Basalts Through Time — Roy et al. (2026), Communications Earth & Environment

This repository contains the supplementary data accompanying the manuscript:Roy, S., Kamber, B. S., Hayman, P. C. & Murphy, D. T. (2026). Tectonic setting and mantle source evolution reconstructed from deep time analysis of basalt geochemistry. Communications Earth & Environment.The study presents a global deep-time analysis of basalt CIPW normative mineralogy, tracking secular changes in basalt petrology from the Archaean to the present day.Key findings include:- Archaean continental basalts are dominantly quartz-normative (~49%), with striking compositional similarity to Phanerozoic continental flood basalts.- Normative clinopyroxene/orthopyroxene ratios argue against dominant hydrous flux-melting as a petrogenetic mechanism for Archaean basalts.- A progressive secular increase in nepheline-normative (alkali) basalts, with a pronounced step-change near the Precambrian–Phanerozoic boundary, attributed to widespread mantle hybridisation following the onset of sustained, modern-style deep subduction in the Neoproterozoic.- Two lulls in Palaeoproterozoic mafic magmatic activity are identified: the established Tectono-Magmatic Lull (~2,365–2,235 Ma) and a newly recognised lull at ~2,000 Ma.FILES INCLUDEDSupplementary Data 1 — Compiled whole-rock geochemical databaseSupplementary Data 2 — Experimental melt compositionsSupplementary Data 3 — LDA analysis outputsSupplementary Data 4 — MAGEMin fractional crystallisation model outputSupplementary Information — Supplementary figures, tables, notes, and references (PDF)Python scripts for all figures are available at:https://github.com/INDeep-earth/roy-2026-basalt-normative-mineralogy本仓库收录随学术论文配套的补充数据，该论文为Roy, S.、Kamber, B. S.、Hayman, P. C. 及Murphy, D. T.于2026年发表在《通讯-地球与环境（Communications Earth & Environment）》的《基于玄武岩地球化学深时分析重建的构造背景与地幔源区演化（Tectonic setting and mantle source evolution reconstructed from deep time analysis of basalt geochemistry）》。本研究开展了全球尺度的玄武岩CIPW标准矿物组合（CIPW normative mineralogy）深时分析，追踪了从太古代（Archaean）至今玄武岩岩石学的长期演化趋势。 主要研究结果如下： - 太古代（Archaean）大陆玄武岩以石英标准矿物组合为主（占比约49%），其成分与显生宙（Phanerozoic）大陆溢流玄武岩具有显著相似性。 - 标准矿物单斜辉石/斜方辉石比值表明，含水流体熔融并非太古代玄武岩形成的主导成岩机制。 - 以霞石标准矿物组合为特征的碱性玄武岩占比随地质时间呈渐进式增长，并在前寒武纪-显生宙界线附近出现显著的阶跃式变化，这一现象被归因于新元古代（Neoproterozoic）出现持续的现代型深部俯冲作用后，地幔发生广泛的混合作用。 - 研究识别出古元古代（Palaeoproterozoic）基性岩浆活动的两幕沉寂期：一是已被学界证实的构造-岩浆沉寂期（约2365~2235 Ma），二是新发现的约2000 Ma岩浆沉寂期。 本仓库包含的文件如下： - 补充数据1：汇编的全岩地球化学数据库 - 补充数据2：实验熔融产物成分数据集 - 补充数据3：线性判别分析（Linear Discriminant Analysis，LDA）输出结果 - 补充数据4：MAGEMin分数结晶模拟输出结果 - 补充信息：包含补充图、补充表、注释及参考文献的PDF文档 所有绘图所用Python脚本可通过以下网址获取：https://github.com/INDeep-earth/roy-2026-basalt-normative-mineralogy