1�� Department of Earth Sciences /Key Laboratory of Guangdong Geological Processes and Mineral Resources Exploration�� Zhongshan University��Guangzhou 510275��China; 2�� Department of Resources and Environmental Engineering��Guilin University of Technology��Guilin 541000��Guangxi��China

There are large scale chert formations of different ages exposed widely in southern Tibet��along Yarlung-Zangbo suture zone�� The typical chert specimens were sampled from Pengcuolin��Xialu and Zongzhuo profiles�� Multivariate statistical analysis is applied for effectively extracting the geochemical information of the chert��and the raw data are processed by R-factor analysis�� The first��second and third factors representing terrigenous�� authigenic and hydrothermal constituents are extracted from the analysis results�� From Pengcuolin�� Xialu to Zongzhuo chert profiles��the variance ratios of continental and authigenetic factors become higher ( 51. 1%→62. 9%→91. 6%) ��while hydrothermal factor rapidly decrease( 40. 9%→32. 2%→0) �� This tendency also present in the analysis for trace elements��indicating that Pengcuolin chert is hydrothermal origin��The Zongzhuo chert belong to normal sedimentation and the Xialu chert exhibit normal deposition interacted with hydrothermal sedimentation�� The facts provide significant implications for understanding the diagenetic and palaeomineralization information of southern Tibet��