Geologic Mapping of the Summit and Western Flank of Alba Mons, Mars David A. Crown Planetary Science Institute 3rd Planetary Data Workshop Planetary Geologic Mappers Annual Meeting June 12-15, 2017 Flagstaff, Arizona Geologic Mapping of Alba Mons, Mars • 1:1M-scale geologic mapping • CTX and THEMIS IR primary image bases • Supported by MDAP • Volcanic, tectonic, and degradational histories of summit region and western flank – Summit caldera complex 500 km – Circumferential graben systems; pit crater chains MOLA color hillshade (128 pxl/deg) – Valley networks Elevation range: -4500 – 21229 m – Lava flow fields; lava flows with diverse flow morphologies • Project Team – PSI: David Crown, Dan Berman, Thomas Platz, Cathy Weitz – University of Arizona: Stephen Scheidt – German Aerospace Center (DLR): Ernst Hauber, Rushana Karimova – Free University of Berlin: Beatrice Cailleau 47.5°N MTM 45127 MTM 45122 MTM 45117 Alba Mons Western Flank MTM 40127 MTM 40122 MTM 40117 37.5°N 230°E 245°E Alba Mons Western Flank Alba Mons Summit Region 32.5°N Alba Mons 255°E Summit Region Geologic Mapping of Alba Mons, Mars: 1:1M-Scale Map Regions MOLA color hillshade (128 pxl/deg) 500 km Elevation range: -4500 – 21229 m Tanaka et al., 2014 1:20M USGS Maps covering Alba Mons Scott and Tanaka, 1986 1:15M Viking Orbiter Analyses of Alba Mons Cattermole, 1990 Schneeberger and Pieri, 1991 Geologic Mapping of Alba Mons, Mars Significance: • Largest Martian volcano in planform • Major volcano-tectonic center with long duration of eruptive activity • Prominent flow fields with diverse flow morphologies • Testing Viking Orbiter-based hypotheses: (e.g., Mouginis-Mark et al., 1988) 500 km 1) Dendritic valleys networks carved into early-stage MOLA color hillshade (128 pxl/deg) pyroclastic deposits Elevation range: -4500 – 21229 m 2) Transitional volcano type between shields and paterae 1:1M-Scale Geologic Mapping: • Systematic, digital geologic mapping investigation using post-Viking datasets with high spatial resolution and wide areal coverage • GIS-based mapping allows for detailed analyses of geologic features (e.g., morphometric characteristics, spatial distribution, cross-cutting relationships) ALBA MONS CALDERA REGION Preliminary map over MOLA DTM/THEMIS day mosaic THEMIS day mosaic 100 km THEMIS night mosaic Craters ≥ 500 m in diameter 100 km (500 m – 21.4 km) Area of tabular flows and lava tubes Age estimates from CraterStats 2 MOLA hillshade Geologic Mapping of Alba Mons: Age Constraints from Crater Counting Geologic Mapping of Alba Mons: Mapping Structural Features Summit Region Fault Mapping CTX mosaic Alba Mons summit caldera 100 km THEMIS IR daytime mosaic 5 km Geologic Mapping of Alba Mons: Mapping Structural Features 5 km CTX mosaic Geologic Mapping of Alba Mons: Mapping Fluvial Features 100 km THEMIS IR daytime mosaic 5 km CTX mosaic Geologic Mapping of Alba Mons: 5 km Mapping Fluvial Features CTX mosaic CTX mosaic 5 km Geologic Mapping of Alba Mons: Mapping Volcanic Features Lava flow lobe Lava tube 100 km Colored MOLA hillshade of Western Flank Map Region 10 km 10 km Lava Tube Systems Tabular Flows Geologic Mapping of Alba Mons: Lava Flow Morphologies Broad Lobe with CTX mosaics sinuous flow front 10 km Geologic Mapping of Alba Mons: 46.5°N Test Area Mapping 44.5°N Test Areas: 114°W 112°W 2° x 2° regions Alba Mons NW and SE of summit region Summit Region • Examine representation of geology at map scale • Evaluate density for mapping geologic features (fluvial, structural, and volcanic) 107°W • Determine cross-cutting relationships at feature 37°N intersections 35°N 105°W 100 km MOLA DTM/THEMIS IR daytime mosaic Alba Mons: NW Test Area Mapping 40 km THEMIS IR daytime mosaic CTX mosaic Volcanic Features (D. Crown) Fluvial Features (S. Scheidt) Structural Features (R. Karimova) Alba Mons NW Test AreaFeature Intersections (younger_older) lava_lava valley_lava valley_valley fault_lava fault_volcanic channel fault_valley THEMIS IR daytime mosaic CTX mosaic Volcanic Features (D. Crown) Fluvial Features (S. Scheidt) Structural Features (R. Karimova) Alba Mons SE Test Area Feature Intersections (younger_older) lava_lava valley_lava valley_valley fault_lava fault_volcanic channel fault_valley THEMIS IR daytime mosaic CTX mosaic Feature Intersections – NW and SE Test Areas 300 250 200 150 100 50 Volcanic Features (D. Crown) 0 DC SS RK Total Geologic Mapping of Alba Mons, Mars Next Steps 1: • Refine feature mapping approach based on test area analyses • Complete feature mapping (fluvial, structural, and volcanic) across 1:1M-scale map areas • Build feature intersection database 500 km MOLA color hillshade (128 pxl/deg) Elevation range: -4500 – 21229 m Next Steps 2: • Map crater rims and ejecta blankets (D ≥ 5 km) • Classification of lava flow types • Morphometric analyses of drainage systems 5 km Geologic Mapping Investigations of Ceres HAMO-Based Global Geologic Mapping of Ceres Mest et al., Icarus, in preparation LAMO-Based Quadrangle Mapping of Ceres Occator Quadrangle Buczkowski et al., Icarus, in review Urvara and Yalode Quadrangles Crown et al., Icarus, in review Rongo Quadrangle Platz et al, Icarus, in review Urvara Quadrangle Yalode Quadrangle Related Studies: Nathues et al., 2017, Evolution of Occator crater on (1) Ceres, The Astronomical Journal, 153. Sizemore et al., 2017, Pitted terrains on (1) Ceres and implications for shallow subsurface volatile distribution, Geophys. Res. Lett., in review..