In recent days,discrimination diagrams have been widely used for tracing the tectonic settings and origins of basalts from orogenic belts.However,conventional discrimination diagrams are not accurate enough.Here,we re...In recent days,discrimination diagrams have been widely used for tracing the tectonic settings and origins of basalts from orogenic belts.However,conventional discrimination diagrams are not accurate enough.Here,we reported six new discrimination diagrams obtained from the global database using data mining methods.For most individual diagrams,island arc basalt can be nearly 100%was identified,whereas ocean island basalt and midocean ridge basalt can be discriminated from each other with less than 10%of overlap,under a confidence coefficient of 85%.Using the six new discrimination diagrams together,basalts of different origins can be efficiently identified.展开更多
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,valida...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.展开更多
文摘In recent days,discrimination diagrams have been widely used for tracing the tectonic settings and origins of basalts from orogenic belts.However,conventional discrimination diagrams are not accurate enough.Here,we reported six new discrimination diagrams obtained from the global database using data mining methods.For most individual diagrams,island arc basalt can be nearly 100%was identified,whereas ocean island basalt and midocean ridge basalt can be discriminated from each other with less than 10%of overlap,under a confidence coefficient of 85%.Using the six new discrimination diagrams together,basalts of different origins can be efficiently identified.
文摘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.
