Abstract Recent studies have shown that the Mesozoic metallogenic event in the southern margin of the North China Craton (NCC) is related to the coeval magma activities generated by the lithospheric thinning and asthenosphere upwelling. However, the reason why some Mesozoic magmatic systems in this area are barren is not clear. In this study, we report new geochronological and geochemical data for a Mesozoic igneous suite of Wenyu monzogranites from the Xiaoqinling area in the southern margin of the NCC, focusing on the petrogenesis and oxidation state with their implications on lithospheric thinning and magma fertility. The Wenyu monzogranites have zircon U Pb ages between 141.4 and 122.2 Ma. Whole-rock major and trace element, Sr Nd and zircon Hf isotope geochemistry suggest that the Wenyu monzogranites were dominantly derived from partial melting of the metamorphic and volcanic rocks from the Neoarchean to Paleoproterozoic, with potential replenishments of mantle-derived magmas triggered by the lithospheric thinning and hot asthenosphere upwelling. Zircon trace element geochemistry suggests a low oxidation state for the Wenyu magmatic system, which probably resulted in early sulfide saturation. Most of the ore-forming chalcophile elements (Au and Cu) were locked in a sulfide phase that was retained in cumulate rocks at depth due to the early sulfide saturation, so that when the magma became fluid saturated at the later stage of magmatic evolution, it did not have access to the Au and Cu. As a consequence, our study suggests that the Wenyu pluton was not prospective for magmatic-hydrothermal Au ± Cu deposits.

中文翻译：

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华北克拉通小秦岭地区温榆火成岩套年代学、岩石成因及氧化态：对岩石圈减薄和岩浆富集的意义

摘要 近年来的研究表明，华北克拉通南缘中生代成矿事件与岩石圈​​减薄和软流圈上涌产生的同期岩浆活动有关。然而，该地区一些中生代岩浆系统贫瘠的原因尚不清楚。在这项研究中，我们报告了华北克拉通南缘小秦岭地区中生代温榆二长花岗岩中生代火成岩套的新的年代学和地球化学数据，重点关注岩石成因和氧化态及其对岩石圈减薄和岩浆肥力的影响。文宇二长花岗岩的锆石 U Pb 年龄介于 141.4 至 122.2 Ma 之间。全岩主微量元素，Sr Nd和锆石Hf同位素地球化学表明，温榆二长花岗岩主要来源于新太古代至古元古代的变质岩和火山岩的部分熔融，岩石圈减薄和热软流圈上涌引发了地幔岩浆的潜在补充。锆石微量元素地球化学表明温榆岩浆系统处于低氧化态，这可能导致早期硫化物饱和。由于早期硫化物饱和，大部分成矿亲硫元素（Au和Cu）被锁定在硫化物相中，保留在深部堆积岩中，因此当岩浆在岩浆演化后期变为流体饱和时，它无法获得 Au 和 Cu。作为结果，