Evolution of plume volcanism at Atla Regio, Venus
File(s)
Published version
Author(s)
Mason, PJ
Klidaras, A
Cirium, D
Ghail, RC
Lea-Wurzbach, S
Type
Journal Article
Abstract
Atla Regio is a large topographic rise, at the equator of Venus, considered to sit above a young mantle upwelling. Hosting several giant shield volcanoes, including Maat Mons, it is a strong candidate for recent eruptive activity. Through detailed analysis of material units and structures at Ozza, Maat and Sapas Mons, northern Dali Chasma and the surrounding plains, we have unraveled the tectono-magmatic evolution at Atla Regio. Lithostratigraphic analysis, of the volcanic styles, lava flow relationships, rift–associated shield clusters, graben-fissure systems and pit cratering, in relation to the regional plains and other older features, has enabled the establishment of a model of the evolution of volcanism. Structural analysis reveals that graben-fissure systems at Ozza Mons transition outward into three major rifts, and two new, unnamed volcanoes are identified. Our model is evidenced by analysis of lava flow stratigraphy and cross-cutting relationships with respect to the stratigraphic marker provided by the ejecta halo of the Uvaysi impact, and using sound stratigraphic principles. A relative chronostratigraphic framework for the area around Ozza and Maat Mons has thus been constructed, and our findings are in agreement with prior research. A new regional history is proposed here, where volcanism was initially concentrated along Dali Chasma, before plume volcanism took over at Ozza Mons and finally, Maat Mons became the most recent locus of volcanism. We propose that the pattern of large shield volcanoes with displaced centers here is indicative of minor crustal adjustments above a relatively long-lived mantle plume.
Date Issued
2025-02-01
Date Acceptance
2025-02-03
Citation
Journal of Geophysical Research: Planets, 2025, 130 (2)
ISSN
2169-9097
Publisher
American Geophysical Union
Journal / Book Title
Journal of Geophysical Research: Planets
Volume
130
Issue
2
Copyright Statement
© 2025. The Author(s). This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Subjects
Atla Regio
BETA-REGIO
CLASSIFICATION
CONSTRAINTS
Geochemistry & Geophysics
GLOBAL DISTRIBUTION
HISTORY
MAAT MONS
Physical Sciences
SAPAS-MONS
Science & Technology
SURFACE
TECTONICS
TOPOGRAPHIC RISES
Venus
volcanism
Publication Status
Published
Article Number
e2024JE008815
Date Publish Online
2025-02-22