ELEMENT GEOCHEMISTRY OF LAKE DEPOSITS MEASURED BY X-RAY FLUORESCENCECORE SCANNER IN NORTHWEST CHINA

Element contents aere measured with high resolution X-ray Fluorescence (XRF) core scanner for the sediments taken from some typical mountain lakes, plateau lakes and oasis lakes in Northwest China. The elements with high and stable XRF intensities are analyzed with multivariate statistic methods, including cluster analysis, factor analysis and correlation analysis. The results of the analysis indicate that the composition of elements in lake sediments is highly related to the regional environment and types of lakes. Exogenous detrital elements brought into lakes by water, such as Al, Si, K, Ti and Rb, are the dominant elements in lake sediments, and the intensities and types of those elements depend upon bedrocks, weathering condition, vegetation coverage and watershed erosion, which are related with the precipitation in drainage basins. The intensities of elements Ca, Sr are related to lake level, water chemistry and lake types, Therefore, they could indicate the hydrological dynamics of lakes.