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Ulf Soderlund - One of the best experts on this subject based on the ideXlab platform.
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emplacement ages of paleoproterozoic mafic dyke Swarms in eastern dharwar craton india implications for paleoreconstructions and support for a 30 change in dyke trends from south to north
Precambrian Research, 2019Co-Authors: Rajesh K. Srivastava, Amiya K. Samal, Ulf Soderlund, Wouter Bleeker, Kursad Demirer, Michael A Hamilton, Mimmi K M Nilsson, Lauri J Pesonen, M JayanandaAbstract:Abstract Large igneous provinces (LIPs) and especially their dyke Swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke Swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke Swarms with emplacement ages within the 2.37–1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight Swarms with their currently recommended names: NE–SW to ESE–WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N–S to NNE–SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N–S to NNW–SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW–SE to WNW–ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW–SE to WNW–ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N–S, NW–SE, and ENE–WSW trending ca. 2.08 Ga Devarabanda swarm. E–W trending 1.88–1.89 Ga Hampi swarm. NW–SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some Swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke Swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
M Jayananda - One of the best experts on this subject based on the ideXlab platform.
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emplacement ages of paleoproterozoic mafic dyke Swarms in eastern dharwar craton india implications for paleoreconstructions and support for a 30 change in dyke trends from south to north
Precambrian Research, 2019Co-Authors: Rajesh K. Srivastava, Amiya K. Samal, Ulf Soderlund, Wouter Bleeker, Kursad Demirer, Michael A Hamilton, Mimmi K M Nilsson, Lauri J Pesonen, M JayanandaAbstract:Abstract Large igneous provinces (LIPs) and especially their dyke Swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke Swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke Swarms with emplacement ages within the 2.37–1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight Swarms with their currently recommended names: NE–SW to ESE–WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N–S to NNE–SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N–S to NNW–SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW–SE to WNW–ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW–SE to WNW–ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N–S, NW–SE, and ENE–WSW trending ca. 2.08 Ga Devarabanda swarm. E–W trending 1.88–1.89 Ga Hampi swarm. NW–SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some Swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke Swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
Rajesh K. Srivastava - One of the best experts on this subject based on the ideXlab platform.
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emplacement ages of paleoproterozoic mafic dyke Swarms in eastern dharwar craton india implications for paleoreconstructions and support for a 30 change in dyke trends from south to north
Precambrian Research, 2019Co-Authors: Rajesh K. Srivastava, Amiya K. Samal, Ulf Soderlund, Wouter Bleeker, Kursad Demirer, Michael A Hamilton, Mimmi K M Nilsson, Lauri J Pesonen, M JayanandaAbstract:Abstract Large igneous provinces (LIPs) and especially their dyke Swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke Swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke Swarms with emplacement ages within the 2.37–1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight Swarms with their currently recommended names: NE–SW to ESE–WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N–S to NNE–SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N–S to NNW–SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW–SE to WNW–ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW–SE to WNW–ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N–S, NW–SE, and ENE–WSW trending ca. 2.08 Ga Devarabanda swarm. E–W trending 1.88–1.89 Ga Hampi swarm. NW–SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some Swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke Swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
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Geochemical characteristics and petrogenesis of four Palaeoproterozoic mafic dike Swarms and associated large igneous provinces from the eastern Dharwar craton, India
2014Co-Authors: Rajesh K. Srivastava, Amiya K. Samal, Gulab C. GautamAbstract:Palaeoproterozoic mafic dike Swarms of different ages are well exposed in the eastern Dharwar craton of India. Available U-Pb mineral ages on these dikes indicate four discrete episodes, viz. (1) ~2.37 Ga Bangalore swarm, (2) ~2.21 Ga Kunigal swarm, (3) ~2.18 Ga Mahbubnagar swarm, and (4) ~1.89 Ga Bastar-Dharwar swarm. These are mostly sub-alkaline tholeiitic suites, with ~1.89 Ga samples having a slightly higher concentration of high-field strength elements than other Swarms with a similar MgO contents. Mg number (Mg#) in the four Swarms suggest that the two older Swarms were derived from primary mantle melts, whereas the two younger Swarms were derived from slightly evolved mantle melt. Trace element petrogenetic models suggest that magmas of the ~2.37 Ga swarm were generated within the spinel stability field by ~15–20% melting of a depleted mantle source, whereas magmas of the other three Swarms may have been generated within the garnet stability field with percentage of melting lowering from the ~2.21 Ga swarm (~25%), ~2.18 Ga swarm (~15–20%), to ~1.89 Ga swarm (~10–12%). These observations indicate that the melting depth increased with time for mafic dike magmas. Large igneous province (LIP) records of the eastern Dharwar craton are compared to those of similar mafic events observed from other shield areas. The Dharwar and the North Atlantic cratons were probably together at ~2.37 Ga, although such an episode is not found in any other craton. The ~2.21 Ga mafic magmatic event is reported from the Dharwar, Superior, North Atlantic, and Slave cratons, suggesting the presence of a supercontinent, ‘Superia’. It is difficult to find any match for the ~2.18 Ga mafic dikes of the eastern Dharwar craton, except in the Superior Province. The ~1.88–1.90 Ga mafic magmatic event is reported from many different blocks, and therefore may not be very useful for supercontinent reconstructions.
