The Fire Within Plate Tectonics Volcanism Across the

The Fire Within: Plate Tectonics & Volcanism Across the Solar System By the Lunar and Planetary Institute USGS Photo by B. Chouet For Use In Teacher Workshops

What’s a Rock? What are the Main Rock Types? How Do They Form? How Do You Tell One from Another?

Igneous n All igneous rocks cool and crystallize from magma or lava n or consolidate from pyroclastic materials n Magma is molten material below the surface n Lava is molten material on the surface n Pyroclastic materials are particles such as volcanic ash n

Metamorphic n Changes in minerals, texture, and/or chemical composition of a rock that result from changes in temperature and pressure … like burial, contact with hot stuff, extreme crunching … n No melting! Photo by J. P. Lockwood. Figure 24 -B, U. S. Geological Survey Bulletin 1595.

Sedimentary Clastic Sedimentary Rocks Carbonate / Other Sedimentary Rocks Sediment particles (skeletal, rock fragment, mineral, plant particles) derived from erosion (breakdown / transport) of rock that are lithified (cemented or compacted) Chemical precipitates (halite) or biologically - produced (organic) material (shell fragments). In-situ. Images from http: //wrgis. wr. usgs. gov/parks/rxmin/rock 2. html

What is the Rock Cycle?

From USGS at http: //3 dparks. wr. usgs. gov/nyc/images/fig 6. jpg

Igneous Part of the Rock Cycle From USGS at http: //3 dparks. wr. usgs. gov/nyc/images/fig 6. jpg

Igneous Rocks n All igneous rocks cool and crystallize from magma or lava n or consolidate from pyroclastic materials n Magma is molten material below the surface n Lava is molten material on the surface n Pyroclastic materials are particles such as volcanic ash n

Identifying Igneous Rocks n Step 1. Is it an igneous rock? Interlocking randomly oriented crystals? Published as figure 14 in U. S. Geological Survey. Bulletin 1595. 1987

Identifying Igneous Rocks n Extrusive or volcanic rocks n n form at the surface from lava or pyroclastic materials Intrusive or plutonic rocks n form from magma in the crust

Identifying Igneous Rocks n Igneous rocks have 4 textures n n determined by the cooling rate of magma or lava Texture n size, shape and arrangement of crystals in a rock

4 Cooling-Rate Textures n Phaneritic – Coarse Grained (Intrusive) n n Aphanitic – Fine Grained (Extrusive) n n visible grains, cooled slowly with grains too small to see, cooled quickly Porphyritic – (Extrusive) n with larger grains surrounded by a finergrained groundmass n cooled n slowly first, then more quickly Glassy n with no grains n cooled too quickly for minerals to grow

Igneous Rock Textures n Also vesicular texture, with holes (vesicles) n n indicates the rock formed as water vapor and other gases became trapped during cooling of lava Pyroclastic or fragmental texture n containing fragments formed by consolidation of volcanic ash or other pyroclastic material

Identifying Igneous Rocks n Step 2. Coarse grained or fine grained? (Porphyritic or Aphanitic) From the USGS photo glossary of volcanic terms

Igneous Rocks n Texture and composition are the criteria used to classify most igneous rocks n Composition categories are based on silica content felsic (>65% silica) n intermediate (53 -65% silica) n mafic (45 -52% silica) n

Identifying Igneous Rocks n Step 3. Light or Dark? … Composition Hints Images from USGS Photo Library

Identifying Igneous Rocks n Step 4. What minerals present? Quartz – gray opaque, concoidal fracture K-Spar - pink Plagioclase feldspar – white to gray Muscovite – light, flakey Biotite – dark, flakey Pyroxene - LBM Amphibole - LBM USGS Mineral Specimen Photography: Bureau of Mines, ___ and Mineral collection of Bringham Young University Department of Geology, Provo, Utah

Igneous Rock Classification Diagram by staff of LPI

A Classification of Igneous Rocks Cooling History / Texture Mafic and Dark Color Slow Cooling and Coarse Grained Fast Cooling and Fine Grained Gabbro Basalt Very Fast Cooling and Glassy/Cellular Scoria Intermediate in composition and color Diorite Andesite Felsic and Light Color Granite Rhyolite Pumice and Obsidian

Green sand beach – why green? Image courtesy of Alison Henning, Rice University

Volcanoes! Lassen Volcanic National Park, CA Image from http: //photo. itc. nps. gov/storage/images/lavo-Full. 00005. html

Volcanic Deposits Shape depends on composition of magma… Basaltic Andesitic Rhyolitic …and gas content … and number and size of eruptions … and the environment of eruption http: //volcanoes. usgs. gov/Hazards/What/hazards. html

Volcanic Deposits http: //volcanoes. usgs. gov/Products/Pglossary/basalt. html

Why does silica matter? n Si - O bonds much stronger than others n In lava, single silica tetrahedra flow easily, like little balls In lava, large silicate polymers flow poorly, like noodles n Diagram by staff of LPI

Basaltic Lava n High temperature (1000 -1200 C) n Lower silica content n Extremely fluid Images courtesy of Alison Henning, Rice University

Basaltic Lava n Flood basalts – huge plateaus (e. g. Columbia Plateau of Washington and Oregon) n Pahoehoe and aa – ropy vs. jagged blocks (e. g. Hawaiian volcanoes) n Pillow lavas – ellipsoidal, cool underwater Images from USGS Photo Glossary of Volcano Terms

Rhyolitic Lava n Most felsic, light in color n Higher silica content n Lower melting point than basalt. Erupts at 8001000 C n Moves 10 X more slowly than basalt n Tends to be explosive – more gas (water) content USGS Photo Glossary of Volcano Terms

