Search results
Results from the WOW.Com Content Network
Accommodation zones may be located where older crustal structures intersect the rift axis. In the Gulf of Suez rift, the Zaafarana accommodation zone is located where a shear zone in the Arabian-Nubian Shield meets the rift. [6] Rift flanks or shoulders are elevated areas around rifts. Rift shoulders are typically about 70 km wide. [7]
Rift valley – Linear lowland created by a tectonic rift or fault; Rôche moutonnée – Rock formation created by the passing of a glacier; Sandur – Plain formed from glacier sediment transported by meltwater; Side valley – Valley with a tributary to a larger river
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 East African Rift system plays a key role in Tanzania's current day structural geology. Graben rift valleys often have volcanism associated with them. The Western Rift is filled with Lake Tanganyika and Lake Nyasa, while the section from Lake Natron to Lake Nyasa is part of the Eastern Rift (also known as the Gregory Rift).
Intracontinental and marine rift basins such as the Gulf of Suez, East African Rift, Rio Grande rift system and the North Sea often contain a series of half-graben sub-basins, with the polarity of the dominant fault system changing along the axis of the rift. Often the extensional fault systems are segmented in these rifts.
Rift phase lavas cover most of the island, not only forming the ridges along each rift zone but also partially infilling the landslide bays. The rift zones extend outwards as submarine volcanic ridges on the ocean floor; for example, the south-south-east rift zone extends underwater to at least 40 km (25 mi) south of the island. [223]
The rift zone known as the mid-Atlantic ridge continued to provide the raw volcanic materials for the expanding ocean basin. [20] North America was slowly pulled westward away from the rift zone. The thick continental crust that made up the new east coast collapsed into a series of down-dropped fault blocks that roughly parallel today's coastline.
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 ...