Properties of some rocks from the section of the Kola ultradeep borehole as a function of the P-T parameters

Using core samples of the Kola ultradeep borehole (SG-3) and their surface analogues, variations in the density and elastic properties of some crystalline rocks of the Earth’s crust are estimated by modeling of in situ conditions. It is shown that the bulk density and the elastic wave velocities in the rocks have a weak depth gradient. In the SG-3 section under consideration, this gradient is negative. The resulting dependences for estimating the variations in the properties of the crystalline rocks are suitable for the depth range from the surface to 20–30 km. The initial data for the linear approximation of the characteristics can be obtained from the results of tests of surface analogue samples. It is shown that the velocity anisotropy of the metamorphic rocks can vary within wide limits.