Amiya K. Samal - One of the best experts on this subject based on the ideXlab platform.
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emplacement ages of paleoproterozoic mafic dyke Swarms in eastern dharwar craton india implications for paleoreconstructions and support for a 30 change in dyke trends from south to north
Precambrian Research, 2019Co-Authors: Rajesh K. Srivastava, Amiya K. Samal, Ulf Soderlund, Wouter Bleeker, Kursad Demirer, Michael A Hamilton, Mimmi K M Nilsson, Lauri J Pesonen, M JayanandaAbstract:Abstract Large igneous provinces (LIPs) and especially their dyke Swarms are pivotal to reconstruction of ancient supercontinents. The Dharwar craton of southern Peninsular India represents a substantial portion of Archean crust and has been considered to be a principal constituent of Superia, Sclavia, Nuna/Columbia and Rodinia supercontinents. The craton is intruded by numerous regional-scale mafic dyke Swarms of which only a few have robustly constrained emplacement ages. Through this study, the LIP record of the Dharwar craton has been improved by U-Pb geochronology of 18 dykes, which together comprise seven generations of Paleoproterozoic dyke Swarms with emplacement ages within the 2.37–1.79 Ga age interval. From oldest to youngest, the new ages (integrated with U-Pb ages previously reported for the Hampi swarm) define the following eight Swarms with their currently recommended names: NE–SW to ESE–WNW trending ca. 2.37 Ga Bangalore-Karimnagar swarm. N–S to NNE–SSW trending ca. 2.25 Ga Ippaguda-Dhiburahalli swarm. N–S to NNW–SSE trending ca. 2.22 Ga Kandlamadugu swarm. NW–SE to WNW–ESE trending ca. 2.21 Ga Anantapur-Kunigal swarm. NW–SE to WNW–ESE trending ca. 2.18 Ga Mahbubnagar-Dandeli swarm. N–S, NW–SE, and ENE–WSW trending ca. 2.08 Ga Devarabanda swarm. E–W trending 1.88–1.89 Ga Hampi swarm. NW–SE ca. 1.79 Ga Pebbair swarm. Comparison of the arcuate trends of some Swarms along with an apparent oroclinal bend of ancient geological features, such as regional Dharwar greenstone belts and the late Archean (ca. 2.5 Ga) Closepet Granite batholith, have led to the hypothesis that the northern Dharwar block has rotated relative to the southern block. By restoring a 30° counter clockwise rotation of the northern Dharwar block relative to the southern block, we show that pre-2.08 Ga arcuate and fanning dyke Swarms consistently become approximately linear. Two possible tectonic models for this apparent bending, and concomitant dyke rotations, are discussed. Regardless of which deformation mechanisms applies, these findings reinforce previous suggestions that the radial patterns of the giant ca. 2.37 Ga Bangalore-Karimnagar dyke swarm, and probably also the ca. 2.21 Ga Anantapur-Kunigal swarm, may not be primary features.
