 
 <translate> A rift valley is a linear-shaped lowland between several highlands or mountain ranges created by the action of a geologic rift or fault. A rift valley is formed on a divergent plate boundary, a crustal extension, a spreading apart of the surface, which is subsequently further deepened by the forces of erosion. When the tensional forces were strong enough to cause the plate to split apart, a center block dropped between the two blocks at its flanks, forming a graben. The drop of the center creates the nearly parallel steeply dipping walls of a rift valley when it is new. That feature is the beginning of the rift valley, but as the process continues, the valley widens, until it becomes a large basin that fills with sediment from the rift walls and the surrounding area. One of the best known examples of this process is the East African Rift. On Earth, rifts can occur at all elevations, from the sea floor to plateaus and mountain ranges in continental crust or in oceanic crust. They are often associated with a number of adjoining subsidiary or co-extensive valleys, which are typically considered part of the principal rift valley geologically.

A rift valley is evidence of which kind of plate boundary? Let's have some stream of consciousness first. <ibo> Ndagwurugwu bụ ala dị larịị nke dị n'etiti ọtụtụ ugwu ma ọ bụ ugwu dị iche iche nke e kere site n'omume nke ọdịiche ma ọ bụ mmejọ. A na-etolite ndagwurugwu na-agbagọ agbagọ n'ókè nke efere dị iche iche, mgbatị nke akpụkpọ ahụ, ịgbasa n'akụkụ nke elu, nke na-eme ka ọ dịkwuo omimi site n'ike nke erosion. Mgbe ike ndị ahụ na-eme ka ihe ahụ na-esi n'elu elu na-agbatị n'ala mere ka ọ kewaa abụọ, otu ihe ahụ dị n'etiti nkume ahụ dara n'agbata ihe abụọ ahụ dị n'akụkụ ya abụọ, nke mere ka ọ bụrụ otu ihe ahụ a na-akpọ graben. Ọdịda nke etiti ahụ na-eme ka mgbidi nke ndagwurugwu na-agbada agbadata nke na-adịkarị n'akụkụ ibe ya mgbe ọ ka dị ọhụrụ. Ọ bụ n'ebe ahụ ka ndagwurugwu ahụ si malite, ma ka ọ na-aga n'ihu, ndagwurugwu ahụ na-agbasawanye, ruo mgbe ọ ghọrọ nnukwu ọdọ mmiri nke ájá si ná mgbidi ya na gburugburu ya jupụtara. Otu n'ime ihe atụ ndị a kasị mara amara nke usoro a bụ Ọwara Oké Osimiri nke Ebe Ọwụwa Anyanwụ Africa. N'ụwa, e nwere ike inwe mgbawa n'ebe ọ bụla dị elu, malite n'ala oké osimiri ruo n'elu ugwu nakwa n'ugwu ndị dị n'ime ala ma ọ bụ n'oké osimiri. A na-ejikọtakarị ha na ọtụtụ ndagwurugwu ndị ọzọ dị n'akụkụ ha, nke a na-ahụkarị dị ka akụkụ nke ndagwurugwu mgbawa bụ isi.  Ndagwurugwu dịgasị iche iche hà bụ ihe àmà nke ụdị ókè efere dịgasị iche iche? Ka anyị buru ụzọ mee ka uche anyị dịrị n'ihe. 