Fundamental geodynamic changes from vertical tectonics to lateral subduction occurred during the Neoarchean, yet detailed processes related to this transition and initiation of modern-style subduction remain enigmatic. Successive Neoarchean magmatic rocks including both plume-derived komatiites and subduction-related supracrustal and intrusive rocks appeared and preserved key information on the late Archean geodynamic changes in the Western Shandong Province granite-greenstone belt (WSP), North China Craton. In this study, whole-rock geochemical and Sm-Nd isotopic data and zircon U-Pb and Lu-Hf isotopes are reported for early Neoarchean supracrustal and intrusive rocks for the WSP. Temporally, the early Neoarchean magmatic movements in the WSP can be subdivided into two stages, including the early stage (2.77–2.69 Ga) and the late stage (2.69–2.60 Ga). Spatially, from southwest to northeast, intrusive rocks with similar ages define three belts (A, B, and C). Early stage tholeiitic and enriched meta-basalts were plume-related, representing oceanic crust opening from a pre-early Neoarchean continent. Slab subduction at least initiated at ca. 2.74 Ga and generated various Neoarchean tonalite-trondhjemite-granodiorites, quartz diorites, and arc-related volcanic rocks and mafic intrusions. Episodic emergence of meta-basaltic rocks and/or mafic intrusions with depleted εHf(t) values and low (La/Yb)N ratios indicates frequent slab break-offs during ca. 2.70–2.68 Ga, 2.66–2.64 Ga, and 2.62–2.60 Ga due to a relatively hotter mantle and regional heating by mantle plume. Secular geochemical changes of mafic and felsic rocks in this study outline roles of slab subduction in contributions of cooling the mantle, secular mantle refertilization, and crustal growth.

中文翻译：

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在新archarean中开始现代俯冲：从羽状流到俯冲，板块频繁断裂

从新构造开始，从垂直构造向侧向俯冲发生了根本的地球动力学变化，但是与这种过渡和现代俯冲开始有关的详细过程仍然是个谜。陆续出现的新古宙岩浆岩，包括羽状科摩铁矿和俯冲相关的上壳和侵入岩，并保存了有关山东西部花岗岩-绿岩带（WSP），华北克拉通晚期太古宙晚期地球动力学变化的关键信息。在这项研究中，据报道了WSP的新新纪古代地壳和侵入岩的全岩石地球化学和Sm-Nd同位素数据以及锆石U-Pb和Lu-Hf同位素。从时间上讲，WSP中的新古构造早期岩浆运动可以分为两个阶段，包括早期（2.77–2.69 Ga）和晚期（2.69–2）。60 Ga）。在空间上，从西南到东北，年龄相似的侵入岩定义了三个带（A，B和C）。早期的富勒索玄武岩和富集的玄武岩与羽流有关，代表着从早古新苏格兰大陆开始的洋壳开放。板坯俯冲至少在大约2时开始。2.74 Ga生成了各种新新纪古代的斜长石-长白云母-红闪长岩，石英闪长岩和与弧有关的火山岩和镁铁质侵入岩。εHf（t）值低且（La / Yb）N比低的准玄武质岩石和/或镁铁质侵入体的偶发性出现表明，大约在2005年，板坯频繁破裂。2.70–2.68 Ga，2.66–2.64 Ga和2.62–2.60 Ga，这是由于地幔相对较热以及地幔柱的局部加热所致。