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Geography 441/541 S/14 Dr. Christine M. Rodrigue. Mars: Third Order Landscapes. Mars: Third 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
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Geography 441/541 S/14 Dr. Christine M. Rodrigue Mars: Third Order Landscapes C.M. Rodrigue, 2014 Geography, CSULB
C.M. Rodrigue, 2014 Geography, CSULB Mars: Third 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 conspicuous large features: • The largest craters: Hellas, Argyre, Isidis, Utopia • Tharsis and Elysium volcanic rises • Valles Marineris system of rifts and landslides • The polar ice caps • Syrtis Major windswept basalt plateau • Chryse Trough possible fluvial drainage system
C.M. Rodrigue, 2014 Geography, CSULB Mars: Third Order Landscapes • 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
C.M. Rodrigue, 2014 Geography, CSULB Mars: Third Order Landscapes • Noachian Era was discussed a few weeks ago • Oldest: • ~4.6 – 3.8 or 3.9 billion BP (or is it 3.5 billion?) • Earliest accretion, melting, differentiation of the planet • Era of bombardment (Earth’s Hadean times) • Intensely cratered with wide range of crater sizes • Some geomorphic erosion of craters • 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
C.M. Rodrigue, 2014 Geography, CSULB Mars: Third Order Landscapes • Hesperian Period was our last topic • Intermediate ages: • Most commonly from ~3.8 – 2.9 billion BP (or 3.5 - 1.8 billion BP) • Intense geological activity: • Shield vulcanism • Folding • Wrinkle ridges in lava covered landscapes • Faulting and formation of linear grabens in extensional zones • Gigantic outwash floods far past Noachian valley networks • Period in which climate began to dry out; dustiness increased; water evaporated, froze, sank into permafrost; acidic geochemistry • Examples: • Hesperia Planum – North Polar Deposits • Malea Planum – Isidis Planitia Basin Deposits • Lunæ Planum – Syrtis Major Planum • Chryse Planitia – Solis Planum
C.M. Rodrigue, 2014 Geography, CSULB Mars: Third Order Landscapes • Amazonian Period is this week's topic • Youngest: • Most commonly from ~3.8 – 2.9 billion BP (or even 1.8 billion BP in some usages) to present • Much more peaceful geologically: • Some vulcanism • Oxidative geochemistry dominates • Some subsurface water releases and gullying • Some meteoroids continue to smack down • May even 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
Mars: Amazonian Landscapes • Amazonis Planitia: C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Elysium Planitia: C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Elysium Planitia: Cerberus Fossæ C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Utopia surfaces C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Utopia surfaces C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Adamas Labyrinthus: ice rich, possibly glacial C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Acidalia Planitia: C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Acidalia Planitia: C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Planum Boreum: • North Polar Layered Deposits C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Planum Boreum: • North Polar Layered Deposits C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • North & South • Polar Layered Deposits C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Planum Australe: South Polar • Layered Deposits C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Planum Australe: South Polar • Layered Deposits C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Arcadia Planitia C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Arcadia Planitia • http://www.ingo-paulussen.de/pictures.htm C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Lavas of Tharsis and Dædalia C.M. Rodrigue, 2014 Geography, CSULB
Mars: Amazonian Landscapes • Lavas of Tharsis and Dædalia C.M. Rodrigue, 2014 Geography, CSULB
C.M. Rodrigue, 2014 Geography, CSULB Mars: Third Order Landscapes • 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