Geoenvironmental assessment wsing geocemical map

点击翻译按钮获取中文摘要

Stream sediments from the northern parts of Aichi Prefecture through the southern parts of Gifu Prefecture were examined for geoenvironmental assessment of the area. New 1100 samples were analyzed for seventeen elements includingAl, Ca, Ce, Co, Cr, Cu, Fe, K, Mn, Mg, Na, Ni, P. Sr, Ti, V and Zn. ICP-AES andAAwere employed for analyzes. The representativeness of the analyzed data for the sampling locality is examined by means of duplicate or triplicate samplings from the same place and by repeated analyzes. The data show ±50% variations in the abundance of Ti and ±30% or less variations for other elements. This variation may have been caused by heterogeneous distribution of small accessory minerals bearing Ti. The elemental abundances vary more than ten times in the examined area. Then the geochemical map obtained here is . Significant to indicate the areal variations of elements. The stream sediments from the area where granitic rockare exposed are rich inAl, Ca, Na, K, and Sr. On the contrary, Co, Cr, Fe, Ni, V, Mn and Zn are enriched in the sediments from the area where the Tertiary sediments are dominant Correlation coefficients higher than 0.6 are found between abundances of Ca-Na-Sr-Al, P-Cu-Zn and Ti-Ce. The coefficients are remarkably higher for the samples from the area of the Tertiary sediments than for the samples from granitic region. Although one sample shows a high Cr-abundance (785ppm), which is 20 times the abundance of the average value for the Tertiary sediments, no clear evidence for artificial pollution of any elements examined here is found. Twenty additional elements including As and Sb are analyzed by INAA and XRF. The results will be published in a shorttime.