GEOMETRICAL CHARACTERISTICS OF NEW TECTONIC MOVEMENTS OF THE EARTH'S CRUST OF NORTH EURASIA

Abstract

Based on the data available for the recent vertical movements of the Earth crust (VMEC), depicted in the Map of Recent Tectonics, scale 1:5 000 000, the geometric characteristics of the recent deformations of the North Eurasia lithosphere were studied. Maps were plotted for the module of the magnitude gradient, for the orientation of the dips, for the maximal, minimal, intermediate, and Gauss curvatures, and for the intensity of the vertical crustal movements. Also analyzed were the kinematic specific features of the vertical crustal movements for the main geostructural regions, and for some of their individual areas. The use of the methods of multidimensional statistics helped to prove correlations between the different geometric characteristics, both for the mapped geostructural regions, and for their individual areas. The analysis of the correlations and the geometric interpretation of the results were based on the study of the gradients and curvatures for some model surfaces. The standard deviations and variation coefficients of the calculated values were determined relative to the average values inside each of the geostructural area and for some individual regions. It was found that the average value of the curvature intensity, introduced as the module of the half-difference between the main curvatures, and correlating (in some types of the regions) with the gradient module and with the modules of the main curvatures, had been determined with the lowest variation coefficient, compared to any other geometrical characteristics. On this basis, a conclusion was derived that the curvature intensity values, averaged over the area, could be treated as scalar characteristic which control the specific deformations in most of the regions. Also discussed in this paper is the point whether the results of this study can be used to solve the problem of locating the fields of tectonic stresses. Described in the Appendix are the procedures used to determine the values used in this study, and some basic quantitative relationships among them.