We present the geochemical and Sr–Nd–Pb isotopic data and the petrological evolution of primitive basaltic lavas that erupted from the Miocene to Quaternary in the East Anatolia Collision Zone to understand the geodynamic conditions and the change in the lithospheric mantle over time. Major trace element abundances, Sr–Nd–Pb isotopic compositions and petrological models show that the primitive basaltic samples were not affected by crustal contamination and fractional crystallization. They are derived from a depleted MORB mantle modified by melts derived from subducted sediments. The primitive melts of the Miocene and Quaternary series were derived from an amphibole-bearing garnet lherzolitic mantle and an amphibole-bearing garnet–spinel lherzolite mantle source, respectively. In contrast, the Pliocene basaltic melts were formed by mixing melts originating from both an amphibole-bearing spinel and garnet lherzolite. Our thermodynamic calculations indicate that the lithosphere–asthenosphere boundary (LAB) is about 30 km shallower in the Pliocene than in the Miocene.This may be explained by lithospheric delamination in the Early Pliocene. In contrast, the LAB in the Quaternary is approximately 9 km deeper than in the Pliocene, which can be explained by relamination of the mantle lithosphere. Thermal calculations have shown that about 5–11 km of the relamination can occur within 5–6 Ma and that asthenospheric melts can relaminate the base of the thinned lithospheric mantle by cooling, and the presence of the relaminated mantle lithosphere is documented throughout the whole EACZ.

我们提供了东安纳托利亚碰撞带中新世至第四纪喷发的原始玄武岩熔岩的地球化学和Sr-Nd-Pb同位素数据以及岩石学演化，以了解地球动力学条件和岩石圈地幔随时间的变化。主要微量元素丰度、Sr-Nd-Pb同位素组成和岩石学模型表明原始玄武岩样品未受到地壳污染和分异结晶的影响。它们源自耗尽的 MORB 地幔，该地幔被俯冲沉积物产生的熔体所改变。中新世和第四纪的原始熔体分别源自含角闪石石榴石二辉橄榄岩地幔和含角闪石石榴石-尖晶石二辉橄榄岩地幔源区。相比之下，上新世玄武岩熔体是通过混合来自含角闪石尖晶石和石榴石二辉橄榄岩的熔体而形成的。我们的热力学计算表明，上新世岩石圈-软流圈边界（LAB）比中新世浅约30公里。这可能是上新世早期岩石圈分层作用所解释的。相比之下，第四纪的 LAB 比上新世深约 9 公里，这可以通过地幔岩石圈的再分层来解释。热计算表明，约 5-11 km 的再层压作用可在 5-6 Ma 内发生，软流圈熔体可通过冷却使变薄的岩石圈地幔底部重新层压，并且在整个 EACZ 中都记录了重新层压的地幔岩石圈的存在。 。