn. A rift valley is a linear shaped lowland between several highlands or mountain ranges produced by the action of a geologic rift. Rifts are formed as a result of the pulling apart of the lithosphere due to extensional tectonics. The linear depression may subsequently be further deepened by the forces of erosion.
Top: Full graben between two faults, each sloping towards center of rift. Bottom: half graben, more common. A rift is a region where the lithosphere extends as two parts of the Earth's crust pull apart. Often a rift will form in an area of the crust that is already weakened by earlier geological activity. [1]