# History of laboratory of tectonophysics

The works of laboratory of tectonophysics or, as it often and reasonably named, Gzovsky laboratory at the all time of its existence may be divided on some periods:

** The first**, time, preceding the foundation of laboratory by M.V.Gzovsky - 1946-1965, may be named romantic, when published in papers new ideas of M.V., confirmed by results of research, made by him with a number of IPE scientists and supported by laboratory team and its head V.V.Belousov, quickly ran between scientists and practitioners and found understanding and adoption as well as supporters both in our country and abroad.

** The second**, time of establishment of new subdivision with all attendant this process problems in 1965 - 1971 – the period of strategic direction of laboratory research making. It finished immature death of its head.

** The third**, period from 1971 – time of the making of tedious research in earlier planned directions may be characterized by pursuit to follow exactly selected course and conduct research on the top scientific level, which was connected with certain difficulties, because the new discipline formed on the joint of such variegated items as generally descriptive science – tectonics and exact one – physics, and thereat in this time the theoretical study was emphasized.

At present the great efforts, directed on the methodological base of tectonophysical study development, begin to bring its benefit. The works of laboratory scientists become more and more claimed in the fields of the geodynamical processes studying, seismic risk zoning, physics of earthquake source, exploration activity.

**PERIOD ****BEFORE 1965**

The tectonophysical research in the frame of V.V.Belousov laboratory was began by M.V.Gzovsky at the end of forty, and to the moment of establishment of laboratory of tectonophysics in 1965 sphere of problems and subject of tectonophysics was determined by him; the sphere of problems on physical principles of tectonophysics was planed in whole and determined in the moment; the main tectonophysical methods of research in frame of this new discipline: field, experimental and theoretical were determined.

At the same time it was considered quite a number of concrete tectonophysical problems, among which were both the traditional tectonics problems, considered now from tectonophysical position, and new problems, decision of which is possible only by methods of tectonophysics.

List the main results of this period, limited ourselves by very important from our point of view.

*CREATE FOUNDATONS OF THE PHYSICAL THEORY OF TECTONIC PROCESSES:*

1. Create the conception of tectonic stress field as the base of new approach to studying of traditional objects of tectonic research – plicate and rupturing deformation of different level, as well as mechanisms of its forming;

2. Perform, taking into account physical aspect of consideration, new classifications of the main objects of tectonic research: folds, fractures, mechanisms of its forming.

3. Undertake a study by tectonophysical methods, essentially by field one and by modeling of following objects:

a. Faults and ruptures – considered the theory of the tectonic rupture forming in the frame of continuum mechanics, studied the fault types, special attention gave study of fracturing, studied mechanism of large fault forming, initiate studying of the rupture influence on the initial field of stress.

b. Folds – determined the basic type mechanisms of the folding, considered mechanisms of lateral flexure, axial compression and flexing.

c. Mechanisms – as main types of tectonic deformation mechanisms and stress fields mechanisms stood out regions: pressing, pumping, transversal flexure and tectonic rupture vicinity.

4. Create the conception of surface displacements vertical velocities gradients, which considered as one from possible arguments for determining of tectonic stress values.

The special attention gave study of *stress fields* during the tectonic structure forming, as well as physical characteristics of structure features, influenced on the behavior of this process, with a glance of its duration. In the frame of conception of tectonic stress fields on the model from optically active materials studies of rupture influence on the preexisted stress field were began.

*PERFORM PHYSICAL FOUNDATIONS OF TECTONOPHYSICS:*

A number of methods of tectonophysical research were devised, including:

1. The reconstruction of principle stress axis on the base of Coulomb’s destruction law with using of field data about orientation of tectonic ruptures or about seismic destruction (mechanisms of earthquake source);

2. The theory of condition similarity was applied to modeling of tectonic structure and choice of a number of equivalent materials was scientifically validated;

3. The methodology of equivalent materials property (including optically active, elastic and viscous) was developed and devices for such tests was made;

4. General conclusion about geomaterials taking into account tectonic process duration was done;

5. The first devices for optical and equivalent on opaque materials modeling of tectonic process were produced.

*TECTONOPHYSICAL RESEARCH OF A NUMBER OF REGIONAL STRUCTURES:*

The tectonophysical research of a number of regional structures with reconstruction of tectonic principle stress direction was made, including large tectonic structure Bajdzansajskij anticlinorium.

