地壳的应力状态、构造附加静压力和岩石矿床形成深度的研究  

On the Stress State, the Additional Tectonically-Induced Static Pressure and the Formation Depth of the Rocks and Ores in Earth Crust

作　　者：吕古贤[1] 刘瑞珣[2] 蔡永恩[2] 王方正[3] 郭涛[1] 马瑞[4] 胡宝群[1,5] 申玉科[1] 周国发[1] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]北京大学,地球与空间科学学院,北京100871 [3]中国地质大学(武汉),武汉430074 [4]吉林大学资源学院,长春130000 [5]东华理工大学地球科学系,抚州344000

出　　处：《高校地质学报》2008年第3期442-449,共8页Geological Journal of China Universities

基　　金：国土资源部科技发展计划重点项目(2002201);国家自然科学基金(40772142,40572127,49672152);国家科委基础司特别支持项目(国科高1994,83号)联合资助

摘　　要：本文对深度计算公式:D=P/d(式中D为深度,P为压力,d为密度)的应用提出质疑。该公式源自一个流体力学原理,即描述静流体中压力与深度关系的帕斯卡原理,所以只适用于流体。如果物质是一种固体,而不是液体或气体,它可以承受剪应力或差应力,则这一公式就不能应用。所有岩石,从出露地表深至核幔边界,都是固体。当外力作用于固体单元上时,固体的应力场存在两部分:均应力和差应力,不论外力是构造力还是重力。而当外力作用于液态物质时,在这个液体应力场中则总是只有均应力而无差应力。地应力测量结果表明,作用于垂直截面上的水平应力通常大于作用于水平截面上的垂直应力,而且越靠近造山带或剪切带,水平应力越大,显示构造力在地壳应力场中起某种主导作用。事实上推动板块运动的力主要是水平的,而非垂直的。地壳中某处的总静压力至少由两部分合成:由构造引起的压力和由重力引起的压力,前者称构造附加静压力。合理计算成岩成矿深度的方法,应该是从总压力中减去构造附加静压力,再除以岩石比重,即D=(P-Pt)/d,式中Pt为构造附加静压力。The paper puts forward some questions to the application of the formula： D--P/d, where D, P and d represent depth, pressure and specific density, respectively. This formula stems from a fluid mechanical principle, the Pascal＇s principle, describing the relationship between pressure and depth in static fluid. This formula is applied to fluid material only. If the material is a solid, and it may undergo shear or differential stress, then this formula can not be applied. All rocks existing from the Earth surface down to the boundary between the mantle and the core show solid character. When a foece is acted on a solid unit, no matter the force is tectonic or gravity, there always exist two stress parts in the solid stress field： the uniform stress and the differential stress. However, in the case of liquid material, the stress is uniform, but not differential. The results of geo-stress measurements show that the horizontal stress acted on the vertical section should be greater than the vertical stress acted on the horizontal section; and that the nearer the distance to the orogen belt or shear zone, the greater the horizontal stress is, thus indicating the leading role of tectonic force in the crust stress field. In fact, the force pushing the plate movement is mainly the horizontal stress, but not vertical stress. The total static pressure at a position in crust is composed of at least two parts： the pressure induced by the tectonic activities and the pressure induced by the gravity. The former pressure is the additional tectonically-induced static pressure. The reasonable method to calculate the depth should be the subtraction of the additional tectonically-induced pressure from the total pressure, and then divided by the rock specific density, i.e. D = （P-Pt）/d, where Pt represents the additional tectonically-induced static pressure.

关 键 词：地壳应力 构造附加静压力 固体力学 成岩成矿深度 构造物理化学 

分 类 号：P554[天文地球—构造地质学] P545[天文地球—地质学]