Electron microprobe chemical ages of monazite from Qinling Group in the Qinling Orogen: Evidence for Late Pan-African metamorphism?

Electron microprobe chemical dating was carried out on monazites enclosed in two generations of mineral paragenesis of St + Ky + Grt and Sil + And + Gil + St, respectively, from the Qinling Group. Two different ages, 520±23 Ma and 435±9 Ma, were obtained from these monazites. This indicates that the Qinling Group experienced a metamorphism during the Early Cambrian, which is probably in response to the Late Pan-African subduction-accretion tectonothermal event. [ABSTRACT FROM AUTHOR]