Magmatic Volatiles, Unraveling the Reservoirs and Processes of the Volcanism in the Antarctic Peninsula

岩浆挥发物，揭示南极半岛火山活动的储层和过程

• 批准号: 1643494
• 负责人: Alberto Saal
• 金额: $ 27.01万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1643494&HistoricalAwards=false
• 关键词: Magmatic; Volatiles; Unraveling; Reservoirs; Processes

The Earth's mantle influences the movement of tectonic plates and volcanism on the surface. One way to understand the composition and nature of the Earth's mantle is by studying the chemistry of basalts, which originate by volcanic eruptions of partially melting mantle rocks. This study will establish the budget and distribution of volatile elements (hydrogen, carbon, fluorine, chlorine, sulfur) in volcanic basalts to better understand the composition of the Earth's interior. Volatiles influence mantle melting, magma crystallization, magma migration and volcanic eruptions. Their abundances and spatial distribution provide important constraints on models of mantle flow and temperature. Moreover, volatiles are key constituents of the Earth's atmosphere and oceans. Establishing the cycles of volatiles between the Earth's interior and surface is of fundamental importance to understand the long-term evolution of our planet. This project supports a graduate student and research scientist at Brown University. It promotes the collaboration with geochemists from eleven institutions representing six different countries: USA, Germany, United Kingdom, Argentina, South Korea and Japan, and utilizes several NSF-funded USA analytical facilities. Communication of results will occur through: 1) peer-reviewed journals, presentations at conferences and invited university lectures, 2) hands-on science learning activities for local elementary and high school classes, and 3) outreach to the general audience through public lectures.Over the last 60 years of funded research, the Antarctic Peninsula and nearby ocean ridges have been extensively investigated providing information on the origin of the magmatism, and the composition, structure, temperature and evolution of the lithospheric and asthenospheric mantle. Diverse hypotheses have been proposed for the origin of the magmatism in the Antarctic Peninsula, from flux melting of the mantle wedge during devolatilization of the subducted Phoenix plate, to adiabatic decompression melting of a carbonated and hydrous asthenosphere, to melting of a volatile-rich metasomatized subcontinental lithospheric mantle. All proposed hypotheses invoke the role of volatiles. Surprisingly, data on the volatile contents of basalts and mantle from this region are non-existent. This is a significant omission from the geochemical data set, given the important role volatile elements play in the generation and composition of magmas and their sources. The focus of our research is to examine the regional variations in volatile contents (C, H, F, S, Cl) in geochemically well-characterized Pliocene-recent basalts from the Antarctic Peninsula and Phoenix ridge. Our goal is to establish the budget and distribution of volatiles in the mantle to understand 1) the processes responsible for the generation of chemically diverse basalts in close spatial and temporal proximity and 2) the nature (lithology, composition and temperature) of the heterogeneous mantle source beneath the Antarctic Peninsula and Phoenix ridge.

地幔影响着地壳板块的运动和地表的火山活动。 了解地球地幔的组成和性质的一种方法是研究玄武岩的化学成分，玄武岩起源于部分熔融的地幔岩石的火山爆发。 这项研究将确定火山玄武岩中挥发性元素（氢、碳、氟、氯、硫）的收支和分布，以更好地了解地球内部的组成。 挥发分影响地幔熔融、岩浆结晶、岩浆运移和火山喷发。 它们的丰度和空间分布对地幔流和温度的模型提供了重要的限制。此外，挥发物是地球大气和海洋的关键组成部分。 建立地球内部和表面之间的挥发物循环对于理解我们星球的长期演化具有根本重要性。 该项目支持布朗大学的一名研究生和研究科学家。它促进了与来自六个不同国家的11个机构的地球化学家的合作：美国，德国，英国，阿根廷，韩国和日本，并利用了美国国家科学基金会资助的几个分析设施。 将通过以下方式通报结果：1）同行评审期刊，会议和邀请大学讲座上的演讲，2）当地小学和高中班级的动手科学学习活动，3）通过公开讲座向普通观众推广。在过去60年的资助研究中，南极半岛及其附近洋脊已被广泛调查，提供了有关岩浆活动起源、成分、结构岩石圈和软流圈地幔的温度和演化。关于南极半岛岩浆活动的成因，人们提出了多种假说，从俯冲的凤凰板块脱挥发分过程中地幔楔的熔融，到碳酸化和含水的软流圈的绝热减压熔融，再到富含挥发分的交代的次大陆岩石圈地幔熔融。所有提出的假说都援引了挥发分的作用。令人惊讶的是，关于该地区玄武岩和地幔挥发物含量的数据是不存在的。鉴于挥发性元素在岩浆的生成和组成及其来源方面发挥着重要作用，这是地球化学数据集的一个重大遗漏。本文研究了南极半岛和菲尼克斯海岭上新世-近代玄武岩中挥发分（C、H、F、S、Cl）的区域性变化。我们的目标是建立地幔中挥发物的预算和分布，以了解1）负责在空间和时间上接近的化学多样性玄武岩的产生的过程和2）在南极半岛和菲尼克斯海岭下的异质地幔源的性质（岩性，成分和温度）。

项目成果

Source variations in volatile contents between Bransfield Strait and Phoenix Ridge, Antarctica

布兰斯菲尔德海峡和南极洲凤凰岭之间挥发物含量的来源变化

• DOI: 10.7185/gold2021.8087
• 发表时间: 2021
• 期刊: Goldschmidt Conference
• 作者: Anderson, Danny;Saal, Alberto;Riley, Teal;Keller, Randall;Haase, Karsten;Mallick, Soumen;Wang, Jianhua
• 通讯作者: Wang, Jianhua

Source Variations in Bransfield Strait and Relation to Nearby Phoenix Ridge

布兰斯菲尔德海峡的源头变化及其与附近凤凰岭的关系

• DOI: 10.46427/gold2020.61
• 发表时间: 2020
• 期刊: Goldschmidt Conference
• 作者: Anderson, Danny W.;Saal, Alberto E.;Riley, Teal R.;Keller, Randall A.;Haase, Karsten M.;Mallick, Soumen;Wang, Jianhua;Boesenberg, Joseph S.
• 通讯作者: Boesenberg, Joseph S.