Ngorongoro Conservation Area
The Ngorongoro Conservation Area (NCA) covers a large, partly mountainous region in northern Tanzania. The diverse ecosystems include the Ngorongoro Highlands with several peaks of over 3,000 m. The most spectacular feature is the Ngorongoro Caldera, a self-contained sanctuary designated as one of the natural wonders of the world. This is one of the premier wildlife destinations in the world, with large concentrations of large mammals occurring on grassy savannahs and in small forests sustained by freshwater lakes and swamps. The caldera is part of the Ngorongoro Volcanic complex, a group of eight, Pliocene age (3.7–1.79 Ma) shield volcanoes associated with the East African Rift System (EARS). This extinct complex of volcanoes is restricted to a discrete structural block, the Eyasi Half-graben, a step-like feature demarcated from the Gregory Rift Valley on the eastern side by a near-vertical regional escarpment. The western boundary of the NCA is associated with smaller, step-like faults on the western edge of the Serengeti Plains. The Ngorongoro volcanism is dominated by alkaline basaltic and trachytic lavas and includes giant calderas resulting from the highly explosive activity which characterises the rift-related activity. The largest feature is the Ngorongoro Volcano (2.5–1.9 Ma) with its almost circular caldera measuring some 22 by 18 km. The caldera is constrained by steep internal walls up to 350 m high. Less well known, but as equally spectacular is the thickly forested Empakaai Caldera located in the northeastern part of the NCA. Other geological features include exposures of the Neoproterozoic Mozambique Belt in the Gol Mountains and the Shifting Sands near the palaeoanthropological site of Oldupai Gorge. The sand dunes are unusual, isolated features that consist of black volcanic ash derived from Holocene age eruptions of the Oldoinyo Lengai Volcano. The temperate climate of the Ngorongoro Highlands, particularly in comparison to the hot and arid rift valley, together with the nutrient-rich volcanic soils supports extensive farming on the perimeter of the NCA.
KeywordsCaldera Escarpment Ngorongoro Pliocene Sanctuary Shifting sands Volcanism
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