Precambrian Research 138 (2005) 235–254 Provenance record of the Jack Hills metasedimentary belt: Source of the Earth’s oldest zircons Stuart J. Dunn ∗ , Alexander A. Nemchin, Peter A. Cawood, Robert T. Pidgeon Tectonics Special Research Centre, Department of Applied Geology, Curtin University, U1987, Perth, WA 6845, Australia Received 21 April 2004; accepted 18 May 2005 Abstract Detrital SHRIMP U–Pb results from four samples of metasediment show that the Jack Hills metasedimentary belt, Narryer terrane, Yilgarn craton, Western Australia contains two lithologically similar siliciclastic associations with discrete age and source characteristics. An older association only contains zircons with ages greater than 3000 Ma and probably accumulated prior to 2700 Ma. Grains in the range 3600–3000 Ma are likely derived from granitic gneisses surrounding the metasedimentary belt. The older association was in part sourced from, and likely accumulated on, gneisses of the Narryer terrane, however, the source of the oldest (>4000 Ma) grains is unknown. The younger association contains zircons with the bulk of the ages between 2800 and 2600 Ma, and detrital grains as young as 1800 Ma. It also shows ages in the range 3600–3000 Ma and a few grains as old as 4100 Ma. The younger association has a significant contribution of zircons derived from Yilgarn craton and Capricorn orogen and was deposited after ∼1800 Ma, possibly in a foreland basin setting close to the older association with the two then tectonically interleaved. © 2005 Elsevier B.V. All rights reserved. Keywords: Zircon; U–Pb; Provenance; Narryer terrane 1. Introduction Detrital zircons up to 4.4 billion years old in a meta- conglomerate from the Jack Hills metasedimentary belt are the oldest terrestrial material found (Wilde et al., 2001). The source rocks of the ancient zircons have not been discovered despite extensive investigations of the U–Pb ages of zircon in the gneisses enclosing both Jack Hills and nearby Narryer metasediments (Nutman et ∗ Corresponding author. E-mail address: s.dunn@exchange.curtin.edu.au (S.J. Dunn). al., 1991; Pidgeon and Wilde, 1998). This leaves these zircons as the only surviving remnants of the first 500 million years of Earth history (Compston and Pidgeon, 1986; Maas and McCulloch, 1991; Mojzsis et al., 2001; Wilde et al., 2001). To date, information on the age pat- tern and concentration of grains older than 4000 Ma in the detrital suite from the Jack Hills has been based solely on samples of metaconglomerate from a single outcrop, with the exception of recently published work of Cavosie et al. (2004). Accumulation of sedimen- tary rocks within the belt is inferred to have occurred between ca. 3000 and 2700 Ma based on constraints 0301-9268/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2005.05.001