Mineral and isotopic data of ooids collected form western Qaidam Basin, Tibetan Plateau
This database includes the mineral analysis and the isotopic analysis of the three ooid samples. By measuring the Th and U isotopes, we also get the ages of the carbonate samples. The XRD, EMPA and Raman spectrum indicating a dolomitic ooid layer formed at 293 ± 4 kyr and cemented by gypsum at 266 ± 3 kyr, an aragonitic ooid layer formed at 163 ± 1 kyr and cemented by halite at 111 ± 0.8 kyr, and another aragonitic ooid layer formed at 38 ± 0.5 kyr and cemented by gypsum at 23 ± 0.3 kyr. The stable carbon and oxygen isotopes indicate an inorganic evaporation environment during the forming stages of the ooids. The Raman spectrum of the extraction from the three ooid samples show the appearance of a cyanobacterial sunscreen pigment, scytonemin.