Asian Potash Occurrences in Central Asia

Two significant potash-bearing basins occur within Central Asia. The Pricaspian Basin refers to an approximately 600 km wide (east-west) structure at the northern end of the Caspian Sea. This structure is filled with up to 4.5 km thick Permian (Kungurian and Roadian (Kazanian)) evaporite rocks and covered mainly by clastic sediments. Due to the large thickness of overlying sediments, diapirism of the salt rocks started with an initial movement phase between the late Permian and the Triassic and a later movement phase in the period between the Juraissic to the Neogene. Several hundreds of salt structure, that bring the potash salt close to the surface are known within the basin.

The Central Asian Salt Basin is a Jurassic to Early Cretaceous evaporite basin that spans across Uzbekistan, Turkmenistan, Tajikistan and Afghanistan. Occurrences of potash salts are largely confined to the Late Jurassic Gaurdak Formation, though evaporites of Paleogene age are also known. The deposition of the salt deposit is connected to the development of the Neotethys. Maximum thickness of the Gaurdak Formation is about 1,200 m with the evaporites being thickest in the vicinity of the Gissar Range. Clastic and carbonatic sedimentary rocks make up the hanging wall of the formation. The basin was divided by uplift of the Gissar range in Miocene times into the Amu Darya Basin towards the west and the Afghan-Tajik Basin to the east. Salt rocks are present at or close to the surface around the Gissar range.