岩浆补给作用对硅质火山岩浆系统演化的制约

Influence of magma recharge on the evolution of silicic volcanic system

硅质火山喷发作为大陆地壳岩浆活动的重要表现,在研究大陆地壳形成与演化、探讨岩浆过程与动力学机制等方面具有重要的价值,其通常所表现的强烈爆炸式喷发,甚至可以导致全球性的环境和气候变迁。硅质岩浆系统在开放体系中不同来源岩浆的贡献和相互作用是目前研究的热点问题。持续的岩浆补给可以延长岩浆存储的时间,促进岩浆房的对流、岩浆的分异演化以及晶体-熔体的分离和晶粥的再活化,同时也是触发火山喷发的重要机制之一。此外,岩浆补给以及硅质岩浆的晶体-熔体演化过程也是火山喷发产物多样性的原因,导致同一火山在其活动过程中喷发产物规律性的变化,如富晶体火山岩、贫晶体火山岩、火山岩成分分层、以及复活岩穹和中央侵入体等。因此,岩浆补给作用是制约硅质火山岩浆系统演化和火山岩成分多样性的重要因素,也是活动火山监测和灾害评估的重要依据。岩石学、岩石地球化学、矿物(长石、石英、石榴子石、锆石等)同位素及成分变化,以及模拟实验、地震层析成像等研究为揭示硅质岩浆系统中的岩浆补给作用和复杂岩浆过程提供了多种视角。

As an important manifestation of continental crust magmatic activity, silicic volcanic eruption is of great significance in studying the formation and evolution of continental crust, and understanding the magmatic processes and dynamic mechanisms. The violent explosive eruption which is usually manifested by silicic volcanic eruption can even cause global environmental and climate change. The contribution and interaction of magma from different sources in open silicic magmatic system is still a hot issue to be further studied. The continuous magma recharge can prolong magma storage time, promote convection in magma chamber, magma differentiation, crystal-melt separation and mush rejuvenation, and is also one of the important mechanisms triggering eruption. Furthermore, magma recharge and crystal-melt evolution processes of silicic magma are also responsible for the diversity of volcanic eruption products. They cause regular variations in eruption products of the same volcano during its eruptive activity, such as crystal-rich volcanic rocks, crystal-poor volcanic rocks, composition stratification of volcanic rocks, as well as the resurgent dome and central intrusive rocks. Therefore, magma recharge is an important constraint factor for the evolution of silicic volcanic magma system and volcanic composition diversity, and can also provide important information for active volcano monitoring and disaster assessment. Petrology, geochemistry, isotope and composition variation of minerals(feldspar, quartz, garnet, zircon, etc.), as well as experiments and seismic tomography studies, provide a variety of perspectives to reveal the magma recharge and complex magmatic processes in silicic magmatic systems.