Playas and their mineral potentials in the Khorasan Province (especially for Li)
Nowadays, playas are important economic geomorphic features in the world that contain mineral resources such as sodium carbonate, sodium sulfate, potash, gypsum, halite, nitrates, borates, iodine, brome, lithium and such other rare elements. For example, about 400000 tons sodium sulfate is extracted from the playas of western Canada or silver peak in USA, is one the greatest source of lithium in the world.
Against the importance of these features, there is little information about the sedimentology, geochemistry and stratigraphy of these environments, especially in Iran. The northeastern branch of GSI started a project for exploration of saline waters of the Khorasan province. Sampling was done in several playas of province including Bajestan and Dehsalm, Chahuk, Dehno, Sahlabad, north of Qaen, Siyahbal, Chah-e Musuyeh, Khur, Chahabbas, Najlabad and Gisour. At whole 89 samples were sent laboratory for chemical analysis. Sampling was done based on the extent of playa. The depth of holes for sampling range between 30 Cm and 2 m.
Based on the result of sampling, the Sirvan playa may be a favorable zone for lithium minerals (53 ppm). The Bajestan playa has maximum potassium content (3100ppm) than other studied playas. Maximum measured magnesium was 85.7 gr/lit that achieved from a evaporative trough. Also the magnesium content of Sirvan, Torbat- Heudariey and North of Qaen playas is more than normal value.
These playas require more attention.