Extracting the geochemical characteristics of magmas in different global tectono-magmatic settings using sparse modeling
Extracting the geochemical characteristics of magmas in different global tectono-magmatic settings using sparse modeling
复制标题
DOI：
10.3389/feart.2022.994580
复制
发表时间：
2022-10
期刊：
影响因子：
--
通讯作者：
K. Ueki;H. Hino;T. Kuwatani
中科院分区：
文献类型：
--
作者：
K. Ueki;H. Hino;T. Kuwatani
在这项研究中，形成在八个不同的构造-岩浆环境（洋中脊，海洋岛屿，海洋高原，大陆溢流玄武岩省，洋内弧，大陆弧，岛弧和弧后盆地）的岩浆的关键地球化学特征，使用基于机器学习的统计模型。利用统计模型拟合方法对全球地球化学数据库中的火山岩地球化学数据进行了分析。我们使用稀疏建模方法，通过这种方法，我们可以从大量的观察中客观地识别出少量的基本特征。这种方法使我们能够从总共857个变量中识别出少量具有代表性的地球化学特征，包括主要和微量元素浓度、同位素比以及元素的所有可能的比率和倍增。在统计分析的基础上，我们提出了少数（2-4）的关键地球化学特征的每一个构造岩浆环境。提取的地球化学特征和相关图解可用于研究构造-岩浆环境之间的地球化学相似性和差异性，并识别未知样品的地球化学特征。根据提取的地球化学特征，讨论了不同构造-岩浆环境下岩浆形成的过程。我们的统计分析表明，岩浆的地球化学特征随构造-岩浆背景而变化，岩浆生成的地球化学过程也是如此。
In this study, key geochemical features of magmas formed in eight different tectono-magmatic settings (mid-ocean ridges, oceanic islands, oceanic plateaus, continental flood basalt provinces, intra-oceanic arcs, continental arcs, island arcs, and back-arc basins) are presented that were obtained using a machine-learning-based statistical model. We analyzed geochemical data for volcanic rocks compiled from the global geochemical databases based on statistical model fitting. We used the sparse modeling approach, with which we can objectively identify a small number of fundamental features from a large number of observations. This approach allowed us to identify a small number of representative geochemical features from a total of 857 variables, including major and trace element concentrations, isotope ratios, and all possible ratios and multiplications of elements. Based on the statistical analysis, we present a small number (2–4) of key geochemical features for each tectono-magmatic setting. The extracted geochemical features and associated diagrams can be used to examine geochemical similarities and differences between tectono-magmatic settings and to identify the geochemical characteristics of unknown samples. Based on the extracted geochemical characteristics, we discuss the processes that may lead to the formation of magmas in different tectono-magmatic settings. Our statistical analysis shows that the geochemical signatures of magmas vary with the tectono-magmatic setting, as do the geochemical processes involved in magma generation.