Collaborative Research: A New Approach to Detrital Provenance Determination: Application of Laser-Induced Breakdown Spectroscopy (LIBS) to the Tourmaline Supergroup Minerals

了解地球的地质历史可以深入了解塑造我们星球的过程和经济资源的分布。 然而，古代地质事件可能很难破译，因为它们的物理存在可能会因侵蚀而消失。幸运的是，关于岩石类型和年龄的信息（即，在风化和侵蚀之前就存在的矿物（例如它们的来源）被编码在一些保存在沉积物和沉积岩中的矿物中。 电气石就是这样一种矿物，它是一个重要的地质信息库，因为它包含了广泛的化学元素，这些元素反映了它形成的岩石环境--也就是说，它编码了岩石的化学特征，类似于指纹。电气石也是一种耐化学和机械腐蚀的矿物，当它从形成它的岩石中风化出来时，它可以变成一种沙粒，被纳入沉积物（和岩石）中。一旦它包含了其原始的化学特征，电气石颗粒就将该特征存储了数百万或数十亿年。这项工作使用了一种协同方法来破译以前的地质事件，它们在沉积物和岩石中的记录，通过使用新技术激光诱导击穿光谱（LIBS）和现有技术电子探针分析（EMP）整合矿物电气石的化学分析。两者都产生原位化学指纹：LIBS是有利的，因为它收集所有元素及其络合物的信号，包括轻元素，并提供元素的相对组成，而EMP是一种成熟的分析技术，用于大多数元素（轻元素H，Li除外）的高度精确和准确的微米级化学数据。这项工作的一个目标是使用这些互补的技术来开发强大的方法来确定来源的基础上广泛收集的已知出处的旅游样品。 在一项个案研究中，将把物源技术应用于东南极山脉的地质发展（6.5亿至4.8亿年前）。本案例研究的目的是测试LIBS和EMP的旅游分析在解读东南极复杂地质历史中的有效性。 这项研究有两个主要的意义。 首先，它将开发来源研究的新途径，以完善我们对地球历史的理解，使用广泛的矿物旅游。另一个社会效益是有可能将碧玺与价格截然不同的不同宝石矿床区分开来。 本研究的样本、数据和技术将用于两所少数民族大学的本科生和研究生课程，以教育下一代地球科学家。 两所大学之间的学生交流将扩大他们的教育和分析经验，今天有必要吗？的全球劳动力。该研究团队包括两名女性共同PI，所有PI都是STEM学科中大量女性的导师。 与产业界的合作汇集了学者和工业合作伙伴，包括一家女性拥有的营利性小企业，此外还与另一所以本科生为重点的大学的教师合作。

Understanding Earth's geological history provides insight into processes that shape our planet and the distribution of economic resources. However, ancient geological events can be difficult to decipher because their physical presence may be lost to erosion. Fortunately, information on the types and ages of rocks (i.e., their provenance) that were present prior to weathering and erosion are encoded in some minerals that are preserved in sediments and sedimentary rocks. Tourmaline is one such mineral. It is a key repository of geologic information because it incorporates a wide range of chemical elements that reflect the rock environment in which it forms - that is, it encodes the chemical signature of that rock, similar to a fingerprint. Tourmaline is also a chemically and mechanically resistant mineral that, when weathered out of the rock in which it formed, it can become a sand grain that is incorporated into sediments (and rocks). Once it incorporates its original chemical signature, the tourmaline grain stores that signature for millions or billions of years.This work uses a synergistic approach to decipher former geological events, their record in sediments and rocks, by integrating chemical analyses of the mineral tourmaline using the new technology Laser-Induced Breakdown Spectroscopy (LIBS) with the established technology Electron Microprobe analyses (EMP). Both yield in-situ chemical fingerprints: LIBS is advantageous because it collects signals of all elements and their complexes, including the light elements, and provides relative compositions of elements, while EMP is a mature analytical technique and is used for highly precise and accurate micrometer-scale chemical data for most elements (except light elements H, Li). One goal of this work is to use these complementary techniques to develop robust approaches to provenance determination based on an extensive collection of tourmaline samples of known provenance. The provenance techniques will be applied, in a case study, to the geologic development of the East Antarctic Mountains (650-480 million years ago). The goal of this case study is to test the efficacy of tourmaline analysis by LIBS and EMP in deciphering complex geologic history of East Antarctic. This study has two major implications. First, it will develop new avenues of provenance studies to refine our understanding of Earth history using the widespread mineral tourmaline. An additional societal benefit is the potential to differentiate tourmalines from different gem deposits that command radically different prices. Samples, data and techniques from this study will be used in both undergraduate and graduate classes at two minority-serving Universities to educate the next generation of geoscientists. A student exchange between the two universities will broaden their educational and analytical experience, necessary for today?s global workforce. This research team includes two female co-PIs and all PIs serve as mentors to a significant number of women in STEM disciplines. Collaboration with industry brings together academics and industrial partners including a woman-owned for-profit small business, in addition to collaborations with faculty at another undergraduate-focused university.