Mars: Fourth Order Landscapes

1. Geography 441/541 S/16 Dr. Christine M. Rodrigue Mars: Fourth Order Landscapes C.M. Rodrigue, 2016 Geography, CSULB

2. C.M. Rodrigue, 2016 Geography, CSULB Mars: 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 caps

3. C.M. Rodrigue, 2016 Geography, CSULB Mars: 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 Era

4. C.M. Rodrigue, 2016 Geography, CSULB Mars: 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 km): • They are landscapes dominated by one or two processes • Fluvial valleys • Sapping alcoves • Outwash channels • Linear fossæ • Folded and faulted mountains of Thaumasia • Lava tubes • Layered mesas • Patterned ground • Wind abraded/etched landscapes • Dune fields • Evidence of mass wasting

5. Mars: 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, 2016 Geography, CSULB

6. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly precipitation-fed overland and channelized surface flow (L to R) • Terra Sirenum • Warrego Vallis, in Thaumasia Highlands • Nanedi Vallis C.M. Rodrigue, 2016 Geography, CSULB

7. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly lake overflow channels • Ma’adim Vallis, pouring into Gusev Crater, where Spirit landed • Nanedi Vallis • Nirgal Vallis west of Chryse Trough C.M. Rodrigue, 2016 Geography, CSULB

8. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly alluvial fans and deltas • Melas C.M. Rodrigue, 2016 Geography, CSULB

9. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly alluvial fans and deltas • Eberswalde Crater near Holden Crater • Jezero Crater in Syrtis Major Planum near Isidis Planitia C.M. Rodrigue, 2016 Geography, CSULB

10. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly lake overflow channels: non-equilibrium systems • Argyre, Holden, Aram craters, Ares Vallis • Ma'adim upland lakes to Gusev? C.M. Rodrigue, 2016 Geography, CSULB

11. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly jökulhlaup-like outflows • Athabasca Valles • Ares Vallis C.M. Rodrigue, 2016 Geography, CSULB

12. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly jökulhlaup-like outflows • Ares Vallis • Aram Chaos and collapsed terrain C.M. Rodrigue, 2016 Geography, CSULB

13. Mars: Fourth Order Landscapes • Valleys dominated by fluvial processes: • Possibly jökulhlaup-like outflows • Dao, Niger, and Harmakhis valles in Hellas Planitia C.M. Rodrigue, 2016 Geography, CSULB

14. Mars: 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, 2016 Geography, CSULB

15. Mars: 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, 2016 Geography, CSULB

16. Mars: 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, 2016 Geography, CSULB

17. Mars: Fourth Order Landscapes • Alcoves, channels, aprons: • Groundwater sapping? Dry ice grain avalanche? • Fresh gullying • MGS’ Mars Orbital Camera C.M. Rodrigue, 2016 Geography, CSULB

18. Mars: Fourth Order Landscapes • Alcoves, channels, aprons: • Groundwater sapping • The triple point of water • Ways around that little issue: • Deep elevations • Fluids with lower freezing C.M. Rodrigue, 2016 Geography, CSULB

19. Mars: Fourth Order Landscapes • Linear fossæ and catenæ: • Extensional stress, faulting, downdropping of terrain between faults • Cerberus Fossæ C.M. Rodrigue, 2016 Geography, CSULB

20. Mars: Fourth Order Landscapes • Linear fossæ and catenæ: • Extensional stress, faulting, downdropping of terrain between faults • Claritas Fossæ C.M. Rodrigue, 2016 Geography, CSULB

21. Mars: Fourth Order Landscapes • Linear fossæ and catenæ: • Extensional stress, faulting, downdropping of terrain between faults • Alba Patera Fossæ C.M. Rodrigue, 2016 Geography, CSULB

22. Mars: Fourth Order Landscapes • Linear fossæ and catenæ: • Extensional stress, possibly with fluid extraction and subsidence • Tithonium Catenæ • Coprates Catenæ C.M. Rodrigue, 2016 Geography, CSULB