Mars: Fourth Order LandscapesSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Mars: Fourth Order LandscapesSlide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42C.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesGeography 494-01S/07Dr. Christine M. RodrigueC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesThe “Orders of Relief” for Martian LandscapesThe first order was the great crustal dichotomy:Northern lowlands: ~ 1/3Southern highlands: ~2/3The second order was the large regional features: Tharsis and Elysium risesThe largest craters: Hellas, Argyre, Isidis, UtopiaValles MarinerisThe polar ice capsC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesThe “Orders of Relief” for Martian LandscapesThe third order was the somewhat smaller major regions associated with the araeological eras:In many ways, this is a cross-cutting categoryIt addresses the “geological column” or relative ages of all Martian landscapes in terms of the three regional units that gave the three-part sequences of Mars’ evolution their names:The Noachian EraThe Hesperian EraThe Amazonian EraC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesThe “Orders of Relief” for Martian LandscapesThe fourth order is “in order” now:These are smaller features (a few kilometers to a few hundred):They are landscapes dominated by one or two processesFluvial valleys Sapping alcoves Linear fossæFolded and faulted mountains of ThaumasiaLava tubes Layered mesas Patterned ground Dune fields Evidence of mass wastingC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly precipitation-fed overland and channelized surface flowEchus Chasma (Mars Odyssey Themis)Echus Chasma (Mars Express)C.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly precipitation-fed overland and channelized surface flowEchusC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly alluvial fans and deltasMelasC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly alluvial fans and deltasEberswalde Crater near Holden CraterC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly lake overflow channelsMa’adim Vallis, pouring into Gusev Crater, where Spirit landedC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly lake overflow channelsArgyre, Holden, Aram craters and Ares VallisNirgal Vallis tributary to that waterway, which still shows signs of water releasesC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly jökulhlaup-like outflowsKasei VallisAres VallisC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly jökulhlaup-like outflowsAres VallisAram Chaos and collapsed terrainC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly jökulhlaup-like outflowsDao, Niger, and Harmakhis valles in Hellas PlanitiaC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesValleys dominated by fluvial processes:Possibly jökulhlaup-like outflowsChasma BorealisKathryn Fischbaugh and James Head created a topographic map and profiles and used them to estimate volume of a catastrophic melt (perhaps subsurface vulcanism): 26,000 km3!Picked out deposits from such an event: could fill lowest portion of north polar basin to a few 10s of m!C.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesAlcoves, channels, aprons:Groundwater sappingEarth on right: Mt. St. HelensMartian crater gully on left: MGS’ Mars Orbital Camera (~-55 at 18)C.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesAlcoves, channels, aprons:Groundwater sappingEarth on top: sides of Houghton Crater, Devon Island, Canada North of Baffin IslandOnly Earth crater on a polar desert surfaceSite of NASA-Houghton ProjectMartian crater gully on left: MGS’ Mars Orbital Camera (where?)C.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesAlcoves, channels, aprons:Groundwater sappingFresh gullyingMGS’ Mars Orbital CameraC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesAlcoves, channels, aprons:Groundwater sappingThe triple point of waterC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLinear fossæ and catenæ:Extensional stress, faulting, downdropping of terrain between faultsCerberus FossæC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLinear fossæ and catenæ:Extensional stress, faulting, downdropping of terrain between faultsClaritas FossæC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLinear fossæ and catenæ:Extensional stress, faulting, downdropping of terrain between faultsAlba Patera FossæC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLinear fossæ and catenæ:Extensional stress, possibly with fluid extraction and subsidenceTithonium CatenæCoprates CatenæC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLinear fossæ and catenæ:Secondary cratering from a primary impact eventTHEMIS, +19 at 348 (Trouvelot Crater)MOC, +16 at 325Maybe a single object breaking up before hitting?MRO image of Candor Chasma wall with this weird chain cutting across at an angle to gravityC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesFolded and Faulted Mountains:Grabens and foldsThaumasiaC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLava Tubes:Lava flows under a crust, which may collapsePavonisCheck out catenaC.M. Rodrigue, 2007Geography, CSULBMars: Fourth Order LandscapesLayered Mensæ:Resistant caprocks protect less resistant