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It is likely that the lava spreads by a process of inflation in which the lava moves beneath a solid insulating crust, which keeps it hot and mobile. [36] Studies of the Ginkgo flow of the Columbia River Plateau, which is 30 to 70 meters (98 to 230 ft) thick, show that the temperature of the lava dropped by just 20 °C (68 °F) over a distance ...
Trap is also used to refer to flood (plateau) basalts, such as the Deccan Traps and Siberian Traps. [2] The erosion of trap rock created by the stacking of successive lava flows often creates a distinct stairstep landscape from which the term trap was derived from the Swedish word trappa, which means "stairs". [1]
Diapirs in a subducting plate boundary. A diapir (/ ˈ d aɪ. ə p ɪər /; [1] [2] [3] from French diapir, from Ancient Greek διαπειραίνω (diapeiraínō) 'to pierce through') is a type of intrusion in which a more mobile and ductilely deformable material is forced into brittle overlying rocks.
Ore-genesis theories generally involve three components: source, transport or conduit, and trap. (This also applies to the petroleum industry: petroleum geologists originated this analysis.) Source is required because metal must come from somewhere, and be liberated by some process.
The Columbia River Basalt Group (including the Steen and Picture Gorge basalts) extends over portions of four states. The Columbia River Basalt Group (CRBG) is the youngest, smallest and one of the best-preserved continental flood basalt provinces on Earth, covering over 210,000 km 2 (81,000 sq mi) mainly eastern Oregon and Washington, western Idaho, and part of northern Nevada. [1]
Columnar jointing in Giant's Causeway in Northern Ireland Columnar jointing in the Alcantara Gorge, Sicily. Columnar jointing is a geological structure where sets of intersecting closely spaced fractures, referred to as joints, result in the formation of a regular array of polygonal prisms (basalt prisms), or columns.
The Deccan Traps region was reduced to its current size by erosion and plate tectonics; the present area of directly observable lava flows is around 500,000 km 2 (200,000 sq mi). The Deccan Traps are segmented into three stratigraphic units: the Upper, Middle, and Lower traps.
Convergent plate boundary volcanoes also have higher H 2 O/H 2, H 2 O/CO 2, CO 2 /He and N 2 /He ratios than hot spot or divergent plate boundary volcanoes. [ 4 ] Magmatic gases and high-temperature volcanic gases