Speaker
Description
Volcanic systems on Earth commonly evolve through repeated eruptive episodes, comprising discrete events grouped into phases. The accumulation of volcanic deposits builds the edifice while obscuring evidence of the system's evolution through space and time. Recent terrestrial eruptions can be characterized at high temporal resolution using satellite- and UAV-based observations supplemented by direct sampling. This is not feasible on other planets, leaving Martian eruptive histories poorly understood. Limited constraints on their temporal evolution hinder the distinction between monogenetic and polygenetic systems, creating ambiguity in terminology and classification. Moreover, lack of detailed remote sensing observations integrated with high-resolution digital elevation models and crater-count age constraints limits recognition of eruptive episodes recorded by discrete lava flows and landforms. Consequently, the eruptive histories of many small Martian volcanic systems have been oversimplified. To address these uncertainties, particularly for late Amazonian distributed volcanism in Tharsis, we investigated a fissure-fed system east of Arsia Mons, near the boundary with Hesperian-aged crust. Detailed geological mapping, topography-based structural analysis, and crater-count age determinations identified several distinct lava flows sourced from the same fissure system. These observations provide evidence of multiple eruptive episodes, indicating repeated eruptions analogous to the recent polygenetic Svartsengi eruptive series (2023–2025) in Iceland. Although crater-count ages of individual units overlap within analytical uncertainties, well-defined lava flow fronts indicate temporal breaks between successive episodes. Collectively, these observations suggest that this Martian system may have been polygenetic and highlight the need to re-examine other small volcanic systems using a multi-approach framework to better characterize their spatiotemporal eruptive histories.