scholarly journals Secondary magnetic inclusions in detrital zircons from the Jack Hills, Western Australia, and implications for the origin of the geodynamo

Geology ◽  
2018 ◽  
Vol 46 (5) ◽  
pp. 427-430 ◽  
Author(s):  
Benjamin P. Weiss ◽  
Roger R. Fu ◽  
Joshua F. Einsle ◽  
David. R. Glenn ◽  
Pauli Kehayias ◽  
...  
Keyword(s):  
Western Australia ◽  
Detrital Zircons ◽  
Jack Hills ◽  
Magnetic Inclusions

Testing continuity of the Hadean-Eoarchean geodynamo with zircon paleomagnetism

2020 ◽  
Author(s):  
John Tarduno ◽  
Rory Cottrell ◽  
Axel Hofmann
Keyword(s):  
Electron Microscope ◽  
Detrital Zircons ◽  
Test Results ◽  
Eastern India ◽  
Technical Challenge ◽  
First Order ◽  
Jack Hills ◽  
Magnetic Inclusions ◽  
Field Strengths

<p>Understanding the pre-Paleoarchean geodynamo is arguably the greatest technical challenge for paleomagnetism: only silicate crystals bearing magnetic inclusions now found in younger sedimentary units may have escaped the metamorphism that otherwise excludes extant Paleoarchean to Hadean whole rocks from consideration. The recent optical and electron microscope documentation of primary magnetite inclusions in Jack Hills zircons (Tarduno et al., <em>PNAS</em>, 2020), previously predicted by paleomagnetic unblocking temperatures, together with microconglomerate test results, Pb-Pb radiometric age data and Li-diffusion constraints, support a geodynamo as old as 4.2 billion-years-old. While the available record is to first-order consistent with a continuous geodynamo since the Hadean, there are several 50-100 m.y. gaps in the record. Herein we examine these gaps and further test the paleointensity history derived from Jack Hills zircons through study of Paleoarchean and older detrital zircons of the Singhbum craton of eastern India. Preliminary paleomagnetic and paleointensity data suggest the presence of a primary magnetism, magnetite inclusion carriers and field strengths similar to those of the Jack Hills record.</p>

The Earth's oldest known crust: A geochronological and geochemical study of 3900–4200 Ma old detrital zircons from Mt. Narryer and Jack Hills, Western Australia

1992 ◽  
Vol 56 (3) ◽  
pp. 1281-1300 ◽  
Author(s):  
Roland Maas ◽  
Peter D. Kinny ◽  
Ian S. Williams ◽  
Derek O. Froude ◽  
William Compston
Keyword(s):  
Western Australia ◽  
Detrital Zircons ◽  
Geochemical Study ◽  
Jack Hills

Jack Hills, evidence of more very old detrital zircons in Western Australia

Nature ◽  
1986 ◽  
Vol 321 (6072) ◽  
pp. 766-769 ◽  
Author(s):  
W. Compston ◽  
R. T. Pidgeon
Keyword(s):  
Western Australia ◽  
Detrital Zircons ◽  
Very Old ◽  
Jack Hills

Mechanisms and consequences of intra-crystalline enrichment of ancient radiogenic Pb in detrital Hadean zircons from the Jack Hills, Western Australia

2019 ◽  
Vol 517 ◽  
pp. 38-49 ◽  
Author(s):  
Rongfeng Ge ◽  
Simon A. Wilde ◽  
Alexander A. Nemchin ◽  
Martin J. Whitehouse ◽  
Jeremy J. Bellucci ◽  
...  
Keyword(s):  
Western Australia ◽  
Jack Hills
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