Fault-blocky structure of the Moho boundary under the central part of the Donets folded structure (along the line of the seismic profile DOBREflection2000)

Abstract

A possibility to reconstruct the fault-blocky structure of geological objects according to the results of solving the inverse dynamic problem of seismic is under consideration in the paper. The initial are seismic data of the deep section of CDP obtained by SGE «Ukrgeophysics», on the profile DOBREflection-2000. The solution is the temporal seismic profile of extinction decrements (LDE) with high space ability. Despite the weak amplitude of reflection at great depths the change of spectral composition of the seismograms allow to select their contours and fault zones filled with mantle breccia or other filling material.As of today the method of deep seismic sounding (DSS) is the principal method of the studies of the upper part of lithosphere. The velocity models of the Earth’s crust and the upper mantle are plotted using hodographs of reflected waves from geological discontinuities. According to these models we have the regularities of velocity change with depth. Still the insufficient spatial and temporal divided ability does not allow recognizing and mapping the distribution of deep faults.Starting from the 80th of the former century for the studies of the deep structure a method of observation of reflected (almost vertical) waves in the area close to the source of seismic waves using SDP technologies began to be used. Seismic section obtained with this method is based on repeated summation of the records from different seismic receivers allowing amplification of the ratio signal-noise considerably. It makes possible to register the seismic waves propagating to much more depths than the extent of observation system located on the surface. Such sections are called deep section (CDP). They have the information on the reflection with arrival time on the surface from 30 s and more. Seismic records of CDP have wider frequency range than the DSS method that is important for solving the inverse dynamic problems.Conducting in the same territory of seismic studies with different deep methods CDP and DSS and interconnection of their results is of great importance for explanation of origin of oil and gas-bearing capacity of definite areas from the viewpoint of detailed deep structure.