气候变化领域集成服务门户(CCPortal): Hales Discontinuity in the Southern Indian Continental Lithosphere: Seismological and Petrological Models

CCPortal

DOI	10.1029/2020JB020564
	Hales Discontinuity in the Southern Indian Continental Lithosphere: Seismological and Petrological Models
	Chaudhury J.; Mitra S.; Sarkar T.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	We model the depth and Vs structure of the Hales discontinuity (H-D) beneath Eastern Dharwar Craton (EDC) and Southern Granulite Terrain (SGT) using P wave receiver function (P-RF) analysis and joint inversion with Rayleigh wave phase velocity dispersion. We calculate P-RFs at higher frequency (fmax = 0.46 Hz), compared to previous studies, to show that the H-D P-to-S converted phase (Phs) is distinct from crustal reverberations. Phs at stations Hyderabad (HYB) and Gauribidanur (GBA), in the EDC, arrive at ∼11.5 s and ∼12 s, respectively. From joint inversion, the H-D is modeled at 107 ± 5 km and 113 ± 4 km depth, with ∼3% and ∼4% Vs increase, beneath HYB and GBA, respectively. For station Kodaikanal (KOD), in SGT, the Phs destructively interferes with the negative midcrustal reverberation at most ray-parameters, which explains its apparent absence in previous studies. We isolated P-RFs where Phs is distinct at ∼11 s and model it at 102 ± 3 km depth. Common conversion point stack profiles constructed by depth migrating P-RFs through the Vs model show an undulatory nature of the H-D. From data of mantle xenoliths (Wajrakarur kimberlite field), we calculate Vs of mantle peridotite and eclogite, using published bulk rock compositions. At the H-D depth and temperature derived from Indian shield geotherm, we observed a good match to the Vs structure of the H-D. Our results support the geodynamic model of the H-D being an interface of paleosubducted eclogitic oceanic crust embedded within the upper mantle peridotite. Global observations of mantle reflectors within the continental lithosphere, at depths similar to H-D, have been related to relict subduction and independently support our model. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	Hales discontinuity; joint modeling; pseudosections; receiver functions; relict subduction; xenoliths
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187353
作者单位	Department of Earth Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, West Bengal, India
推荐引用方式 GB/T 7714	Chaudhury J.,Mitra S.,Sarkar T.. Hales Discontinuity in the Southern Indian Continental Lithosphere: Seismological and Petrological Models[J],2021,126(2).
APA	Chaudhury J.,Mitra S.,&Sarkar T..(2021).Hales Discontinuity in the Southern Indian Continental Lithosphere: Seismological and Petrological Models.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Chaudhury J.,et al."Hales Discontinuity in the Southern Indian Continental Lithosphere: Seismological and Petrological Models".Journal of Geophysical Research: Solid Earth 126.2(2021).