摘要
Based on the investigation of petrography and zircon CL imaging, LA-ICP-MS trace elements and U-Th-Pb isotope analyses were carried out on zircon grains of UHP eclogite and associated garnet amphibolite from Guanpo area, the North Qinling orogeny. The geochemical characteristics are the same as those of the adjacent UHP eclogite in this area. Combined the geochemical data with the field occurrence, petrographic features and chronological results, it suggests that the garnet amphibolite resulted from the recrystallization of the UHP eclogite under amphibolite facies during exhumation. Therefore, the ages of (502±11) Ma, (791±6) Ma and (366±4) Ma obtained from eclogite and garnet amphibolite should represent the metamorphic,the protolith and the retrograde metamorphic age of Qinling UHP eclogite, respectively.