摘要
东秦岭泥盆纪山阳－柞水成矿区内众多层控贱金属硫化物矿床含矿层中含有相当比例的电气石，这些电气石属于黑电气石－镁电气石类质同象系列，一般Ｍｇ＞Ｆｅ、Ｎａ＞Ｃａ（阳离子比较），明显的成分环带记录了主成矿期的海底（喷气）热液沉积成矿方式和随后的区域变质及热液叠加过程，在主成矿期形成的电气石的化学成分［ＦｅＯ／（ＦｅＯ＋ＭｇＯ）＝０．３４—０．３９］和硼同位素组成（δ１１Ｂ＝－７．６—－８．８）与海底（喷气）热液沉积成因块状硫化物矿床中电气石相似。由此。
Tourmaline occurs in an important quantity in the ore bearing bed of most stratabound base metal sulphide ore deposits at Shanyang-Zhashui Devonian metallogenic area in eastern Qin Ling.They belong to the solid solution series of schorl-dravite in which Mg>Fe and Na>Ca (cation basis).Most of the tourmalines are zoned chemically and the zones recorded the seafloor (exhalative) hydrothermal sedimentary and diagenesis process during the main metallogenic epoch and the subsequent regional metamorphism and hydrothermal overprinting process.The chemical compositions[FeO/(FeO+MgO)=0.34—0.39]and the boron isotopic compositions (δ 11 B=-7.6‰? ?.8‰ ) of the tourmalines formed in the main metallogenic epoch are simelar to those of tourmalines in the seafloor (exhalative) hydrothermal sedimentary massive sulphide ore deposits.This suggests that the seafloor (exhalative) hydrothermal sedimentary process is the main metallogenic mechanism for the stratabound ore deposits in the metallogenic area.
出处
《地球化学》
CAS
CSCD
北大核心
1997年第1期36-44,共9页
Geochimica
基金
国家自然科学基金青年基金
关键词
硼同位素
泥盆纪
成矿区
电气石
矿物化学
tourmaline,chemical composition,borom isotope,eastern Qin Ling
