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The granite outcrops of the Seychelles Islands in the central Indian Ocean were amongst the earliest examples cited by Alfred Wegener as evidence for his continental drift theory. [1] Ridge–plume interactions have been responsible for separating a thinned continental sliver from a large continent (i.e. India).
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 Precambrian , about 1.1 ...
The granitoid rocks are mainly potassic granite and were derived principally from reworked older (3.1–2.8 Ga) gneiss. [3] During the Paleoproterozoic, island-arc terrane associated with the Colorado orogeny accreted to the Wyoming Craton along the Cheyenne belt, a 500-km-wide belt of Proterozoic rocks named for Cheyenne, Wyoming.
Cratons of South America and Africa during the Triassic Period when the two continents were joined as part of the Pangea supercontinent. A craton (/ ˈ k r eɪ t ɒ n / KRAYT-on, / ˈ k r æ t ɒ n / KRAT-on, or / ˈ k r eɪ t ən / KRAY-tən; [1] [2] [3] from Ancient Greek: κράτος kratos "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two ...
They are found in several places within the Inner Gorge, such as at River Miles 81, 83, and 91, Salt Creek, Granite Park, and Diamond Creek. These ultramafic rocks occur typically as tectonic fault-bounded slivers, which are often associated with tectonic shear zones and exhibit coarse-grained relict cumulate textures .
The rift zone that contains the Gulf of Corinth in Greece; The Reelfoot Rift, an ancient buried failed rift underlying the New Madrid Seismic Zone in the Mississippi embayment; The Rhine Rift, in southwestern Germany, known as the Upper Rhine valley, part of the European Cenozoic Rift System; The Taupō Volcanic Zone in the North Island of New ...
Little is known about the history of the oldest exposed rocks in the area due to extensive metamorphism.This somber, gray, almost featureless crystalline complex is composed of originally sedimentary and igneous rocks with large quantities of quartz and feldspar mixed in. [1] The original rocks were transformed to contorted schist and gneiss, making their original parentage almost unrecognizable.
Gregory was the first well-known European to use the term "rift valley", which he defined as "a linear valley with parallel and almost vertical sides, which has fallen owing to a series of parallel faults". [7] In 1913 the German geologist Hans Reck made the first European study of the strata in the Olduvai Gorge to the west of the Crater ...