Abstract Number of dismembered ophiolite bodies crop out between Sivas and Malatya on the top of the Eastern Tauride platform in the central-eastern Turkey. One of which at the southern margin of the Sivas basin in the Tecer Mountain area comprises melange and the lower part of an oceanic lithospheric section on top of the Tauride platform. The mantle tectonites are characterized by variably serpentinized harzburgites and dunites, and are intruded by numerous isolated dykes. The gabbroic cumulates consist of olivine gabbro, gabbro and gabbronorite. The major and trace element geochemistry of the mafic cumulate rocks suggests that the primary magma was compositionally similar to those observed in modern island-arc tholeiitic sequences. The isolated dykes are exclusively basaltic in composition and display geochemically two distinct subgroups: Group I is represented by high TiO2 (.87–1.47 wt.%) and other incompatible elements, whereas Group II is characterized by low TiO2 (.36–.66 wt.%) and other incompatible elements. The Group I isolated diabase dykes have flat to slightly LREE-depleted profiles (La/YbN = .32–.79), whereas the Group II isolated diabase dykes are more depleted in general and have a LREE-depleted character (La/YbN = .19–.49). This suggests that the isolated dykes were derived from an island arc tholeiitic magma (Nb/Y = .02–.05) with different degrees of partial melting (Group II > Group I) and relatively high oxygen fugacity in intra-oceanic subduction zone. The ophiolitic rocks in the study area may well be compared with the Divriği ophiolite to the southeast. All the evidence suggests that the isolated dykes in the Tecer Mountain area differ from the alkaline isolated dykes cutting the Divriği ophiolite. Since the late stage dykes (~76 Ma) in the Divriği area are alkaline, the tholeiitic isolated dykes in the present study should have been emplaced prior to the alkaline dykes during Late Cretaceous SSZ-spreading (~90 Ma) within the Inner Tauride Ocean.

中文翻译：

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锡瓦斯盆地南缘蛇绿岩的地球化学特征及其对土耳其中东部内托里德洋的影响

摘要 在土耳其中东部的东陶里德台地顶部的锡瓦斯和马拉蒂亚之间出土的肢解蛇绿岩体的数量。其中之一位于 Tecer 山地区 Sivas 盆地南缘，包括混杂岩和 Tauride 地台顶部的大洋岩石圈剖面的下部。地幔构造岩的特征是不同程度的蛇纹石化菱镁矿和硬质辉石，并被许多孤立的岩脉侵入。辉长岩堆积体由橄榄石辉长岩、辉长岩和辉长岩组成。镁铁质堆积岩的主要和微量元素地球化学表明，原生岩浆的成分与现代岛弧拉斑岩层序中观察到的岩浆成分相似。孤立的岩脉在成分上完全是玄武岩，在地球化学上显示出两个不同的亚群：第 I 组以高 TiO2 (.87–1.47 wt.%) 和其他不相容元素为代表，而第 II 组以低 TiO2 (.36–.66 wt.%) 和其他不相容元素为特征。I 组孤立辉绿岩岩脉具有平坦到轻微的 LREE 耗尽剖面 (La/YbN = .32–.79)，而 II 组孤立辉绿岩岩脉总体上更为贫化并具有 LREE 耗尽特征 (La/YbN = .19–.49）。这表明孤立的岩脉来自岛弧拉斑岩浆（Nb/Y = .02-.05），在洋内俯冲带中具有不同程度的部分熔融（第 II 组 > 第 I 组）和相对较高的氧逸度。研究区的蛇绿岩很可能与东南部的 Divriği 蛇绿岩相比较。所有证据表明，Tecer 山区的孤立岩脉不同于切割 Divriği 蛇绿岩的碱性孤立岩脉。由于 Divriği 地区的晚期岩脉 (~76 Ma) 是碱性的，本研究中的拉斑岩孤立岩脉应该在晚白垩世 SSZ 扩张期间 (~90 Ma) 内陶里德洋中的碱性岩脉之前就位.