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  2. Midcontinent Rift System - Wikipedia

    en.wikipedia.org/wiki/Midcontinent_Rift_System

    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 ...

  3. Rift zone - Wikipedia

    en.wikipedia.org/wiki/Rift_zone

    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 ...

  4. Rift - Wikipedia

    en.wikipedia.org/wiki/Rift

    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 ...

  5. New Madrid Seismic Zone - Wikipedia

    en.wikipedia.org/wiki/New_Madrid_Seismic_Zone

    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.

  6. Geology of Ohio - Wikipedia

    en.wikipedia.org/wiki/Geology_of_Ohio

    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 ...

  7. Divergent boundary - Wikipedia

    en.wikipedia.org/wiki/Divergent_boundary

    Divergent boundary. In plate tectonics, a divergent boundary or divergent plate boundary (also known as a constructive boundary or an extensional boundary) is a linear feature that exists between two tectonic plates that are moving away from each other. Divergent boundaries within continents initially produce rifts, which eventually become rift ...

  8. Newark Supergroup - Wikipedia

    en.wikipedia.org/wiki/Newark_Supergroup

    Newark, New Jersey. The Newark Supergroup, also known as the Newark Group, is an assemblage of Upper Triassic and Lower Jurassic sedimentary and volcanic rocks which outcrop intermittently along the east coast of North America. They were deposited in a series of Triassic basins, the Eastern North American rift basins, approximately 220–190 ...

  9. Half-graben - Wikipedia

    en.wikipedia.org/wiki/Half-graben

    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]