Major magmatic events in Mt Meredith, Prince Charles Mountains: First evidence for early Palaeozoic syntectonic granites

Precambrian rocks at Mt Meredith underwent granulite-facies metamorphism M1. Zircon isotope dating for
two orthogneisses revealed the following age signatures: 1294±3 and 957±4Ma; 1105±5 and 887±2Ma. The oldest ages
could reflect the time of orthogneiss protolith crystallization and the latest age determinations date Grenvillian
metamorphism. The metamorphic rocks were intruded by two-mica and garnet-biotite granites. The granites and host
rocks underwent amphibolite-facies metamorphism M2. Zircon isotope analysis of the two-mica granites showed age
estimation within 550-510Ma and zircon dating of the garnet-biotite granites revealed the ages of 1107±5, 953±8, and
551±4Ma. As Pan-African age signatures were obtained from only the granite samples, it is possible to suggest that the
granites were formed at the time of 510-550Ma and the zircons with greater age values were captured by granites from
the host rocks.