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Short‐Term and Global‐Wide Effusive Volcanism on Mercury Around 3.7 Ga

Patches of small smooth plains cover a substantial portion of the Mercurian surface, but their origin and relation to the global evolution are not completely understood. Here, we update the global inventory of small smooth plains on Mercury, classifying their spatial distribution, absolute model ages, and possible origins. We reveal that both large and small smooth plains on Mercury were dominantly emplaced within ∼200 million years around 3.7 Ga, and at least ∼24.9% of the global surface was resurfaced during this period. Small smooth plains formed by effusive volcanism are preferentially located around the contemporaneous Caloris, Rembrandt, and Beethoven basins and at thin crust areas. We also report small smooth plains that were likely emplaced by basin ejecta. Together with the distribution of similarly aged large smooth plains, our results reveal that peaked formation of large impact basins may be a major trigger for this short‐term and global‐wide volcanism.