Diverse origins of pyroxenite xenoliths from Yangyuan, North China Craton: implications for the modification of lithosphere by magma underplating and melt-rock interactions
Diverse origins of pyroxenite xenoliths from Yangyuan, North China Craton: implications for the modification of lithosphere by magma underplating and melt-rock interactions
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华北克拉通阳原辉石岩捕虏体的多种成因：岩浆底侵和熔岩相互作用对岩石圈改造的意义
DOI：
10.1016/j.lithos.2020.105680
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发表时间：
2020-11
期刊：
影响因子：
3.5
通讯作者：
Teng Fang-Zhen
中科院分区：
文献类型：
--
作者：
Liu Ya-Dong;Ying Ji-Feng;Li Jian;Sun Yang;Teng Fang-Zhen
(W)e对华北克拉通阳原县渐新世玄武岩中的一系列辉石岩包体进行了详细的主量元素、微量元素和Sr-Nd-Mg同位素地球化学研究，以揭示其成因，并进一步制约该地区岩石圈地幔的演化。阳原辉石岩的岩石类型从斜方辉石岩、富斜方辉石二辉橄榄岩、富单斜辉石二辉橄榄岩到单斜辉石岩。它们的平衡温度（874-975摄氏度）在上地幔和下地壳的温度范围内，表明它们来自壳幔过渡带。阳原辉石岩捕虏体根据单斜辉石的成分可分为三类。第一类辉石岩中的单斜辉石以高Mg-（88.3-92.0; Mg- = Mg/（Mg + Fe ~（2+））100）和Cr_2 O_3（0.86- 1.63wt.%）为特征。它们与橄榄岩包体的相似性以及轻稀土元素的富集表明，I型辉石岩的形成可能是地幔岩石的不均一性造成的，其中可能存在包体交代作用。II型辉石岩中的单斜辉石具有中间Mg-（81.0-86.7）和Cr 2 O 3（0.53-0.73重量%）含量，与强烈交代的幔源铁二辉橄榄岩捕虏体相似。它们的轻稀土富集成分，以及高镍含量的正辉石和单斜辉石，表明II型辉石岩的熔体橄榄岩相互作用。来自III型辉石岩的单斜辉石具有最低的Mg-（65.2-76.5）和Cr 2 O 3含量（0.05-0.38重量%），它们与原生玄武岩的分离结晶作用相当，表明它们是分离结晶作用的产物。阳原辉石岩的Mg、Ti/Eu比值高，（La/Yb）（N）和Ca/Al比值低，Rb和Ba含量低，Sr-Nd同位素亏损，表明其形成可能与软流圈或年轻岩石圈幔源硅酸盐熔体有关，而样品YY 17 -5富集的Sr-Nd同位素表明其源区可能与再生古下地壳的熔体混合。阳原辉石岩的轻和可变的Mg同位素组成（δ Mg-26 = -0.23至-0.46ppm）表明来自俯冲洋板。这些辉石岩捕虏体的不同成因提供了证据，阳原之下的岩石圈深部已被多次熔体-岩石相互作用和岩浆底侵作用的修改。(C)2020 Elsevier B. V. Al（版权所有。
(W)e present detailed major-, trace-element and Sr-Nd-Mg isotopic geochemistry for a suite of pyroxenite xenoliths entrained in Oligocene basalts in Yangyuan county, North China Craton, to reveal their origins and to further constrain the evolution of the lithospheric mantle beneath this area. The Yangyuan pyroxenites exhibit a lithologic spectrum ranging from orthopyroxenite, through orthopyroxene-rich websterite and clinopyroxene-rich websterite to clinopyroxenite. Their equilibrium temperatures (874-975 degrees C), which are within the temperature range of the upper mantle and lower crust, suggest that they came from the crust-mantle transition zone. The Yangyuan pyroxenite xenoliths can be subdivided into three types based on the compositions of their constituent clinopyroxene. Clinopyroxenes in the type I pyroxenites are characterized by high Mg- (88.3-92.0; Mg- = Mg/(Mg + Fe2+)100) and Cr2O3 contents (0.86-1.63 wt.%). Their resemblance to those from the peridotite xenoliths, together with their light rare earth element (LREE) enrichment, indicates that the type I pyroxenites should be produced by lithological heterogeneity in the mantle, which may have including metasomatism. Clinopyroxenes in the type II pyroxenites have intermediate Mg- (81.0-86.7) and Cr2O3 contents (0.53-0.73 wt.%), which are similar to those of strongly metasomatized mantle-derived Fe-lherzolite xenoliths. Their LREE-enriched compositions, as well as the high Ni contents of the orthopyroxenes and clinopyroxenes, suggest that the type II pyroxenites were produced by melt-peridotite interactions. Clinopyroxenes from type III pyroxenites have the lowest Mg- (65.2-76.5) and Cr2O3 contents (0.05-0.38 wt.%), which are comparable to those formed by fractional crystallization of primary basalts, suggesting that they are the products of fractional crystallization. The high Mg-, Ti/Eu ratios, the low (La/Yb)(N) and Ca/Al ratios, and Rb and Ba contents of the clinopyroxenes, as well as the depleted Sr-Nd isotopes of most of the Yangyuan pyroxenites, suggest that asthenosphere or juvenile lithospheric mantle-derived silicate melts were probably involved in their formation, whereas the enriched Sr-Nd isotopes of sample YY17-5 indicate that its source may have mixed with melts derived from recycled ancient lower crust. The light and variable Mg isotopic compositions (delta Mg-26 = -0.23 to -0.46 parts per thousand) of the Yangyuan pyroxenites suggest contributions from a subducted oceanic slab. The diverse origins of these pyroxenite xenoliths provide evidence that the deep lithosphere beneath Yangyuan has been modified by multiple melt-rock interactions and magma underplating. (C) 2020 Elsevier B.V. Al( rights reserved.
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DOI：
10.1086/422668
发表时间：
2004-09
期刊：
The Journal of Geology
影响因子：
--
作者：
Yigang Xu;Sun‐Lin Chung;Jinlong Ma;Lanbin Shi
通讯作者：
Yigang Xu;Sun‐Lin Chung;Jinlong Ma;Lanbin Shi
华北克拉通汉诺坝橄榄岩捕虏体锂同位素系统学：岩石圈地幔减薄中熔岩相互作用的意义
影响因子：
5
作者：
T. Moriguti;K. Kobayashi;H. F. Zhang;E. Nakamura;Y. J. Tang;J. F. Ying
通讯作者：
J. F. Ying
DOI：
--
发表时间：
2007
期刊：
--
影响因子：
--
作者：
SrnpHnN T. NBr;Anr MoNrANrA
通讯作者：
SrnpHnN T. NBr;Anr MoNrANrA
影响因子：
3.8
作者：
Guochun Zhao;S. Wilde;Peter A. Cawood;M. Sun
通讯作者：
Guochun Zhao;S. Wilde;Peter A. Cawood;M. Sun
DOI：
10.1016/s1464-1895(01)00124-7
发表时间：
2001
期刊：
Physics and Chemistry of The Earth Part A-solid Earth and Geodesy
影响因子：
--
作者：
Yigang Xu
通讯作者：
Yigang Xu