*PUBLICATIONS OF THIS PERIOD*

All listed research and developments were published in series of paper of fifties of M.V.Gzovsky, some of which were written with coauthors, his colleagues, IPE and other institute workers, as well as with his pupil: V.V.Belousov, G.N.Osokina, I.M.Kuznetsova, E.I.Chertkova, V.I.Krestnikov, I.L.Nersesov, G.I.Rejsner, N.N.Leonov, I.A.Rezanov, V.I.Bune, K.K.Zapolsky, V.I.Kejlis-Borok, L,N,Malinovskaya, G.I.Pavlova, T.G.Rautian, Yu.V.Riznichenko, V.I.Halturin, N.A.Schegolevskaya, S.I.Sokolov, G.V.Vinogradov, V.P.Pavlov, G.P.Gorshkov, G.A.Shenkarjova, Ma Jin, L.S.Gembitsky, as well as in two-volume monograph “The main issue of tectonophysics and tectonic of Bajdzansajskij anticlinorium. P. I-IV” by M.V.Gzovsky and in monograph “Ductile and elastic low-modular optical active materials for research of the earth crust stress by modeling” D.N.Osokina.

**PERIOD 1965 – 1971.**

In considered period with connection of laboratory financing from contract with GIDEP a lot of force and time was given evaluation of seismic danger problem and seismic zoning, A number of this time publications described this research results. At the same time principles of earth crust deep structure zoning and data about modern movements interpretation were developed.

As before the problem of tectonic stress field reconstruction, as by value, so by direction, remained at the center of attention, the results of determining of stress tensor parameters by different methods were classified and summarized, the first attempts of formalization the reconstruction of stress path.

It was improved the methods of experimental tectonophysical modeling, the first optical model of the concrete earth crust area (Garm geophysical polygon) was made. The method of quantitative estimation of deformations, displacements and properties (viscosity) was developed, as well as estimations of energy consumption on destruction and deforming stepwise in process of tectonic structure modeling on opaque materials were made.

The first in our laboratory mathematical models of stress and deformation distribution in initial moment of tectonic structure forming was produced. The deformations and stresses in the layer above lowered block, in layer, experienced lateral pressure, as well as deformations and displacement in layer (crust) above hypothetic convection flows in mantle was studied; and also the review of existing methods of mathematical modeling was made and results were generalized.

The works, made by D.N.Osokina jointly with Laboratory of High Pressures IPE AS, deals with studying absorbing and elastic rock characteristics and correlation between it, refer to this period. The development of these works with organization of durational deformation measurement in rocks and on samples, comparison of this data with results of measurement in pillar (in-situ) and detection of correlation with geophysical measurement data so as to enhance possibilities of estimation mechanical properties of geological massifs by geophysical characteristics was assumed in the sequel.

Except the cycle of papers, published in this period, in 1971 collection of papers “Tectonophysics and mechanical properties of rock” jointly with Laboratory of High Pressures, and then monograph by M.V.Gzovsky “Mathematics in geotectonics”, which though provoked some complaint of mathematicians, reflects understanding in this period by laboratory team and head necessity of quantitative research, therewith physically more strictly grounded, than formerly, were published. Finally, in 1975 monograph: M.V.Gzovsky “The principles of tectonophysics”, prepared and edited by laboratory team and authors wife posthumously, which completed this cycle of works and resumed author research in tectonophysics, was published.

**LABORATORY WORK AFTER 1971**

From 1971 the laboratory work was fulfilled in the following directions:

1. Reconstruction of tectonic stresses field and tectonic deformation of different level by geological and seismological data (O.I.Goutschenko, Yu.L.Rebetsky, V.V.Stepanov).

