New Data on the Chronology of Eclogite and Associated Rock from Guanpo Area, North Qinling Orogeny and Its Constraint on Nature of North Qinling HP-UHP Eclogite Terrane

详细信息   

• 责任者：Chen Danling (State Key Laboratory of Continental Dynamics ; Department of Geology ; Northwest University ; Xi’an 710069 ; China) ; Liu Liang
• 刊名：Earth Science Frontiers
• 出版年：2011
• 卷期：18(2)
• 关键词：榴辉岩 ; eclogite ; 板块俯冲 ; subduction ; 铀—铅计时 ; U-Pb dating ; 秦岭 ; Qinling Mountains
• 页码：p.158-169
• 图表：6 illus., 4 tables, 49 refs.
• 分类号：0802
• 出版序号：20120170
• issnNo：ISSN1005-2321
• isbnNo：CN11-3370/P

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.