Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South 
Africa

Fu, Roger R.; Drabon, Nadja; Wiedenbeck, Michael; Brenner, Alec R.; Lowe, Donald R.; Borlina, Cauê S.

doi:10.1016/j.epsl.2021.116999

Item

ITEM ACTIONSEXPORT

Add to Basket

Local TagsRelease HistoryDetailsSummary

Released

Journal Article

Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa

Authors

Fu, Roger R.
External Organizations;
GFZ SIMS Publications, Deutsches GeoForschungsZentrum;

Drabon, Nadja
External Organizations;
GFZ SIMS Publications, Deutsches GeoForschungsZentrum;

/persons/resource/michawi

Wiedenbeck, Michael
3.1 Inorganic and Isotope Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;
GFZ SIMS Publications, Deutsches GeoForschungsZentrum;

Brenner, Alec R.
External Organizations;
GFZ SIMS Publications, Deutsches GeoForschungsZentrum;

Lowe, Donald R.
External Organizations;
GFZ SIMS Publications, Deutsches GeoForschungsZentrum;

Borlina, Cauê S.
External Organizations;
GFZ SIMS Publications, Deutsches GeoForschungsZentrum;

External Ressource

No external resources are shared

Fulltext (public)

There are no public fulltexts stored in GFZpublic

Supplementary Material (public)

There is no public supplementary material available

Citation

Fu, R. R., Drabon, N., Wiedenbeck, M., Brenner, A. R., Lowe, D. R., Borlina, C. S. (2021): Paleomagnetism of 3.5-4.0 Ga zircons from the Barberton Greenstone Belt, South Africa. - Earth and Planetary Science Letters, 567, 116999.
https://doi.org/10.1016/j.epsl.2021.116999

Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5006774

Abstract

The existence of a core dynamo during the first billion years of Earth history is closely related to the thermal state of the Earth’s interior and composition of the early atmosphere. The scarcity of well-preserved rock units older than 3.5 billion years (Ga) has motivated the paleomagnetic analysis of detrital zircons. Studies of zircons from Jack Hills, Australia, however, have found the pervasive occurrence of secondary ferromagnetic minerals, casting doubt on the ability of these zircons to record a >3.5Ga geomagnetic field. Here we report paleomagnetic analyses on a set of 19 zircons with crystallization age 3.5-4.0Ga from the Barberton Greenstone Belt (BGB) of South Africa, which have undergone lower grade metamorphism compared to all other known >3.5Ga detrital zircon localities. We find that BGB zircons have magnetic moments nearly one order of magnitude weaker than Jack Hills zircons, precluding the retention of primary paleomagnetic information. This result corroborates findings from the Jack Hills and other Archean zircon populations that primary ferromagnetic inclusions are readily eliminated from zircons during sedimentary transport and metamorphism, likely facilitated by radiation damage-induced permeability. Paleomagnetic determination of geodynamo activity prior to 3.5Ga may require investigation of other detrital grains with lower radiation damage potential or whole-rock samples that have escaped high degree metamorphism.