Abstract Crustal recycling into Earth’s deep mantle has been inferred from both seismic tomography and geochemical observations. As a further line of evidence, we report on zircons having a wide range of ages that were recovered from the Aladag chromitites, providing direct evidence for crustal recycling. Mesozoic zircons represent the earliest stages of Neotethyan seafloor spreading magmatism, whereas Neoproterozoic and Mesoproterozoic–Archean zircons record recycled old crustal material entrained in the ophiolitic mantle melt sources. The incorporation of such old, crustal zircons into the Neotethyan mantle might have followed from previous subduction events, from lithospheric delamination, and/or from the dismantling of West Gondwana in the Permo-Triassic. Subduction–affiliated ophiolitic melts may have picked up these recycled zircons and integrated them into chromitites, which precipitated from peridotite–melt interactions in a mantle wedge beneath the Inner–Tauride (a Neotethyan seaway) seafloor spreading system. Common in ophiolitic chromitites within the Neotethyan realm, such unusually old zircons present unique archives for tracking crustal recycling and mantle processes during rift–drift, seafloor spreading and subduction zone evolution of the oceanic mantle. We conclude that ophiolitic mantle peridotite and chromitite may be an important archive for preserving the recycling history of crustal material back into Earth’s deep mantle.

中文翻译：

---

白垩纪 Aladag 蛇绿岩（土耳其）铬铁矿中的前寒武纪锆石表明大洋地幔深部地壳再循环

摘要 从地震层析成像和地球化学观测中推断出地壳循环进入地球深部地幔。作为进一步的证据，我们报告了从 Aladag 铬铁矿中回收的年龄范围广泛的锆石，为地壳循环提供了直接证据。中生代锆石代表了新特提斯海底扩张岩浆作用的最早阶段，而新元古代和中元古代-太古代锆石则记录了蛇绿岩地幔熔融源中夹带的再生旧地壳物质。这些古老的地壳锆石并入新特提斯地幔可能是由于先前的俯冲事件、岩石圈分层和/或二叠纪-三叠纪西冈瓦纳大陆的解体造成的。俯冲附属蛇绿岩熔体可能已经拾取了这些回收的锆石并将它们整合到铬铁矿中，铬铁矿是从 Inner-Tauride（新特提斯海道）海底扩张系统下方地幔楔中的橄榄岩-熔体相互作用中沉淀出来的。在新特提斯界的蛇绿岩铬铁矿中很常见，这种异常古老的锆石提供了独特的档案，可用于跟踪裂谷漂移、海底扩张和大洋地幔俯冲带演化过程中的地壳循环和地幔过程。我们得出结论，蛇绿岩地幔橄榄岩和铬铁矿可能是保存地壳物质返回地球深部地幔的再循环历史的重要档案。它是从 Inner-Tauride（新特提斯海道）海底扩张系统下方的地幔楔中的橄榄岩-熔体相互作用中沉淀出来的。在新特提斯界的蛇绿岩铬铁矿中很常见，这种异常古老的锆石提供了独特的档案，可用于跟踪裂谷漂移、海底扩张和大洋地幔俯冲带演化过程中的地壳循环和地幔过程。我们得出结论，蛇绿岩地幔橄榄岩和铬铁矿可能是保存地壳物质返回地球深部地幔的再循环历史的重要档案。它是从 Inner-Tauride（新特提斯海道）海底扩张系统下方的地幔楔中的橄榄岩-熔体相互作用中沉淀出来的。在新特提斯界的蛇绿岩铬铁矿中很常见，这种异常古老的锆石提供了独特的档案，可用于跟踪裂谷漂移、海底扩张和大洋地幔俯冲带演化过程中的地壳循环和地幔过程。我们得出结论，蛇绿岩地幔橄榄岩和铬铁矿可能是保存地壳物质返回地球深部地幔的再循环历史的重要档案。