Correlations between petrophysical properties of ultra-high pressures rocks ana its significance on establishing the geophysical interpretation standards for crystalline rockst
超高压变质岩物理性质的相关性对建立结晶岩区地球物理解释标尺的意义

Scientific Drilling has become a critical tool to provide data essential to understand the structure, composition, mechanical behavior and physical state of the deeper curst. Petrophysical studies are necessary for the calibration of borehole logging results and for the interpretation of surface geophysical investigations. Such studies, in combination with petrological investigations, are also required for the understanding of chemical alteration and metamorphism. Correlation investigation and cluster analysis are preformed on petrophysical properties of ultra-high pressure rocks from 100 - 3100m of CCSD main hole, and the conclusions are given as following: (1) the strong correlations among seismic wave, density and thermal conductivity are controlled by the mineral assemblage and proportion in the rocks; (2) electrical resistivity and susceptibility are controlled by the metal oxide in the rocks and associated with the lithology of the rocks, but the porosity and permeability have no correlation with lithology; (3) the lithology of the rocks can be classified according to their petrophysical properties. Eclogite and gneiss can be distinguished according to the seismic velocity, density and thermal conductivity, but the ultra-mafic tocks, prargneiss and orthgneiss can be well recognized if the susceptibility and resistivity are added to the analysis parameters. These conclusions are of great important to the parameter selection in geophysical interpretation and also have the great significance on establishing the geophysical interpretation standards for crystalline rocks.