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C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Great Crustal Dichotomy Geography 441/541 S/14 Dr. Christine M. Rodrigue.

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Presentation on theme: "C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Great Crustal Dichotomy Geography 441/541 S/14 Dr. Christine M. Rodrigue."— Presentation transcript:

1 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Great Crustal Dichotomy Geography 441/541 S/14 Dr. Christine M. Rodrigue

2 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes

3 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes

4 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – On Earth, the orders of relief scheme Is sometimes seen in geography textbooks Organizes topographic variation in a scale-dependent manner Geographers often focus on _ Spatial analysis of particular phenomena _ Regional synthesis to integrate assemblages of phenomena _ Scales at which processes and regional patterns operate _ The interactions among phenomena at different scales

5 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Examples of interactions among scales _ In spatial statistics: the Modifiable Areal Unit Problem (MAUP) _ In human geography: local cultural and political responses to global economic and political processes _ Biogeography: alpha, beta, and gamma measures of biodiversity _ Geomorphology: "megageomorphology" has emerged as remote sensing technology has made the simultaneous examination of form and process at large scale (small map scale) possible

6 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – For Mars, a handy descriptive scheme for handling the regional variations in Mars physical landscapes The First Order of Relief = the crustal dichotomy The northern lowlands: Vastitas Borealis The southern highlands If Earths oceans evaporated (which they will …), there would remain a crustal dichotomy here Former ocean basins: low elevation, thin crust, basaltic, with a veneer of pelagic sediments Former continents: high elevation, thick crust, granitic rocks and their extrusive igneous, sedimentary, and metamorphic derivatives

7 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Regional subdivisions: _ Utopia Planitia _ North Polar Basin _ Embayments: _ Acidalia Planitia _ Chryse Planitia _ Amazonis Planitia _ Arcadia Planitia _ Isidis Planitia

8 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Relatively young surface – Smooth with few craters – This is exactly what youd expect if Mars had had an ocean _ It could be expected to receive sediments from rivers, floods, and coastal processes and create terrigenous sediments nearshore _ They would be turned into minerals that would eventually precipitate out of the water column onto the abyssal floor _ The oceans would thus cover the underlying original rock surface, much as pelagic sediments here do

9 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Further suggestions of an ocean: _ Drainage of Martian outflow channels and valley networks _ This is also exactly what youd expect if Mars had had an ocean to serve as base level for stream networks

10 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Drainage: _ Valles Marineris' outflow channels, which drain into Chryse Planitia _ Nanedis north of Ganges _ Ares and Aram Chaos _ Argyre to Aram and Ares

11 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes

12 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Even better: Coastlines!? – Transition between the southern highlands and the northern lowlands is quite abrupt

13 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes

14 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Even better: Coastlines!? – Terraces on the Arcadia side of Alba Patera

15 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Even better: Coastlines!? – Tim Parkers analysis of Viking imagery

16 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Even better: Coastlines!? _ Tim Parkers analysis of Viking imagery (1994) _ His and others re-analysis using MOC imagery seemed to debunk his argument, which even he admitted in 2001 _ But its as though the new imagery is so fine in resolution that it cant detect the coarser scale at which this putative oceans coastline features might exist _ MOLA suggests that, in fact, at least one of the coastlines is at the same elevation (water seeks a level constant with respect to the geoid)

17 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Plot complication _ That "ocean" floor is dominated by andesitic rock _ Not sediments with minerologies consistent with precipitation out of water. _ No carbonates! No ocean?

18 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis About those andesites _ "Surface Type 1" (basalts dominating the southern highlands) _ "Surface Type 2" (andesites and andesitic basalts dominating the northern lowlands)

19 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes

20 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Vastitas Borealis Rampart craters

21 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – The Southern Highlands _ Mostly 1-5 km above the mean Martian geoid _ Versus 0-3 km below for the northern lowlands _ Sharp ~1 km scarp dividing the two

22 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Arabia Terra

23 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain _ Noachis Terra is another old land (for which Noachian era named) _ West of Hellas, east of Argyre _ Signs of water or fluid _ Channels _ Softened terrain

24 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Hellas, with Isidis and Utopia from the Northern Lowlands beyond

25 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Noachis Terra, Holden Crater, Vallis Uzboi

26 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Noachis Terra, Holden Crater, alluvial fan/bajada?

27 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Syrtis Major Planum, volcanic province, basaltic, not dusty

28 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Terra Tyrrhena, battered basalt, fluvial dissection, mineral precipitation (sulfates?), wind deposition

29 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Promethei Terra, east of Hellas, basaltic, landslides, dust devils

30 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Cimmeria Terra, basaltic, cratered, E of Hellas, S of Elysium, SW of Tharsis, Maadim Valles

31 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Ancient, battered terrain Margaritifer Terra, basaltic, cratered, fluvial alteration, chaos terrain, east of Valles Marineris outflow, west of Meridiani

32 C.M. Rodrigue, 2014 Geography, CSULB Mars: First Order Landscapes The Orders of Relief for Martian Landscapes – Basalt terrain and dust dominate the Southern Highlands _ Spectra showing high proportions of basalt shown in the green _ Andesite shown in the red channel _ Hæmatite shown in blue (small area) _ Dust-dominated areas come out brown


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