2. In-situ and theoretical research of relationship of non-uniformly scaled stress and deformation fields, developing in heterogeneous massifs (ruptures and inclusions) and in massifs with texture in appearance ordered systems of ruptures and folds (O.I.Goustchenko, D.N.Osokina, Yu.L.Rebetsky, F.L.Yakovlev)

3. Research of typical elementary tectonic structure deformation mechanisms with assistance of theory and on models. (I.M.Volovich, A.S.Grigorjev, O.I.Goustchenko, A.V.Mikhailova, D.N.Osokina, Yu.L.Rebetsky)

4. Study and reconstruction of regional tectonic structure deformation mechanisms. (O.I.Goustchenko, E.S.Nikitina, Yu.L.Rebetsky, F.L.Yakovlev, A.V.Marinin)

5. Improvement of tectonophysical research methods. (A.S.Grigorjev, O.I.Goustchenko, A.V.Mikhailova, D.N.Osokina, Yu.L.Rebetsky, F.L.Yakovlev)

6. Reconstruction of tectonic stresses and tectonic deformation of various levels fields by geological and seismological data. (O.I.Goustchenko, Yu.L.Rebetsky, V.V.Stepanov, A.V.Marinin)

*Development of the reconstruction of natural tectonic stresses field methods by data about shift ruptures and earthquake source mechanisms*

This laboratory of tectonophysics always gave particular place and attention, whereas just this data equally with displacement characteristics is the base of tectonophysical research, allowed to get necessary information about tectonic structure deformation mechanisms and realize its reconstruction.

On the first stage of this direction formation, M.V.Gzovsky developed “Method of Cleavage Rupture Conjugate Pair Analysis” (M.V.Gzovsky, “Sov. Geolog.”, col.41, 1954). This method followed from cleavage rupture system analysis on the base of postulates of rock massif strength theory.

To 1979 new method of stress trajectory reconstruction, “Cleavage Rupture Kinematic Analysis”, the base of which was model of fissured mountain mass quasi-homogeneous deformation from position of dislocation plasticity theory Batdorf-Budjansky [O.I.Goustchenko, V.Kuznetsov, “Stress and Deformation Fields in Lithosphere”, col., 1979], was made, tested and published. As the previous “Method of Cleavage Rupture Conjugate Pair Analysis”, “Method of Kinematic Analysis” allowed to use both geological and seismological data, determined on its base not only principle axis of stress, but also ratio of principle stresses – coefficient Lode-Nadai. In the same years V.V.Stepanov, developing the ideas of Yu.V.Riznichenko, created the method of tectonic deformation velocity tensor account by cleavage totality [V.V.Stepanov, “Stress and Deformation Fields in Lithosphere”, col., 1979].

From the middle of 90, it is developing method “Cleavage Rupture Totality Cataclastic Analysis”, the base of which are postulates and principles of modern theory of solid body plasticity [Yu.L.Rebetsky, Journal of earthquake prediction research, Beijing, China, 1997, V6, N 1; Yu.L.Rebetsky, Doklady RAN, 1997, V. 354, N 1, Doklady RAN, 2003, V. 3, N 2, pp. 237-241]. This method is not postulate isotropy of rock massif property and allows calculating tectonic stress tensor parameter as well as tectonic deformation velocities. The use at analysis on Mohr diagram of Coulomb strength criteria with account of existed rock fracturing for the first time allows developing procedures of spherical and deviator component of stress tensor relative value estimation.

