Fig. 1. Location map of Prydz Bay within East Antarctica, showing localities used in the text.

Fig. 2. Close-up of (a) the Rauer Group, showing sample localities and (b) the Bolingen Islands, showing sample localities.

Fig. 3. CL images of zircons with cores having Archaean or Palaeoproterozoic inherited ages. Sample ‘Lunnyj’ is not shown, but also has zircons cored with Archaean and Palaeoproterozoic ages. The two pegmatites from the Bolingen Islands did not contain any Archaean or Palaeoproterozoic detritus. The diameter of the LA-ICPMS analysis circle in each case is 30 μm.

Fig. 4. CL images of zircon grains, zircon cores and zircon overgrowths having Neoproterozoic ages. Note that Neoproterozoic cores do not tend to be oscillatorily zoned, particularly for samples 11104B, Lunnyj, BI-554 and BI-118. The ‘Pan-African’ aged overgrowths for sample ‘Lunnyj’ are provided as examples of zircon overgrowth on Neoproterozoic cores. The diameter of the LA-ICPMS analysis circle in each case is 30 μm.

Fig. 5. CL images of zircon grains or zircon overgrowths having an age corresponding to the Ediacaran–Cambrian granulite-facies event. This event involved overgrowths on existing zircon cores of Neoproterozoic, Palaeoproterozoic or Archaean age, or completely new grain growth (e.g. as in BI-118 and 10036). The diameter of the LA-ICPMS analysis circle in each case is 30 μm.

Fig. 6. Tera–Wasserburg plots displaying all the zircon age data collected from the six samples. Samples 10036 and 18129 are rich with inherited Palaeoproterozoic and Archaean zircon cores, whereas all the samples contain a significant Neoproterozoic signature.

Fig. 7. Probability density plots for the six analysed samples. The vertical shaded areas on each plot correspond to the age of the Mesoproterozoic to Neoproterozoic crustal growth episode recorded in Prydz Bay and the age of Early Palaeozoic tectonism. The light-gray shaded regions under the probability density curves include all geochronological data (i.e. discordant and concordant data). The darker-gray shaded regions under the probability density curves include all data within 90–110% concordancy. In all the samples there exists a distinct presence of Neoproterozoic-aged detrital zircon grains.

Fig. 8. Th/U vs. age plot for some of the analysed samples. Only the Neoproterozoic data points are shown for the samples. Data points plotting within the gray shaded band are interpreted as metamorphic grains. Thus, many of the Neoproterozoic grains in samples 10036 and 18129 are interpreted as having a metamorphic origin. This is substantiated by the trace element chemistry for these two samples (Fig. 9) and the CL images of these particular zones in zircon.

Fig. 9. Trace element zircon chemistry for mainly the Neoproterozoic portions (zircon cores, overgrowths) of selected samples. Samples 10036 (a) and 18129 (b) have a trace element trend that when combined with CL imaging and Th/U ratios is indicative of a metamorphic origin. Pegmatite samples BI-118 and BI-554 have notable Cerium and Europium anomalies that are typically the signature of igneous zircon. Archaean and ‘Early Palaeozoic’ zircon REE chemistry are provided for BI-118. Dashed REE patterns for sample 18129 are for Palaeoproterozoic cores.

Fig. 10. Tectonic map for a postulated assembly of East Gondwana during the Ediacaran–Cambrian. Abbreviations: PCMs: Prince Charles Mountains. P–T data sources for Early Palaeozoic tectonism are: Rauer Group ([Harley, 1998b], [Kelsey et al., 2003b] and [Kelsey et al., 2007]); Prydz Bay ([Nichols and Berry, 1991], [Fitzsimons, 1996], [Fitzsimons, 1997] and [Carson et al., 1997]); Grove Mountains (Liu et al., 2006); PCMs: (Boger and Wilson, 2005); Meghalaya ([Lal et al., 1978] and [Chatterjee et al., 2007]); Napier Complex (Sandiford, 1985); Leeuwin Complex (A. Collins, unpublished Data). Sources for structural trends and vergence of Early Palaeozoic structures are: Prydz Bay (Dirks and Wilson, 1995), Grove Mountains (Liu et al., 2006), Prince Charles Mountains ([Boger et al., 2002], [Boger and Wilson, 2005], [Phillips et al., 2005] and [Phillips et al., 2006]) and Napier Complex ([Sandiford and Wilson, 1984] and [Sandiford, 1985]). The ages indicated for the Dharwar, Bastar, Singhbhum Cratons, Eastern Ghats Belt, Vestfold Hills, Napier Complex, Rayner Complex, Rauer Group, SW Prydz Bay, Prince Charles Mountains, Grove Mountains, Leeuwin Complex and Meghalaya are largely U–Pb zircon protolith ages ([Sheraton and Black, 1983], [Taylor et al., 1984], [Black et al., 1986], [Black et al., 1987], [Black et al., 1991], [Chimote et al., 1988], [Peucat et al., 1989], [Peucat et al., 1993], [Friend and Nutman, 1991], [Ghosh et al., 1991], [Ghosh et al., 1994], [Ghosh et al., 1996], [Sengupta et al., 1991], [Sengupta et al., 1996], [Young and Black, 1991], [Manton et al., 1992], [Kinny et al., 1993], [Kinny et al., 1997], [Naha et al., 1993], [Beliatsky et al., 1994], [Hensen and Zhou, 1995a], [Selvam et al., 1995], [Zhao et al., 1995], [Zhao et al., 1997], [Harley and Black, 1997], [Snape et al., 1997], [Harley et al., 1998], [Bruguier et al., 1999], [Mezger and Cosca, 1999], [Mikhalsky et al., 1999], [Mikhalsky et al., 2001], [Mikhalsky et al., 2006], [Misra et al., 1999], [Nelson, 1999], [Singh and Chabria, 1999], [Boger et al., 2000], [Boger et al., 2006], [Jayananda et al., 2000], [Jayananda et al., 2006], [Kelly, 2000], [Cobb et al., 2001], [Mukhopadhyay, 2001], [Kelly et al., 2002], [Kelly et al., 2004], [Collins, 2003], [Hokada et al., 2003], [Mojzsis et al., 2003], [Ghosh, 2004], [Corvino et al., 2005], [Halpin et al., 2005], [Kelly and Harley, 2005], [Misra and Johnson, 2005], [Wang et al., 2005], [Carson and Grew, 2006], [Dobmeier et al., 2006], [Carson et al., 2007], [Corvino and Henjes-Kunst, in press], [Liu et al., 2007a] and [Liu et al., 2007b]). The ages indicated for the Ruker Province orthogneisses and supracrustals are protolith and detrital ages (Phillips et al., 2006). The 550 Ma age of A-type magmatism in the Grove Mountains is from Liu et al. (2006). The sinistral transpression indicated near the Leeuwin Complex (Pinjarra Orogen) is based on the study of Neoproterozoic rocks by Harris (1994).

Fig. 11. Tectonic map of East Antarctica, India and Australia summarising previous studies that postulated the locations of sutures responsible for the final amalgamation of eastern Gondwana during the Ediacaran–Cambrian. The Kuunga Suture (Boger et al., 2001) trends east-west through the southern PCMs (Alternative 1 of Fitzsimons, 2003).

LA-ICPMS zircon data (sample 10036)

LA-ICPMS zircon data (sample 18129)

LA-ICPMS zircon data (sample 11104B)