Northern Mozambique hosts numerous occurrences of gold mineralization in metamorphic terranes, which are little known because of the insufficient studies. In this work, we describe the main geological and geochemical characteristics of the Nanlia and Makorongo gold prospects located in the Namuno district, northeastern Mozambique. We report the mode of occurrence of gold, petrography and mineralogy of the host rocks and ores, fluid inclusion characteristics and stable isotope data, to understand the genesis of gold mineralization in the study area. The gold mineralization in the Nanlia and Makorongo prospects is hosted by the Neoproterozoic Xixano Metamorphic Complex in the Mozambique Belt, which is composed of mafic granulite, amphibolite, paragneiss and marble. The host rock amphibolite consists mainly of amphibole, plagioclase, biotite and minor quartz, titanite and sulfides. The gold mineralization is associated with E-W to ENE-WSW trending quartz veins, oriented parallel to low angle to the foliation of the host rock amphibolite. The ore mineralogy consists of pyrite, pyrrhotite, chalcopyrite, magnetite, galena and sphalerite, with minor tellurides, xilingolite, electrum and native gold. Mineralized quartz veins in the Nanlia and Makorongo prospects host two types of fluid inclusions which locally coexist in the same assemblage: type 1, one-phase CO₂ inclusions with final melting temperature between −58 and −52 °C; and type 2, two-phase H₂O + NaCl (±CO₂ ± N₂ ± CH₄) inclusions with homogenization temperature ranging from 246 to 370 °C and 239 to 382 °C in the Nanlia and Makorongo prospects, respectively, and salinity of 12–21 wt% NaCl eq. Pressure and temperature (P-T) conditions of ore-formation were estimated from fluid inclusions and sphalerite geobarometry at 420–620 °C and 160–280 MPa, and 330–440 °C and 150–200 MPa in the Nanlia and Makorongo prospects, respectively. The Nanlia and Makorongo gold prospects are classified as orogenic-type gold deposits. We suggest that gold mineralization was caused by an aqueous-carbonic fluid with low-moderate salinity originated by devolatilization during prograde metamorphism of underlying rocks. The gold mineralization post-dates the peak of metamorphism of the host rocks, thus formed during the retrograde metamorphism of the host rocks. The precipitation of gold in the Nanlia and Makorongo prospects was caused by fluid phase separation induced by pressure drop as the mineralizing fluid migrated to shallower depths.

莫桑比克北部拥有大量发生在变质地层中的金矿化事件，由于研究不足，因此鲜为人知。在这项工作中，我们描述了位于莫桑比克东北部纳穆诺地区的Nanlia和Makorongo金矿的主要地质和地球化学特征。我们报告了金的发生方式，主体岩石和矿石的岩石学和矿物学，流体包裹体特征和稳定的同位素数据，以了解研究区金矿的成因。Nanlia和Makorongo矿床中的金矿化是由莫桑比克地带的新元古代Xixano变质复合体控制的，该复合体由镁铁质花岗石，闪石，方石矿和大理石组成。寄主岩闪石主要由闪石，斜长石，黑云母和次要石英，钛矿和硫化物。金矿化与EW到ENE-WSW趋势石英脉相关，该石英脉定向成与主岩闪石的叶面平行的低角度。矿石矿物学由黄铁矿，黄铁矿，黄铜矿，磁铁矿，方铅矿和闪锌矿组成，伴有少量碲化物，黄铁矿，伊斯特鲁姆和原生金。Nanlia和Makorongo勘探区的矿化石英脉含有两种类型的流体包裹体，它们在同一组合中局部共存：1型，一相CO 电子和本机黄金。Nanlia和Makorongo勘探区的矿化石英脉含有两种类型的流体包裹体，它们在同一组合中局部共存：1型，一相CO 电子和本机黄金。Nanlia和Makorongo勘探区的矿化石英脉含有两种类型的流体包裹体，它们在同一组合中局部共存：1型，一相CO_2个夹杂物，最终熔化温度在-58至-52°C之间；和2型两相H ₂ O + NaCl（±CO ₂  ±N ₂  ±CH ₄）夹杂物，在Nanlia和Makorongo勘探区的均质温度分别为246至370°C和239至382°C。盐度为12–21 wt％NaCl当量。压力和温度（PT）的成矿条件是通过分别在Nanlia和Makorongo勘探区中的流体包裹体和闪锌矿大气压力法在420-620°C和160-280 MPa以及330-440°C和150-200 MPa估算的。Nanlia和Makorongo金矿床被归类为造山型金矿床。我们认为，金矿化是由含盐度较低的碳酸盐水流体引起的，该盐分是在下伏岩石的正变质过程中由脱挥发分引起的。金矿化作用晚于基质岩变质的峰值，因此在基质岩的逆转变质过程中形成。Nanlia和Makorongo矿床中的金沉淀是由于矿化流体迁移到较浅的深度而引起的压降引起的液相分离引起的。