Palaeoproterozoic to Mesoproterozoic Geology of North Queensland

Other Proterozoic Inliers – Coen•Holroyd Group– Divided into 5 named units– Fine to medium-grained clastic sediments becomingmore pelitic to east– Some mafic rocks with MORB-like geochemistry– Isotopic constraints (OZCHRON)• Laminated slate has a MDA of 1560±22Ma with a widerange of older ages up to ~3300Ma• Phyllite has a MDA of 1550±10Ma with other agegroups at ~1593, ~1639 1696 and ~1750Ma• Zircon rims in a gneiss sample have an age of1430±10Ma•Edward River Metamorphic Group– Divided into 5 named units– Similar siliciclastic sedimentary rocks to Holroyd Group– No isotopic constraints•Sefton Metamorphics– Schist, quartzite, phyllite, greenstone, marble, calcsilicatesand ironstone– MDA zircon age of ~1200Ma – probably Neoproterozoic toCambrian