Collaborative Research: Spatiotemporal Evolution of the Neogene Ignimbrite Flare-up in the Altiplano-Puna Volcanic Complex, Central Andes: Insights into the Development of Large

该合作项目由岩石学和地球化学项目（地球科学）、美洲项目（国际科学与工程办公室）和EPSCoR项目支持。该研究的中心重点将是更好地确定安第斯山脉中部Altiplano-Puna火山复合体（APVC）中火成岩火山活动的时间、模式和数量，以解决大型岩浆系统如何发展和演化的基本问题。研究人员希望了解，导致这个火山复合体形成的岩浆活动是否真的是偶发的，还是这种最初的印象是对爆炸事件年表的不完整描述的结果。如果是偶发性的，那么连续喷发的频率和规模是多少，喷发系列的空间格局是什么。他们将通过野外测绘、40Ar/39Ar地质年代学以及地球化学和古地磁（NRM）对比技术，为玻利维亚西南部Lipez地区APVC的主要部分建立地层和火山学框架，以解决这些问题。这一记录将与APVC在智利和阿根廷的邻近部分相关联，那里存在更连贯的框架。这些数据，结合岩石成因和岩浆演化的知识，将形成计算岩浆产量和侵入率的关键基线。将这些数据整合到区域地理信息系统中，将有助于进行定量的时空分析。该项目的更广泛影响包括培养一名博士生掌握各种火成岩对比技术和现代40Ar/39Ar地质年代学方法。本科生将参与古地磁分析工作和实地考察。调查结果将通过火山世界网站（http://volcano.und.nodak.edu/vw.html）和协同活动传播给K-12教育工作者、非传统学生和公众。科学成果将及时传播给专业的同行团体，并应在促进我们对大型爆炸性火山系统的偶发活动的理解方面产生社会影响，这些活动是减灾计划所关注的。与一名玻利维亚同事和一名学生的密切合作确保了培训、数据和知识的转移以及国际合作研究的巩固。与阿根廷同事的合作将有助于跨越国际边界的相互关系进程。

This collaborative project is supported by the Petrology and Geochemistry program (in Earth Sciences), the Americas Program (in the Office of International Science and Engineering), and the EPSCoR program. The central focus of the research will be to better define the timing, pattern, and volume of ignimbrite volcanism in the Altiplano-Puna Volcanic Complex (APVC) of the Central Andes to address fundamental, yet persistent, questions about how large magmatic systems develop and evolve. The investigators hope to understand if the magmatic activity that led to the formation of this volcanic complex was truly episodic or if this initial impression is a function of incomplete characterization of the chronology of explosive events. Also, if episodic, what was the frequency and size of successive eruptions and what was the spatial pattern of the eruption series. They will address these questions by establishing a stratigraphic and volcanological framework for the major part of the APVC in the Lipez region of SW Bolivia through field mapping, 40Ar/39Ar geochronology, and geochemical and paleomagnetic (NRM) correlation techniques. This record will be correlated into the adjacent parts of the APVC in Chile and Argentina where a more coherent framework exists. These data, combined with knowledge of the petrogenesis and evolution of the magmas, will form the critical baseline from which magma production and intrusion rates can be calculated. Integration of these data into a regional GIS will facilitate a quantitative spatiotemporal analysis.Broader impacts of this project include training of a Ph.D. student in a variety of ignimbrite correlation techniques and modern 40Ar/39Ar geochronology methods. Undergraduate students will be involved in paleomagnetic analytical work and fieldwork. The findings will be disseminated to K-12 educators, non-traditional students, and the general public through the VolcanoWorld web site (http://volcano.und.nodak.edu/vw.html) and synergistic activities. Scientific results will be disseminated in a timely fashion to professional peer-groups and should have societal impact in furthering our understanding of episodic activity in large, explosive volcanic systems that are of concern for hazard mitigation programs. The close collaboration with a Bolivian colleague and a student ensures training, data and knowledge transfer, and consolidation of international cooperative research. Collaboration with an Argentine colleague will aid the process of correlation across the international border.