海底热液硫化物矿体内部流体混合过程的数值模拟:以大西洋TAG热液活动区为例

李怀明; 翟世奎; 于增慧; 陶春辉; 初凤友

海底热液硫化物矿体内部流体混合过程的数值模拟:以大西洋TAG热液活动区为例

1.
中国海洋大学海洋地球科学学院, 山东, 青岛, 266100;国家海洋局第二海洋研究所国家海洋局海底科学重点实验室, 浙江, 杭州, 3100122;国家海洋局第二海洋研究所, 浙江, 杭州, 3100122
2.
中国海洋大学海洋地球科学学院, 山东, 青岛, 266100
3.
国家海洋局第二海洋研究所国家海洋局海底科学重点实验室, 浙江, 杭州, 3100122;国家海洋局第二海洋研究所, 浙江, 杭州, 3100122

基金项目: 中国大洋协会DY115-02-1-01课题资助;国家重大基础研究发展规划(“九七三”)项目(G2000078503)资助

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出版历程
- 收稿日期: 2008-06-02
- 修回日期: 2008-08-04

Numerical simulation for mixing process of fluid within seafloor sulfide deposit:taking example for the TAG field

1.
College of Marine Geoscience, Ocean University of China, Qingdao 266100, China;Key Laboratory of Submarine Geosciences of State Oceanic Administration, Second Institute Oceanography, State Oceanic Administration, Hangzhou 310012, China;Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China
2.
College of Marine Geoscience, Ocean University of China, Qingdao 266100, China
3.
Key Laboratory of Submarine Geosciences of State Oceanic Administration, Second Institute Oceanography, State Oceanic Administration, Hangzhou 310012, China;Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China

摘要

摘要: 大型海底热液硫化物矿体的形成机制是涉及多种控制因素的复杂地质过程,其中热液流体同海水的混合扮演着重要角色。大洋钻探计划(ODP)资料表明在大西洋TAG区热液硫化物矿体内部,热液流体同经过改造的海水之间发生着广泛的混合作用,这个过程在很大程度上控制着海底热液硫化物矿体的内部结构和化学组成。以TAG热液硫化物矿体为例,利用数值模拟方法模拟了热液流体与经过不同程度改造的海水的混合过程,试图探讨海水与热液流体混合在热液硫化物矿体形成中的作用。模拟计算结果表明:(1)来自矿体深部的热液流体与经围岩加热的下渗海水的混合是造成TAG热液活动区硬石膏大量沉淀的重要原因;(2)在热液流体与海水的混合过程中,混合流体的化学性质和矿物沉淀情况在330~310℃上下发生了较大变化,330~310℃是一个特殊的温度区域;(3)利用数值计算结果探讨了TAG热液活动区不同区块(TAG-1,TAG-2和TAG-5等)的流体混合作用和热液活动过程。
- 热液硫化物矿体 /
- 流体混合过程 /
- TAG热液活动区 /
- 数值模拟
Abstract: Formation mechanismof the sizable hydrothermal sulfide deposit is a complex geological process involving many types of controlling factors. Mixing between hy drothermal fluid and seawater plays a key role in this process. The previous results of Ocean Drilling Program(ODP)indicate that mixing of the evolveds eawater with the hydrothermal fluid is wildly developed within the TAG hydrothermal deposit, which governs the internal structure and chemical compositions of the deposit to great extent. Taking example for the TAG field,the mixing process of the hydrothermal fluid is calculated with the seawater that is heated to different extent,in order to discuss the impact of hydrothermal fluid/seawater mixing on the formation process of the sulfide deposit. The results indicate that:(1)mixing between the heated seawater and the hydrothermal fluid derived from the deep deposit should be largely responsible for the wild precipitation of anhydrite within the TAG hydrothermal deposit;(2)330~310 is a special temperature zone in the mixing process between the seawater and the hydrothermal fluid;(3)the mixing and hydrothermal processes in differentareas(TAG-1,TAG-2 and TAG-5,etc)of the TAG hydrothermal deposithave been discussed based on the calculated results.
- hydrothermal sulfide deposit /
- mixing process /
- TAG hydrothermal field /
- numerical simulation

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参考文献(30)

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