281-4 Will Upcoming Missions be able to Determine the Composition of Canali?

Session: Petrology, Volcanology, and Mantle Plumes across the Solar System, Part II

Presenting Author:

Authors:

Abstract:

Canali are long (on average ~600 km) sinuous channels and a volcanic feature unique to Venus. Their morphology is similar to terrestrial fluvial channels, but previous studies have indicated a volcanic origin. Truesell et al., (2025) modeled the formation of Venus canali using different compositions of lava, including Basalt (high-Ti, low-Ti, Tholeiitic, and Ocean Island), Komatiite, and Carbonatites. The study concluded that carbonatite was the most feasible lava composition to form the canali. This conclusion has substantial implications for the volcanic and atmospheric evolution of Venus. A key objective of the upcoming VERITAS and EnVision missions is to investigate volcanic features on Venus and use visible-near infrared (VNIR) spectral data from the Venus Emissivity Mapper (VEM) instrument to measure surface composition. Our study performed VNIR hyperspectral reflectance measurements of the above-mentioned compositional possibilities for the canali. Specifically, basalt samples from Etna (Italy), Kilauea (USA), Klyuchevskoy (Russia), and Tolbachik (Russia); and carbonatite samples from Tororo (Uganda). We then deconvolve the spectral resolution to match the anticipated spectral resolution of the VEM instrument and converted them to emissivity to simulate the data acquired by the instrument. Results indicate that Fe rich basaltic material would be identifiable with the VEM instrument, owing to conduction band electronic processes that occur at ~1 µm. Carbonatites that are calcite rich on the other hand would exhibit lower overall emissivity (ε ≤0.5), as would its likely weathering product, anhydrite, especially when compared to the mafic spectra. The lack of spectral features in this wavelength region, however, would make them hard to distinguish from each other. At the current planned spectral resolution and available atmospheric windows on Venus, it may not be feasible to determine the composition of the canali. The low spatial resolution (~100 km/pixel) of the VEM instrument further complicates this issue. However, a sub-cloud ballon mission, as proposed in the VEXAG strategy for exploration of Venus document, would not have the atmospheric interference of an orbital mission and may be able to determine the composition of the canali.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7824

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.