Geodynamics of synconvergent extension on Venus and earth

Revealing the characteristics and origins of surface deformation in planetary bodies is fundamental to understanding the biogeodynamic cycle. Investigating how mountains and basins (topography) as well as magmatism (carbon cycling) develop with or without subduction—and therefore, plate tectonics—provides critical insights into the habitability and climate stability of a planet. This study aims to identify tectonic deformation on Venus, specifically describing extensional and shortening features. High-resolution, scaled laboratory experiments combined with structural observations suggest that lithospheric drips (sinking plumes) influence strain distribution and the geometric characteristics of various coronae. Notably, the linear shortening structures observed at the centers of coronae appear to form above downwelling regions, while material pulling results in crustal stretching at the topographic rims. These findings support the hypothesis that multiple geodynamic processes may collectively control coronae formation, with lithospheric drips often overlooked due to the prevalence of plume models. Ultimately, the coexistence of crustal extension/rifting and plate shortening (fold and thrust belt) by lithospheric instabilities offers a possible explanation for clarifying deformation patterns on Venus and earth.