Sublithospheric diamonds and the inclusions they may carry crystallize in the asthenosphere, transition zone, or uppermost lower mantle (from 300 to ∼800 km), and are the deepest minerals so far recognized to form by plate tectonics. These diamonds are distinctive in their deformation features, low nitrogen content, and inclusions of these major mantle minerals: majoritic garnet, clinopyroxene, ringwoodite, CaSi perovskite, ferropericlase, and bridgmanite or their retrograde equivalents. The stable isotopic compositions of elements within these diamonds (δ11B, δ13C, δ15N) and their inclusions (δ18O, δ56Fe) are typically well outside normal mantle ranges, showing that these elements were either organic (C) or modified by seawater alteration (B, O, Fe) at relatively low temperatures. Metamorphic minerals in cold slabs are effective hosts that transport C as CO3 and H as H2O, OH, or CH4 below the island arc and mantle wedge. Warming of the slab generates carbonatitic melts, supercritical aqueous fluids, or metallic liquids, forming three types of sublithospheric diamonds. Diamond crystallization occurs by movement and reduction of mobile fluids as they pass through host mantle via fractures—a process that creates chemical heterogeneity and may promote deep focus earthquakes. Geobarometry of majoritic garnet inclusions and diamond ages suggest upward transport, perhaps to the base of mantle lithosphere. From there, diamonds are carried to Earth's surface by eruptions of kimberlite magma. Mineral assemblages in sublithospheric diamonds directly trace Earth's deep volatile cycle, demonstrating how the hydrosphere of a rocky planet can connect to its solid interior. ▪ Sublithospheric diamonds from the deep upper mantle, transition zone, and lower mantle host Earth's deepest obtainable mineral samples. ▪ Low-temperature seawater alteration of the ocean floor captures organic and inorganic carbon at the surface eventually to become some of the most precious gem diamonds. ▪ Subduction transports fluids in metamorphic minerals to great depth. Fluids released by slab heating migrate, react with host mantle to induce diamond crystallization, and may trigger earthquakes. ▪ Sublithospheric diamonds are powerful tracers of subduction—a plate tectonic process that deeply recycles part of Earth's planetary volatile budget.Expected final online publication date for the Annual Review of Earth and Planetary Sciences, Volume 52 is May 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

中文翻译：

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岩石圈下钻石：来自地球最深地幔样本的板块构造


岩石圈下的钻石及其可能携带的包裹体在软流圈、过渡带或最上层的下地幔（300 至~800 公里）中结晶，是迄今为止已知由板块构造形成的最深矿物。这些钻石的独特之处在于其变形特征、低氮含量以及这些主要地幔矿物的内含物：多数石榴石、单斜辉石、尖橄榄石、硅钙钛矿、铁方镁石和桥锰矿或其逆行等同物。这些钻石（δ11B、δ13C、δ15N）及其包裹体（δ18O、δ56Fe）内元素的稳定同位素组成通常远远超出正常地幔范围，表明这些元素要么是有机元素（C），要么是通过海水蚀变而改变的（B， O、Fe）在相对较低的温度下。冷板片中的变质矿物是在岛弧和地幔楔下方以 CO3 形式输送 C、以 H2O、OH 或 CH4 形式输送 H 的有效宿主。板块变暖会产生碳酸盐熔体、超临界水性流体或金属液体，形成三种类型的岩石圈下钻石。钻石结晶是通过流动流体通过裂缝穿过主地幔时的移动和减少而发生的，这一过程会产生化学不均匀性，并可能引发深源地震。大多数石榴石包裹体和钻石年龄的地质气压测量表明向上运输，可能到地幔岩石圈的底部。从那里，钻石通过金伯利岩岩浆的喷发被带到地球表面。岩石圈下钻石中的矿物组合直接追踪地球的深层挥发循环，展示了岩石行星的水圈如何与其固体内部连接。 ▪ 来自上地幔深处、过渡带和下地幔的岩石圈下钻石蕴藏着地球可获取的最深矿物样本。 ▪ 海底的低温海水蚀变捕获了地表的有机和无机碳，最终成为最珍贵的宝石级钻石。 ▪ 俯冲作用将变质矿物中的流体输送到很深的地方。板坯加热释放的流体会迁移，与宿主地幔发生反应，诱发金刚石结晶，并可能引发地震。 ▪ 岩石圈下钻石是俯冲作用的强大示踪剂，俯冲是一种板块构造过程，可深度回收地球行星挥发预算的一部分。《地球与行星科学年度评论》第 52 卷的预计最终在线出版日期为 2024 年 5 月。请参阅 http:// www.annualreviews.org/page/journal/pubdates 了解修订后的估计。