Publication Date:
2023-02-10
Description:
We re-evaluate 357 Jurassic-Holocene paleomagnetic datasets from Tibet-Indochina and compare them with present-day Global Position System velocity field. SE Tibet NW of the East Himalaya Syntaxis (EHS) underwent 20°–30° counterclockwise rotations around 50 Ma, and mostly clockwise rotations after 40 Ma. NE of the EHS, post-50 Ma clockwise rotation occurred, whereas highly scattered clockwise rotations took place on northern Indochina at 25–15 Ma, after a remagnetization episode. We suggest that the indentation of Greater India NE corner at ∼50 Ma resulted in a wide orogenic reentrant characterized by opposite rotations at orocline limbs. Rotations East of EHS after 40 Ma were likely due to local strike-slip fault activity. After 30 Ma, the ongoing India collision fragmented Indochina into km-scale blocks that experienced independent rotations. The present-day clockwise rotation pattern around the EHS started at 15–10 Ma along with eastward Tibet crustal spreading, and has not produced yet a detectable paleomagnetic rotation.
Description:
The Ph.D. grant of the Istituto Nazionale di Geofisica e Vulcanologia (INGV) and of the Department of Science of Roma Tre University is gratefully acknowledged.
Description:
Published
Description:
e2021GL096623
Description:
1A. Geomagnetismo e Paleomagnetismo
Description:
JCR Journal
Keywords:
tectonics
;
paleomagnetism
;
geodesy
;
tibet
;
04.04. Geology
;
04.03. Geodesy
;
04.07. Tectonophysics
;
03.01. General
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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