摘要
从贵州铜仁西溪堡矿区新元古界大塘坡组第一段"含锰岩系"中选取8件黄铁矿样品,对其进行了Re-Os同位素分析。结果表明其等时限年龄为(459±16)Ma,明显晚于间冰期大塘坡组的沉积时代(670~635 Ma),表明该地区受加里东晚期的构造热事件影响。此次所分析的所有样品均具有高Re、低Os含量、高Re/Os比值及高^(187)Os/^(188)Os同位素比值,且^(187)Os/^(188)Os初始值为1.02±0.41,明显大于地幔特征值(0.12~0.13),指示成矿物质来源于壳源。
Eight pyrites from the manganese -bearing rock series of the First Member of Neoproterozoic Datangpo Formation are used for Re -Os isotopic dating at Xixibao orefield in Tongren area, Guizhou province. The analyses yield an isochronic age 459± 16 Ma, significantly later than the interglacial depositional age of Datangpo Formation （670 -635 Ma）, which suggest that the Datangpo Formation was probably affected by the tectonic thermal activity of Late Caledonian. The pyrites also show high Re, low Os abundance, high Re/Os and 187Os/ 188Os ratio. The initial 187Os/188Os value is 1.02± 0.41, significantly higher than the eigenvalue of mantle magma, which indicate the ore -forming materials are mainly derived from the crustal source.
出处
《中国地质调查》
2015年第7期53-57,共5页
Geological Survey of China
基金
中国地质调查局"川滇黔相邻区重要矿产成矿规律和找矿方向研究(编号:1212011085162)"
"重庆秀山锰矿整装勘查区关键基础地质研究(编号:12120114016201)"和"川滇黔关键地区区域地质调查(编号:12120113050300)"项目联合资助
