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A view looking west over the Fish River Canyon in southern Namibia across the large meander known as 'Hell's Bend'. The canyon is over 550 m deep and is the second largest river canyon in the world (after the Grand Canyon in the USA). The Fish river, a major tributary to the Orange river which drains most of southern Africa, has incised into the metamorphic basement rocks of the 1.1-1.2 Ga Namaqua Metamorphic Complex. The crystalline basement is unconformably overlain by the unmetamorphosed late Precambrian clastic and carbonate sedimentary rocks of the lower Nama Sequence (c. 650 Ma). The unconformity is clearly marked by the break-in-slope of the valley sides where the horizontal sedimentary strata form near vertical cliffs in places. Apatite fission track ages of the basement rocks in the river bed yield AFT ages of c. 70 Ma.
Thanks to Professor Rod Brown, University of Glasgow for the image and Cath Lewis for digital edit.
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