川西高原地区岩石中硒的地球化学特征和影响因素  

Geochemical Characteristics of Selenium in Rocks from the Western Sichuan Plateau

作　　者：杨妍萍 刘晓端[1] 刘久臣[1] 汤奇峰[1] 孟拓 朱晓华[1] YANG Yan-ping;LIU Xiao-duan;LIU Jiu-chen;TANG Qi-feng;MENG Tuo;ZHU Xiao-hua(Key Laboratory of Eco-Geochemistry,Ministry of Natural Resources,National Research Center for Geoanalysis,Beijing 100037,China;The Sceond Geological Brigade of Hebei Coal Geology Bureau,Xingtai 054001,China)

机构地区：[1]自然资源部生态地球化学重点实验室,国家地质实验测试中心,北京100037 [2]河北省煤田地质局第二地质队,河北邢台054001

出　　处：《岩矿测试》2020年第1期115-126,共12页Rock and Mineral Analysis

基　　金：中国地质科学院基本科研业务费项目(YYWF201617);中国地质调查局地质调查项目(DD20190655)

摘　　要：川西高原土壤、水体等多种介质研究表明,该地区的硒含量偏低,天然土壤剖面硒为0.06~0.16μg/g,表层土壤中硒含量为0.075~0.204μg/g,沉积物中硒含量为0.069~0.310μg/g,地表水中硒含量为nd^0.096μg/L,地下水中硒含量为nd^0.058μg/L,均低于我国相应环境介质中硒的平均含量,影响到当地人体健康。本文采集川西高原地区80件岩石样品,同时采集6套岩心样品,这些样品主要以板岩、砂岩、灰岩和页岩为主。采用原子荧光光谱法(AFS)测定硒含量,研究川西高原阿坝地区岩石与岩心样品中硒的地球化学特征和低硒的影响因素。结果表明:岩石硒含量范围为0.030~0.282μg/g,平均值0.09μg/g,低于硒土壤背景值。不同类型岩石中的硒含量大小为:页岩>灰岩>板岩>砂岩。岩石中硒含量在不同地区也表现出较大的差异:松潘>阿坝>壤塘>马尔康>九寨沟>若尔盖>红原,可能是受到岩石类型及有机质和地质环境的影响所致。岩心各剖面的硒含量最小值为0.02~0.07μg/g,最大值为0.21~0.34μg/g,平均值为0.06~0.17μg/g,各钻孔的硒含量明显低于硒的地壳丰度。本研究认为,硒的分布受地质环境、有机质、岩石致密性等条件限制,低硒的地质环境是导致岩石中的硒含量较低的最主要因素。BACKGROUND: Studies on soil, water and other media in the Western Sichuan Plateau show that the selenium content in this area is very low. The selenium concentrations of the natural soil profile, surface soil, sediment, surface water, and groundwater are 0.06-0.16μg/g, 0.075-0.204μg/g, 0.069-0.310μg/g, nd-0.096μg/L and nd-0.058μg/L, respectively, which are all lower than the average selenium content in the corresponding environmental media in China, affecting the health of local people.OBJECTIVES: To explore the geochemical characteristics of selenium in rocks in the study area and to find the influencing factors for low selenium in rocks.METHODS: Eighty rock samples were collected from the Western Sichuan Plateau, and six core samples were collected at the same time. These samples were mainly slate, sandstone, limestone and shale. Atomic fluorescence spectrometry(AFS) was used to determine the selenium content, and the geochemical characteristics of selenium in rocks and core samples in the Aba area of the Western Sichuan Plateau were studied.RESULTS: The selenium content of rocks ranged from 0.030 to 0.282μg/g, with an average value of 0.09μg/g, which was lower than the crustal abundance of selenium. The content of selenium in different types of rocks was: shale>limestone>slate>sandstone. The selenium content in the rock also showed large differences in different regions: Songpan>Aba>Land Pond>Maerkang>Jiuzhaigou>Ruoergai>Hongyuan, which may be caused by rock type, organic matter and geological environment. The minimum, maximum and average selenium content in each section of the core was 0.02-0.07μg/g, 0.21-0.34μg/g and 0.06-0.17μg/g, respectively. Moreover, the selenium content of each borehole was significantly lower than the crustal abundance of selenium.CONCLUSIONS: The distribution of selenium in rocks is significantly affected by organic matter, lithology and rock compactness. Low selenium in rocks is mainly due to low selenium in environmental media in Western Sichuan.

关 键 词：岩石 岩心 硒 有机质 原子荧光光谱法 地质环境 

分 类 号：X142[环境科学与工程—环境科学]