The Cretaceous superchron geodynamo: Observations near the tangent cylinder
TLDR
P paleomagnetic and paleointensity data from lavas of the Cretaceous Normal Polarity Superchron that formed at high latitudes near the tangent cylinder that surrounds the solid inner core suggest that the basic features of the geomagnetic field are intrinsically related.Abstract:
If relationships exist between the frequency of geomagnetic reversals and the morphology, secular variation, and intensity of Earth's magnetic field, they should be best expressed during superchrons, intervals tens of millions of years long lacking reversals. Here we report paleomagnetic and paleointensity data from lavas of the Cretaceous Normal Polarity Superchron that formed at high latitudes near the tangent cylinder that surrounds the solid inner core. The time-averaged field recorded by these lavas is remarkably strong and stable. When combined with global results available from lower latitudes, these data define a time-averaged field that is overwhelmingly dominated by the axial dipole (octupole components are insignificant). These observations suggest that the basic features of the geomagnetic field are intrinsically related. Superchrons may reflect times when the nature of core–mantle boundary heat flux allows the geodynamo to operate at peak efficiency.read more
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Absolute plate motions in a reference frame defined by moving hot spots in the Pacific, Atlantic, and Indian oceans
Pavel V. Doubrovine,Pavel V. Doubrovine,Bernhard Steinberger,Bernhard Steinberger,Bernhard Steinberger,Trond H. Torsvik +5 more
TL;DR: In this article, a new global moving hot spot reference frame (GMHRF) was defined using a comprehensive set of radiometric dates from arguably the best-studied hot spot tracks, refined plate circuit reconstructions, a new plate polygon model, and an iterative approach for estimating hot spot motions from numerical models of whole mantle convection and advection of plume conduits in the mantle flow that ensures their consistency with surface plate motions.
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Strength of the geomagnetic field in the Cretaceous Normal Superchron: New data from submarine basaltic glass of the Troodos Ophiolite
Lisa Tauxe,Hubert Staudigel +1 more
TL;DR: In this article, the authors present new paleointensity data from 39 sampling sites collected from the quenched margins of pillow lavas and dikes exposed within the Troodos Ophiolite, formed during the Cretaceous Normal Superchron (CNS), a period of approximately 40 million years when the geomagnetic field reversed extremely infrequently if at all.
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Geomagnetic Secular variation in the Cretaceous Normal Superchron and in the Jurassic
Andrew J. Biggin,Douwe J.J. van Hinsbergen,Douwe J.J. van Hinsbergen,Cor G. Langereis,G. B. Straathof,G. B. Straathof,Martijn H. L. Deenen +6 more
TL;DR: McFadden et al. as mentioned in this paper analyzed a database of new and published palaeomagnetic directions from lavas emplaced during these periods in order to obtain first-order descriptions of the palaeosecular variation (PSV) during these times.
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