Regularities of trace element distribution in water-salt systems as indicators of the genesis of potassium salt rocks: An example from the Upper Jurassic halogen formation of Central Asia

Main aspects of the theory and methods of measurement of trace element distribution coefficients in water-salt systems are discussed. Data on the interphase distribution of Br, Rb, Cs, and Tl in chloride systems were used to evaluate the abundances and distribution of these elements in the potassium salt rocks of the Gaurdak Formation of the Upper Jurassic halogen formation in southern Central Asia. It was concluded that these rocks were strongly metamorphosed after sedimentation, and some considerations were presented on the character, scales, and reasons of these processes. It is emphasized that the traditional factors used to decipher the genesis of salt minerals, rocks, and deposits should be supplemented by the determination of the contents of trace element that are incorporated into the crystal lattice of salts via isomorphic substitution.