Advances in melt inclusion studies in back-arc basin volcanic rocks in Western Pacific

Melt inclusions are small silicate droplets trapped in minerals during growth. Due to the protection of host minerals, they are little affected by the late magmatic process, and thus can effectively retain the important information such as the original magmatic composition, the nature of the mantle source and the magmatic evolution process. The study of melt inclusions may make up for the deficiencies in the partial information distortion of traditional whole rocks due to the influence of complex geological processes in the later period. This article briefly summarizes the main research fields and current status of melt inclusions. The current research progress of melt inclusions in volcanic rocks in the typical back-arc basins in the western Pacific is reviewed. The study of melt inclusions in the Okinawa Trough, the Lau Basin and the North Fiji Basin has proved the heterogeneity of the mantle source area, and clarified the source of magma material and the addition of subducted material in the source area. The study of volatiles in melt inclusions in Mariana Trough and Manus Basin indicates the contribution of subducted slab materials to the volatile composition of the magma source area in the back-arc basin. The analysis of the concentration of metal elements in the melt inclusions in the Manus Basin indicates that the magmatic fluid can provide metallogenic metals for the submarine hydrothermal system. In addition, the temperature measurement experiments of melt inclusions in the Mariana Trough and Okinawa Trough reflect the multi-phase evolution of magma. Although melt inclusions have been studied in many aspects of magmatic activity in the western Pacific back-arc basins, the researches in the back-arc basins are uneven and the degree of comprehensive research is low. In the future, on the basis of further development of the testing and analysis technology of melt inclusions, increasing the research intensity of melt inclusions in the back-arc basin will help us to clearly understand the material composition of the magma source in the back-arc basin and clarify source and transformation of magma material in the back-arc basin under subduction.