Several gabbro, gabbroic diorite, and diorite intrusions were emplaced in the Neotethyan Urumieh-Dokhtar magmatic arc in the Kahak area of the Zagros Orogen. The plutonic rocks intruded Cenozoic volcanic and pyroclastic succession. U-Pb dating via LA-ICP-MS of zircon yields early to middle Eocene ages of ~53 to 38 Ma for the diorite and gabbroic diorite in Veshnaveh and Naragh areas and Miocene ages of 23 to 20 Ma for gabbroic rocks in the Kerogan and Fordou areas. The Eocene magmatic phase occurred quite possibly as three continuous pulses. The Eocene and Miocene intrusions have negative Nb-Ta anomalies like those of subduction-related magmas. The Pb isotopic compositions show the involvement of subducted sediment in the source of the studied samples. The Eocene intrusions are tholeiitic and enriched in incompatible-trace-elements (especially the HFSE) compared to the Miocene intrusions which are calc-alkaline and have lower concentrations of most incompatible trace elements. Sr-Nd isotopic compositions of the Eocene rocks lie close to the mantle array and near Bulk Silicate Earth, but the Miocene suite is shifted to higher (⁸⁷Sr/⁸⁶Sr)_i. The higher (⁸⁷Sr/⁸⁶Sr)_i, along with larger Ba, K, Pb, and Sr anomalies, in the Miocene suite imply more slab fluid input and/or crustal contamination. Apparently, the Eocene mafic magmas formed in slightly metasomatized sub-continental lithospheric mantle (SCLM), whereas the Miocene suite was derived from highly metasomatized, deeper levels of the SCLM. We suggest that slab roll back occurred between the Eocene and Miocene and transferred the location of mantle partial melting to greater depths.

在Zagros造山带的Kahak地区的Neotethyan Urumieh-Dokhtar岩浆弧中放置了几个辉长岩，辉长岩闪长岩和闪长岩侵入体。古生岩侵入新生代火山和火山碎屑演替。通过锆石的LA-ICP-MS进行的U-Pb测年在Veshnaveh和Naragh地区的闪长岩和辉长岩闪长岩的早新世至中新世年龄约为53至38 Ma，而在Kerogan和Kraggan的辉长岩的中新世年龄为23至20 Ma。福杜地区。始新世岩浆相很可能以三个连续脉冲的形式出现。始新世和中新世侵入岩具有负Nb-Ta异常，与俯冲有关的岩浆一样。铅同位素组成表明，俯冲沉积物参与了研究样品的来源。与中新世入侵相比，始新世入侵者多生且富含不相容的痕量元素（尤其是HFSE），而中新世入侵者为钙碱性且大多数不相容痕量元素的浓度较低。始新世岩石中的Sr-Nd同位素组成接近地幔阵列，且位于硅碳酸盐大块土附近，但中新世套件已转移到更高的位置（⁸⁷ Sr / ⁸⁶ Sr）_i。中新世组中较高的（⁸⁷ Sr / ⁸⁶ Sr）_i以及较大的Ba，K，Pb和Sr异常，意味着更多的平板流体输入和/或地壳污染。显然，始新世镁铁质岩浆形成于陆交界的岩石圈地幔（SCLM）交代程度稍高的地方，而中新世套件则是由交代程度高，层次更深的SCLM衍生而来的。我们认为板坯回滚发生在始新世和中新世之间，并将地幔部分熔融的位置转移到了更大的深度。