Hadean rocks are very rare, largely consisting of granular zircons from one locality in Western Australia. [7] Hadean geophysical models remain controversial among geologists: plate tectonics and the growth of cratons into continents may have started in the Hadean, but there is still uncertainty. [8] [9] [10]
The only identified materials on the Earth with unequivocal UePb ages extending into the Hadean are ancient >4000 Ma zircon grains that are dominantly found as detrital grains in Archean rocks in the ancient crustal nuclei of Western Australia and are only rarely found elsewhere. In Western Australia, variably metamorphosed metasedimentary
2024年10月1日 · Detrital zircons from the Jack Hills are the dominant source of Hadean (pre-4000 Ma) terrestrial material available for study today. Values of δ 18 O in many of these zircons (6.0 to 7.5‰) are above the mantle-equilibrated value.
2021年11月22日 · Hadean zircons, from the Jack Hills (Western Australia) and other localities, are currently the only window into the earliest terrestrial felsic crust, the formation of which remains enigmatic.
2021年2月18日 · The geochemistry of Hadean detrital zircon from a newly discovered site in South Africa suggests that the parental melts formed from variably hydrous melting of crust derived from the ambient mantle and show little evidence for an origin in arc-like settings.
2014年2月23日 · Here we use atom-probe tomography 8 to identify and map individual atoms in the oldest concordant grain from Earth, a 4.4-Gyr-old Hadean zircon with a high-temperature overgrowth that formed...