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Paleomagnetic and Geochronological Results From the Zhela and Weimei Formations Lava Flows of the Eastern Tethyan Himalaya: New Insights Into the Breakup of Eastern Gondwana.

Authors :
Bian, Weiwei
Yang, Tianshui
Ma, Yiming
Jin, Jingjie
Gao, Feng
Wang, Suo
Peng, Wenxiao
Zhang, Shihong
Wu, Huaichun
Li, Haiyan
Cao, Liwan
Shi, Yuruo
Source :
Journal of Geophysical Research. Solid Earth; Jan2019, Vol. 124 Issue 1, p44-64, 21p
Publication Year :
2019

Abstract

The breakup of eastern Gondwana is among the hottest topics in the Earth sciences because of its effect on global climate during the Jurassic‐Cretaceous, its influence on the evolution of life, and its importance to paleogeographic reconstruction. To better constrain the Jurassic and Cretaceous paleogeographic position of the Tethyan Himalaya and the breakup of eastern Gondwana, a combined paleomagnetic and geochronological study was performed on the Zhela and Weimei Formations lava flows, dated at ~138–135 Ma, in the Luozha area of the eastern Tethyan Himalaya. Both positive fold and reversal tests together with a maximum grouping at 100% unfolding indicate that the characteristic remanent magnetization directions are primary magnetizations acquired before folding. The tilt‐corrected directions yielded a paleopole at 0.9°N, 293.4°E with A95 = 7.0° and a corresponding paleolatitude of 53.5°S ± 7.0°S for the Luozha sampling area (28.9°N, 91.3°E), validating that the original erupted position of the Zhela and Weimei Formations lava flows was located in the center of the Kerguelen mantle plume. Our new results, together with the published paleomagnetic, geochronological, and geochemical results, demonstrate that the Comei‐Bunbury large igneous province originated from the Kerguelen mantle plume. The temporal and spatial relationships between the Comei‐Bunbury large igneous province and the Kerguelen mantle plume indicate that eastern Gondwana initially rifted at ~147 Ma and that the Indian Plate fully separated from the Australian‐Antarctic Plate before ~124 Ma. Key Points: The Luozha sampling area was located at ~53.5 degrees south plus‐minus 7.0 degrees south at ~138‐135 MaThe Comei‐Bunbury large igneous province (LIP) originated from the Kerguelen mantle plumeEastern Gondwana initially rifted at ~147 Ma, and the Indian Plate fully separated from the Australian‐Antarctic Plate before ~124 Ma [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
21699313
Volume :
124
Issue :
1
Database :
Complementary Index
Journal :
Journal of Geophysical Research. Solid Earth
Publication Type :
Academic Journal
Accession number :
134931252
Full Text :
https://doi.org/10.1029/2018JB016403