發(fā)布時(shí)間：2019-01-10 12:33

【摘要】：通常流體的沸騰、混合及與圍巖的反應(yīng)被認(rèn)為是成礦元素沉淀的3種有效途徑。報(bào)道了一種較少見的由二氧化碳引起的成礦元素沉淀方式,即二氧化碳不混溶成礦作用。拜仁達(dá)壩是一超大型巖漿熱液型銀多金屬礦床,銀儲量1442t。對該礦床中與多金屬硫化物共(伴)生方解石典型樣品進(jìn)行了碳、氧同位素、流體包裹體均一溫度-鹽度和稀土元素的系統(tǒng)測試分析。結(jié)果顯示,方解石發(fā)育富氣相和富液相兩類包裹體,其富氣相包裹體均一溫度集中在360~380℃,富液相包裹體為280~340℃,它們鹽度集中在6%~9%NaCleqv;方解石具正Eu異常(Eu/Eu*=2.64~5.88)且富集輕稀土元素[(La/Yb)N=4.74~63.91],表明其為熱液成因;方解石碳和氧同位素平均值分別為-13.2‰和12.85‰,依此進(jìn)行二氧化碳不混溶建模,其結(jié)果與實(shí)測情況吻合。研究結(jié)果表明,在拜仁達(dá)壩礦床的成礦元素沉淀過程中,二氧化碳的不混溶起著一定成礦作用。
[Abstract]:Generally, boiling, mixing and reaction with surrounding rock are considered to be three effective ways to precipitate ore-forming elements. In this paper, a rare way of precipitating metallogenic elements caused by carbon dioxide, i.e. carbon dioxide immiscible mineralization, is reported. Bayern Daba is a very large magmatic hydrothermal silver polymetallic deposit with silver reserves of 1442 t. The typical samples of calcite coexisting with polymetallic sulphides in the deposit were systematically tested and analyzed for carbon oxygen isotopes fluid inclusions homogenization temperature salinity and rare earth elements. The results show that both gas-rich and liquid-rich inclusions are developed in calcite. The homogenization temperature of gas-rich inclusions is 360- 380 鈩，

本文編號：2406312