Collaborative Research: Hawaiian Plume Heterogeneity Revealed by Kilauea's Ongoing Eruption, Prehistoric Lavas and Olivine-hosted Melt Inclusions

合作研究：基拉韦厄火山的持续喷发、史前熔岩和橄榄石熔融包裹体揭示了夏威夷羽流的异质性

• 批准号: 0738817
• 负责人: Michael Garcia
• 金额: $ 22万
• 依托单位: University of Hawaii
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0738817&HistoricalAwards=false
• 关键词: Collaborative; Research; Hawaiian; Plume; Heterogeneity

Intellectual Merit. Kilauea, on the island of Hawaii, is one of the most active and best-monitored volcanoes in the world. Its high magma supply rate and well delineated magmatic plumbing system make Kilauea an ideal venue for addressing fundamental questions about basaltic magma genesis. Its lavas provide essential petrologic and geochemical clues for delineating the nature of compositional heterogeneity within the Hawaiian plume and for assessing magma generation processes that cannot be readily ascertained by other methods. The PIs previously documented systematic short- and moderate-term (decades to centuries) geochemical variations within Kilauea's recent lavas. Over several centuries, Kilauea summit lavas record cyclic geochemical trends that correlate with volcanic processes such as eruption rates (more depleted sources appear to have undergone lower degrees of melting and produced less magma). To continue this work, a three-pronged approach is proposed combining field work with petrography, mineral chemistry, whole-rock major element and trace element abundances, and O, Pb, Sr, and Nd isotope ratios to assess the mantle causes (source and process) for compositional variation in Kilauea lavas. Part 1 involves continued monitoring of the geochemical evolution of the Puu Oo eruption, which has shown remarkable compositional variation related to crustal and mantle processes. Changing lava compositions provide new insights into magmatic processes. Part 2 examines the AD 900 to 1400 Uwekahuna Bluff lava section on the northwestern wall of the Kilauea's caldera. This study will allow evaluation of apparently cyclic geochemical variations at Kilauea on a few century time scale, and elucidate distribution of small-scale heterogeneities and the dynamics of mantle melting within the Hawaiian plume. Part 3 utilizes electron microprobe, LA-ICPMS, O isotope laser mass spectrometry and SHRIMP ionprobe to study olivine-hosted melt inclusions in high forsterite olivines (86%) from selected Kilauea historical summit lavas. Preliminary work on these inclusions shows tremendous compositional diversity within individual lavas that may be related to the relatively short residence of magma in the summit reservoir (30-100 years). Major- and trace-element abundances, and O and Pb isotope ratios will be determined in these inclusions to better constrain the mantle heterogeneities and melting processes within the Hawaiian plume.Broader Impacts. Broader impacts of this research include (1) developing teaching modules for undergraduate and graduate petrology classes using the results from our Kilauea research to highlighting magmatic processes at an active volcano and emphasing cooperative learning and development of higher order thinking skills, (2) mentoring graduate and undergraduate students, (3) giving public lectures to school groups and the local community, (4) gaining a better understanding of volcanoes that can negatively influence the quality of life, and (5) increasing international and national scientific cooperation through collaboration and utilization of multiuser facilities.

智力优点。夏威夷岛上的基拉伊亚是世界上最活跃，最受监控的火山​​之一。其高岩浆供应率和良好的岩浆管道系统使Kilauea成为解决有关玄武岩岩浆创世纪基本问题的理想场所。它的熔岩提供了必不可少的岩石学线索和地球化学线索，用于描述夏威夷羽流中构图异质性的性质，并评估其他方法无法轻易确定的岩浆产生过程。 PI先前记录了Kilauea最近的熔岩中系统的系统短期和中期（数十年至几个世纪）的地球化学变化。在几个世纪以来，基拉韦阿峰会熔岩创纪录的环状地球化学趋势与火山过程（例如喷发速率）相关（较少枯竭的来源似乎经历了较低的熔化程度，并且产生了较少的岩浆）。为了继续这项工作，提出了一种三管齐下的方法，将现场工作与岩石学，矿物化学，全摇滚主要元素和微量元素丰度以及O，Pb，SR和ND同位素比评估kilauea lavas中组成变化的地幔原因（来源和过程）。第1部分涉及对PUU OO喷发的地球化学演化的持续监测，该演变显示出与地壳和地幔过程相关的显着组成变化。更换熔岩组成为岩浆过程提供了新的见解。第2部分检查了基拉韦阿火山口西北墙壁上的公元900至1400 Uwekahuna Bluff Lava部分。这项研究将允许在几个世纪的时间范围内评估基洛伊亚的明显环状地球化学变化，并阐明小尺度异质性的分布以及夏威夷羽流中地幔融化的动力学。第3部分利用电子微探针，LA-ICPM，O同位素激光质谱法和虾离子螺旋桨来研究来自选定的Kilauea历史峰会的高硅酸盐橄榄石（86％）中的橄榄石托管融合物（86％）。这些夹杂物的初步工作显示了各个熔岩中的巨大组成多样性，这可能与岩浆在山顶储层中相对较短的住所有关（30-100年）。在这些包含物中将确定主要和微量元素的丰度，以及O和Pb同位素比，以更好地限制夏威夷羽流中的地幔异质性和熔化过程。这项研究的更广泛的影响包括（1）使用我们的基拉韦阿研究的结果开发本科和研究生质学课程的教学模块，以突出在活跃的火山上突出玛格玛蒂的过程，并强调合作学习和更高阶段思维技能的发展，（2）指导研究生和毕业生，以更好地理解学校和不足的社区（3），（3），（3），（3），（3），（3），（3），（4）诺斯（4），4）（4），4）（4），4）（4），4）（4），4）（4），4）（4），4）（4），4）（4），4）（4），4）生活质量，以及（5）通过合作和利用多源设施来增加国际和国家科学合作。