粤北石人嶂钨矿区角闪辉长岩地球化学、年代学特征及其地质意义

石人嶂钨矿区发育的角闪辉长岩与钨矿密切共生，研究该矿区对认识粤北地区区域地质演化、深部岩浆信息以及区域基性岩与成钨作用关系研究意义重大，但到目前为止，尚未开展相关系统的研究。文章报道了角闪辉长岩的锆石和磷灰石U-Pb年代学、地球化学资料。磷灰石U-Pb年龄指示角闪辉长岩的结晶年龄为（171±14） Ma，形成于燕山早期晚阶段古太平洋板块俯冲背景下的岩石圈伸展的构造环境，其中，锆石为捕获锆石，具有3组年龄，分别记录了区域古元古代陆核增生，新元古代古华南板块的聚合和裂解，早中生代华南板块与华北板块，印支地块聚合的后造山伸展等多起构造事件。角闪辉长岩具有低Si、K、Mn，高Ca、Fe、Mg、Na、Ti的特征，富集Rb、Ta、Zr、Ti等，亏损Ba、Nb、Sr、Hf、Be、Cs、U、Th等元素，表明其源区具有E-MORB型富集地幔的属性。角闪辉长岩的形成主要受控于软流圈地幔的部分熔融。同时，由于角闪辉长岩的高氧逸度的特征及其较石人嶂钨矿成矿更早，角闪辉长岩的存在可能主要是为后期的钨矿化的叠加提供部分Ca、Fe等元素，并为富矿流体的运移提供通道。

Geochemical, geochronological charateristics of hornblende gabbro in Shirenzhang tungsten deposit, North Guangdong Province, and its geological significance

Hornblende gabbro in Shirenzhang deposit is closely associated with tungsten ore. The study of hornblende gabbro is of great significance to the understanding of regional geological evolution of north Guangdong pro-vince, deep magma information and the relationship between mafic rocks and tungsten mineralization. However, there is still no systematic study has been carried out so far. This paper reports the zircon and apatite U-Pb geochronology and geochemistry of hornblende gabbro. The apatite U-Pb data indicates that the hornblende gabbro has a crystallization age of (171±14)Ma, which was formed in a tectonic setting of lithosphere extension under the subduction of the paleo-pacific plate in the late stage of Early Yanshanian. The captured zircons have three stages of age. It recorded multistage of tectonic events such as regional Paleoproterozoic continental nucleus accretion, South China Plate convergence and splitting in Neoproterozoic, convergence between South China Plate and North China Plate, and post-orogenic extension of Indosinian block in Early Paleozoic. Hornblende gabbro has high contents of Ca, Fe, Mg, Na, Ti, but low contents of Si, K, Mn. It is characterized by enrichment of Rb, Ta, Zr, Ti, and depletion of Ba, Nb, Sr, Hf, Be, Cs, U, and Th, indicating that the source region has the property of E-MORB type enriched mantle. The formation of hornblende gabbro is mainly controlled by partial melting of asthenosphere mantle. Moreover, the characteristics of high oxygen fugacity and the formation age of hornblende gabbro are obviously earlier than tungsten mineralization, indicating that the emplacement of hornblende gabbro may provide Ca, Fe and other elements for the superposition of tungsten mineralization in the later period, and provide a channel for the migration of ore-rich fluid.