Investigations on boron isotopic geochemistry of salt lakes in Qaidam basin, Qinghai

Abstract

The isotopic compositions of boron in salt lakes located in Qaidam Basin, Qinghai, have been determined using the procedure of thermal ionization mass spectrometry of cesium borate with graphite loading. The salt lakes were controlled by evaporation of brine and are related to boron origin, the corrosion of salt and to certain chemical constituents. The distribution of boron isotopes in Quidam Basin showed a regional feature: salt lake brines in the west and northwest basin have the highest d11B values with an average of 22.2 ppt and those in the central basin have the lowest d11B values with an average of 3.4ppt. The overall average of d11B values gave a value of 9.6 ppt, which indicated a non-marine origin of the salt lakes of Qaidam Basin