U/Pb zircon ages constrain the architecture of the ultrahigh-pressure Qinling-Dabie Orogen, China

被引:978
作者
Hacker, BR [1 ]
Ratschbacher, L
Webb, L
Ireland, T
Walker, D
Shuwen, D
机构
[1] Univ Calif Santa Barbara, Dept Geol, Santa Barbara, CA 93106 USA
[2] Univ Wurzburg, Inst Geol, D-97070 Wurzburg, Germany
[3] Stanford Univ, Stanford, CA 94305 USA
[4] Univ Kansas, Dept Geol, Lawrence, KS 66045 USA
[5] Chinese Acad Geol Sci, Nanjing 210016, Peoples R China
关键词
Dabie Mountains; zircon; absolute age; Sino-Korean platform; high pressure; orogenic belt;
D O I
10.1016/S0012-821X(98)00152-6
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
New SHRIMP and TIMS zircon ages, 40Ar/39Ar ages, and eclogite locations contribute significantly to our understanding of the ultrahigh-pressure Dabie Shan. (I) The geographic extent of the Yangtze craton that was subducted to ultrahigh pressure extends to the northern edge of the Dabie Shan. (2) The northern half of the Dabie Shan is a magmatic complex, intruded over a 10-Myr interval between 137 and 126 Ma, that accommodated similar to 100% N-S stretching of the pre-existing collisional architecture. (3) Granitic orthogneisses and enclosing ultrahigh-pressure paragneisses have indistinguishable zircon populations. The population of Triassic zircon ages ranges from similar to 219 to similar to 245 Ma, leading us to question the prevailing assumption that 219 Ma zircons formed at ultrahigh pressure, and to propose instead that they reflect late retrogression at crustal pressures following the bulk of exhumation. (C) 1998 Elsevier Science B.V. All rights reserved.
引用
收藏
页码:215 / 230
页数:16
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