The temporal association with this Ordovician tectonism suggests that this magmatic activity may be related to fracturing of mantle rock at the junction of two Taconic age tectonic salients that intersect in the New York region.
22.
In the Northern Kaapvaal Craton ( Renosterkoppies Greenstone Belt, Pietersburg area ) tectonism took place under amphibolite facies conditions at ca . 2.75 Ga and can therefore not be related to any events in the Limpopo belt.
23.
The existence of basaltic eruptions in the interior of tectonic plates, however, are not directly related to plate tectonism and models involving magma upwelling from deep mantle sources, such as mantle plumes and hotspots have been developed to explain them.
24.
Locally, however, strata of the same age have been affected by a late pulse of tectonism, during which they were faulted, contorted into tight symmetrical folds, or overridden by pre-Tertiary basement rocks along southwesterly dipping thrust faults.
25.
Researchers from NASA's Ames Research Center in 2017 confirmed that icy plate tectonism occurred in the past, giving rise to many of its more prominent geological features, observing evidence of subduction of tectonic plates while also noting the absence of orogeny resulting from the freezing of the mantle.
26.
For example, large-scale studies have been conducted for Stable Continental Regions ( SCR's ), which are defined " as regions of continental crust that have not experienced any major tectonism, magmatism, basement metamorphism or anorogenic intrusion since the early Cretaceous, and no rifting or major extension or transtension since the Paleogene ."
27.
The origin of modern circulation of cold, deep water & mdash; known as the " Big Flush " & mdash; is associated with Early Eocene ( ) geological events; tectonism that resulted in the opening of the north-east Atlantic and fracture zones that developed in the subsiding Rio Grande Rise, which allowed cold water from the Antarctic Weddell Sea to flow northward into the North Atlantic ., the generation of cold bottom water in the Antarctic resulted in the formation of thermospheric circulation to a meridional thermohaline circulation.
