豫西熊耳山吉家洼金矿床同位素特征与成矿模式

Characteristics of isotopic compositions and metallogenic model of Jijiawa gold deposit in the western Henan

吉家洼金矿位于华北地台南缘,是一个受构造控制的岩浆热液型金矿床。吉家洼金矿床的S、Pb同位素特征暗示其成矿物质主要来源于深部地幔,并混入了部分太华群、熊耳群的物质成分;主成矿阶段石英的H-O同位素说明其成矿溶液具有以岩浆水为主并混入大气降水、变质水的特点;C-O同位素图解显示吉家洼金矿δ^(13)_(CPDB)应属地幔射气和岩浆来源,并受到低温蚀变的影响。在对成矿背景、矿床地质特征及成矿流体、成矿物质来源分析的基础上,结合成矿年代学资料,初步建立了吉家洼金矿床的成矿模式,以期对区内金矿勘查工作提供理论依据。

The Jijiawa gold deposit located in the southern margin of North China Craton, is a structure-controlled magmatic hy- drothermal type deposit. The study result of sulfur and lead isotopic compositions suggested that the ore-forming material of Jijiawa gold deposit mainly originated from the deep mantle, and mixed with the material composition of Taihua Group and Xionger Group strata. The SD-δ18O graphic curve of quartz mineral deposited from main mineralization stage displays the ore-forming solution has the charac- teristics of magmatic water mixed with meteoric water and metamorphic water, and the 13CPDB -18 OSMOW graphic displays the δ13 CpD. should belong to mantle emanation and magmatic source, and is affected by low temperature alteration. Based on study of metallogenic setting, geological characteristics, ore-forming fluids and ore-forming source materials in combination of chronological data, the metal- logenie model of the gold deposit was proposed in order to to provide a theoretical basis for the prospecting in this area.