Zircon geochronology and geochemistry of felsic gneisses from Harvey Nunatak, Napier Complex in East Antarctica

The Napier Complex in East Antarctica has a complex thermal history, including ultra-high-temperature (UHT) metamorphism. Geochronology, trace element, and isotope geochemistry of zircon, apatite, monazite three felsic gneisses collected from Harvey Nunatak were studied using sensitive high-resolution ion microprobe (SHRIMP) for the first time. Most zircons showed nebulous to fir-tree zoning, which is common feature granulite facies rocks, regardless core or rim. U-Pb dating rare earth element abundance zircon indicated that crystallization by regional metamorphism continued 2567–2460 Ma, consistent with previously proposed timing UHT grains contained large amount Li (59–668 ppm). was incorporated Cl at interstitial sites structure, crystallized melts an abundant supply Cl. Monazite apatite after events 2071 Ma 1799 Ma. system completely disturbed 1785 In addition, systems approximately 500