{"title":"STRUCTURAL-GEODYNAMIC CONTROL OF KIMBERLITE PIPES OF THE YAKUT DIAMOND PROVINCE ACCORDING TO THE DATA OF GRAVISTRUCTURAL ANALYSIS","authors":"S. M. Makeev","doi":"10.5800/gt-2021-12-4-0567","DOIUrl":null,"url":null,"abstract":"The article deals with the fundamental concepts of a new method of interpretation of regional gravimetry (scale 1:1 000 000) based on the idea of the deformational nature of low-frequency gravity anomalies. The method provided an opportunity to identify the direction of tectonic compression in the Yakut diamond-bearing province, to localize segments and axes of inter-shear compression and extension of different kinematics and on that basis to distinguish the shear interaction zones spatially correlating with the location of kimberlite pipes. Particularly, the whole area is characterized by four transpressive compression directions: a pair of orthogonal (dextral with azimuth 8° and sinistral with azimuth 98°) and a pair of diagonal (dextral with azimuth 38° and sinistral with azimuth 128°). These data correlate to those from the regional tectonophysical studies not only within the compression direction azimuths but also within kinematics of transpressive motions for two main phases in geodynamical evolution of the Yakutsk diamond-bearing province (YDP) predominantly dextral for the first phase of the northeastern compression and sinistral for second phase of the northwestern compression. The article also shows that the Alakit-Olenek mineragenic zone is an extensive (~500 km) area of plastic deformation of rocks ~90 km in width with the right-lateral kinematics of apparent motions of the rocks along its northern and southern boundaries. The southern boundary of the mineragenic zone exhibits the northeaststriking continuity whereas its northern boundary is discontinuous. The boundaries of the Alakit-Olenek mineragenic zone are controlled by the zones of shear interaction of different dynamics and kinematics, which are spatially related to kimberlite pipes and diamond placer deposits. The results of this study imply that the method proposed for interpretation of gravity field can predict the occurrence of structures of geodynamic control of kimberlite magmatism of the Yakut diamond-bearing province.","PeriodicalId":44925,"journal":{"name":"Geodynamics & Tectonophysics","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geodynamics & Tectonophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.5800/gt-2021-12-4-0567","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
The article deals with the fundamental concepts of a new method of interpretation of regional gravimetry (scale 1:1 000 000) based on the idea of the deformational nature of low-frequency gravity anomalies. The method provided an opportunity to identify the direction of tectonic compression in the Yakut diamond-bearing province, to localize segments and axes of inter-shear compression and extension of different kinematics and on that basis to distinguish the shear interaction zones spatially correlating with the location of kimberlite pipes. Particularly, the whole area is characterized by four transpressive compression directions: a pair of orthogonal (dextral with azimuth 8° and sinistral with azimuth 98°) and a pair of diagonal (dextral with azimuth 38° and sinistral with azimuth 128°). These data correlate to those from the regional tectonophysical studies not only within the compression direction azimuths but also within kinematics of transpressive motions for two main phases in geodynamical evolution of the Yakutsk diamond-bearing province (YDP) predominantly dextral for the first phase of the northeastern compression and sinistral for second phase of the northwestern compression. The article also shows that the Alakit-Olenek mineragenic zone is an extensive (~500 km) area of plastic deformation of rocks ~90 km in width with the right-lateral kinematics of apparent motions of the rocks along its northern and southern boundaries. The southern boundary of the mineragenic zone exhibits the northeaststriking continuity whereas its northern boundary is discontinuous. The boundaries of the Alakit-Olenek mineragenic zone are controlled by the zones of shear interaction of different dynamics and kinematics, which are spatially related to kimberlite pipes and diamond placer deposits. The results of this study imply that the method proposed for interpretation of gravity field can predict the occurrence of structures of geodynamic control of kimberlite magmatism of the Yakut diamond-bearing province.
期刊介绍:
The purpose of the journal is facilitating awareness of the international scientific community of new data on geodynamics of continental lithosphere in a wide range of geolchronological data, as well as tectonophysics as an integral part of geodynamics, in which physico-mathematical and structural-geological concepts are applied to deal with topical problems of the evolution of structures and processes taking place simultaneously in the lithosphere. Complex geological and geophysical studies of the Earth tectonosphere have been significantly enhanced in the current decade across the world. As a result, a large number of publications are developed based on thorough analyses of paleo- and modern geodynamic processes with reference to results of properly substantiated physical experiments, field data and tectonophysical calculations. Comprehensive research of that type, followed by consolidation and generalization of research results and conclusions, conforms to the start-of-the-art of the Earth’s sciences.