微堆中子活化分析测定碳酸盐岩中痕量元素

研究了微堆中子活化分析测定碳酸盐岩中痕量元素的测量条件和测定中的影响因素。一般样品采用仪器中子活化分析直接测定;痕量元素含量太低的样品,用1mol/LHCl浸取试样,在pH8的NH4Cl NH3·H2O缓冲溶液中用1 (2 吡啶偶氮) 2 萘酚沉淀富集痕量元素,去除大量的钙、镁基体,可降低方法测定下限,检出限为0.001～20μg/g。方法经国家碳酸盐岩标准物质GBW07108和GBW07114分析验证,结果与标准值相符,RSD(n=11)<12%。

Geotechnogenesis problems

Geotechgjgensis is mineralogical geochemical transformation of minerals, rocks, and ores as consequence of impact on them in the process of performing geological-exploration and irrigation works, extracting and processing mineral resources, constructing transport, civil and military objects. These effects lead to discontinuity and moving different scale fragments of upper part of lithospere and conjugate hydro-and biosphere zones. Discontinuity predttermines the disturbance of matural systems dynamic equilibriu and acceleration ofmftter transformation and migration processes. The final aim of studying geotechnogenesis minseralogy and geochemistry is the establishment of scientific foundations for developing ecological safety measures including also utilization fo geotechnogene deposits.

西藏斯弄多银多金属矿床地球物理和地球化学勘查进展

近年来在西藏冈底斯-念青唐古拉成矿带林子宗群火山岩分布区发现一系列中-大型铅锌银矿床,该区显示出巨大的找矿潜力.由于林子宗群火山岩分布范围广,如何有效地圈定成矿远景区,缩小找矿靶区是取得找矿突破的关键.选取产于谢通门县娘热地区典中组火山岩中的斯弄多银多金属矿床为研究对象,开展了大量勘查地球化学测量和激电中梯测量.结果显示典中组火山岩中铅锌银成矿作用具有Au、Mo、Pb、Zn、Ag异常,金银成矿作用具有强Au、Ag、Mo、As、Sb异常,主成矿元素变异系数大于3.以极化率大于2.5%和电阻率小于800Ω·m圈定隐伏铅锌银矿体的找矿靶区,取得了很好的找矿效果.上述结果表明激电中梯方法在林子宗群火山岩中寻找浅成低温热液型铅锌银矿体效果良好,能够为西藏冈底斯-念青唐古拉成矿带林子宗群火山岩中的找矿工作提供十分重要的指导.