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Geochemical characteristics and petrogenesis of four Palaeoproterozoic mafic dike Swarms and associated large igneous provinces from the eastern Dharwar craton, India
2014Co-Authors: Rajesh K. Srivastava, Amiya K. Samal, Gulab C. GautamAbstract:Palaeoproterozoic mafic dike Swarms of different ages are well exposed in the eastern Dharwar craton of India. Available U-Pb mineral ages on these dikes indicate four discrete episodes, viz. (1) ~2.37 Ga Bangalore swarm, (2) ~2.21 Ga Kunigal swarm, (3) ~2.18 Ga Mahbubnagar swarm, and (4) ~1.89 Ga Bastar-Dharwar swarm. These are mostly sub-alkaline tholeiitic suites, with ~1.89 Ga samples having a slightly higher concentration of high-field strength elements than other Swarms with a similar MgO contents. Mg number (Mg#) in the four Swarms suggest that the two older Swarms were derived from primary mantle melts, whereas the two younger Swarms were derived from slightly evolved mantle melt. Trace element petrogenetic models suggest that magmas of the ~2.37 Ga swarm were generated within the spinel stability field by ~15–20% melting of a depleted mantle source, whereas magmas of the other three Swarms may have been generated within the garnet stability field with percentage of melting lowering from the ~2.21 Ga swarm (~25%), ~2.18 Ga swarm (~15–20%), to ~1.89 Ga swarm (~10–12%). These observations indicate that the melting depth increased with time for mafic dike magmas. Large igneous province (LIP) records of the eastern Dharwar craton are compared to those of similar mafic events observed from other shield areas. The Dharwar and the North Atlantic cratons were probably together at ~2.37 Ga, although such an episode is not found in any other craton. The ~2.21 Ga mafic magmatic event is reported from the Dharwar, Superior, North Atlantic, and Slave cratons, suggesting the presence of a supercontinent, ‘Superia’. It is difficult to find any match for the ~2.18 Ga mafic dikes of the eastern Dharwar craton, except in the Superior Province. The ~1.88–1.90 Ga mafic magmatic event is reported from many different blocks, and therefore may not be very useful for supercontinent reconstructions.
Vijay Kumar - One of the best experts on this subject based on the ideXlab platform.
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guest editorial special section on aerial swarm robotics
IEEE Transactions on Robotics, 2018Co-Authors: Soon-jo Chung, Philip Dames, Aditya A. Paranjape, Shaojie Shen, Vijay KumarAbstract:Aerial robotics has been one of the most active areas of research within the robotics community, and recently there have been many reports of promising results in aerial swarm systems. This is partly due to the commoditization of multicopter platforms, and communication, sensing, and processing hardware that has substantially lowered the barriers to entry to the field of aerial swarm robotics. Aerial Swarms differ from Swarms of ground-based vehicles in two major respects: Aerial robots or unmanned aerial vehicles (UAVs) operate in a three-dimensional space, and the dynamics of individual vehicles add an extra layer of complexity to the problems of path planning and trajectory design. Furthermore, the success of aerial Swarms is predicated on the distributed and synergistic capabilities of individual and cooperative control, estimation, and decision making of aerial robots with limited resources, such as modest onboard computation and sensing capabilities and size, weight, and power constraints. This special section, starting with the survey paper, presents recent advances in aerial swarm robotics, and aims to put together a cohesive set of research goals and visions toward realizing fully autonomous aerial swarm systems. One objective is to emphasize the three-way tradeoff among computational efficiency for large-scale Swarms, stability, and robustness under uncertainty, and the optimal system performance.
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A Survey on Aerial Swarm Robotics
IEEE Transactions on Robotics, 2018Co-Authors: Soon-jo Chung, Philip Dames, Aditya A. Paranjape, Shaojie Shen, Vijay KumarAbstract:The use of aerial Swarms to solve real-world problems has been increasing steadily, accompanied by falling prices and improving performance of communication, sensing, and processing hardware. The commoditization of hardware has reduced unit costs, thereby lowering the barriers to entry to the field of aerial swarm robotics. A key enabling technology for Swarms is the family of algorithms that allow the individual members of the swarm to communicate and allocate tasks amongst themselves, plan their trajectories, and coordinate their flight in such a way that the overall objectives of the swarm are achieved efficiently. These algorithms, often organized in a hierarchical fashion, endow the swarm with autonomy at every level, and the role of a human operator can be reduced, in principle, to interactions at a higher level without direct intervention. This technology depends on the clever and innovative application of theoretical tools from control and estimation. This paper reviews the state of the art of these theoretical tools, specifically focusing on how they have been developed for, and applied to, aerial Swarms. Aerial Swarms differ from Swarms of ground-based vehicles in two respects: they operate in a three-dimensional space and the dynamics of individual vehicles adds an extra layer of complexity. We review dynamic modeling and conditions for stability and controllability that are essential in order to achieve cooperative flight and distributed sensing. The main sections of this paper focus on major results covering trajectory generation, task allocation, adversarial control, distributed sensing, monitoring, and mapping. Wherever possible, we indicate how the physics and subsystem technologies of aerial robots are brought to bear on these individual areas.
