Evidence for a Large-Scale Reorganization of Early Cambrian Continental Masses by Inertial Interchange True Polar Wander

Science ◽  
1997 ◽  
Vol 277 (5325) ◽  
pp. 541-545 ◽  
Author(s):  
J. L. Kirschvink
Geology ◽  
2019 ◽  
Vol 47 (12) ◽  
pp. 1112-1116 ◽  
Author(s):  
Zhiyu Yi ◽  
Yongqing Liu ◽  
Joseph G. Meert

Abstract A drastic environmental change occurred during the Middle to Late Jurassic as much of East Asia transitioned from a wet seasonal to an extremely arid climate. The timing, scope, and especially mechanism for this aridification are contentious. In this study, we report paleomagnetic data and ages from Jurassic volcanic rocks in North China and for the first time reveal a large-scale southward displacement of ∼25° for the Eastern Asian blocks (EABs) sometime between 174 ± 6 Ma and 157 ± 4 Ma. We suggest that the rapid motion documented by our paleomagnetic studies resulted from large-scale true polar wander (TPW). The TPW rotation displaced the EABs from the Northern Hemisphere humid-temperate belt into the subtropical/tropical arid zone. The resultant latitudinal motion coincided with a remarkable environmental change recorded over 10,000,000 km2 in East Asia between ca. 165 Ma and 155 Ma. We call the climate transition the “Great Jurassic East Asian Aridification” and argue that TPW-induced climatic shifts were also responsible for the demise of the Yanliao Biota and subsequent radiation of the Jehol Biota during the Late Jurassic and Early Cretaceous.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ross N. Mitchell ◽  
Christopher J. Thissen ◽  
David A. D. Evans ◽  
Sarah P. Slotznick ◽  
Rodolfo Coccioni ◽  
...  

AbstractTrue polar wander (TPW), or planetary reorientation, is well documented for other planets and moons and for Earth at present day with satellites, but testing its prevalence in Earth’s past is complicated by simultaneous motions due to plate tectonics. Debate has surrounded the existence of Late Cretaceous TPW ca. 84 million years ago (Ma). Classic palaeomagnetic data from the Scaglia Rossa limestone of Italy are the primary argument against the existence of ca. 84 Ma TPW. Here we present a new high-resolution palaeomagnetic record from two overlapping stratigraphic sections in Italy that provides evidence for a ~12° TPW oscillation from 86 to 78 Ma. This observation represents the most recent large-scale TPW documented and challenges the notion that the spin axis has been largely stable over the past 100 million years.


2002 ◽  
Vol 107 (B10) ◽  
pp. ETG 16-1-ETG 16-17 ◽  
Author(s):  
R. Sabadini ◽  
A. M. Marotta ◽  
R. De Franco ◽  
L. L. A. Vermeersen

Science ◽  
2000 ◽  
Vol 288 (5475) ◽  
pp. 2283a-2283 ◽  
Author(s):  
R. D. Cottrell

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