The Ordovician turbidites, consisting of greywacke, feldspathic sandstone, micaceous siltstone, micaceous shale, chert, and phyllite, are very similar in all parts of the Tasman Orogen, including New Zealand and the Transantarctic Mountains. Detrital zircons from the turbidites have been isotopically dated with age ranges of 0.46 and 0.60 Gya, 1.0 and 1.2 Gya, and at ~1.8 Gya, ~2.2 Gya and ~2.7 Gya. These do not match the age of zircons from the interior of the Australian Shield, so the source of the sediments is from another continent. The other evidence from the Ordovician sediments are chemical composition indicates granitic source, with the absence of feldspar. Secondly the fine grained nature shows the sediments have been transported a long way from their ultimate, source, and could have been second cycle, derived from sedimentary rocks.