WebA craton is an ancient part of the Earth's continental crust which has been more or less stable since Precambrian times. Cratons whose ancient rocks are widely exposed at the surface, often with relatively subdued relief, are known as shields.If the ancient rocks are largely overlain by a cover of younger rocks then the 'hidden' craton may be referred to …

WebThe African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south.It is bounded by the North American Plate and South American Plate to the west (separated by the Mid-Atlantic Ridge); the Arabian Plate and Somali Plate to the east; the Eurasian …

WebThe East African Rift (EAR) or East African Rift System (EARS) is an active continental rift zone in East Africa.The EAR began developing around the onset of the Miocene, 22–25 million years ago. In the past it was considered to be part of a larger Great Rift Valley that extended north to Asia Minor.. A narrow zone, the rift is a developing divergent tectonic …

WebThe area's geology spans a geological time period of over 3.8 billion years, therefore featuring some of the oldest rocks on earth. There are three main cratonic shields of recognised Archaean age within the Australian landmass: The Yilgarn, the Pilbara and the Gawler cratons. Several other Archaean-Proterozoic orogenic belts exist, usually …

WebThis is a list of tectonic plates on Earth's surface. Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere.The plates are around 100 km (62 mi) thick and consist of two principal types of material: oceanic crust (also called sima from silicon and magnesium) and continental crust (sial from silicon and aluminium).

WebA craton (/ ˈ k r eɪ t ɒ n /, / ˈ k r æ t ɒ n /, or / ˈ k r eɪ t ən /; from Greek: κράτος kratos "strength") is an old and stable part of the continental lithosphere, which consists of Earth's two topmost layers, the crust and the uppermost mantle.Having often survived cycles of merging and rifting of continents, cratons are generally found in the interiors of tectonic …

WebDiamond is a solid form of pure carbon with its atoms arranged in a crystal. Solid carbon comes in different forms known as allotropes depending on the type of chemical bond. The two most common allotropes of pure carbon are diamond and graphite.In graphite the bonds are sp 2 orbital hybrids and the atoms form in planes, with each bound to three …

WebA shield is a large area of exposed Precambrian crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas. These rocks are older than 570 million years and sometimes date back to around 2 to 3.5 billion years. [citation needed] They have been little affected by tectonic events following the end of the Precambrian, …

WebThe cause of Alpine orogeny. The Alpine orogeny is caused by the continents Africa and India and the small Cimmerian Plate colliding (from the south) with Eurasia in the north. Convergent movements between the tectonic plates (the African Plate and the Indian Plate from the south, the Eurasian Plate from the north, and many smaller plates and …

WebUr is a hypothetical supercontinent that formed in the Archean (3.1 billion).. In a reconstruction by Rodgers, Ur is half a billion years older than Arctica and, in the early period of its existence, it was probably the only continent on Earth, and as such can be considered a supercontinent, though it was probably smaller than present-day …