51st Lunar and Planetary Science Conference (2020) 1131.pdf Timing of Smooth-Topped Chaotic Terrains, Southern Circum-Chryse, Mars. J. Walmsley1 <
[email protected]>, F. Fueten1 <ffueten@ brocku.ca>, R. Stesky2, A. P. Rossi3, 1Dept. of Earth Sciences, Brock University, St. Catharines, Ontario, Canada L2S 3A1, 2Pangaea Scientific, Brockville, Ontario, Canada K6V 5T5, 3Dept. of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany. Introduction: Primary chaotic terrains are the larg- during collapse when compared with their surrounding est type of chaotic terrain on Mars, covering the largest near horizontal plateaus. Total volume loss calculated area and deepest collapse, producing catastrophic for each site are: Hydraotes Chaos (179,000 km3), floods which erode large outwash channels [1]. Sec- Hydraspis FFC (10,900 km3), Candor Chaos (<2,000 ondary chaotic terrains are much smaller than primary km3), Baetis Chaos (3,200 km3), and the East Chaos chaos and are confined to the floors and walls of pre- (400 km3). Estimated depth of collapse for each chaot- existing outflow channels [2]. They usually do not ic terrain was also calculated: Hydraotes Chaos (2.1 generate catastrophic floods during their formation [2], km), Hydraspis FFC (1.45 km), Candor Chaos (< 0.2 though examples of flooding do exist [3]. Fractured- km), Baetis Chaos (no collapse), and the East Chaos Floor Craters (FFCs) are a subset of primary chaotic (no collapse). Relative timing of chaos forming events terrains which are completely contained within a pre- was determined using data from previous studies, as existing crater and can produce catastrophic flooding well as from cross-cutting relationships.