Understanding the Diverse Isotopic Record of Volcanism in Kamchatka

了解堪察加火山活动的多种同位素记录

• 批准号: 0537872
• 负责人: Ilya Bindeman
• 金额: $ 27.96万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0537872&HistoricalAwards=false
• 关键词: Understanding; Diverse; Isotopic; Record; Volcanism

This project is to undertake a detailed investigation of the oxygen and radiogenic isotope record of volcanic rocks in one of the most active subduction-related volcanic arcs, the Kamchatka Peninsula, Russia. The study will focus on the geochemical effects caused by the interplay of glaciation and volcanism occurring between the Pleistocene to recent on the three largest multi-caldera centers. This study will add a complementary 40Ar/39Ar geochronologic dataset to the abundant 14 C tephrochronological record that will allow unprecedented calibration of the volcanic stratigraphy of Kamchatka throughout the Pleistocene. This information will be combined with radiogenic isotope measurements by the international collaborators to fingerprint sources and constrain the origin and longevity of 18O isotopic depletions. Kamchatka is ideally suited for this investigation because it hosts the largest subarctic meteoric-geothermal and geyser system on Earth. These oxygen isotope depletions characterize caldera-derived silicic rocks and may be due to assimilation/melting of the very shallow hydrothermally-altered crust. The project will test the model derived from preliminary evidence that links these oxygen isotope depletions to caldera collapse and deglaciation The study proposed here will test the hypothesis that there is a glacial feedback on volcanism, a phenomenon that has rarely been investigated. The results of this research will have important applications to several urgent social issues including climate change, volcanic hazards, and environmental stability in the subarctic. Dating of ignimbrites of major caldera-forming eruptions (100 km3) in Kamchatka will better constrain the record of global volcanism during the late Pleistocene in the context of human settlement of Kamchatka and migration to N. America through the Bering land bridge, and identify major caldera-forming centers for correlation with the ice core record in Greenland and with marine ash sequences in the N. Pacific and Beringia. This project will provide a basis for professional development of a new faculty member, aid in the enhancement of the infrastructure of the newly established stable isotope laboratory at the University of Oregon. The project will also foster international collaborations and allow the training of an identified graduate student as a research scientist as well as provide an opportunity for an undergraduate student to gain significant research experience.

该项目将对俄罗斯堪察加半岛这一与俯冲有关的最活跃火山弧之一的火山岩的氧和放射性同位素记录进行详细调查。该研究将侧重于更新世到最近三个最大的多破火山口中心之间发生的冰川作用和火山作用的相互作用所造成的地球化学效应。这项研究将增加一个互补的40 Ar/39 Ar地质年代学数据集丰富的14 C火山灰年代学记录，将允许前所未有的校准整个更新世的堪察加半岛的火山地层。这些信息将与国际合作者的放射性同位素测量相结合，以确定来源并限制18 O同位素耗尽的起源和寿命。堪察加半岛非常适合这项调查，因为它拥有地球上最大的亚北极气象地热和间歇泉系统。这些氧同位素亏损的特点是火山口衍生的火山岩，可能是由于同化/熔融的非常浅的热液蚀变地壳。 该项目将测试从初步证据中得出的模型，这些证据将这些氧同位素耗尽与火山口坍塌和冰川消退联系起来。这里提出的研究将测试火山活动存在冰川反馈的假设，这是一种很少被调查的现象。这项研究的结果将对几个紧迫的社会问题，包括气候变化，火山灾害和亚北极地区的环境稳定性有重要的应用。堪察加半岛主要火山口形成喷发（100 km 3）的熔结凝灰岩定年将更好地限制更新世晚期全球火山活动的记录，在堪察加半岛的人类定居和迁移到N。通过白令陆桥，确定主要的火山口形成中心，与格陵兰的冰芯记录和北大西洋的海洋火山灰序列相关联。太平洋和白令吉亚。该项目将为一名新教员的专业发展提供基础，有助于加强俄勒冈州大学新建立的稳定同位素实验室的基础设施。该项目还将促进国际合作，并允许一个确定的研究生作为研究科学家的培训，以及为本科生提供一个机会，以获得重要的研究经验。