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
(2019) In Precambrian Research 329. p.26-43- 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... (More)
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.
(Less)
- author
- organization
- publishing date
- 2019-08
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Eastern Dharwar craton, India, Mafic dyke swarms, Oroclinal bending, Paleoproterozoic, U-Pb baddeleyite
- in
- Precambrian Research
- volume
- 329
- pages
- 18 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:85052845108
- ISSN
- 0301-9268
- DOI
- 10.1016/j.precamres.2018.12.017
- language
- English
- LU publication?
- yes
- additional info
- Funding Information: This is publication no. 72 of the Large Igneous Provinces – Supercontinent Reconstruction – Resource Exploration Project (CAMIRO Project 08E03, and Canadian government grant NSERC CRDPJ 419503-11) (www.supercontinent.org, www.camiro.org/exploration/ongoing-projects). REE was partially funded by the Russian Federation grant No. 14.Y26.31.0012. Reviewer Martin Klausen, a second anonymous review, and journal editors are sincerely thanked for constructive comments that helped to improve the quality of the paper. Funding Information: This is publication no. 72 of the Large Igneous Provinces – Supercontinent Reconstruction – Resource Exploration Project ( CAMIRO Project 08E03 , and Canadian government grant NSERC CRDPJ 419503-11 ) ( www.supercontinent.org , www.camiro.org/exploration/ongoing-projects ). REE was partially funded by the Russian Federation grant No. 14.Y26.31.0012 . Reviewer Martin Klausen, a second anonymous review, and journal editors are sincerely thanked for constructive comments that helped to improve the quality of the paper. Publisher Copyright: © 2018 Elsevier B.V.
- id
- 7feb8acf-261f-413d-99d8-367376fa1d1b
- date added to LUP
- 2023-04-14 18:11:27
- date last changed
- 2023-04-17 13:36:34
@article{7feb8acf-261f-413d-99d8-367376fa1d1b,
abstract = {{<p>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.</p>}},
author = {{Söderlund, Ulf and Bleeker, Wouter and Demirer, Kursad and Srivastava, Rajesh K. and Hamilton, Michael and Nilsson, Mimmi and Pesonen, Lauri J. and Samal, Amiya K. and Jayananda, Mudlappa and Ernst, Richard E. and Srinivas, Madabhooshi}},
issn = {{0301-9268}},
keywords = {{Eastern Dharwar craton; India; Mafic dyke swarms; Oroclinal bending; Paleoproterozoic; U-Pb baddeleyite}},
language = {{eng}},
pages = {{26--43}},
publisher = {{Elsevier}},
series = {{Precambrian Research}},
title = {{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}},
url = {{http://dx.doi.org/10.1016/j.precamres.2018.12.017}},
doi = {{10.1016/j.precamres.2018.12.017}},
volume = {{329}},
year = {{2019}},
}