Re-Discussion on the Granulometric Characteristics of Sediments and Sedimentary Environment at Altitude of 3200m in Mountain than Day of Linzhi in Southern Tibet

The stratum at altitude of 3278m in Mountain Than Day of Linzhi in Southern Tibet was considered to be lacustrine deposit, but this paper holds that it was aeolian deposit. Good outcrops could be seen and layers was thick. The section was observed in field investigation. In laboratory, the laser granularity instrument was used to do grain size analysis to samples. This paper analysed the grain size parameter of samples, and compared all kinds of size curves, established and extracted substitutive indexes for recording environment of monsoon climate. Meanwhile, grain size fractions that were most sensitive to monsoon change were also extracted through method of grade-standard deviation. Results showed that the eastern Tibetan had positive response to the fluctuation of ancient monsoon. Finally, the Aeolian deposit environment was further demonstrated by means of Sahu environmental discriminant formula.