Late Mesozoic granitoids in the Qinling Orogen, Central China, and tectonic significance
Late Mesozoic granitoids in the Qinling Orogen, Central China, and tectonic significance
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华中秦岭造山带晚中生代花岗岩及其构造意义
DOI：
10.1016/j.earscirev.2018.05.004
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发表时间：
2018-07
影响因子：
12.1
通讯作者：
Pirajno Franco
中科院分区：
文献类型：
--
作者：
Li Nuo;Chen Yan-Jing;Santosh M.;Pirajno Franco
中国中部的秦岭造山带是一个复杂的拼贴，它是由古特提斯最北端和扬子、华北造山带闭合而成的。本文综合整理了秦岭晚中生代花岗岩类的年代学、地球化学和同位素资料，并结合秦岭造山带的构造体制，对它们的成因进行了较为全面的研究。在160-195 Ma的岩浆间断期后，广泛侵位晚中生代花岗岩类，其年龄范围为108-160 Ma。它们以I型花岗岩为主，表明它们是在中地壳至下地壳水平通过重熔地壳岩石形成的，尽管岩浆温度通常低于800 °C。晚中生代花岗岩类的Sr-Nd-Hf同位素数据具有区域性特征，反映了其源区物质成分的区域性差异，进而反映了地壳深部物质成分的区域性差异，晚中生代花岗岩类的形成有3个脉冲，即108-125 Ma、125-140 Ma和140-160 Ma，没有岩浆活动的平静期。125 Ma前后的花岗岩类在空间分布、岩石学、地球化学和同位素特征等方面存在明显的差异。以勉略缝合线为界，老岩套表现出向北的展布趋势。该套岩石由石英闪长岩-花岗闪长岩-二长花岗岩-花岗岩组合组成，广泛分布于109°E ~ 112°E之间。较年轻的岩套只出现在造山带的最东端（111°E ~ 113°E），主要由二长花岗岩、花岗岩和正长花岗岩组成。与老岩套相比，新岩套的成分演化（硅含量高，而Al 2 O3、FeOT、MgO和CaO含量低），并含有年轻地壳。岩浆源区浅，Sr/Y比值低，Sr、Ba、Eu负异常明显，表明秦岭造山带晚中生代构造体制是碰撞后挤压-伸展转换、与古太平洋俯冲有关的弧后伸展和/或白垩纪太平洋超地幔柱事件的综合作用。
The Qinling Orogen in central China is a complex collage built through the closure of the northernmost Paleo-Tethys and the suturing of the Yangtze and the North China cratons. In this contribution, geochronological, geochemical and isotopic data of Late Mesozoic granitoids are compiled, which in turn allow for a broad overview on their petrogenesis with respect to tectonic regime of the Qinling Orogen. After a magmatic hiatus during 160–195 Ma, extensive Late Mesozoic granitoids were emplaced, with an age range of 108–160 Ma. They are dominated by I-type granites that indicate formation through remelting crustal rocks at mid to lower crustal levels, although the magma temperatures are generally lower than 800 °C. The Sr-Nd-Hf isotopic data have provincial characters, which could be a reflection of regional differences in the compositions of their source rocks, and hence of the deep crust.Late Mesozoic granitoids occur in three pulses without any magmatic quiescence: i.e. 108–125 Ma, 125–140 Ma and 140–160 Ma. There is a marked variation between granitoids aged pre- and post-125 Ma in terms of spatial distribution, petrology, geochemistry and isotopic features. The older suite displays a northward younging trend if taking the Mian-Lue suture as the boundary line. Rocks in this suite are composed of quartz diorite-granodiorite-monzogranite-granite association, and occur widespread between 109°E and 112°E. The younger suite occurs only in the easternmost part of the orogen (between 111°E and 113°E), and is dominated by monzogranite, granite and syenogranite. Compared with the older suite, the younger suite is characterized by evolved composition (with higher silica but lower Al2O3, FeOT, MgO and CaO contents) and involved juvenile crust. The magma has a much shallower source as evidenced by low Sr/Y ratios and pronounced Sr, Ba and Eu negative anomalies.The above features indicate that the Late Mesozoic tectonic regime of the Qinling Orogen was an integrated effect of post-collisional compression-extension transition, the back-arc extension related to paleo-Pacific subduction and/or a Cretaceous Pacific superplume event.
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影响因子：
1.8
作者：
Jiao Jian
通讯作者：
Jiao Jian
DOI：
--
发表时间：
2015
期刊：
Geological Review
影响因子：
--
作者：
Liang Ta
通讯作者：
Liang Ta
影响因子：
1.8
作者：
Diwu Chun
通讯作者：
Diwu Chun
中国西部Qinling山的多相发掘：沿着岩石圈尺寸的撕裂断层和脉冲的新生代隆起的快速早白垩纪冷却。
影响因子：
2.9
作者：
Heberer B;Anzenbacher T;Neubauer F;Genser J;Dong Y;Dunkl I
通讯作者：
Dunkl I
DOI：
--
发表时间：
2011
期刊：
Geology in China
影响因子：
--
作者：
L. Hong;Mlr Key
通讯作者：
L. Hong;Mlr Key