气候变化领域集成服务门户(CCPortal): Baddeleyite Pb–Pb geochronology and paleomagnetic poles for ~1.89–1.86 Ga mafic intrusions from the Dharwar craton, India, and their paleogeographic implications

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DOI	10.1016/j.tecto.2021.228789
	Baddeleyite Pb–Pb geochronology and paleomagnetic poles for ~1.89–1.86 Ga mafic intrusions from the Dharwar craton, India, and their paleogeographic implications
	Parashuramulu V.; Shankar R.; Sarma D.S.; Nagaraju E.; Babu N.R.
发表日期	2021
ISSN	00401951
卷号	805
英文摘要	We present new key paleomagnetic pole at 13°S, 152°E (k = 21, A95 = 7.8°) for recently identified 1864.4 ± 2.7 Ma (weighted mean age of four Pb–Pb ages) mafic magmatic event, based on a detailed paleomagnetic study of dolerite dykes and sills intruding Archean basement rocks and Tadipatri formation of the Cuddapah basin, Dharwar craton respectively. The Pb–Pb baddeleyite geochronology yields a crystallisation age of 1867.1 ± 1.0 Ma (MSWD = 1.02) for N77°E trending dyke in the southern region to Cuddapah basin. This new age obtained, confirms the presence of ~1864 Ma magmatic episode with a spatial extent of ~400 km in the Eastern Dharwar craton, within the brief period of ~5 Ma. The paleomagnetic results in these dykes revealed reverse polarity magnetisation direction with mean D = 107°, I = 24° (N = 13 sites, α95 = 10°). Here, we also update the normal polarity magnetic directions on ~1.89 Ga swarm, and the corresponding paleopole situated at 21°N, 336°E (N = 79 sites, A95 = 3.6°). The paleoposition of India is constrained around the equator during ~1.89–1.86 Ga time. The paleogeographic reconstructions were also been attempted at ~1.89 Ga and ~ 1.86 Ga with available key poles from other cratons, indicates the possibility of single plume acting as a source for two distinguishable radial emplacement of mafic dyke swarms across India (Dharwar and Bastar craton) and Western Australia (Yilgarn craton) within a time span of ~35 Ma. The individual movement of India, Baltica and Siberia with a drift rate of ~5.55 cm/yr towards the south, whereas Amazonia craton has moved rapidly to the north (~24.9 cm/yr), do not suggest the amalgamation of a supercontinent (Columbia/ Nuna) during ~1.88–1.86 Ga time. © 2021 Elsevier B.V.
关键词	Baddeleyite geochronology Dharwar craton Large Igneous Province Mafic dykes Paleomagnetism Supercontinent
英文关键词	Magnetic polarity; Metals; Dykes and sills; Mafic intrusion; Paleogeographic reconstruction; Paleomagnetic poles; Reverse polarity; Supercontinents; Western Australia; Yilgarn cratons; Geochronology; baddeleyite; craton; dike; geochronology; igneous intrusion; large igneous province; lead-lead dating; mafic rock; paleogeography; paleomagnetism; supercontinent; Dharwar Craton; India; Columbia
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/208048
作者单位	CSIR-National Geophysical Research Institute, Council of Scientific and Industrial Research, Uppal Road, Hyderabad, 500 007, India
推荐引用方式 GB/T 7714	Parashuramulu V.,Shankar R.,Sarma D.S.,等. Baddeleyite Pb–Pb geochronology and paleomagnetic poles for ~1.89–1.86 Ga mafic intrusions from the Dharwar craton, India, and their paleogeographic implications[J],2021,805.
APA	Parashuramulu V.,Shankar R.,Sarma D.S.,Nagaraju E.,&Babu N.R..(2021).Baddeleyite Pb–Pb geochronology and paleomagnetic poles for ~1.89–1.86 Ga mafic intrusions from the Dharwar craton, India, and their paleogeographic implications.Tectonophysics,805.
MLA	Parashuramulu V.,et al."Baddeleyite Pb–Pb geochronology and paleomagnetic poles for ~1.89–1.86 Ga mafic intrusions from the Dharwar craton, India, and their paleogeographic implications".Tectonophysics 805(2021).