论文部分内容阅读
对 1998年 7月发现的辽宁岫岩县苏子沟镇罗圈里直径 1.8km的撞击坑构造作了一系列地质、地球化学测试工作。从坑内出露的基岩 (下元古界辽河群里尔峪组变质砂岩 )与充填碎屑物质界面上取样 ,经XRD定性分析显示有自然铂、锇铱矿、自然铑、自然铱的存在。进一步对这一类样品作等离子质谱分析 (ICP MS) ,则发现有PGE异常。特别是Pt,Pd ,Ru甚至高于原始地幔的丰度值。进一步淘选坑里重砂样品则发现数颗粗铂矿物。已作电子探针分析表明PGE质量分数 :Pt为 85 .30 % 98.6 8% ,Pd为 0 .45 % 0 .87% ,Rh为 0 .5 6 % 0 .74% ,Os为 0 .6 6 % 1.31% ,Ir为 1.72 % 2 .43% ,Ru为 0 .16 % 0 .31% ,此外Ni为 0 .0 0 % 0 .5 0 % ,Fe为 4.98% 5 .42 %。笔者认为这种PGE元素异常和粗铂矿的发现是陨石及其撞击作用的重要依据之一。
A series of geological and geochemical tests were carried out on the craters with a diameter of 1.8km in Luozhaoli, Suzigou Town, Xiuyan County, Liaoning Province in July 1998. Samples of the bedrock (metamorphic sandstone of Lieryu Formation in the Liaohe Group in the Lower Proterozoic) and the filling detritus material were sampled from the pit and qualitatively analyzed by XRD showed the presence of natural platinum, osmium iridium, natural rhodium and natural iridium . Further analysis of this type of sample by mass spectrometry (ICP MS), we found that PGE abnormalities. In particular, Pt, Pd, Ru even higher than the original mantle abundance value. Further panning pit heavy sand samples found a few rough platinum minerals. Electron probe analysis showed that the mass fraction of PGE: Pt was 85.30% 98.6 8%, Pd was 0.45% 0.87%, Rh was 0.56% 0.74%, Os was 0. 6 6 % 1.31%, Ir 1.72% 2.43%, Ru 0.16% 0.31%, Ni addition 0.0% 0 .0 0%, Fe 4.98% 5 .42%. I believe that this PGE anomalies and the discovery of crude platinum mine is an important basis for the meteorite and its impact.