Textures of magnetic and gravitational fields of the Pre-Caspian syneclise

UDK: 550.83

DOI: 10.24887/0028-2448-2023-5-43-47

Key words: Pre-Caspian syneclise, Caspian Sea, gravitational field, magnetic field, lineaments, satellite images, planetary fault system

Authors: L.V. Miloserdova (Gubkin University, RF, Moscow), K.I. Dantsova (Gubkin University, RF, Moscow)

The textural characteristics of the anomalous gravitational and magnetic fields of the Pre-Caspian syneclise are studied using the WinLESSA software package. The results are compared with the lineament network deciphered from space images in the visible and infrared zones of the spectrum. It has been established that the WinLESSA software is applicable for revealing textural features of geophysical fields. It has been established that changes in the texture of geophysical fields have distinct patterns. The anisotropy of the magnetic field is oriented in the northwest direction. The texture of the gravitational field has sublatitudinal, northeastern and northwestern directions. Lineament bundles identified by anomalous fields have a quasi-periodic character and planetary orientation (rays of orthogonal and two diagonal directions), which indicates their connection with planetary stress systems. The largest lineaments are reproduced on all materials, but their density (abundance) depends on the settings adopted and the details of the original image. The textural characteristics of the anomalous gravitational and magnetic fields of the Pre-Caspian syneclise and the results of lineament interpretation are compared with the results of known fault maps. In the north of the Pre-Caspian syneclise, additional blocks have been identified by other methods according to magnetic survey data. Conclusions are presented about the main characteristics of lineaments identified from satellite images, maps of magnetic and gravitational anomalies. The lineaments are generally comparable, with regard to clusters of rose diagrams, and elongation vectors, for which it is impossible to either find correspondences in the previously identified faults, or identify any patterns  a chaotic distribution was revealed, the maxima and minima are also randomly and irregularly located on the density map strokes. References 1. Volozh Yu.A., Antipov M.P., Garagash I.A., Lobkovskiy L.I., Eklogitovaya model' formirovaniya Prikaspiyskoy vpadiny (Eclogitic model of the formation of the Pre-Caspian Basin), In: Osadochnye basseyny: metodika izucheniya, stroenie i evolyutsiya (Sedimentary basins: a technique of studying, a structure and evolution): edited by Leonov Yu.G., Volozh Yu.A., Moscow: Nauchnyy mir Publ., 2004, pp. 471-486. 2. Leonov Yu.G., Volozh Yu.A., Antipov M.P., Konsolidirovannaya kora Kaspiyskogo regiona: opyt rayonirovaniya (Consolidated crust of the Caspian region: zoning experience): edited by Leonov Yu.G., Moscow: GEOS Publ., 2010, 64 p. 3. Karta razlomov territorii SSSR i sopredel’nykh stran (Fault map of the territory of the USSR and neighboring countries): edited by Belyaevskiy N.A., Unksov V.A., Moscow: Publ. of Aerogeologiya, 1980. 4. Miloserdova L.V., Aerokosmicheskie metody v neftegazovoy geologii (Aerospace methods in petroleum geology): edited by Florenskiy P.V., Moscow: Nedra Publ., 2022, 502 p 5. Zlatopol’skiy A.A., Automation of lineament analysis - LESSA methodology. Extended lineaments. Methodological review (In Russ.), Dinamicheskaya geologiya, 2020, no. 1, pp. 55-66.