Geochronology, geochemistry and zircon Hf isotopes of the Dongfanghong gabbroic complex at the eastern margin of the Jiamusi Massif, NE China: Petrogensis and tectonic implications
Geochronology, geochemistry and zircon Hf isotopes of the Dongfanghong gabbroic complex at the eastern margin of the Jiamusi Massif, NE China: Petrogensis and tectonic implications
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佳木斯地块东缘东方红辉长岩杂岩的年代学、地球化学和锆石Hf同位素：岩石成因及其构造意义
DOI：
10.1016/j.lithos.2015.07.015
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发表时间：
2015-10
期刊：
影响因子：
3.5
通讯作者：
Wang Zhihui
中科院分区：
文献类型：
--
作者：
Bi Junhui;Ge Wenchun;Yang Hao;Zhao Guochun;Xu Wenliang;Wang Zhihui
本文报道了中亚造山带(CAOB)最东段佳木斯地块东缘出露的辉长岩、斜长花岗岩和花岗斑岩的LA-ICPMS锆石U-Pb年龄、地球化学数据和锆石Hf同位素组成。La-ICPMS锆石U-Pb年龄数据表明，这些岩石的侵位年龄分别为290-274 Ma、277 Ma和110 Ma。辉长岩具中、低钾拉斑玄武岩成分，镁含量为3.92-12.59%，K2O含量为0.12-0.77%，二氧化钛含量为0.59-1.37%。它们富含大离子亲石元素(如Rb、Sr)，亏损高场强元素(如Nb、Ta)，并显示正的锆石εHf(T)值(3.1-13.8)。推测这些岩石的原生岩浆来源于亏损的岩石圈地幔源区，在其形成前不久被俯冲板片派生的流体交代。此外，东方红辉长岩具有低的Sr/Y(7.32~26.2)和(La/Yb)N(0.99~3.02)比值，高的HREE、Y和Sc含量，表明岩石圈地幔的部分熔融发生在相对较低的压力条件下。早白垩世花岗斑岩为准铝质中钾钙碱性I型花岗岩，原生岩浆来源于地壳物质的部分熔融。根据新的地球化学资料和区域地质调查，我们认为东方红辉长杂岩和花岗斑岩都形成于活动大陆边缘环境，前者很可能与佳木斯地块之下的古洋板向西俯冲有关，后者与欧亚大陆之下的古太平洋板块向西俯冲有关。辉长岩和花岗斑岩清楚地代表了佳木斯地块东部晚古生代以来与俯冲有关的两次地壳增生事件。
This paper reports LA–ICP–MS zircon U–Pb ages, geochemical data and zircon Hf isotope compositions of gabbroic rocks, plagiogranites, and granite porphyries exposed at the eastern margin of the Jiamusi Massif in the easternmost segment of the Central Asian Orogenic Belt (CAOB). LA–ICP–MS zircon U–Pb age data indicate that these rocks were emplaced at 290–274, 277, and 110 Ma, respectively. The gabbroic rocks have low- and medium-K tholeiitic compositions, with variable MgO (3.92–12.59%) and low K2O (0.12–0.77%) and TiO2(0.59–1.37%) contents. They are enriched in large ion lithophile elements (e.g., Rb, Sr), depleted in high field-strength elements (e.g., Nb, Ta), and exhibit positive zircon εHf(t) values (3.1–13.8). It is inferred that the primary magmas of these rocks were derived from a depleted lithospheric mantle source that was metasomatized by subducted-slab-derived fluids shortly before their generation. In addition, the Dongfanghong gabbroic rocks have low Sr/Y (7.32–26.2) and (La/Yb)N(0.99–3.02) ratios, and high HREEs, Y, and Sc contents, indicating that the partial melting of lithospheric mantle occurred under relatively low-pressure conditions. The Early Cretaceous granite porphyries are metaluminous medium-K calc-alkaline I-type granites, where the primary magma originated from the partial melting of crustal material. Based on the new geochemical data and regional geological investigations, we propose that the Dongfanghong gabbroic complex and granite porphyry were both formed in an active continental margin setting, the former most likely related to westward subduction of the paleo-oceanic plate beneath the Jiamusi Massif, and the latter associated with westward subduction of the Paleo-Pacific plate beneath the Eurasian continent. The gabbros and the granite porphyries clearly represent two subduction-related crustal accretion events in the eastern part of the Jiamusi Massif since the late Paleozoic.
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影响因子：
3.3
作者：
Tang Kedong;W. Ying;He Guoqi;Shao Jian
通讯作者：
Tang Kedong;W. Ying;He Guoqi;Shao Jian
影响因子：
4.2
作者：
Jian‐Bo Zhou;Jia-Lin Cao;S. Wilde;Guochun Zhao;Jinjiang Zhang;Bin Wang
通讯作者：
Jian‐Bo Zhou;Jia-Lin Cao;S. Wilde;Guochun Zhao;Jinjiang Zhang;Bin Wang
影响因子：
1.8
作者：
Cheng Rui
通讯作者：
Cheng Rui
影响因子：
12.1
作者：
J. Veevers;A. Saeed;E. Belousova;W. Griffin
通讯作者：
J. Veevers;A. Saeed;E. Belousova;W. Griffin
影响因子：
56.9
作者：
E. Scherer;C. Münker;K. Mezger
通讯作者：
E. Scherer;C. Münker;K. Mezger