东沟坝多金属矿床同位素地质特征  

ISOTOPIC GEOLOGICAL FEATURES OF THE DONGGOUBA MULTIMETAL DEPOSIT

作　　者：卢武长[1] 张萍[1] 杨绍全[1] 

机构地区：[1]成都理工学院材料科学与工程系

出　　处：《成都理工学院学报》1998年第3期447-456,共10页Journal of Chengdu University of Technology

基　　金：国家自然科学基金

摘　　要：通过对陕西东沟坝多金属矿床成矿过程中同位素交换动力学的研究，认为：含矿溶液中ＣＯ２的逸失是碳酸盐矿物同位素组成变化的主要原因；含矿溶液的δＤＨ２Ｏ值的变化明显受ＣＨ４含量和温度变化控制；成矿溶液来自变质水，硫来源于古海洋水硫酸盐和岩浆硫的混合；估计成矿时的δ３４Ｓ∑Ｓ值接近９．８‰，ｆＯ２为１０－２９．５～１０－３１．５，ｐＨ值为６～７。并用同位素交换动力学方程评估了硫在矿液中的停留时间。Kinetics of isotopic exchange in ore bearing fluids of the Donggouba deposit is studied in dedail and the main conclusions are as follows: (1) The loss of CO 2 in ore forming fluids may be the primary cause of carbon isotopic variation for calcites. (2) The δ D H 2O variation is strongly controlled by the CH 4 contents and temperature in ore forming fluids. (3) The ore forming fluids were derived from metamorphic waters. The sulfur elements were derived from old seawaters aqueous sulfates and magmatic sulfur. (4) The δ 34 S ∑S (9.8‰) , f O 2 (10 -29.5 ～10 -31.5 ) and pH(6～7) of mineralization period are estimated from sulfur isotopic composition of coprecipitation sulfate sulfide minerals. The residemcetime of sulfur species in hydrothermal systems is evaluated using the kinetic equation of sulfur isotopic exchange.

关 键 词：交换动力学 成矿溶液 同位素地质 多金属矿床 

分 类 号：P618.204[天文地球—矿床学] P597[天文地球—地质学]