Planetary Geology. Geology Colloquium. Tucker County Research Assistants

Transcription

1 Planetary Geology Geology Colloquium Dr. Peter Sak, Dickinson College Interseismic Coupling, Quaternary Uplift Rates, and Fore Arc Deformation along the Costa Rican Segment of the Middle American Trench Thursday 4/ snacks, 400 talk 310 White Hall Tucker County Research Assistants Beau Downing & Kory Konsoer taking group out at 10:00 on Monday 1

2 Light Web Based Reading Assignment for today: Susan Reichley, undated, Water: Life's Elixir in the Solar System, URL: Jet Propulsion Laboratory, National Aeronautics and Space Administration, California Institute of Technology, 4 web pages. Sun Relative Size of All 9 Planets 4 Terrestrial Planets 4 Jovian Planets Pluto 2

3 Distance from Sun Terrestrial Planets Comets Ort Cloud Jovian Planets Asteroid Belt Characteristics of Planets in Our Solar System Terrestrial Planets Jovian Planets Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Diam Mass Density Moons ? Rings no no no no yes yes yes yes no Craters many few few some no no no no yes? Updated 2004 from NASA data & Update Characteristics of Planets in Our Solar System Terrestrial Planets Jovian Planets Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto Diam Mass Density Moons ? Rings no no no no yes yes yes yes no Craters many few few some no no no no yes? Updated 2004 from NASA data & Update 3

4 Earth Oldest Mineral: 4.4 BY Oldest Rock: 3.8 BY Oldest Ocean: ~200 MY Oldest Landforms: <50 MY?? Antarctic View of Earth Oldest Mineral: 4.4 BY Oldest Rock: 3.8 BY Oldest Ocean: ~200 MY Oldest Landforms: <50 MY?? What will be the last evidence of human beings? Last Evidence of Humankind Left on the Lunar Surface 4

5 Earth s Moon Mare Major Landforms Types: Impact Craters (Breccia) Mare (Basalt) Highlands (Anorthosite = Gabbro) Highlands Highlands BY Lunar Surface Mare BY Rill = Collapsed Lava Tube Impact Craters Impact Craters Ejecta 5

6 Large Lunar Impact Crater Central Upland Rim Ejecta Blanket Generic Terrestrial Planet History Accretion Rapid Contraction, Heating, Outgassing Magma Ocean ~100,000,000 years Slow Contraction, Heat Loss Fractionation into Crust, Mantle, Core (Continued Impacts-Breccias) Partial Melting, Volcanoes, Plate Tectonics Larger Planets: Active Longer Mercury 6

7 Venus Sister Planets? Not! Two Views of Venus Visual RADAR 7

8 Venus Topography Akna Mountains Folded Mountain Belt? 200 km X 125 km Artemis Corona Possible Subduction Zone & Magmatic Arc 2000 km diameter 6 vertical km chasma to rim 8

9 Maat Mons volcano & Lava Flow Venus Landscape on an Impossibly Clear Day Domes Near Alpha Regio 25 km diam. 750 m high 9

10 Wind Streaks 35 km long Volcano = 5 km diam Mead Crater Wind Streaks Surface From Venera 13 10

11 Mars Vallis Marinaris Mars Topography 11

12 Map of Martian Impact Craters >100 km Diameter Martian Surface Ages Amazonian by Noachian by Hesperian by 12

13 Cratered Highlands Cratered Highlands Same Imaged, But Rotated to Show Shadow Effect Mass Wasting 13

14 Tyrrhena Petera Ceraunius & Uranius Tholi Ulysses Patera Volcano with Impact Craters 14

15 Ulysses Patera Mars Topography Tharsis Volcanoes 15

16 Olympus Mons Solar System s Largest Volcano Basaltic? Shield Volcano Polar Ice Sheet Map of Channels 16

17 Dendritic Channels Martian Meanders JSK: Debris Flow or Avalanche Tracks Feeding Debris Cones that Lap Over Megaripples Gullies in Nirgal Vallis, Mars Next Slide: Source Info & Discussion by Malin Science Center 17

18 Gullies in Nirgal Vallis, Mars Mars Global Surveyor Mars Orbiter Camera Release No. MOC2-535, 5 November 2003 This is a Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) narrow angle image of gullies carved into debris on the south-facing wall of Nirgal Vallis, an ancient martian valley. The gullies were conduits for sediment that has accumulated at a point where each channel met the valley floor. The aprons of debris are superposed upon the large ripple-like dunes, suggesting that the gullies are younger than these bedforms. Gullies such as these might have been formed by a liquid, such as water, seeping from the layered bedrock exposed in the valley wall, or perhaps by mass movement of the smooth-surfaced debris that covers much of the lower two-thirds of the valley wall. Image is located near 28.6 S, 41.5 W, and covers an area 3 km (1.9 mi) across, illuminated by sunlight from the upper left. 18