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

摘要（Neal - 0452102）了解岩浆是如何演化的对于了解火山爆发的原因很重要。对整个岩石样本的分析给出的成分只反映了熔岩在喷发前所经历的过程的平均值。然而，对单个晶体和晶体群的检查可以更好地了解岩浆演化的动力学。这项研究涉及圣母大学的研究人员，并利用火成岩中不同的晶体群（即，晶体尺寸分布）具有相关的成核和生长历史。它将这种方法与矿物规模的成分研究相结合（即，晶体地层学）。 这种组合的方法限制了分化过程的时间和程度（即，岩浆混合、地壳混染），这使得能够量化自岩浆体与其来源分离以来改变岩浆体的过程的动力学和时间，并可导致对来源本身的识别。 该研究使用样本从Kerguelen大火成岩省的Elan银行在南部/南印度洋开发一种新的技术，重建岩浆房的演化，使用晶体尺寸分布和小波相关性，以确定不同的斜长石晶体种群在7个共同的岩浆流从大洋钻探计划网站1137。 样品的年龄范围从107-108 Ma，并包括三个不同的中断岩浆作用，这是由火山岩夹层。 这些火山岩单元将熔岩流序列分为四个部分。 每个部分将从顶部，中部和底部进行研究。 将通过电子探针、SEM和原位激光烧蚀ICP质谱法分析来自不同晶区的代表性斜长石晶体的主要、次要和痕量元素。 这些数据将允许分配系数被确定和重建的母液组成和局部结晶环境。将对一组晶体进行锶同位素测量，以进一步限制母岩浆的成分和地壳污染的程度。晶体停留时间的独立估计将从晶体尺寸和地球化学数据中获得。更广泛的影响，这一建议的更广泛的影响包括教育的研究生和参与的K-12教师和学生在一所学校在西班牙裔占主导地位的高中德明，新墨西哥州。 这项努力将使西班牙裔高中生感受到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研究人员的国际合作。 这项工作的成果将纳入圣母大学的研究生和本科生教学。 还将建立一个“晶体地层学”网站，向公众和其他研究人员介绍这项技术及其潜在的应用。

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.