The Pozantı-Karsantı ophiolite is one of the well-preserved supra-subduction-zone oceanic lithosphere slices. It offers a unique opportunity to study oceanic crust formation, and to specify subduction initiation processes of the Inner Tauride ocean in the Neo-Tethyan subduction system. The Pozantı-Karsantı ophiolite is tectonically underlain by a subophiolitic metamorphic sole and mélanges. The metamorphic sole is mostly amphibolites that are enriched in light rare earth elements and large-ion lithophile elements, low ε_Nd(t) values (+ 5.4 to + 8.3) and high ²⁰⁷Pb/²⁰⁴Pb ratios, suggesting an OIB-like geochemical affinity. Secondary ion mass spectrometry (SIMS) zircon and titanite U–Pb ages reveal a protolith age at ~ 122.2 ± 1.3 Ma and metamorphic age at 92–90 Ma for the amphibolites. Gabbro and diabase dikes intruded the metamorphic sole rocks and ophiolitic units at ~ 91 to 90 Ma. Their elemental and Sr–Nd–Pb isotopic characteristics indicate a MORB-like mantle source, different from subduction fluid-altered dikes formed at 86.9 ± 3.1 Ma. The temporal-geochemical sequence therefore suggests that the intra-oceanic subduction initiated at 91.9 ± 0.8 Ma within an older lithosphere (> 122 Ma) of the Inner Tauride ocean. Incipient subduction led to forearc (ultra-)slow-spreading seafloor with mafic dikes of 91–90 Ma. The fast switch from MORB- to SSZ-type oceanic spreading might have occurred in less than 3 Myr and marks the inception of a mature subduction zone.

Pozantı-Karsantı蛇绿岩是保存完好的超俯冲带海洋岩石圈切片之一。它提供了一个独特的机会来研究大洋地壳的形成，并在新特提斯俯冲系统中详细说明内陶瑞德洋的俯冲起始过程。Pozantı-Karsantı蛇绿岩在构造上由亚蛇绿岩变质底部和混杂岩构成。变质底多为角闪岩，富含轻稀土元素和大离子亲石元素，ε _Nd ( t )值低（+ 5.4 to + 8.3），²⁰⁷ Pb/ ²⁰⁴高Pb 比率，表明类似 OIB 的地球化学亲和力。二次离子质谱 (SIMS) 锆石和钛铁矿 U-Pb 年龄显示角闪石的原岩年龄为 ~ 122.2 ± 1.3 Ma，变质年龄为 92-90 Ma。辉长岩和辉绿岩脉在约 91 至 90 Ma 侵入变质单岩和蛇绿岩单元。它们的元素和 Sr-Nd-Pb 同位素特征表明一个类似 MORB 的地幔源，不同于在 86.9 ± 3.1 Ma 形成的俯冲流体改变岩脉。因此，时间地球化学序列表明大洋内俯冲开始于 91.9 ± 0.8 Ma，位于内陶瑞德大洋的较旧岩石圈（> 122 Ma）内。初期的俯冲导致前弧（超）缓慢扩张的海底具有 91-90 Ma 的基性岩脉。