Arun K. Ojha , D.P. Monika Saini , Amar Agarwal , Ambrish K. Pandey
{"title":"从堤坝群解密印度东北部辛格布姆克拉通的构造发展:了解 Archean - Proterozoic 超大陆岩浆动力学的窗口","authors":"Arun K. Ojha , D.P. Monika Saini , Amar Agarwal , Ambrish K. Pandey","doi":"10.1016/j.pepi.2024.107169","DOIUrl":null,"url":null,"abstract":"<div><p>Singhbhum Craton (SC) hosted eight different dyke swarm events, which are collectively known as the Newer Dolerite Dykes. These have been correlated with different cratons and supercontinents based on age, geochemistry, and paleomagnetic data. However, our understanding of stress conditions during and after the dyke intrusions and the magma chamber dynamics is limited due to lack of information. In this study, we have investigated magma dynamics and crustal extension for different dyke swarm events in the SC to explore the magma chamber dynamics during the supercontinent breakup and at other cratons around the globe. Further, we have also quantified post-intrusion response to the far-field stress in different dyke swarms of the SC. For a comprehensive understanding of the magma dynamics and deformation history of the dyke swarms, we investigated dykes associated structures and estimated the magma pressure relative to the principal stresses. We used dyke wall attitude data to explore the paleostress conditions during the dyke intrusion, fault-slip data for post-emplacement deformation, and field structures with dyke thickness data to understand magma dynamics and crustal extension.</p><p>Paleostress analysis in four dyke swarms indicates relatively higher magma pressure in the Pipilia dyke swarm compared to Ghatgaon, Keonjhar, and Kaptipada dyke swarms. This is further supported by the fact that Pipilia dykes are thicker than the other three dyke swarms. Post-emplacement deformation is evident from the fault-slip observations, tectonic fractures, and veins cross-cutting dykes and host rock. Fault-slip observations suggest an extensional tectonic event followed by a compressive one. The extensional stress regime, active during the intrusion of Pipilia dyke swarm, overprints the Ghatgaon dyke swarm, while the far-field stress from the Singhbhum Shear Zone affects all the analyzed dykes and the host rock. These observations are in agreement with the thinned lithosphere of SC. We estimate that the Ghatgaon swarm caused the maximum average crustal extension/dilation of 9.65%, while the Keonjhar swarm led to the least average extension of 1.58%. We suggest that the Pipila dyke swarm event may have dilated a part of the Columbia supercontinent by ∼8.5% as the dilations for other regions in the supercontinents are not known.</p></div>","PeriodicalId":54614,"journal":{"name":"Physics of the Earth and Planetary Interiors","volume":"350 ","pages":"Article 107169"},"PeriodicalIF":2.4000,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Tectonic development in Singhbhum Craton, NE India decrypted from dyke swarms: A window to understand magma dynamics in Archean-Proterozoic supercontinents\",\"authors\":\"Arun K. Ojha , D.P. Monika Saini , Amar Agarwal , Ambrish K. Pandey\",\"doi\":\"10.1016/j.pepi.2024.107169\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Singhbhum Craton (SC) hosted eight different dyke swarm events, which are collectively known as the Newer Dolerite Dykes. These have been correlated with different cratons and supercontinents based on age, geochemistry, and paleomagnetic data. However, our understanding of stress conditions during and after the dyke intrusions and the magma chamber dynamics is limited due to lack of information. In this study, we have investigated magma dynamics and crustal extension for different dyke swarm events in the SC to explore the magma chamber dynamics during the supercontinent breakup and at other cratons around the globe. Further, we have also quantified post-intrusion response to the far-field stress in different dyke swarms of the SC. For a comprehensive understanding of the magma dynamics and deformation history of the dyke swarms, we investigated dykes associated structures and estimated the magma pressure relative to the principal stresses. We used dyke wall attitude data to explore the paleostress conditions during the dyke intrusion, fault-slip data for post-emplacement deformation, and field structures with dyke thickness data to understand magma dynamics and crustal extension.