*In-situ and theoretical research of relationship of non-uniformly scaled stress and deformation fields, developing in heterogeneous massifs (ruptures and inclusions) and in massifs with texture in appearance ordered systems of ruptures and folds *

The new devices for stress field research on models from optically active low-modular elastic and plastic materials were made. Research of different type materials, available for tectonic deformation and processes modeling was proceed [D.N.Osokina, Ductile and Elastic Low-modular Optical Materials for Research Stresses in Earth Crust by Modeling. Publishing house of AS SSSR, 1963]. On the base of these devices and theoretical calculations it was research: influence on the stress field of one rupture, as well as different ruptures combination; influence of shearing rupture with friction between its edges; as well as influence of “soft” and “hard” inclusion [D.N.Osokina, N.Yu.Tsvetkova, “Stress and Deformation Fields in Lithosphere”, col., 1979; D.N.Osokina, V.N.Fridman, “Stress and Deformation Fields in Earth Crust”, col., 1987].

The method of equivalent modeling of geological tectonic structure on optically active and opaque materials, methods and devices for research of equivalent materials property in the range of property, meet a demand of similarity in modeling, were developed. It was developed techniques of displacements, deformations, properties and stresses estimation at models from opaque materials with computer using (Osokina, Mikhailova).

Tectonic stress field hierarchy and its peculiarities were studied, method of different ranks fields in the vicinity of point dividing and marking of boundary between them was assumed. Unity of analytical and experimental methods allowed to study character of secondary disturbances distribution, to predict their type in different regions at the rupture neighborhood subject to the ratio of principle stresses value, as well as from orientation of rupture refer to path of initial stresses field and friction on its edge value [D.N.Osokina, “Stress and Deformation Field in Earth Crust”, col., 1987].

Simultaneously with described “theoretical” research it was studied tectonic rupture influence on the modern stressed state of some regional tectonic structure in seismic-dangerous regions, such as junction of the Pamirs and Tien Shan, Kopet Dagh, [D.N.Osokina, O.I.Goustchenko, V.I.Lykov, N.Yu.Tsvetkova, “Stress and Deformation Fields in Lithosphere”, col., 1979; D.N.Osokina, V.I.Lykov, E.L.Shihanovich, “Stress and Deformation Fields in Lithosphere”, col., 1979;], San-Andreas [D.N.Osokina, A.A.Nikonov, N.Yu.Tsvetkova, “Stress and Deformation Fields in Lithosphere”, 1979] for the purpose of seismic danger in different parts of this regions estimation.

For research of rheological anisotropy of multiplayer folded system, it was developed analytical method, allowed for some folds types (chevron folds) in fact, on the one hand to give the dependence of effective rheological constants of medium from peculiarity of structure of stratified massif (degree of stratification of undeformed massif, rheological properties of separate stratum, degree of massif deformity and character of outer loading), and on other – to observe for case of invariable external loading of stratified massif local stresses field evolution in the stratum of fold limbs up to intensive folding stage [Rebetsky Yu.L., Goustchenko O.I., Izv. RAS Fisika Zemli, 1995, N 8, pp. 5-24]. In this paper it was firstly in respect to mountain mass analytically obtained state equations, described non-linear deforming anisotropic creep of solid body.

For natural folded region it was developed the conception about linear folding objects hierarchy, the base of which is different volume of enveloped stratification: (1) deformed object in the interior of the layer; (2) separate fold (layers and alternations); (3) folded domain (homogeneous massive cluster of strata); (4) structure cells (all sediment cover); (5) tectonic zones (all crust); (6) mega-anticlinorium (tectonosphere); (7) movable belt (mantle plus crust) [F.L.Yakovlev, Diagnostics Linear Folding Forming Mechanisms by Quantitative Criteria of Its Morphology (On Example of The Great Caucasus). M., UIPE RAS, 1997, 76 p.] Value of this system is that complex natural system analysis makes separately for object of each level and it is not necessary to produce models, which covers individual folds (first meters) and mega-anticlinorium (tens of kilometers). Analysis of structure forming mechanisms makes sequentially from more simple objects (for example, types of oolite – strain-analysis) to more and more big and complex. Analysis makes using same quantitative object morphology measuring both natural and model (with known genesis), that allows methodically correct to compare its one with another for the purpose of clearing nature of the first. It was developed the system of morphological and kinematic analysis methods, enveloping objects of all levels.

