The history of the Campi Flegrei Magma System through time: the key to understand present and future volcanic processes

Campi Flegrei火山口(氟氯化碳；意大利南部)是地球上最危险的火山区之一，因为它的爆炸性和高强度喷发的发生(Orsi等人，2004年)。尽管火山危险性很高，但意大利2011年人口普查(www.istat.it)估计，目前有超过150万人生活在火山口及其周围地区，这使得该地区的火山危险性极高(Orsi等人，2004年)。要了解目前的动乱时期，界定为活火山提供燃料的岩浆系统的现状，就需要了解过去的喷发前岩浆作用及其与喷发动力学之间的关系。由于这些原因，火山喷发的历史以及喷发产物的地球化学和同位素特征一直是广泛的科学研究问题。我们项目的目的是扩展目前关于CF岩浆源及其补给系统的演化以及火山演化的现有知识，因为它涉及到不同的岩浆批次的特征，它们的来源(S)，演化和在这个演化的岩浆系统中的相互作用。通过结合分离矿物和全岩的新的地球化学(主量、微量元素)和同位素(放射性成因的~(87)Sr/~(86)Sr和稳定的增量~(18)O)数据，我们的目标是探测在新的岩浆批次到达之前的过程，并从深处表征这些过程。作为第二个目标，我们将使用玄武岩和斜长石斑晶中的Ba和Sr扩散模型来限制晶体在以下方面的停留时间：(A)Campi Flegrei内许多小的分散和孤立的喷发，以及(B)形成火山口的大型灾难性喷发，如Campanian Ignimbrite和那不勒斯黄色凝灰岩。

The Campi Flegrei caldera (CFc; South Italy) is one of the most dangerous volcanic areas on Earth, due to of its explosive character and the occurrence of high-magnitude eruptions (Orsi et al., 2004). In spite of high volcanic hazard the Italian 2011 census (www.istat.it) estimates that over 1.5 million of people are currently living within the caldera and its surroundings, making the volcanic risk of the area extremely high (Orsi et al., 2004). The understanding of present unrest episodes, the definition of the present state of the magmatic system feeding active volcanoes, requires the knowledge of past pre-eruptive magmatic processes and of the relationships between them and the eruptive dynamics. For these reasons the volcanological history as well as and the geochemical and isotopic characteristic of the erupted product has been a matter of extensive scientific studies. The purpose of our project is to extend the present knowledge on the evolution of the CF magma sources, its feeding system as well as the volcanological evolution as it relates to the characterization of distinct magma batches, their source(s), evolution and interaction in this evolving magma system. By combining new geochemical (major-, trace elements) and isotopic (radiogenic 87Sr/86Sr and stable delta18O) data on separated minerals and whole rocks we aim to detect processes that precede and characterize the arrival of fresh magma batches from depth. As a second goal, we will use Ba and Sr diffusion modeling in sanidines and plagioclase phenocrysts to constrain the residence times of crystals prior to erution of (a) many small scattered and isolated eruptions within the Campi Flegrei and the shift to (b) large catastrophic caldera-forming eruptions such as the Campanian Ignimbrite and Neapolitan Yellow Tuff.