The Ajabshir rhyolitic magma in the northwest (NW) of Iran is an Early Carboniferous (332.5 ± 2.2 Ma), approximately 50m-thick succession, consisting of quartz, alkali feldspar, and biotite phenocryst with a porphyritic texture. This magmatic unit occurred as lava flows and sills intruded into the early Cambrian Lalun Formation. The Ajabshir magma has a calc-alkaline to high potassic calc-alkaline affinity and peraluminous character and displays many of the classic features of A-type magmas, enrichment in HFSEs (Zr + Nb + Ce + Y = 664–808 ppm), Nb (120−218 ppm), Zr (298−362 ppm), Ga (34−38 ppm), Ce (100−132 ppm), high Ga/Al and FeO*/(FeO*+MgO), zircon saturation temperature, and low contents of CaO, Sr, and Eu. The LREE enrichment, non-depletion in HREE, and negative Eu anomalies in the chondrite normalized diagrams exhibit similarities to the REE patterns of “hot-dry-reduced rhyolites”, further pointing to the evolution of Ajabshir rhyolitic magma from an OIB-type parental melt via a fractional crystallization process. The zircon yield εHf_(t) values of +1.4 to +5.5 correspond to two-stage zircon Hf model ages of 0.9–1.2 Ga. The δ¹⁸O values of the zircon range from +5.8‰ to +7.37‰. The zircon isotopic data together with whole-rock geochemical signatures suggest that the mantle-derived magma was modified by crustal components during its ascent to the surface. The Ajabshir A-type rhyolitic magma provides more evidence for an extensional tectonic setting during the Early Carboniferous in NW Iran, contemporaneous with the rifting of the Neotethyan Ocean at the northern margin of Gondwana.

伊朗西北部（AW）的阿贾拜尔流纹岩浆是早期石炭纪（332.5±2.2 Ma），相继形成约50m厚，由石英，碱性长石和黑云母斑晶组成，具有斑状质地。该岩浆单元发生在熔岩流和基岩侵入早期寒武纪拉伦组的过程中。Ajabshir岩浆具有钙碱性到高钾钙碱性亲和力和高铝质特征，并显示出A型岩浆的许多经典特征，富含HFSE（Zr + Nb + Ce + Y = 664–808 ppm），Nb （120-218 ppm），Zr（298-362 ppm），Ga（34-38 ppm），Ce（100-132 ppm），高Ga / Al和FeO * /（FeO * + MgO），锆石饱和温度， CaO，Sr和Eu的含量低。LREE富集，HREE中的非消耗，球粒晶归一化图中的负Eu异常与“热干还原流纹岩”的REE模式相似，进一步指出了阿伊卜舍尔流纹岩浆是通过分步结晶过程从OIB型母体熔体演化而来的。锆石的产量εHf_（T）的1.4至5.5对应值，以两阶段的锆石的0.9-1.2佐治亚州的δHf模式年龄^18个‰锆石范围的O值从+ 5.8‰至+ 7.37。锆石同位素数据以及整个岩石的地球化学特征表明，地幔衍生的岩浆在上升到地表的过程中被地壳成分所修饰。Ajabshir A型流纹岩浆为伊朗西北部石炭纪早期的伸展构造背景提供了更多证据，与此同时在冈瓦纳北缘的新特提斯洋裂谷。