Eocene intermediate to felsic subvolcanic rocks of the Torud-Ahmad Abad magmatic belt (TAMB), in the northern part of the Central Iran zone, are exposed between the Torud and Ahmad Abad regions in South-Southeast Shahrood. These igneous rocks include hypabyssal dacite, trachyte, andesite, trachy-andesite, and basaltic andesite; they are mainly composed of phenocrysts and microcrystalline groundmass of pyroxene, amphibole, and plagioclase, with minor biotite and titanomagnetite; they form domal structures (plugs and stocks), dikes, and sills that intruded into Neoproterozoic to cogenetic Eocene volcano-sedimentary sequences. Based on isotopic analysis of these intermediate to acidic rocks, initial ratios of ¹⁴³Nd/¹⁴⁴Nd range from 0.512 775 to 0.512 893 and initial ratios of ⁸⁷Sr/⁸⁶Sr range from 0.703 746 to 0.705 314, with quite positive ε_Nd(i) values of +3.69 to +6.00. They are enriched in light rare earth elements and large ion lithophile elements and depleted in heavy rare earth elements and high-field strength elements, the SiO₂ content is (52–62) wt.%, and Na₂O content >3 wt.%, Al₂O₃ content >16 wt.%, Yb <1.8 ppm, and Y <18 ppm. These geological, geochemical, and Sr and Nd isotopic data are consistent with adakitic signatures originating by partial melting of the subducted Neo-Tethys oceanic slab (Sabzevar branch) and lithospheric suprasubduction zone mantle. The mantle signatures typifying the rapidly emplaced adakitic rocks (slab (high-silica adakite) and suprasubduction zone (low-silica adakite) melts) together with their locally voluminous extent are evidences that support a locally extensional geodynamic setting; and the evidence is consistent with an evolution to local transpression in the Late Eocene in this convergent margin arc environment to rifting (basalts to adakites) towards submarine conditions in the Neogene.

伊朗中部地区北部Torud-Ahmad Abad岩浆带（TAMB）的长英质次火山岩中间的始新世暴露于Shahrood东南的Torud和Ahmad Abad地区之间。这些火成岩包括hypabyssal dacite，trachyte，安山岩，trachy-安山岩和玄武质安山岩。它们主要由辉石，闪石和斜长石的隐晶和微晶质构成，并有少量黑云母和钛磁铁矿。它们形成了侵入新元古代到共生始新世火山沉积序列的穹顶结构（栓塞和砧木），堤坝和窗台。根据这些中酸性岩石的同位素分析，¹⁴³ Nd / ¹⁴⁴ Nd的初始比率为0.512 775至0.512 893，而初始比率为⁸⁷ SR / ⁸⁶的Sr范围从0.703到746 0.705 314，具有相当积极ε_钕（I）的3.69至6.00的值。它们富含轻稀土元素和大型离子亲石元素，而贫重稀土元素和高场强元素，SiO ₂含量为（52–62）wt。％，Na ₂ O含量> 3 wt。 ％，Al ₂ O ₃含量＞ 16重量％，Yb ＜1.8ppm，Y ＜18ppm。这些地质，地球化学以及Sr和Nd同位素数据与由俯冲的新特提斯海洋板块（萨布泽瓦支）和岩石圈超俯冲带地幔部分融化而产生的反冲特征相一致。代表着快速沉积的埃达克质岩石（板状（高硅质的埃达克特）和超俯冲带（低硅质的埃达克特）的熔融）的地幔特征及其局部体积范围是支持局部扩展地球动力学环境的证据。证据表明，在这种渐近的边缘弧环境中，始新世晚期发生了局部压变，逐渐向新近纪的海底条件下裂变（玄武岩到Adakite）。