[Application of X-Ray Fluorescence Spectrometry in Xujiahe Formation of Sichuan Basin for the Study of Sedimentary Facies].

Currently, X-ray fluorescence spectrometer (XRF) is not widely used in the determination of geological samples, and it's much less used in the study of sedimentary facies. XRF was firstly used to identify sedimentary environment of the T3x2 formation in central Sichuan region. In order to investigate the controversy of sedimentary facies and sedimentary environment of T3x2 formation of the Upper Triassic in the Central Part of Sichuan Basin, particularly whether the T3x2 formation is continental deposit or marine deposit, samples were collected in four representative zones from Xujiahe formation in Sichuan Basin. The method of X-ray fluorescence spectrometry were used to analyze the element contents and its' changing characteristics of the deposition from target formation. The sedimentary facies and sedimentary environment of target formation could be quantificationally analyzed by the symbol of corresponding element content. The results of the study show that the ratio of Sr/Ba, Mn/Fe and Sr/Ca of T3x2 formation belong to continental deposits, and it has no significant difference with characteristics of element contents from T3x3 or T3x4. The analysis results about the ratio of Sr/Cu show that the climatic environment of target formation was warm and humid, and T3x2 formation was belong to continental deposits in warm and humid environment, which is similar to the sedimentary environment of T3x3 or T3x4 formation. The relative errors between this method and conventional chemical analysis are less than 3%. The method of X ray fluorescence spectrometry is simple and feasible, which provides a quantitative analysis method for identification of sedimentary facies and sedimentary environment. The paper provides a new feasible method to solve the controversial sedimentary facies, which will promote the using of X-ray fluorescence spectrometric analysis method in geology.