Research of typical elementary tectonic structure deformation mechanisms using theory and model was made. (I.M.Volovich, A.S.Grigorjev, O.I.Goustchenko, A.V.Mikhailova, D.N.Osokina, Yu.L.Rebetsky). It was produced analitico-experimental method of tectonic structure forming processes studying, by which initial stage of forming at small deformation and in the absence of discontinuity studied in detail analytically by the methods of continuum mechanics, the further stage of process studied on models from equivalent materials, on which was researched whole class of structures, formed in stratum above active fracture in basement [A.S.Grigorjev, A.V.Mikhailova, col., Experimental Tectonics in Theoretical and Applied Geology, M.,Nauka, 1985]..

On the base of given approach it were research: displacements and its characteristics, including vertical surface displacements velocities gradients, deformation and its velocities in forming structures distributions, principle strain (stress) and destruction path pattern. On models it was observed structure on some stages up to its destruction development. This was allowed not only made up full its forming pattern, but also be assured in rightness of theoretical calculations, predicted destruction structures [A.S.Grigorjev, I.M.Volovich, A.V.Mikhailova, Yu.L.Rebetsky, Z.E.Shahmuradova, “Stress and Deformation Fields in Earth Crust”, col., 1987]. Research was made in respect to both homogeneous and stratified massifs. The works made in contact with IGiRGI subdivision, studied modern movements in Pripjat’ and Tersko-Sunzensk depressions.

*Studying of regional tectonic structure deformation mechanisms*

Research of modern regional tectonic structures deformation mechanisms made on the base of modern tectonic stresses fields, reconstructed in our laboratory, and added up to reconstruction by methods of modeling, analytical or experimental (equivalent modeling), of these mechanisms. Modeling considered successful, and mechanisms considered reconstructed with necessary degree of approximation satisfactorily, if modeling deformation field was identical natural one, as well as were satisfied with prescribed order of accuracy some other conditions: if were recognized identically surface displacements, destruction character, coefficient Lode-Nadai and so on.

Using “Method of Kinematic Analysis” it was constructed the path of a number of areas of Pamiro-Tien Shan (including the ridge of Peter I) and Kamchatka, as well as the map of principle normal and shear stresses path for whole Eurasia [O.I.Goustchenko, “Stress and Deformation Fields in Lithosphere”, col., 1979]. From 1989 work of reconstruction on the base of “Method of Kinematic Analysis” methodology algorithms improvement continued with usage of new technologies, computer variant of method, rested upon [O.I.Goustchenko, Yu.L.Rebetsky, Reports of the first international seminar “Stresses in lithosphere (global, regional, local)” theses, 1994]. It was produced catalogue of earthquake source mechanisms for a number of regions, what allows to make reconstruction of modern principle stresses paths and study stress state types for a number of regions, including: Caucasus-Iran [O.I.Goustchenko, A.O.Mostrjukov, V.A.Petrov, DAS SSSR ser. geoph., 1990, V. 312, N 4], South-East Asia [O.I.Goustchenko, Yu.L.Rebetsky, A.V.Mikhailova, G.V.Rossanova, A.A.Lomakin, T.P.Arefjeva, Mechanics of Structurization in Lithosphere and Seismicity, 1991, pp. 165-166].

Research of folded (non modern) structure forming mechanisms was made by come in laboratory in 1992 F.L.Yakovlev. In contrast to the rest directions, specificity of object forced to study not stresses fields, but displacement (deformation) fields of both natural and model structures. The main developed methods allow study structures of some scaled levels from individual folds to megaanticlinorium forming mechanisms. It was developed two approach – morphological (semiquantitative), revealed the list of possible forming mechanisms, and kinematic (quantitative), allowed to determine in digits deformation dimension and quota of each single mechanism in a complicated process by compare of natural (or experimental) structure with process model, underlying in the base of kinematic method. Already obtained reconstructions refer to individual folds, folded domains, a number of tectonic zones and megaanticlinorium of the Great Caucasus itself.