Origin and Tectonic Implications of Post-Orogenic Lamprophyres in the Sulu Belt of China
Origin and Tectonic Implications of Post-Orogenic Lamprophyres in the Sulu Belt of China
复制标题
中国苏鲁带造山后辉斑岩的成因及其构造意义
DOI：
10.1007/s12583-020-1070-y
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发表时间：
2020-12
影响因子：
3.3
通讯作者：
Zhuocheng Wang
中科院分区：
文献类型：
--
作者：
Songjie Wang;Lu Wang;Yue Ding;Zhuocheng Wang
三叠纪苏鲁超高压造山带中广泛分布着横切不同类型超高压变质岩的层状岩墙。尽管对这些岩墙进行了大量的研究，但其成因和成因仍然是有争议的话题。通过对苏鲁超高压带中段出露的层状脉岩的岩石学、全岩地球化学和锆石U-Pb、Lu-Hf同位素研究，旨在揭示其岩石成因，为研究中国东部大陆白垩纪的地质演化提供线索。层状岩体是典型的斑状，斑晶主要由角闪石和单斜辉石组成，镶嵌在层状岩体基质中。岩墙具有中等SiO2（47.70 wt.%约60.44重量%），高MgO（2.58wt.% -8.28重量%）和Fe 2 O3 T（4.88wt.%约9.26重量%）Mg#为49-66的高含量。地球化学特征为轻稀土富集，重稀土配分模式平坦（（La/Gd）N=5.14-10.56;（Dy/Yb）N=1.43-1.54），Eu异常可忽略（Eu/Eu*=0.83-1.10），富集大离子亲石元素（如：Eu、Eu、Yb、Eu、Eu Ba和K），但在高场强元素（例如，原位锆石U-Pb年代学研究表明，层状岩体的一致年龄为120-115 Ma，表明岩墙形成于早白垩世。这些锆石的εHf（t）值介于−26.0至−11.0之间。岩墙中的继承锆石被确定为新元古代，与其宿主的原岩年龄一致（即，UHP岩石）。这些数据的整合使我们能够提出，lamaberres在白垩纪期间，通过熔融的次大陆岩石圈幔源交代岩与丰富的化学成分下的华北盆地。交代岩主要是由橄榄岩-流体/熔体反应形成的，流体/熔体主要是在三叠纪从俯冲的扬子陆壳中释放出来的。古太平洋板块俯冲后滚导致的区域伸展、岩石圈减薄和地幔上隆是早白垩世中国大陆东部层状岩浆岩和广泛的弧形岩浆岩形成的原因。
Lamprophyre dykes that crosscut different types of ultrahigh pressure (UHP) metamorphic rocks are widely distributed in the Triassic Sulu UHP orogenic belt. Although abundant studies have been performed on these dykes, their origin and petrogenesis remain topics of controversy. This study presents the results of a detailed field-based study of petrology, whole-rock geochemistry and zircon U-Pb and Lu-Hf isotopes on lamprophyre dykes exposed in the central Sulu UHP zone, aiming at shedding lights on their petrogenesis and providing clues on the geological evolution of eastern continental China during the Cretaceous. The lamprophyres are typically porphyritic, with phenocrysts dominantly composed of amphibole and clinopyroxene set in a lamprophyric matrix. The dykes have moderate SiO2(47.70 wt.%–60.44 wt.%), variably high MgO (2.58 wt.%–8.28 wt.%) and Fe2O3T(4.88 wt.%–9.26 wt.%) contents with high Mg#of 49–66. Geochemically, they have enriched light rare earth element (REE) and flat heavy REE patterns ((La/Gd)N=5.14–10.56; (Dy/Yb)N=1.43–1.54) with negligible Eu anomalies (Eu/Eu*=0.83–1.10), and they show enrichment in large ion lithophile elements (e.g., Ba and K) but depletion in high-field strength elements (e.g., Nb, Ti and P).In-situzircon U-Pb geochronology reveals that the lamprophyres have concordant ages of 120–115 Ma, demonstrating that the dykes emplaced in the Early Cretaceous. These zircons haveεHf(t) values ranging from −26.0 to −11.0. Inherited zircons that occur in the dykes are dated to be Neoproterozoic, in line with the protolith ages of their host (i.e., the UHP rocks). An integration of these data allows us to propose that the lamprophyres were generated during the Cretaceous, by melting of subcontinental lithospheric mantle-derived metasomatite with enriched chemical compositions underneath the North China Craton. The metasomatite was formed mainly by peridotite-fluid/melt reactions, with the fluids/melts mainly liberated from subducted Yangtze continental crust during the Triassic. Regional extension, lithospheric thinning and mantle upwelling caused by rollback of the subducted paleo-Pacific plate is considered to account for the generation of the lamprophyres as well as the extensive arc-like magmatic rocks in eastern continental China during the Early Cretaceous.
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影响因子：
5
作者：
Foley, SF;Jackson, SE;Jenner, GA
通讯作者：
Jenner, GA
DOI：
10.1144/gsl.sp.1987.030.01.09
发表时间：
1987
期刊：
Geological Society, London, Special Publications
影响因子：
--
作者：
N. Rock
通讯作者：
N. Rock
中国东部苏鲁造山带早白垩世安山岩岩脉的岩石成因
影响因子：
1.8
作者：
Wang Songjie;Li Xuping;Schertl Hans Peter;Feng Qingda
通讯作者：
Feng Qingda
影响因子：
3.9
作者：
Jin-Hui Yang;Fu-Yuan Wu;Sun‐Lin Chung;S. Wilde;M. Chu;C. Lo;B. Song
通讯作者：
Jin-Hui Yang;Fu-Yuan Wu;Sun‐Lin Chung;S. Wilde;M. Chu;C. Lo;B. Song
华北克拉通东南部岩石圈地幔与俯冲相关的交代作用：苏鲁造山带北部镁铁质岩脉到中间岩脉的证据
影响因子：
2.9
作者：
M. Santosh;Fang-Fang Hu;Kui-Feng Yang;Zhaochu Hu
通讯作者：
Zhaochu Hu