沙漠における天然水の水質形成機構について-内蒙古自治区毛烏素沙漠を例として-

Abstract

27 water and 5 soil samples were collected to investigate a mechanism of water quality formation of natural waters in the Mu Us Shamo desert, Inner Mongolian Autonomous Region. The chemical and isotopic compositions in water samples were analyzed.Quartz, feldspar, muscovite, chlorite, slate, chert, calcite and magnetite in soil samples were identifled by means of both the polarization microscope and X-ray diffraction data. And also the chemical composition in the mineral was studied using X-ray microanalyser.The results obtained were examined from a geochemical view point. The minerals reacted with C02-contained water in this area. Chemical constituents such as Ca2+, Mg2+, Na+ and K+ were dissolved from the minerals to natural waters, and the Na-HCO3･Cl water type of final evolution in this area was formed through ion exchange, precipitation and evaporation processes.