</p><p>Paleostress analysis in four dyke swarms indicates relatively higher magma pressure in the Pipilia dyke swarm compared to Ghatgaon, Keonjhar, and Kaptipada dyke swarms. This is further supported by the fact that Pipilia dykes are thicker than the other three dyke swarms. Post-emplacement deformation is evident from the fault-slip observations, tectonic fractures, and veins cross-cutting dykes and host rock. Fault-slip observations suggest an extensional tectonic event followed by a compressive one. The extensional stress regime, active during the intrusion of Pipilia dyke swarm, overprints the Ghatgaon dyke swarm, while the far-field stress from the Singhbhum Shear Zone affects all the analyzed dykes and the host rock. These observations are in agreement with the thinned lithosphere of SC. We estimate that the Ghatgaon swarm caused the maximum average crustal extension/dilation of 9.65%, while the Keonjhar swarm led to the least average extension of 1.58%. We suggest that the Pipila dyke swarm event may have dilated a part of the Columbia supercontinent by ∼8.5% as the dilations for other regions in the supercontinents are not known.</p></div>\",\"PeriodicalId\":54614,\"journal\":{\"name\":\"Physics of the Earth and Planetary Interiors\",\"volume\":\"350 \",\"pages\":\"Article 107169\"},\"PeriodicalIF\":2.4000,\"publicationDate\":\"2024-03-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physics of the Earth and Planetary Interiors\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S003192012400027X\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physics of the Earth and Planetary Interiors","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S003192012400027X","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Tectonic development in Singhbhum Craton, NE India decrypted from dyke swarms: A window to understand magma dynamics in Archean-Proterozoic supercontinents
Singhbhum Craton (SC) hosted eight different dyke swarm events, which are collectively known as the Newer Dolerite Dykes. These have been correlated with different cratons and supercontinents based on age, geochemistry, and paleomagnetic data. However, our understanding of stress conditions during and after the dyke intrusions and the magma chamber dynamics is limited due to lack of information. In this study, we have investigated magma dynamics and crustal extension for different dyke swarm events in the SC to explore the magma chamber dynamics during the supercontinent breakup and at other cratons around the globe. Further, we have also quantified post-intrusion response to the far-field stress in different dyke swarms of the SC. For a comprehensive understanding of the magma dynamics and deformation history of the dyke swarms, we investigated dykes associated structures and estimated the magma pressure relative to the principal stresses. We used dyke wall attitude data to explore the paleostress conditions during the dyke intrusion, fault-slip data for post-emplacement deformation, and field structures with dyke thickness data to understand magma dynamics and crustal extension.
Paleostress analysis in four dyke swarms indicates relatively higher magma pressure in the Pipilia dyke swarm compared to Ghatgaon, Keonjhar, and Kaptipada dyke swarms. This is further supported by the fact that Pipilia dykes are thicker than the other three dyke swarms. Post-emplacement deformation is evident from the fault-slip observations, tectonic fractures, and veins cross-cutting dykes and host rock. Fault-slip observations suggest an extensional tectonic event followed by a compressive one. The extensional stress regime, active during the intrusion of Pipilia dyke swarm, overprints the Ghatgaon dyke swarm, while the far-field stress from the Singhbhum Shear Zone affects all the analyzed dykes and the host rock. These observations are in agreement with the thinned lithosphere of SC. We estimate that the Ghatgaon swarm caused the maximum average crustal extension/dilation of 9.65%, while the Keonjhar swarm led to the least average extension of 1.58%. We suggest that the Pipila dyke swarm event may have dilated a part of the Columbia supercontinent by ∼8.5% as the dilations for other regions in the supercontinents are not known.
期刊介绍:
Launched in 1968 to fill the need for an international journal in the field of planetary physics, geodesy and geophysics, Physics of the Earth and Planetary Interiors has now grown to become important reading matter for all geophysicists. It is the only journal to be entirely devoted to the physical and chemical processes of planetary interiors.
Original research papers, review articles, short communications and book reviews are all published on a regular basis; and from time to time special issues of the journal are devoted to the publication of the proceedings of symposia and congresses which the editors feel will be of particular interest to the reader.