Leucogranite Records Multiple Collisional Orogenies
Leucogranite Records Multiple Collisional Orogenies
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DOI：
10.1029/2021gl096817
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发表时间：
2022-07
影响因子：
5.2
通讯作者：
Li Liu;Di‐Cheng Zhu;Qing Wang;Peter A. Cawood;D. Stockli;L. Stockli;Chao Lin;Jinjiang Zhang
中科院分区：
文献类型：
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作者：
Li Liu;Di‐Cheng Zhu;Qing Wang;Peter A. Cawood;D. Stockli;L. Stockli;Chao Lin;Jinjiang Zhang
造山带的地质演化既与造山带的生成旋回有关，又与造山带的基底单元所继承的特征有关。喜马拉雅造山带提供了活动板块汇聚和造山作用叠加早古生代造山带的新生代活动历史。共1,627个喜马拉雅浅花岗岩锆石被深度剖面化，显示出高分辨率(0.6μm)的内部年龄结构。锆石边缘年龄记录了详细而复杂的熔融和变形历史，其年龄为锆石核心年龄数据所记录的北印度-澳大利亚造山带(约490-460 Ma)。一个有趣的发现是，喜马拉雅地区的碎屑锆石和继承的浅色花岗岩锆石核心的年龄组不一致，重新评估了浅色花岗岩纯粹来自变质沉积岩熔融的论点。锆石边缘厚度的变化与新生代造山阶段的变化相对应，边缘厚度大于4μm表明为伸展体制。
The geological evolution of orogens is the sum of events related to both their cycle of generation as well as features inherited from their basement units. The Himalayan Orogen provides a well‐constrained Cenozoic history of active plate convergence and orogenic processes overprinting an early Paleozoic orogen. A total of 1,627 Himalayan leucogranite zircons were depth‐profiled showing high resolution (0.6 μm) internal age structures. Zircon rim ages record a detailed and complex history of melting and deformation, postdating the North Indo‐Australie Orogen (ca. 490–460 Ma) documented by the zircon core age data. An interesting finding is the inconsistency of age groups between detrital zircons in the Himalaya and inherited cores of leucogranite zircons, re‐evaluating the argument that leucogranites are purely derived from melting of metasedimentary rocks. Variations in the thickness of zircon rims corresponds with changing Cenozoic orogenic stages with rims thicker than 4 μm indicating the extensional regime.