Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 2021

Идентификатор DOI: 10.5800/GT-2021-12-4-0567

Ключевые слова: deformation, extension, fractality, gravimetry, kimberlite pipe, mesomechanics, rock flow, shear, shear interaction, transpression

Аннотация: The article deals with the fundamental concepts of a new method of interpretation of regional gravimetry (scale 1:1000000) 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 northeast-striking 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. © 2021 Institute of the Earth's Crust. All rights reserved. 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 degrees and sinistral with azimuth 98 degrees) and a pair of diagonal (dextral with azimuth 38 degrees and sinistral with azimuth 128 degrees). 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 (similar to 500 km) area of plastic deformation of rocks similar to 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 northeast striking 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. 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 degrees and sinistral with azimuth 98 degrees) and a pair of diagonal (dextral with azimuth 38 degrees and sinistral with azimuth 128 degrees). 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 (similar to 500 km) area of plastic deformation of rocks similar to 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 northeast striking 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. 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 degrees and sinistral with azimuth 98 degrees) and a pair of diagonal (dextral with azimuth 38 degrees and sinistral with azimuth 128 degrees). 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 (similar to 500 km) area of plastic deformation of rocks similar to 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 northeast striking 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.

Журнал: Geodynamics and Tectonophysics

Выпуск журнала: Vol. 12, Is. 4

Номера страниц: 992-1008

ISSN журнала: 2078502X

Издатель: Institute of the Earth's Crust

• Makeev S.M. (Siberian Federal University, 79 Svobodny Ave, Krasnoyarsk, 660041, Russian Federation)

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