Pre-eruptive conditions of the Campanian Ignimbrite eruption: Experimental constraints from phase equilibria and volatile solubility studies and its implication for the Campi Flegrei drilling project

对Campi Flegrei火山和脱气过程的理解和模拟的前提是（1）岩浆储存条件的确定;（2）岩浆补充过程的理解，特别是注入岩浆房的新岩浆的成分、温度、挥发分含量;（3）岩浆上升过程中脱气和结晶过程的模拟。到目前为止，实验数据和热力学模型在升高的压力和温度，使我们能够获得这些信息，是稀缺的，不能直接应用于响岩和粗面岩系统的Campi Flegrei。这些信息对于解释钻探产品和在Campi Flegrei计划钻探地点（CFDDP）进行观察至关重要。在本提案中，我们计划研究岩浆房中的长期过程，如结晶和分异，以及在爆发前Campi Flegrei岩浆房中发生的新岩浆输入所导致的短期过程（例如，脱气、混合、再平衡）。在蒂宾根，将探索岩浆从岩浆房上升到地表的过程（见M. Nowak）。不同的实验方法（即相平衡，动力学实验，混合H2O-CO2-Cl-S-轴承挥发物在硅酸盐熔体中的溶解度）使用粗面岩和响岩从坎帕尼亚火山灰岩将被用来调查岩浆储存条件，端员岩浆的性质补充之前，以及与熔体共存的岩浆房中的流体的组成。这些参数的知识是至关重要的了解和模拟的流变岩浆性质，破碎，喷发风格，这是记录在纹理模式的坎帕尼亚火山灰凝灰岩和火山灰的演变。实验数据将为高风险Campi Flegrei火山区的火山灾害评估提供有用的约束。

A prerequisite for the understanding and modeling of volcanic and degassing processes at Campi Flegrei is (1) the determination of magma storage conditions, (2) the understanding of magma replenishment processes, especially the composition, temperature, volatile contents of the new magmas injected in magmatic chamber and (3) the simulation of degassing and crystallization processes during magma ascent. So far experimental data and thermodynamic models at elevated pressures and temperatures, allowing us to gain this information, are scarce and can not be directly applied for the phonolitic and trachytic systems of Campi Flegrei. Such information is crucial for the interpretation of drilling products and of observations at the planned drilling site at Campi Flegrei (CFDDP). In this proposal we plan to investigate long term processes in the magma chamber(s), such as crystallization and differentiation, as well as short term processes resulting from new magma inputs occurring in the Campi Flegrei magma chamber prior to eruptions (e.g., degassing, mixing, re-equilibration). Processes during magma ascent from the magma chamber to the surface will be explored in Tübingen (see application of M. Nowak). Different experimental approaches (i.e. phase equilibria, kinetic experiments, solubility of mixed H2O-CO2-Cl-S-bearing volatiles in silicate melts) using trachytic and phonolitic rocks from the Campanian Ignimbrite will be used to investigate magma storage conditions, the properties of end-member magmas before replenishment, as well as the composition of fluids coexisting with melts in the magma chamber. The knowledge of these parameters is crucial to understand and model the evolution of rheological magma properties, fragmentation, eruptive style, which are recorded in the textural patterns of the Campanian Ignimbrite and of the volcanic ashes. The experimental data will provide useful constraints for volcanic hazard assessment at the high risk Campi Flegrei Volcanic Area.