5095 x 3604 px | 43,1 x 30,5 cm | 17 x 12 inches | 300dpi
Data acquisizione:
23 giugno 2017
Ubicazione:
Uluru-Kata Tjuta National Park, Petermann, Northern Territory, Australia
Altre informazioni:
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The Park covers extensive sand plains, sand dunes and alluvial desert, surrounding the vast rounded red inselbergs of Uluru and Kata Tjuta. The gently sloping plains of red earth sands, sandy loams and red earths are separated from dunes of red siliceous sand by a zone of mainly very coarse siliceous sand. The dunes are stable, up to 30m high, with mobile crests, vegetated flanks and swales rilled and gullied by water. With the sand plains they occupy the bulk of the Park. The Park is situated on the southern margin of the Amadeus sedimentary basin. The massive rocks are derived from thick Palaeozoic marine sediments: sands in Uluru, conglomerate in Kata Tjuta, which were tilted, Uluru vertically and Kata Tjuta slightly, during a period of past folding and fracturing. Both are only the tips of vast blocks of rock extending 6, 000m deep. Uluru is composed of steeply dipping, feldspar-rich arkosic sandstone ribbed by differential erosion of the vertically tipped strata. It has a base circumference of 9.4km, smooth sloping sides with a gradient of up to 80° and a relatively flat top. The surface of the rock shows sheet erosion of exfoliating layers 1-3m thick, deep parallel fissures and, at its base, a number of caves, inlets and overhangs eroded by sand and chemical decomposition. The arkose is grey but colored red by oxidation of iron in the rock. Kata Tjuta, 32km west, comprises 36 steep-sided rock domes covering about 3, 500ha. They consist of gently dipping Mount Currie conglomerate with phenocrysts of fine-grained acid and basic rocks, granite and gneiss in an epidote-rich matrix. Kata Tjuta has hemispherical summits, near vertical sides and steep-sided intervening valleys. Lithosols, gravelly red earths, red earthy sands and calcareous red earth soils are derived from weathered Mount Currie conglomerate, and found as isolated pockets on scree slopes and alluvial fans. Surface water is only found in seasonal pools fed by short shallow watercourses
