Volcanic geology of the easternmost sector of the Trans-Mexican Volcanic Belt, Mexico

This work presents the volcanic geology of the easternmost sector of the Trans-Mexican Volcanic Belt, including the Serdán-Oriental basin and Cofre de Perote-Citlaltépetl volcanic range, two contrasting Quaternary volcanic fields. The first comprises dominant monogenetic volcanism of bimodal composition including isolated rhyolitic domes and tuff rings, basaltic andesite maar volcanoes, cinder and lava cones, and an active caldera complex (Los Humeros). The second is dominated by large composite polygenetic volcanoes of andesitic-dacitic composition, including the shield-like compound Cofre de Perote volcano, La Gloria and Las Cumbres complexes, and the active Citlaltépetl stratovolcano. Mapping units include a pre-volcanic basement made of metamorphic (Paleozoic), and sedimentary (Jurassic-Cretaceous); intrusive (Miocene) rocks; multiple basaltic-andesitic lava flows and rhyolitic domes; volcaniclastic sequences (debris avalanches and lahars; and pyroclastic deposits (block-and-ash flows, ignimbrites, fallouts, and surges) (Miocene-Holocene). This map provides a comprehensive view of the highly diverse volcanism, which may reference for future research work.

本研究阐述了跨墨西哥火山带（Trans-Mexican Volcanic Belt）最东端区段的火山地质特征，涵盖塞尔丹-东方盆地（Serdán-Oriental basin）与科弗雷德佩罗特-锡特拉尔特佩特火山带（Cofre de Perote-Citlaltépetl volcanic range）这两处特征迥异的第四纪火山场。前者以双峰组分的单成因火山作用（monogenetic volcanism）为主，涵盖孤立流纹岩穹丘、凝灰岩环、玄武安山岩玛尔火山、火山渣锥与熔岩锥，以及一处活跃的破火山口复合体——洛斯乌梅罗斯（Los Humeros）。后者则以安山岩-英安岩组分的大型复合多成因火山为主，包括盾状复合科弗雷德佩罗特火山、拉格洛里亚与拉斯昆布雷斯复合体，以及活跃的锡特拉尔特佩特层状火山。本次填图的地质单元包括：由古生代变质岩、侏罗纪-白垩纪沉积岩构成的火山前基底；中新世侵入岩；多套玄武安山岩熔岩流与流纹岩穹丘；火山碎屑岩序列（包含碎屑崩落与火山泥流（lahars））；以及火山碎屑沉积（包括块体-碎屑流、熔结凝灰岩（ignimbrites）、火山碎屑沉降物与火山碎屑涌浪（surges）），形成时代为中新世至全新世（Miocene-Holocene）。本填图成果全面展现了该区域高度多样的火山作用类型，可为未来相关研究提供参考依据。