Geology of the Southern Rim of Hellas Basin, Mars: Investigations of Amphitrites Patera and Barnard Crater

Hellas is the largest preserved impact feature on Mars and its deepest depositional basin. The geology of the Hellas basin floor, rim, and surroundings presents a detailed record of the numerous processes affecting the Martian surface from the Noachian to the Amazonian. The Martian highland patera class of volcanoes and adjacent ridged plains located in the circum-Hellas highlands indicate the prominent role of early Martian volcanism in the eastern (Hadriacus and Tyrrhenus Mons, Hesperia Planum) and southern (Amphitrites, Malea, Peneus, and Pityusa Paterae, Malea Planum) Hellas regions. This investigation uses high-resolution imaging and topographic datasets for detailed analyses of the geologic processes that created landscapes along Hellas’ southern rim and seeks to determine the histories of volcanism, impact cratering, and degradation.

Scientific questions to be addressed by this investigation include: 1) What is the distribution of deposits (volcanic, volcaniclastic, and sedimentary) associated with Amphitrites Patera within Malea Planum and northward across Hellas’ southern rim? 2) What are the types, magnitudes, and ages of degradational processes (including fluvial, glacial, lacustrine activity and ice-rich mantling) that have affected the flank deposits of Amphitrites Patera and Hellas’ southern rim. 3) What constraints do the morphology and distribution of Amphitrites Patera flank deposits place on its formation? 4) Based on CTX images, what do the morphologic and topographic characteristics of Amphitrites Patera reveal about its volcanic formation processes and subsequent degradation? 5) Based on CTX images and the preserved ice-related landforms, what constraints on regional geologic history can be inferred from the geomorphology of Barnard Crater? This research will include compilation of a geologic transect map across the southern rim of Hellas (~52-64°S, 50-70°E at ~1:1,000,000 scale) based on THEMIS IR and CTX datasets and a detailed geomorphic map of Barnard Crater (~1:250,000 scale) based on CTX. Geologic and geomorphic mapping will be combined with morphometric and spatial analyses of geologic features and compilation and examination of crater size-frequency distributions to provide relative and absolute age constraints.