GRSG 34th Conference 2023

Title: Constraining tessera evolution in Phoebe Region

Author: Connor Hoad


Tesserae are novel chaotic planetary terrains that occupy ~8% of Venus’ surface, characterized by radar bright returns, the presence of multiple intersecting tectonic lineaments and their local occupation of lowest stratigraphic positions (1). They are generally isostatically compensated crustal blocks (2), with folded and layered strata, which record Venus’ deep geologic history (3).

Phoebe Regio is a tessera dominated topographic rise situated on the Eastern margin of a trio of Volcanic rises termed the Beta-Atla-Themis (BAT) region. Prior works have proposed upwelling induced formation of tessera in Pheobe on the basis of gravity data (2), although it is possible the tessera formed in an episode of crustal thickening prior to the onset of upwelling.

Tessera of Phoebe Regio were initially mapped as a single unit in the V-41 quadrangle (4), through more specific terrain classifications, 12 morphologically distinct tessera terrain types have since been identified in Phoebe Regio (5). While new data acquisitions for Venus from the upcoming EnVision and Shukrayaan missions are eagerly awaited by planetary scientists, there is still knowledge to be extracted from Magellan through the application of modern approaches to planetary remote sensing. Ongoing detailed remote sensing study of Pheobe Regio using a primary dataset of 75m/pixel resolution Magellan SAR imagery aims to improve upon current morphologic mapping in the region, as to constrain the tectonic evolution these diverse tessera terrains and assess the geologic history of Phoebe Regio.