长白山天池火山系统中岩浆演化的非线性动力过程研究

Volcanic system is a typical complex system coupling with multiple components and parameters. Many complex nonlinear behaviors of evolution emerge from the coupling of many processes (e.g. cooling, crystallization, convection, mixing, gas dissolving, etc.) in the magmatic evolution. All these behaviors make the procise prediction face great challenges. In order to explore the nonlinear behaviors of magmatic evolution, and supply the effective nonlinear theoritical foundation for the quantitative forecasting of volcanic eruptions, the nonlinear dynamical processes of magmatic evolution in Tianchi composite volcanic system will be our subject of investigation.On the basis of the researches of the geological profiles of representative basic, intermediate and silicic volcanic rocks, we will focus the phenomena of oscillatory zoning, resorption and regeneration, etc. of plagioclase, clinopyroxene and amphibole phenocrysts in the rocks from the profiles, the local aggregation features of chemical elements, minerals and bubbles in the different scales, as well as the form and distribution of pyroclasts, and further explore the nonlinear dynamical processes of magmatic evolution resulting of the emergence of these phenomena, especially the chaotic behaviors of magmatic evolution, the self-organized aggregation, fragmentation and critical transition and their fractal dynamics. From the perspective of nonlinear dynamics, the project will unveil the characteristics of activities and the complexity of prediction of Tianchi volcanic system, and promote the advance of physical volcanology.

火山系统是典型的多组分多参数耦合的复杂系统。在其岩浆演化的多种作用（如冷却、结晶、对流、混合、气体出溶过程等）耦合过程中产生了复杂的非线性演化行为。这些行为使得火山喷发的精确预测面临巨大挑战。为了探索岩浆演化的非线性行为，为给火山喷发定量预测提供有力的非线性理论基础，本项目聚焦于天池复式火山系统的岩浆演化的非线性动力过程的研究。在代表性的基性、中性和酸性火山岩剖面研究的基础上，以取自剖面的火山岩中的斑晶矿物（斜长石、单斜辉石等）的振荡环带、熔蚀和再生等现象，不同尺度下化学元素、矿物晶体和气孔的局域聚集规律，以及火山碎屑的形态和分布为研究重点，探索导致这些现象发生的岩浆演化的非线性动力学过程，特别是岩浆演化的混沌动力学行为、自组织聚集、破碎、临界转变及其形成的分形动力学行为。本项目将从非线性动力学新视角揭示天池火山系统的活动特征和预测复杂性，并促进物理火山学的发展。

火山系统是一个开放的、远离平衡的耗散系统。火山活动过程不仅是一个地质过程，也是一个物理和化学耦合过程，蕴含着丰富的非线性行为和复杂性。项目以天池火山造盾喷发、造锥喷发和造伊格尼姆岩的主要期次的熔岩和火山碎屑堆积物的野外研究为基础，对代表性的基性、中性和酸性火山岩剖面上的样品的化学组成、非平衡岩相结构和矿物学，特别是长石、辉石和橄榄石矿物斑晶的振荡环带、熔蚀和再生现象进行了系统的成因研究。为了探索岩浆体系的自组织临界性，对天池火山全新世空降浮岩岩相结构的形态学及其形成机制、不同时期熔岩的斑晶矿物晶粒形态与局域聚集规律进行了研究。除此之外，为了更好地认识岩浆演化的非线性动力学过程的物理约束，开展了泉阳期玄武质熔岩的动力结晶实验、玄武岩柱状节理模拟实验研究。在此基础上，理论上重点探索了岩浆冷却结晶、岩浆破碎的临界转变的非线性动力机制，进而从非线性动力学视角探讨了天池火山活动的预测的复杂性和评估策略。