【摘要】 冀北地区是火山岩型铀矿的有利产出区域,本文以该区的水系沉积物区域化探数据与典型铀矿矿区岩石和土壤地球化学数据为研究基础,建立适用于火山岩型铀矿的地球化学勘查评价指标。含矿围岩富铀、钍、硅、钾。铀富集于粗粒级(-4～+20目)水系沉积物和细粒级(-100目)土壤。因此,粗粒级水系沉积物是区域测量的有效采样介质,细粒级土壤是矿区测量的有效采样介质。火山岩型铀矿直接的特征指示元素为U和Mo,其它伴生元素还有Th、La、Hg、Sb、Zr、B、F等。该指标的建立对冀北地区及北方火山岩型铀矿勘查评价具有实际意义。更多还原

【Abstract】 North Hebei is a favorable area in search for volcanic-rock type uranium ore deposits. This study combined the regional geochemical data and local data of 460 and 534 uranium ore deposits so as to establish regional geochemical evaluation indicators of the volcanic type uranium deposits and provide guidance for the evaluation of uranium deposits in this area. Uranium deposits are hosted in volcanic rocks with high background of U(8.9×10^–6～13.5×10^–6), Th(37×10^–6～48×10^–6), SiO₂（75%～80%） and K₂O（5%～6%） and with low background of Fe₂O₃, MgO, Na₂O and Sr. Uranium is concentrated in coarse grain fraction（–4～+20 mesh） of stream sediments and in fine grain fraction of soils（–100 mesh）, which indicates that coarse-grained stream sediments and fine-grained soils are useful sample media for regional and local geochemical survey respectively. U and Mo are direct indicator elements for volcanic type uranium deposits. The other associated elements include Th, La,Hg, Sb, Zr, etc. The indicators are helpful for the evaluation of volcanic type uranium deposits not only in north Hebei but also in the whole North China.更多还原