Early Permian A-type granites from central Inner Mongolia, North China: Magmatic tracer of post-collisional tectonics and oceanic crustal recycling
Early Permian A-type granites from central Inner Mongolia, North China: Magmatic tracer of post-collisional tectonics and oceanic crustal recycling
复制标题
华北内蒙古中部早二叠世A型花岗岩：碰撞后构造和洋壳再生的岩浆示踪
DOI：
10.1016/j.gr.2014.02.011
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发表时间：
2015-08
影响因子：
6.1
通讯作者：
Zhang, X.H., Yuan, L.L., Xue, F.H., Yan, X., Mao, Q
中科院分区：
文献类型：
--
作者：
Zhang, X.H., Yuan, L.L., Xue, F.H., Yan, X., Mao, Q
A型花岗岩类构成了地球上大多数后太古代大陆块的体积较小但具有重要成因的构造块体，其多样化的成因包含了确定大陆地壳形成和分异的关键地球动力学控制的关键信息。本文对中亚造山带东部中国内蒙古中部早二叠世过碱性花岗岩进行了锆石U-Pb定年和地球化学研究。这些花岗岩具有A型岩浆亲和性，具有典型的碱性、Ga、Zr、Nb和Y的富集性，亏损的锶、磷和分馏的稀土元素配分模式显示出强烈的Eu负异常。它们的~(87)Sr/~(86)Sr比值为0.70594，ε-Nd(T)为+44.25~+66.05，锆石εHf(T)为+99.8~+616.0，δ~(18)O值为2.41~4.72‰。这些元素和同位素特征表明，母岩浆来自新捕获的查诺克质下地壳原岩的部分熔融和随后的分离结晶。这类A型花岗岩具有固有的热液蚀变洋壳遗迹和可能与碰撞后板片剥离有关的构造联系，不仅可以作为监测CAOB内不同组成部分地体之间融合的有洞察力的时间里程碑，而且可以作为大型造山事件最后阶段年轻地壳改造成熟阶段的空间岩浆代理。
A-type granitoids constitute volumetrically minor but genetically important building blocks of most post-Archean continental landmasses on Earth and their diversified genesis encapsulates key information for ascertaining critical geodynamic controls on continental crustal formation and differentiation. This zircon U–Pb dating and geochemical study documents the Early Permian peralkaline granites from central Inner Mongolia of China, eastern Central Asian Orogenic Belt (CAOB). These granites show an A-type magmatic affinity, with typical enrichment in alkalis, Ga, Zr, Nb and Y, depletion in Sr and P and fractionated REE patterns showing strong negative Eu anomalies. They have meaningful initial87Sr/86Sr ratio of 0.70594, εNd(t) of + 4.25 to + 6.05, zircon εHf(t) from + 9.8 to + 16.0 and δ18O values from 2.41 to 4.72‰. These elemental and isotopic characters argue for parental magmas from partial melting of a newly trapped charnockitic lower crustal protolith and their subsequent fractional crystallization. With an inherent hydrothermally altered oceanic crustal heritage and possible tectonic linkage to post-collisional slab breakoff, this kind of A-type granites could not only serve as an insightful temporal milestone for monitoring the amalgamation between various constituent terranes in the CAOB, but also present a spatial magmatic proxy for marking the maturation stage of juvenile crustal reworking during the final phase of a large orogenic event.
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DOI：
10.1144/gsl.sp.2003.219.01.04
发表时间：
2003
期刊：
Geological Society, London, Special Publications
影响因子：
--
作者：
P. Clift;H. Schouten;A. Draut
通讯作者：
P. Clift;H. Schouten;A. Draut
影响因子：
3.9
作者：
F. Tomaschek;A. Kennedy;I. Villa;M. Lagos;C. Ballhaus
通讯作者：
F. Tomaschek;A. Kennedy;I. Villa;M. Lagos;C. Ballhaus
影响因子：
5.3
作者：
STEIGER, RH;JAGER, E
通讯作者：
JAGER, E
DOI：
10.1016/0024-4937(92)90029-x
发表时间：
1992-07
期刊：
--
影响因子：
--
作者：
S. Turner;J. Foden;R. S. Morrison
通讯作者：
S. Turner;J. Foden;R. S. Morrison
影响因子：
3.9
作者：
Yongsheng Liu;Xiaohong Wang;Dong-bing Wang;Detao He;K. Zong;Changgui Gao;Zhaochu Hu;H. Gong
通讯作者：
Yongsheng Liu;Xiaohong Wang;Dong-bing Wang;Detao He;K. Zong;Changgui Gao;Zhaochu Hu;H. Gong