Geochemistry and petrogenetic implications of a Late Devonian mafic–ultramafic intrusion at the southern margin of the Central Asian Orogenic Belt
Geochemistry and petrogenetic implications of a Late Devonian mafic–ultramafic intrusion at the southern margin of the Central Asian Orogenic Belt
复制标题
中亚造山带南缘晚泥盆世镁铁质—超镁铁质侵入岩的地球化学和岩石成因意义
DOI：
10.1016/j.lithos.2012.03.010
复制
发表时间：
2012-07
期刊：
影响因子：
3.5
通讯作者：
Song Xie-Yan
中科院分区：
文献类型：
--
作者：
Xie Wei;Song Xie-Yan
黑山镁铁质-超镁铁质岩体侵位于中亚造山带南缘北山褶皱带东部新元古代变质地层中。侵入岩的主要岩石为方辉橄榄岩和二辉橄榄岩。橄榄辉长岩和辉长岩仅见于侵入体南缘。黑山侵入体岩石具有大离子亲石元素富集性、Nb(Ta)强负异常和K、Pb正异常的特征。这些特征与北山褶皱带泥盆纪火山岩的特征完全一致，表明与俯冲有关的岩浆作用。黑山侵入岩具有限制εNd(T)(+0.34~+3.95)和大范围(87Sr/86Sr)比值(0.7041~0.7087)的特征。它们的高(207Pb/204Pb)t(15.55-15.64)和(208Pb/204Pb)t(37.71-38.29)值与美洲太平洋边缘的火山岩相当。锆石ID-TIMS U-Pb年龄(356.4±0.6 Ma和366.6±0.6 Ma)和SHRIMP U-Pb年龄(358±5 Ma和357±4 Ma)表明该岩体侵位于晚泥盆世。计算表明，黑山侵入体的母岩浆具有高镁玄武岩成分，镁含量约为11.3wt.%，FeOt含量约为10.0wt.%。认为高镁玄武岩岩浆是由活动大陆边缘板块断裂引起的软流圈上涌触发的软流圈和地幔楔体的部分熔融形成的。
The Heishan mafic–ultramafic intrusion was emplaced into Neoproterozoic metamorphic strata in the eastern Beishan Fold Belt at the southern margin of the Central Asian Orogenic Belt. The dominant rocks of the intrusion are harzburgite and lherzolite. Olivine gabbro-norite and gabbro dyke occur only along the southern margins of the intrusion. The rocks of the Heishan intrusion are characterized by enrichments of large ion lithophile elements, strong negative Nb (Ta) anomalies and positive K and Pb anomalies. These features are perfectly consistent with those of the Devonian volcanics in the Beishan Fold Belt and indicate subduction-related magmatism. The Heishan intrusive rocks have restricted εNd(t)(+0.34 to +3.95) and a large range of (87Sr/86Sr)tratios (0.7041 to 0.7087). Their high (207Pb/204Pb)t(15.55–15.64) and (208Pb/204Pb)t(37.71–38.29) values are comparable with those of the volcanics along the Pacific margins of the Americas. Zircon ID-TIMS U–Pb age data (356.4±0.6Ma and 366.6±0.6Ma) and SHRIMP U–Pb age data (358±5Ma and 357±4Ma) indicate that the intrusion was emplaced in the Late Devonian. Our calculations indicate that the parental magma of the Heishan intrusion had a high-Mg basaltic composition with ~11.3wt.% MgO and ~10.0wt.% FeOT. It is proposed that the high-Mg basaltic magma was generated from partial melting of the asthenosphere and mantle wedge triggered by upwelling of asthenosphere due to slab break-off in an active continental margin.
登录
查看更多内容
影响因子：
2.6
作者：
B. Su;K. Qin;P. Sakyi;Dongmei Tang;Ping Liu;S. Malaviarachchi;Qing-Hua Xiao;He Sun
通讯作者：
B. Su;K. Qin;P. Sakyi;Dongmei Tang;Ping Liu;S. Malaviarachchi;Qing-Hua Xiao;He Sun
影响因子：
3.9
作者：
A. D. Paktunc
通讯作者：
A. D. Paktunc
DOI：
10.1007/bf02831532
发表时间：
2002-10
期刊：
Chinese Journal of Geochemistry
影响因子：
--
作者：
Guo Jian;Shu Liangshu;Charvet Jaques;Laurent Sebastien;Sun Shuwen
通讯作者：
Guo Jian;Shu Liangshu;Charvet Jaques;Laurent Sebastien;Sun Shuwen
DOI：
--
发表时间：
2005
期刊：
Acta Geological Sinica
影响因子：
--
作者：
Wu Hua
通讯作者：
Wu Hua
影响因子：
3.9
作者：
G. Chai;A. J. Naldrett
通讯作者：
G. Chai;A. J. Naldrett