Mars: Third Order Landscapes

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C.M. Rodrigue, 2018Geography, CSULB

Geography 441/541S/18

Dr. Christine M. Rodrigue

• The “Orders of Relief” for Martian Landscapes– The first order was the great crustal dichotomy:

– Northern lowlands: ~ 1/3– Southern highlands: ~2/3– Tharsis straddling the dichotomy and covering ~1/4

– The second order was the conspicuous large features: – The largest craters: Hellas, Argyre, Isidis, Utopia– Elysium volcanic rise– Valles Marineris system of rifts and landslides– The polar ice caps– Syrtis Major windswept basalt plateau– Chryse Trough possible fluvial drainage system– Kasei Valles outflow channels

• The “Orders of Relief” for Martian Landscapes– The third order is what we're working on now:

• This is a cross-cutting category that 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 Period– The Hesperian Period– The Amazonian Period

Mars: Third Order Landscapes• Noachian Era was discussed a while back

– Oldest: – ~4.6 – 3.8 or 3.7 Ga– Earliest accretion, melting, differentiation of the planet– Era of bombardment (Earth’s Hadæan times)– Establishment of and shutting down of planetary magnetic field– Some geological activity:

– Valley networks– Volcanic activity (low viscosity flows, small pateræ)– Oceans?

– Examples:– Noachis Terra – Terra Tyrrhena– Aonia Terra – Terra Sabæa– Terra Sirenum – Margaritifer Terra– Terra Cimmeria – Xanthe Terra– Promethei Terra –Tempe Terra

Mars: Third Order Landscapes• Hesperian Period was our last topic

– Intermediate ages: – Most commonly from ~3.75 – 2.9 billion Ga– Intense geological activity:

– Edifice vulcanism, eventually shield vulcanism– Folding and wrinkle ridges (compression)– Faulting and formation of linear grabens in extensional zones – Gigantic outwash floods far past Noachian valley network scale

– Period in which climate began to dry out; dustiness increased; water evaporated, froze, sank into permafrost; acidic geochemistry

– Examples:– Hesperia Planum – Vastitas Borealis– Malea Planum – Isidis Planitia Basin Deposits– Lunæ Planum – Syrtis Major Planum– Chryse Planitia – Solis Planum– Sisyphi Planum – Argentea Planum

Mars: Third Order Landscapes• Amazonian Period is our newest topic

– Youngest: – Most commonly from ~3.0 – 2.9 Ga to present– Much more peaceful geologically:

– Shield vulcanism winds down– Oxidative geochemistry dominates– Some subsurface water releases and gullying– Some meteoroids continue to smack down– May be obliquity-related ice ages– Extent and recency of these are energetically debated

– Examples:– Amazonis Planitia – Arcadia Planitia– Utopia Planitia – Elysium Planitia– Dædalia Planum – North and South Polar Deposits– Acidalia Planitia – Lava flows on Tharsis & Elysium rises

Amazonian Landscapes Amazonis Planitia:

Amazonian Landscapes

Amazonis Planitia:MRO HiRISE

Amazonian Landscapes Elysium Planitia:

Elysium Planitia: – pack ice? MEX

HRSC →

– Rahway Vallis \

Elysium Planitia: Cerberus Fossæ

Amazonian Landscapes Utopia Planitia floor:

Utopia surfaces

Amazonian Landscapes Utopia surfaces

Amazonian Landscapes Acidalia Planitia:

Acidalia Planitia:

Amazonian Landscapes Acidalia Planitia:

Planum Boreum: North Polar Layered Deposits

(SHARAD)

Planum Boreum: North Polar Layered Deposits

(HiRISE)

North & South Polar Layered Deposits

Planum Australe: South Polar Layered Deposits

Planum Australe: South Polar Layered Deposits (HRSC)

Planum Australe: South Polar Layered Deposits (HiRISE)

Amazonian Landscapes Arcadia Planitia:

Arcadia Planitia

Arcadia Planitiahttp://www.ingo-paulussen.de/pictures.htm

Amazonian Landscapes Lavas of Tharsis:

Lavas of Tharsis and Dædalia

Amazonian Landscapes Lavas of Elysium:

Lavas of Elysium Rise

Amazonian Landscapes Lavas of Elysium Rise

• The “Orders of Relief” for Martian Landscapes– Thus concludes our consideration of third order

landscapes:• These are large regions that are subtly different from one

another, marked by differences in crater density, crater alteration, and geomorphic evidence of processes that dominated particular periods on Mars

• I used this scale to discuss and illustrate the three major periods of Mars' geological history– The Noachian Period– The Hesperian Period– The Amazonian Period

– On to the finer scale features of the fourth order

Mars: Third Order Landscapes

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