云南思茅-南坪盆地边缘造山带金(铜)成矿流体动力学

曹志敏; 郑建斌; 徐则民; 任建国; 李保华; 覃功炯

云南思茅-南坪盆地边缘造山带金(铜)成矿流体动力学

1.
青岛海洋大学地球科学学院, 山东青岛 266003
2.
南京大学内生矿床成矿机制国家重点实验室, 江苏南京 210005
3.
成都理工大学地球科学学院, 四川成都 610059
4.
中国地质大学地球科学与资源学院, 北京 100029

基金项目:

国家重大基础研究发展规划项目 1999043205

详细信息

作者简介:
曹志敏（1957－），男，博士学位，教授，从事资源与环境地球化学研究. E-mail：zmcao@mail.ouqd.edu.cn

中图分类号: P611; P618.5
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出版历程
- 收稿日期: 2001-11-19
- 刊出日期: 2002-07-25

Au (Cu) Ore-Fluid Dynamics in Bordering Orogenic Belt of Simao-Nanping Basin, Yunnan Province

1.
Faculty of Earth Sciences, Ocean University of Qingdao, Qingdao 266002, China
2.
State Key Laboratory of Mineral Deposits Research in Nanjing University, Nanjing 210005, China
3.
Faculty of Earth Sciences, Chengdu University of Technology, Chengdu 610059, China
4.
Faculty of Earth Sciences and Mineral Resources, China University of Geosciences, Beijing 100029, China

摘要

摘要: 从研究云南思茅-南坪盆地边缘造山带金(铜) 成矿流体的地质地球化学特征和物理化学条件入手, 通过氢-氧、碳-氧、氦-氩同位素组成示踪和矿物流体包裹体温度-压力、流体成分测试及物理化学参数计算, 认为成矿溶液主要来自大气降水, 并且成矿物质具有壳源的特点, 不能排除构造/岩浆活动中其他壳源流体加入的可能性, 其性状为浅成(低压)、低温、高盐度、弱碱性和弱还原性, 流体组分别具有Na⁺ > K⁺和Ca²⁺ +Mg²⁺、Cl^- > F^-的特点, 还原形式存在的硫占绝对优势, 它对金的迁移和沉淀起着关键的作用; 运用古水文地质学方法模拟成矿流体的水动力场与排泄条件, 强调多成因含矿流体受古水文动力场运移、分布形式制约, 高能量、高矿化度成矿流体经历漫长的地下反复溶滤、渗透、岩浆和构造驱动双重作用下, 在水动力低压区排泄、沉淀富集成矿.
- 金(铜)矿床 /
- 成矿流体 /
- 造山带 /
- 云南思茅-南坪盆地
Abstract: We studied geologic and geochemical characteristics and physical chemical condition of the Au (Cu) ore fluid, bordering the orogenic belt of the Simao Nanping basin. The studies of isotopic tracing on H-O, C-O, He-Ar, T and p, composition in the mineral inclusions testing and their physical chemical parameter calculation in the fluid inclusion indicate that ore forming fluid is derived from meteoric water and that the ore forming materials may be from crustal source and other origin fluid joined. The fluid presents some characteristics such as epithermal, high salinity, alkalescency and deoxidizescency, Na⁺ > K⁺ and Ca²⁺+Mg²⁺, Cl^- > F^- in the compositions. In the fluid, S^2- is dominated and plays a key role in transference and precipitation of Au. The hydrodynamic field and discharge conditions are simulated by paleo hydrogeologic method with a stress on the control of migration and distribution pattern of paleo hydrodynamics field over the multi genetic ore fluid. The ore fluid of high energy and high degree of mineralization is discharged in the low hydrodynamics pressure area and precipitated to form the ore after a long time of repeated leaching and permeation, driven by magmatic dynamics and tectonics.
- Au (Cu) deposit /
- ore fluid /
- orogenic belt /
- Simao Nanping basin of Yunnan Province

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图 1 区域地质构造略图

1.陆块; 2.南坪-思茅盆地; 3.子陆块边缘; 4.皱系; 5.印支板块边缘; 6.绿混杂岩带; 7.造推覆体

Fig. 1. Regional geologic and tectonic sketch

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图 2 成矿流体的氢、氧同位素组成

A.变质水区; B.原始岩浆水区(图中样品序号与表 1相同)

Fig. 2. Hydrogen and oxygen isotope compositions in ore fluid

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图 3 均一温度直方图

Fig. 3. Histogram of homogenization temperature in mineral inclusions

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图 4 泥盆纪—石炭纪沉积期古水流动力场

Fig. 4. Paleohydrodynamics field in Devonian-Carboniferous sedimentation period

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图 5 地质模型略图

Fig. 5. Sketch map of geologic model

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图 6 最大主应力(a)、最大剪应力(b) 等值线(MPa)

(a) and the maximum shear stress (b) XT.学堂; ZY.镇源金矿; SG.双沟; ML.马鹿塘; JC.金厂金矿

Fig. 6. Isograms of the maximum principal field of stresses

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图 7 平面构造应力场有限元计算模型

Fig. 7. Calculated model of finite-element simulation

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图 8 金厂剖面最大主应力(a)、最大剪应力(b) 等值线(MPa)

AM.阿墨江断裂; JM.九甲-墨江断裂; AL.哀牢山断裂; HH.红河断裂; TT.藤条江断裂

Fig. 8. Isograms of the maximum principal of stresses (a) and the maximum shear stress (b) in Jinchang profile

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图 9 成矿期最大主应力分布与成矿流体运移模式

1.最大主应力高值区; 2.最大主应力低值区; 3.成矿流体运移方向; 其他图例同图 8

Fig. 9. Distribution graph of the maximum principal of stresses and migratory model of ore fluid in metallogenic period

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表 1 石英氢氧同位素组成

Table 1. Hydrogen and oxygen isotope compositions in quartz

表 2 岩石和矿石的碳氧同位素组成

Table 2. Carbon and oxygen isotope compositions in wall rock and ore

表 3 金满矿床的稀有气体同位素组成

Table 3. Noble gases isotope composition in Jinman Au (Cu) mineral deposit

表 4 包裹体均一温度、盐度、压力测试结果

Table 4. Analysis results of homogenization temperature, salinity and pressure in mineral inclusions

表 5 石英中流体包裹体成分分析结果

Table 5. Analysis results of fluid composition of inclusions in quartz

表 6 成矿物理化学条件

Table 6. Metallogenic physical-chemical parameters

表 7 总硫活度和总碳活度计算结果

Table 7. Calculated result of ΣC and ΣS activities in fluid

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