The Hadean Crust: Evidence from >4 Ga Zircons

  title={The Hadean Crust: Evidence from >4 Ga Zircons},
  author={T. Harrison},
  journal={Annual Review of Earth and Planetary Sciences},
  • T. Harrison
  • Published 2009
  • Geology
  • Annual Review of Earth and Planetary Sciences
A review of continental growth models leaves open the possibilities that Earth during the Hadean Eon (∼4.5–4.0 Ga) was characterized by massive early crust or essentially none at all. Without support from the rock record, our understanding of pre-Archean continental crust must largely come from investigating Hadean detrital zircons. We know that these ancient zircons yield relatively low crystallization temperatures and some are enriched in heavy oxygen, contain inclusions similar to modern… Expand
Insights into the Hadean Earth from experimental studies of zircon
Geologists investigate the evolution of the atmosphere, crust, and mantle through time by direct study of the rock record. However, the Hadean eon (>3.85 Ga) has been traditionally viewed asExpand
Iceland is not a magmatic analog for the Hadean: Evidence from the zircon record
Abstract Tangible evidence of Earth's earliest (Hadean; >4.0 Ga) crust, and the processes and materials that contributed to its formation, exists almost entirely in a record of detrital zircon fromExpand
Eoarchean crustal evolution of the Jack Hills zircon source and loss of Hadean crust
Given the global dearth of Hadean (>4 Ga) rocks, 4.4–4.0 Ga detrital zircons from Jack Hills, Narryer Gneiss Complex (Yilgarn Craton, Western Australia) constitute our best archive of earlyExpand
The role of detrital zircons in Hadean crustal research
Abstract Meso-Archean sedimentary sequences at Mt. Narryer and the Jack Hills of the Narryer Terrane in Western Australia's Yilgarn Craton contain detrital zircon grains with ages as old as 4.37 Ga,Expand
Detrital zircon evidence for change in geodynamic regime of continental crust formation 3.7–3.6 billion years ago
Abstract The nature of the early terrestrial crust and how it evolved through time remains highly controversial. Whether conventional plate tectonics operated in the Hadean and early Archean and whenExpand
From the Hadean to the Himalaya: 4.4 Ga of felsic terrestrial magmatism
Abstract Detrital zircons as old as nearly 4.4 Ga offer insights into the earliest moments of Earth history. Results of geochemical investigations of these grains have been interpreted to indicateExpand
A relatively reduced Hadean continental crust and implications for the early atmosphere and crustal rheology
It is widely believed that the Earth was strongly reduced during its early accretion, however, the transition from the reduced state that prevailed during Earth's early period to the modern oxidizedExpand
Reworking of Earth's first crust: Constraints from Hf isotopes in Archean zircons from Mt. Narryer, Australia
Abstract Discoveries of >4 Ga old zircon grains in the northwest Yilgarn of Western Australia led to the conclusion that evolved crust formed on the Earth within the first few 100 Ma after accretion.Expand
New evidence for ~4.45Ga terrestrial crust from zircon xenocrysts in Ordovician ignimbrite in the North Qinling Orogenic Belt, China
Abstract Evidence for the earliest known terrestrial crust comes predominantly from Jack Hills in Western Australia, where hafnium isotopic results from > 3.8 Ga detrital zircons indicate crustalExpand
Proposed Sources of Hadean Zircons
Any successful geodynamic or environmental model for early Earth must be consistent with ten robust lines of evidence derived from geochemical and petrologic observations of Hadean Jack HillsExpand


Low heat flow inferred from >4 Gyr zircons suggests Hadean plate boundary interactions
An examination of over 400 Hadean zircons from Jack Hills is presented, which shows that some inclusion assemblages are conducive to thermobarometry, and it is suggested that the magmas from which the Jack Hills Hadeans zircon crystallized were formed largely in an underthrust environment, perhaps similar to modern convergent margins. Expand
Ophiolitic trondhjemites: a possible analogue for Hadean felsic 'crust'
It has been argued that >4.0 Ga detrital zircons preserved in sediments of the Jack Hills, western Australia, preserve evidence for a well-developed continental crust on the Earth at 4.4–4.5 Ga ago.Expand
Heterogeneous Hadean Hafnium: Evidence of Continental Crust at 4.4 to 4.5 Ga
The view that continental crust had formed by 4.4 to 4.5 Ga and was rapidly recycled into the mantle and was supported by initial 176Hf/177Hf values from Jack Hills, Western Australia. Expand
Evidence from detrital zircons for the existence of continental crust and oceans on the Earth 4.4 Gyr ago
The discovery of a detrital zircon with an age as old as 4,404 ± 8 Myr is reported, about 130 million years older than any previously identified on Earth and represents the earliest evidence for continental crust and oceans on the Earth. Expand
4.2 Ga zircon xenocryst in an Acasta gneiss from northwestern Canada : Evidence for early continental crust
Evidence for the existence of continental crust older than 4.06 Ga has so far been obtained only from zircons in the Yilgarn Craton of Western Australia. In this paper we report the first occurrenceExpand
Zircon Thermometer Reveals Minimum Melting Conditions on Earliest Earth
The temperatures substantiate the existence of wet, minimum-melting conditions within 200 million years of solar system formation and suggest that Earth had settled into a pattern of crust formation, erosion, and sediment recycling as early as 4.35 Ga. Expand
Hadean diamonds in zircon from Jack Hills, Western Australia
Mineralogical features of the Jack Hills diamonds resemble those of diamonds formed during ultrahigh-pressure metamorphism and imply a relatively thick continental lithosphere and crust–mantle interaction at least 4,250 million years ago. Expand
Trace-element fractionation in Hadean mantle generated by melt segregation from a magma ocean
It is shown that the observed Nd and Hf signatures could have been produced by segregation of melt from a crystallizing magma ocean at upper-mantle pressures early in Earth's history, which would have risen buoyantly and ultimately formed the earliest terrestrial protocrust. Expand
Oxygen-isotope evidence from ancient zircons for liquid water at the Earth's surface 4,300 Myr ago
In situ U–Pb and oxygen isotope results for detrital zircons found within 3-Gyr-old quartzitic rocks in the Murchison District of Western Australia are consistent with the presence of a hydrosphere interacting with the crust by 4,300 Myr ago and are postulated to form from magmas containing a significant component of re-worked continental crust. Expand
Geochemical Constraints on the Growth of the Continental Crust
Several lines of evidence indicate that the Archean upper crust was considerably more mafic than the present-day upper crust. There has been no significant change in REE and Th abundances inExpand