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为了确定Calabrian弧南部Palmi—Bagnara地区英云闪长质片麻岩类的地球化学特征、可能的母岩和构造一变质的演化,对其进行了复查。根据野外资料、构造特征,31个全岩地球化学研究(主要和痕量元素)和4个矿物年龄测定(K—Ar和Rb—Sr)等资料,可以得到如下结论:(ⅰ)在元素丰度和它们的地球化学趋势方面,英云闪长质片麻岩类显示与钙碱性中性侵入岩体明显的亲和性,它们以高的Al_2O_3、CaO、LaCe、Ce/Nb和低的TiO_2、K_2O/Na_2O比值、Nb和过渡元素含量为特征;(ⅱ)认为英云闪长质片麻岩类的前身属于深成火成来源,象那些典型的钙—碱性深成杂岩体那样,埋在英云闪长质主岩中的镁铁质微粒状片麻岩类,可能相当于早先镁铁质微粒状包体;(ⅲ)早先深成杂岩在海西造山运动期间被变质成高角闪岩相,这与精选的角闪石所获得的323±11MaK—Ar年龄值一致。因此,这一母岩是在海西期变质前或是海西以前侵入的;(ⅳ)黑云母所获得的K—Ar和Rb—Sr放射性年龄资料说明了英云闪长质片麻岩中广泛叠加了阿尔卑斯期糜棱岩化作用的影响,这种影响可能与剪切构造有关。就Calabrian弧演化的含义而言,这次研究的一些结果说明在早阿尔卑斯时期弧的南部被强烈的剪切构造所影响。
They were reviewed to determine the geochemical characteristics of the Ying-dioritic gneiss in the Palmi-Bagnara area of southern Calabrian arc, possible parent rocks and tectono-metamorphic evolution. Based on the field data, tectonic features, 31 whole-rock geochemical studies (major and trace elements) and four mineral age determinations (K-Ar and Rb-Sr), the following conclusions can be drawn: (i) Degrees and their geochemical trends, the Yingke dioritic gneiss show a clear affinity with calc-alkaline neutral intrusive rocks with high contents of Al 2 O 3, CaO, LaCe, Ce / Nb and low TiO 2, K 2 O / Na 2 O ratio, Nb and transitional element contents; (ii) It is considered that the predecessor of the Yingyun dioritic gneisses belongs to the deep craton source, like those typical calc-alkaline deep complex bodies In that case, the mafic fine-grained gneiss buried in the Ying-diorite host rock may correspond to the earlier mafic-type inclusions; (iii) the earlier deep-plutonic complex was trapped during the Hercynian orogeny Metamorphic into a high amphibolite facies, which is consistent with the 323 ± 11MaK-Ar age value of the selected amphiboles. Therefore, this parent rock intruded before the Hercynian metamorphosis or before the Hercynian; (ⅳ) K-Ar and Rb-Sr radioactive age data obtained from biotite illustrate that in the English dioritic gneiss The effect of mylonitization in the Alps is extensively superimposed and this effect may be related to the shear structure. In terms of the Calabrian arc evolution, some of the results of this study suggest that the southern part of the arc was strongly influenced by strong shear structures during the Early Alps.