Practical applications and limitations of basalt discrimination diagrams

作     者：Kentaro Nakamura 

作者机构：Frontier Research Center for Energy and Resources(FRCER)School of EngineeringThe University of TokyoTokyoJapan 

出 版 物：《Big Earth Data》 (地球大数据（英文）)

年 卷 期：2023年第7卷第4期

页      面：1081-1093页

核心收录：

学科分类：0709[理学-地质学] 07[理学] 070901[理学-矿物学、岩石学、矿床学] 08[工学] 0708[理学-地球物理学] 0804[工学-仪器科学与技术] 0816[工学-测绘科学与技术] 0812[工学-计算机科学与技术（可授工学、理学学位）] 

基　　金：I am grateful to the three anonymous reviewers for their valuable comments and suggestions  which have significantly improved the manuscript. I would also like to thank Editage (www.editage.com) for the English language editing. 

主　　题：Discrimination diagram tectonic setting support vector machine big data large petrological databases 

摘      要：Determining the tectonic setting of unknown volcanic rocks continues to be one of the key challenges in geoscience.While discrimination diagrams have been successfully employed due to their ease of use,recently,validation with big data has raised questions about their performance.In this study,the discrimination boundaries of Th/Yb versus(vs.)Nb/Yb and TiO2/Yb vs.Nb/Yb diagrams,which are the most used types of discrimination diagrams,were redefined based on a large amount of compiled data and support vector machine,a machine learning method.The effectiveness of discrimination diagrams was verified,and the limitations and conditions when using them were clarified.The results show that when using the Th/Yb vs.Nb/Yb diagram,only basalts with Th/Yb ratios higher than the discrimination boundary can be identified as volcanic arcs in origin.In contrast,a significant overlap occurs across boundaries in other cases when using these diagrams,particularly for enriched samples with Nb/Yb ratios higher than five.Therefore,when using these diagrams to determine the tectonic setting of unknown samples,their limitations must be considered when interpreting their results.