超临界地质流体的物性

The Physical Properties of Supercritical Geofluids

超临界态流体具有接近液体的密度、高于液体的扩散系数和低于液体的粘度等不寻常特性。在地球内部,伴随板块俯冲带入的水等流体进入超临界态,并与壳幔物质混合及相互作用会形成对地球内部结构演化、元素和能量运移有重要影响的流体,即超临界地质流体。然而,目前对于超临界地质流体的性质、作用的认识还极其有限,准确测定超临界流体的物理性质更是严峻挑战。金刚石对顶砧装置(DAC)的优势就是适合极端条件下原位物性探测,这对于超临界地质流体研究是不可或缺的。本文基于金刚石对顶砧装置原位加温的技术特点,对超临界地质流体物性测量的有关问题进行了讨论,并扼要回顾了超临界流体物性研究的进展。

Supercritical fluid has unusual properties,such as approximated density of liquid,higher diffusion coefficient and lower viscosity than those of liquid.In the Earth's interior,the fluid such as the water brought by the subducted slab had changed to the supercritical fluid with the plate subduction interacted with crust-mantle materials to form the supercritical geological fluid which plays very important roles for influencing the internal structure evolution,the elements and energy migration in the Earth's interior.However,due to the technical obstacles,our understanding on the supercritical geofluids is still extremely limited at present.To accurately determine physical properties of the supercritical geofluids is still a very serious challenge at present.The diamond anvil cell(DAC)has an advantage of the in situ detection of physical properties under extreme conditions and is indispensable for the study of supercritical geo-fluids.In this paper,on the basis of the in situ heating technical characteristics of the diamond anvil cell under high pressure,we have discussed relevant questions on the in-situ detection of physical properties of supercritical geological fluids,and briefly reviewed the progress on the physical property studies of supercritical geological fluid.