昆陽地域 河床堆積物에 對한 地球化學的 特性

Abstract

It is necessary to make the geochemical map for working out a countermeasure about change of the earth environment and understanding about a serious problem of environment. The purpose of this study is to get geochemical natural background in Konyang area so we can estimate the environment contamination and understand geochemical disaster. Stream sediments is not only the transfer media of the contaminated materials but the function as latent contamination, and is reservoir for heavy metallic element as a heterogeneous complex of several different particles. Also stream sediments is well reflected the natural environment, So we use stream sediments in this study. In the study, we are collected 183 samples in 1:50,000 Konyang area map in consideration of the connection of the geochemical environment and contamination and separated four groups as Anorthosite area, Gneiss area, Sedimentary rock area and Quartz porphyry area according to geology We collected the stream sediments samples by wet sieving along the primary channels from November to December in 1999 and dried these samples slowly in the laboratory and rubbed in to under 200mesh using the alumina mortar for chemical analysis. Major elements, trace and rare earth elements were determined by XRF, ICP-AES, NAA analysis methods. Contents of major element for stream sediments in the Konyang area range are SiO2 41.86～76.74wt.%, Al2O3 9.92～30.00wt.%, Fe2O3 2.74～12.68wt.%, CaO 0.22～3.31wt.%, MgO 0.34～3.97wt.%, K2O 0.75～5.93wt.%, Na2O 0.25～1.92wt.%, TiO2 0.40～3.00wt.%, MnO 0.03～0.21wt.%, P2O5 0.05～0.38wt.% Contents of trace and REE for stream sediments in the Konyang area range are Cu 7～102ppm, Pb 15～47ppm, Sr 48～513ppm, V 29～129ppm, Zr 31～217ppm, Li 14～94ppm, Co 5.6～32.1ppm, Cr 23～259ppm, Cs 1.7～8.7ppm, Hf 2.1～109.0ppm, Rb 34～247ppm, Sc 4.5～21.9ppm, Zn 24～609ppm, Sb 0.8～2.6ppm, Th 3～213ppm. Ce 22～1000ppm, Eu 0.7～5.3ppm, Yb 0.6～6.4ppm. Generally, Al2O3 and SiO2 have a good relationships with each elements in rocks but it had a bad relationships in stream sediments fo this study area. Fe2O3, CaO, MnO and P2O5 had a good relationships with major and minor element in stream sediments of this study area. Co and V had a good relationships with other toxic elements Only a few samples had a high content against specific element but it had not particular factor which influence element contents in this area. There, assay values which not contained abnormality value could used as a natural background in this study area.