Evolution of the Kerguelen LIP: Insights from Crystal Stratigraphy & Crystal Size Distributions from Site 1137, Elan Bank

凯尔盖朗 LIP 的演化：水晶地层学的见解

• 批准号: 0452102
• 负责人: Clive Neal
• 金额: $ 16.26万
• 依托单位: University of Notre Dame
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0452102&HistoricalAwards=false
• 关键词: Evolution; Kerguelen; LIP; Insights; Crystal

ABSTRACT (Neal - 0452102)Understanding how magmas evolve is important for knowing why volcanoes erupt. Analysis of whole-rock samples gives compositions that reflect only an average of the processes that the lava has experienced prior to eruption. Examination of individual crystals and crystal populations, however, provides better insight into the dynamics of magma evolution. This research involves researchers at the University of Notre Dame and utilizes different populations of crystals in igneous rocks (i.e., crystal size distributions) that have related nucleation and growth histories. It them combines this approach with mineral-scale compositional studies (i.e., crystal stratigraphy). This combined methodology constrains the timing and extent of differentiation processes (i.e., magma mixing, crustal contamination) that permits quantification the dynamics and timing of processes that have modified a magma body since separation from its source and can lead to identification of the source itself. The research uses samples from the Kerguelen Large Igneous Province on the Elan Bank In the Southern/South Indian Ocean to develop a new technique for reconstructing magma chamber evolution using crystal size distributions and wavelet based correlations to determine different plagioclase crystal populations in seven co-magmatic flows from Ocean Drilling Program Site 1137. Samples range in age from 107-108 Ma and encompass three distinct breaks in magmatism, which are represented by volcaniclastic interbeds. These volcaniclastic units divide the lave flow sequence into four parts. Each section will be studied from the top, middle, and base. Representative plagioclase crystals from different crystal zones will be analyzed for major, minor, and trace elements via electron microprobe, SEM, and in-situ laser ablation ICP mass spectrometry. These data will allow partition coefficients to be determined and the reconstruction of parent liquid compositions and local crystallization environments. Strontium isotope measurements will be made on a sub-set of crystals to further constrain parent magma compositions and the extent of crustal contamination. Independent estimates of crystal residence times will be obtained from the crystal size and geochemical data. Broader ImpactsBroader impacts of this proposal include education of a graduate student and involvement of a K-12 teacher and students at a school in a Hispanic dominated high school in Deming, New Mexico. This effort will expose Hispanic high school students to the excitement of geochemical and petrological research. The research also involves international collaboration with researchers at the University of Durham in the UK. Results of the work will be integrated into graduate and undergraduate teaching at the University of Notre Dame. A "crystal stratigraphy" web site will also be set up to inform the public and other researchers about the technique and its potential applications.

摘要（Neal -0452102）了解岩浆的发展对于了解为什么火山爆发至关重要。对全岩样品的分析提供的成分仅反映了熔岩在喷发前经历的过程的平均值。然而，检查各个晶体和晶体种群，可以更好地了解岩浆进化的动力学。这项研究涉及巴黎圣母大学的研究人员，并利用具有相关成核和生长历史的火成岩（即晶体大小分布）中的不同晶体种群。它们将这种方法与矿物尺度的组成研究（即晶体层学）结合在一起。 这种合并的方法限制了分化过程的时机和程度（即岩浆混合，地壳污染），该过程允许量化自由化岩浆物体的动力学和时机，因为自从岩浆体与源头分离并可能导致源本身的识别。 该研究使用来自南部/南印度洋Elan Bank上的Kerguelen大型火成岩省的样品开发了一种新技术，用于使用晶体尺寸分布和基于小波的相关性重建岩浆室进化，以确定不同的斜长石晶体晶体种群在七个型号中的七个型号的共同流量中，来自海洋钻探站点1137年龄段的杂志。由火山碎裂的间层表示。 这些火山碎屑单元将湖泊流序列分为四个部分。 每个部分将从顶部，中间和底座进行研究。 将通过电子微探针，SEM和原位激光消融ICP质谱法分析来自不同晶体区域的代表性斜长石晶体。 这些数据将允许确定分区系数，并重建父液体成分和局部结晶环境。将在晶体的子集上进行锶同位素测量，以进一步限制父岩浆成分和地壳污染的程度。从晶体大小和地球化学数据中获得了晶体停留时间的独立估计。该建议的更广泛的影响力影响包括对研究生的教育以及K-12老师的参与以及在新墨西哥州戴明市的西班牙裔高中的一所学校的学生参与。 这项努力将使西班牙裔高中生对地球化学和岩石学研究的兴奋。该研究还涉及与英国达勒姆大学的研究人员的国际合作。 这项工作的结果将纳入巴黎圣母院大学的研究生和本科教学。 还将设立一个“水晶地层”网站，以告知公众和其他研究人员有关该技术及其潜在应用的信息。