The fluid characterisation and oxygen isotope studies of pegmatites in the Igangan area in southwest Nigeria was carried out to delineate the source and evolution of mineralising fluid, and to determine the crystallisation temperature of the pegmatites that are associated with I-type metaluminous granites. The geochemical analysis was carried out using ICPMS, the mineralogical analysis was carried out with the aid of a Scanning Electron Microscope. In contrast, microthermometry measurements were carried out on pegmatitic quartz using a Linkam THMSG600 Conventional and laser fluorination was used to determine the oxygen isotope composition of selected minerals from the pegmatites.

The geochemical analysis revealed a low concentration of Ta, Nb, W, Cs and low mineralisation potential for the pegmatites; while the mineralogical analysis of accessory spinels revealed a high concentration of Zn. Two types of hydrocarbon/CO₂ free aqueous inclusions were observed; which were Primary/pseudo primary (Type 1) inclusion with 0–11 wt % NaCl eq. salinity and secondary (Type 2) inclusions with a salinity range of 15–22 wt % NaCl eq. The density of the inclusions ranged from 0.57 to 1g/cc. δ¹⁸O values in quartz varied from 9.88 to 14.63‰ with an average of 13.13‰; feldspar, 8.9–13.85‰ with an average of 11.9‰ and tourmaline, 10.63–11.96‰ with an average of 11.40‰. Homogenisation temperature ranged from 175 to 370 °C with all inclusions homogenising into the liquid phase.

Bivariate plot of salinity against Th_total reveals the possibility of magmatic-meteoric mixing with Na/Ca rich fluids in the pegmatite evolution and equilibrium temperature calculations yield values of 496–685 °C and 392–713 °C for the quartz–tourmaline pair and the quartz-feldspar pair, respectively. The pegmatites are muscovite class LCT pegmatites with low rare metal mineralisation potential and crystallised from a H₂O–NaCl (±CaCl₂) fluid which was preserved in the primary/pseudo-primary inclusions.

在尼日利亚西南部伊冈甘地区，对伟晶岩进行了流体表征和氧同位素研究，以确定矿化液的来源和演化，并确定了与I型金属质花岗岩有关的伟晶岩的结晶温度。使用ICPMS进行地球化学分析，借助扫描电子显微镜进行矿物学分析。相比之下，使用Linkam THMSG600传统型在伟晶石上进行了微量热测量，并使用激光氟化法确定了伟晶石中选定矿物的氧同位素组成。

地球化学分析显示，伟晶岩的Ta，Nb，W，Cs浓度低，成矿潜力低。尖晶石的矿物学分析表明锌含量很高。观察到两种类型的不含烃/ CO _2的含水夹杂物：它们是主要/伪主要（类型1）夹杂物，含0-11 wt％NaCl当量。盐度和盐度范围为15–22 wt％NaCl当量的次生（2型）夹杂物。夹杂物的密度为0.57至1g / cc。δ ^18个O值在石英从9.88变化到14.63‰，平均为13.13‰; 长石为8.9–13.85‰，平均为11.9‰；电气石为10.63–11.96‰，平均为11.40‰。均质温度为175至370°C，所有夹杂物均化为液相。

盐度对Th_总值的二元图揭示了伟晶岩演化过程中富Na / Ca流体与岩浆-岩浆混合的可能性，而石英-电气石对和平衡温度计算得出的值分别为496–685°C和392–713°C。分别是石英-长石对。伟晶岩为白云母类LCT伟晶岩，具有极低的稀有金属矿化潜能，并从H ₂ O–NaCl（±CaCl ₂）流体中结晶，该流体保留在主要/伪主要夹杂物中。