Zn-Rich Spinel in Association with Quartz in the AI-Rich Metapelites from the Mashan Khondalite Series, NE China

Al-richmetapelitesfromtheMashankhondaliteseriesarecharacterizedbytheassemblageSpl+Grt+Sil+Crd+Bt+Pl(An72)+Kfs+Quartz+graphite.Largeamountsofspinel+quartzassemblagesoccurasinclusionsingarnetandprismaticsillimaniteintheAl-richmetapelitesoftheMashancomplex,NEChina.ThechemicalcompositionofspinelischaracterizedbyZn-rich(XZn=0.33–0.40.XZn=Zn/Zn+Mg+Fe*)(Fe*=Fe2++Fe3+)andFe3+rich(upto0.31p.f.u.).ThecharacteristicchemicalcompositionandthemineralassociationindicatedthattheformationofspinelandquartzassemblagemaybeduetothebreakdownofZn-richstaurolite.ThegeothermobarometersstudiesshowthatthepeaktemperatureoftheMashancomplexisaround820℃andthepeakpressuresis8.0kbar.TheMashancomplexshowsatypicalorogenstyleP-Tpath.