Geology of Uzbekistan

The geology of Uzbekistan consists of two microcontinents and the remnants of oceanic crust, which fused together into a tectonically complex but resource rich land mass during the Paleozoic, before becoming draped in thick, primarily marine sedimentary units.

The upper unit is a 1.5 kilometres (4,900 ft) thick cooled lava and tuff overlain by sandstone, conglomerate and Carboniferous plant remnants.

The Karakum-Tajik microcontinent's other two zones cold high-temperature, but low-pressure metamorphic ophiolite complexes, overlain by Ordovician and Silurian flysch, tuff, andesite lava and shallow-water sandstone.

Rocks left over from the Turkestan Ocean crust form allochthon units on the northern edge of the Karakum-Tajik microcontinent.

In the western part of the Turkestan structure, in the Kyzylkum Desert, andesite lava flows and tuff overlie Ordovician-Silurian carbonate and pelite.

Nappe formations, such as the Kulkuduk Unit are composed of basal serptinized dunite and lherzolite, with overlying harzburgite and layered gabbro.

The base of the Tamdy Unit is metabasic and metasedimentary rocks ranging from a few hundred meters to a few kilometers thick and reaching blueschist grade on the sequence of metamorphic facies.

Particularly in the Fergana Basin and the Kughitang and Zaravshansky ridges or the Gasly-Bukhara Depression, Jurassic coal and fine grained sedimentary rocks are more common, with thicknesses of 150 to 300 meters.

Cretaceous rocks are most common in the Kyzylkum Desert, Gissar-Kughitang, Bukhara-Kiva Depression, Fergana Valley and around Tashkent, with carbonates, sandstones and red shales up to 900 metres (3,000 ft) thick.

During the last 2.5 million years in the Quaternary, sedimentary rocks deposited in river valleys, and repeating layers with conglomerate at the base ascending to sandstone and shale indicate four different phases of uplift.