C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Geography 441/541 S/14 Dr. Christine M. Rodrigue

C.M. Rodrigue, 2014 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

C.M. Rodrigue, 2014 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

C.M. Rodrigue, 2014 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

C.M. Rodrigue, 2014 Geography, CSULB 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, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly precipitation-fed overland and channelized surface flow – Echus

C.M. Rodrigue, 2014 Geography, CSULB 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, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly lake overflow channels – Ma’adim Vallis, pouring into Gusev Crater, where Spirit landed – Elsewhere on Nanedi Vallis – Nirgal Vallis west of Chryse Trough

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly alluvial fans and deltas – Melas

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly alluvial fans and deltas – Eberswalde Crater near Holden Crater

C.M. Rodrigue, 2014 Geography, CSULB 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, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly jökulhlaup-like outflows – Kasei Vallis – Ares Vallis

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly jökulhlaup-like outflows – Ares Vallis – Aram Chaos and collapsed terrain

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Valleys dominated by fluvial processes: – Possibly jökulhlaup-like outflows – Dao, Niger, and Harmakhis valles in Hellas Planitia

C.M. Rodrigue, 2014 Geography, CSULB 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 km 3 ! – Picked out deposits from such an event: could fill lowest portion of north polar basin to a few 10s of m!

C.M. Rodrigue, 2014 Geography, CSULB 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, 2014 Geography, CSULB 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, 2014 Geography, CSULB Mars: Fourth Order Landscapes Alcoves, channels, aprons: – Groundwater sapping – Fresh gullying – MGS’ Mars Orbital Camera

C.M. Rodrigue, 2014 Geography, CSULB 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, 2014 Geography, CSULB Mars: Fourth Order Landscapes Linear fossæ and catenæ: – Extensional stress, faulting, downdropping of terrain between faults – Cerberus Fossæ

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Linear fossæ and catenæ: – Extensional stress, faulting, downdropping of terrain between faults – Claritas Fossæ

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Linear fossæ and catenæ: – Extensional stress, faulting, downdropping of terrain between faults – Alba Patera Fossæ

C.M. Rodrigue, 2014 Geography, CSULB Mars: Fourth Order Landscapes Linear fossæ and catenæ: – Extensional stress, possibly with fluid extraction and subsidence – Tithonium Catenæ – Coprates Catenæ