摘要
本文以广西南丹芒场锡多金属矿田为例,对构造地球化学理论中的一个基本问题——构造应力场与地球化学场的关系进行了半定量的研究,说明了进行这方面研究的必要性和研究方法。总结了芒场沉积-岩浆热液叠加型层控多金属矿床在其形成过程中的热液活动期,构造应力场与Sn,Zn,Pb,Cu,As,Ag等元素富集之间的数量关系,并从上述元素的地球化学性质对这种关系作了解释。
<ABSTRACT>
This paper studies mainly the relationship between stress field and geochemical field, tries to set up a sequence of various elements according to their sensitivity to tectonic stress. All conclusions are derived from the researches in Mangchang tin-polymetal ore field. Applying geostatistics, about 3000 halo data are dealt with and the spacial distribution characteristics of six elements is known. Based on the measurement to Small structrue and miero-structrue and rock machanics tests, Yanshanian tectonics stress field is mathematically modeled with finite element method in computer program. From the test of this work, not only main stress distributions are convinced, but also sheer stress distribution characteristics are known.
Simply, taking T and D as independent variables, C as function, a series of regression equations can be set up as follows:
C( Zn ) = -15.25+50.85T-1.37D C( Sn ) = -0.73+7.60T-1.09D C( Cu ) = -8.96+4.96T-0.41D C( Ag ) = -8.34+4.43T-0.23D C( Pb ) = -1.06+3.85T+0.08D C( As ) = -0.25+1.12T-0.11D
Here, T, D, C, represent respectively stress vaule in an unit and the distance between the unit and the center of concealed granite body, the enrichment amount of each element within the unit during hydrothermal ore-forming period.
According to the vaule of regression coefficient of T, we can make a sequence of elements. Comparing it with the natures of elements, such as atom weight, atomatic density, ionic radius, and so on, we can find that the lighter atom is, the larger regression coefficient of T is, and, the larger ionic radius is, the less regression coefficient is. That is to say the control degree of stress field over elements enrichment is related to natures of elements.
出处
《现代地质》
CAS
CSCD
1990年第2期75-82,共8页
Geoscience
关键词
构造
应力场
地球化学场
控制
应力
: tectonic stress field, geochemical field, stress control
