Subduction of the Paleo-Pacific slab beneath the North China Craton (NCC) has exerted a strong influence on the Mesozoic destruction of the craton. However, no Andean-type arc magmatism has been reliably identified in the eastern NCC. Here we report the occurrence of Jurassic arc-like lamprophyres in the Liaodong Peninsula, providing a snapshot of the Paleo-Pacific slab subduction beneath the NCC in the early Mesozoic. Zircon U-Pb dating of the lamprophyres yields consistent ages of 158–155 Ma for magma crystallization. These lamprophyres all exhibit typical arc-like trace element distribution patterns, but show a series differences in their radiogenic isotope compositions and the other geochemical variables. Type 1 lamprophyres exhibit weakly enriched Sr-Nd-Hf isotopes with (87Sr/86Sr)i ratios of 0.7075–0.7085, εNd(t) values of −3.9 to −1.3 and εHf(t) values of −5.4 to −0.3, whereas Type 2 lamprophyres exhibit moderately enriched radiogenic isotopes with (87Sr/86Sr)i ratios of 0.7096–0.7117, εNd(t) values of −12.2 to −7.6 and εHf(t) values of −12.8 to −4.7. There are also systematic differences in zircon Hf isotopes and whole-rock Ba/Th, Ba/La, Sr/Nd, Th/Nd, Th/Yb, and La/Sm ratios for the two types of lamprophyre. Taken together, these similarities and differences can be accounted for by metasomatic reaction of the cratonic mantle wedge with two properties of liquid phase derived from subducting Paleo-Pacific slab. One is aqueous solutions from the subducting basaltic oceanic crust, and the other is hydrous melts from the subducting terrigenous. The two properties of subduction zone fluids were incorporated in different proportions into the mantle sources of these lamprophyres. Accordingly, the lamprophyres were derived from the metasomatic mantle sources. This qualitative interpretation is verified by quantitative modeling of the geochemical transfer at the slab-mantle interface in a paleo-oceanic subduction zone. Therefore, the Jurassic lamprophyres in the eastern NCC provide the geochemical evidence for the crust-mantle interaction during the Paleo-Pacific slab subduction beneath eastern Asia in the early Mesozoic, when the chemical metasomatism by the slab-derived fluids would have weakened the cratonic mantle for its thinning and destruction in the Early Cretaceous.

中文翻译：

---

华北克拉通东部侏罗系基性弧岩浆作用的识别：古太平洋板块向西俯冲的地球化学证据

华北克拉通（NCC）之下的古太平洋板块俯冲对克拉通中生代的破坏产生了强烈的影响。然而，在 NCC 东部没有可靠地确定安第斯型弧岩浆活动。在这里，我们报告了辽东半岛侏罗纪弧形灯藻的出现，提供了早中生代 NCC 下方古太平洋板块俯冲的快照。斑岩的锆石 U-Pb 定年产生一致的 158-155 Ma 岩浆结晶年龄。这些萤石都表现出典型的弧形微量元素分布模式，但在其放射性同位素组成和其他地球化学变量方面表现出一系列差异。1 型萤石显示出弱富集的 Sr-Nd-Hf 同位素，(87Sr/86Sr)i 比率为 0.7075–0.7085，εNd(t) 值为 -3.9 到 -1。3 和 εHf(t) 值为 -5.4 至 -0.3，而 2 型萤火虫表现出中等富集的放射性同位素，(87Sr/86Sr)i 比率为 0.7096-0.7117，εNd(t) 值为 -12.2 至 -7.6 和 εHf( t) -12.8 至 -4.7 的值。两类斑岩的锆石Hf同位素和全岩Ba/Th、Ba/La、Sr/Nd、Th/Nd、Th/Yb和La/Sm比值也存在系统差异。综上所述，这些异同可以通过克拉通地幔楔的交代反应来解释，该地幔楔具有来自俯冲古太平洋板块的两种液相性质。一种是俯冲玄武质洋壳的水溶液，另一种是俯冲陆源的含水熔体。俯冲带流体的两种特性以不同的比例结合到这些灯藻的地幔来源中。因此，斑岩来源于交代地幔源。这种定性解释通过对古海洋俯冲带板片-地幔界面地球化学转移的定量模拟得到验证。因此，华北克拉通东部侏罗系斑岩为早中生代东亚下方古太平洋板块俯冲过程中壳幔相互作用提供了地球化学证据，当时板块衍生流体的化学交代会削弱克拉通地幔因为它在早白垩世的变薄和破坏。