摘要
根据湘南高温地热区硼同位素研究 ,总结了硼同位素的分馏特征。湘南高温热液交代矿床硼酸盐矿物的δ11B值均为负值 (- 1.34‰～ - 13.2 8‰ ) ;不同蒸馏阶段获得样品的δ11B值有较大差异 ,早期蒸馏硼酸较晚期蒸馏硼酸有较高的δ11B值 ,晚期蒸发阶段样品的δ11B值较早期阶段的δ11B值低近 4 0 % ,表明在热液交代过程中11B较10 B活跃 ,优先进入流体相或蒸汽相 ;水岩作用中硼同位素分馏与硅化交代强度成正相关关系 ,并且是硅置换11B ,造成岩石亏损11B ,而呈现低的δ11B值 ;水化反应中硼被吸入 ,并优先吸入11B ,导致蚀变岩中δ11B升高。研究认为 ,硼同位素分馏特征可以用于分析成矿流体演化及水岩作用性质 ,而不限于分析成矿物质来源。
Based on study of composition and fractionation of boron isotope in the hyperthermal deposits in south Hunan province,it is concluded that the δ 11 B values vary between -1.34‰ and -13.28‰ and differ a lot with evaporation stages: approximately 40% higher in the early evaporite boric acid than that in the later evaporite boric acid, which indicates that 11 B is more active than 10 B and firstly enters fluid or steam phase in the hydrothermal metasomatic process; Boron isotope fractionation is positive to the silicification intensity and the deficit of 11 B may be resulted from replacement 11 B by Si during the water rock reaction;B (especially 11 B) is absorbed in the process of water absorption reaction,contributing to rise of δ 11 B value in the alteration rock. It suggests that the fractional characterization of boron isotope can not only be applied to analyze the sources of metallogenetic material,but also to the evolution of mineralizing fluid and nature of water rock reaction.
出处
《华南地质与矿产》
CAS
2001年第2期1-7,共7页
Geology and Mineral Resources of South China
基金
国家自然科学基金项目 (No 40 0 730 13)
国家基金委与日本学术振兴会 (98外 0 2 8号 )
国土资源部国际合作与科技司自由探索项目 (2 0 0 0 44 0 )资助。