Gas Content n Magma rises close to surface, pressure drops n Volatiles released with explosive force n Explosive eruptions most likely with gas-rich, viscous rhyolitic andesitic magmas n Pyroclasts – rock material ejected into air Image courtesy of Alison Henning, Rice University

Volcanic Landforms n Shield volcanoes – Mauna Loa n n n Big Broad, Low Slope Properties of lava? Number of flows? Types of rocks? Image from http: //hvo. wr. usgs. gov/maunaloa/

Volcanic Landforms Lava Plateau n Extensive n Stacked flows n Virtually no slope n n Properties of lava? Number of flows? Type of rock? Photo from http: //en. wikipedia. org/wiki/Image: 3 -Devils-grade-Moses-Coulee-Cattle-Feed-Lot-PB 110016. JPG

Columbia Plateau 130, 000 Km 2 x 1. 5 km thick Buried topography ~16 Ma

n n n Cinder Cones Small Steep slope (30 o) Basaltic … hmmmm Properties of lava? Number of flows? Types of rocks? USGS image Volcanic Landforms USGS Photo by K. Segerstrom NPS image from Capulin, NM

n Small n Few events n Flanks of Mauna Kea n Common on shield volcano flanks USGS Photo Glossary of Volcano Terms

Volcanic Landforms n n n Composite Volcano Big High slope (30 o) Made of multiple lava and ash flows Explosive USGS Photo Glossary of Volcano Terms Properties of lava? Number of flows? Types of rocks?

Composite Volcano - Mt St Helens Images from http: //vulcan. wr. usgs. gov/Volcanoes/MSH/Slide. Set/ljt_slideset. html

Pinatubo USGS photo by Dave Harlow

Volcanic Landform n n Dome Small Steep slope Properties of lava? Number of flows? Type of rock?

Foreshadowing … Patterns to where types of volcanos occur?

If a planet has active volcanos, what do we know about the planet? NASA/JPL/NGA image from http: //photojournal. jpl. nasa. gov/catalog/PIA 06668

Where Does the Heat Come From? Hubble Image from http: //hubblesite. org/newscenter/archive/releases/1998/38/image/a/

Where Does the Heat Come From? (Terrestrial Planets) Image by LPI: http: //solarsystem. nasa. gov/multimedia/display. cfm? IM_ID=168 Originally: n Impacts (accretion), differentiation, radioactive decay Presently: n Mostly radioactive decay

What Evidence Suggests Volcanism on Other Planets? NASA image at http: //photojournal. jpl. nasa. gov/catalog/pia 00254

Past • Mercury, Venus, Earth, Moon, Mars, Io, Titan Presently Photo montage from http: //solarsystem. nasa. gov/multimedia/display. cfm? IM_ID=2167 • Earth, Io, Enceledus, Triton • Probably Venus and Mars What Planets Are / Have Been Volcanically Active?

Image: Lunar and Planetary Laboratory: http: //solarsystem. nasa. gov/multimedia/display. cfm? IM_ID=178 Why Might a Planet Have Ceased Being Volcanically Active?

Our Moon What do you observe? Image at http: //www. lpi. usra. edu/education/timeline/gallery/slide_61. html

Big Impact Basins Filled by Lava Mare Imbrium Apollo image from http: //www. lpi. usra. edu/expmoon/Apollo 15/A 15_Photography_orbital. html Volcanism after impacts – most before 3 Ga (to 1 Ga)

Fissure Eruption Courtesy of USGS. http: //www. geology. sdsu. edu/how_volcanoes_work/Thumblinks/Puuoorift_page. html

Lunar Basalts 15555 Apollo image from http: //curator. jsc. nasa. gov/lunar/compendium. cfm 15016 Apollo image at http: //www. lpi. usra. edu/expmoon/Apollo 15/A 15_Basalt. FS. gif 3. 3 Billion Years Old

Lunar Volcanism Aristarchus Photo of Aristarchus Plateau at Plateau http: //lunar. gsfc. nasa. gov/images/gallery/2 Craters_br-browse. jpg Marius http: //history. nasa. gov/SP-168/section 2 b. htm Hills photo by Lunar Orbiter V at

Mercury n n Tons of Craters Some Flat Plains … hmmmmmm… Only ~ 1/3 imaged Messenger spacecraft on its way to orbit! Image: http: //www. lpi. usra. edu/publications/slidesets/ss_tour/slide_2. html

Craters and Plains 500 km Mariner image at http: //photojournal. jpl. nasa. gov/catalog/PIA 02948

Venus Magellan image from http: //antwrp. gsfc. nasa. gov/apod/ap 020330. html

Venera Images - 1982 Image: http: //www. lpi. usra. edu/publications/slidesets/ss_tour/slide_5. html

Sapas Mons – 1. 5 km high, 400 km across Atla Regio Magellan image at http: //www 2. jpl. nasa. gov/magellan/image 28. html

Maat Mons – 8 km high, Aphrodite Terra Region Magellan color image at http: //solarsystem. nasa. gov/multimedia/display. cfm? IM_ID=2085 Courtesy of David P. Anderson (Southern Methodist University) Image at http: //www. lpi. usra. edu/publications/slidesets/venus/slide_21. html

Pancake Domes n n Single Flows, Steep sides Height 1/2 - 1 km. n n What kind of volcano? What kind of lava? NASA Image from LPI: http: //www. lpi. usra. edu/publications/slidesets/venus/slide_24. html

Pancake Domes n n Rhyolite? Or merely cold, crystal-rich basalt? USGS photo by R. A. Bailey n n What kind of volcano? What kind of lava?

What’s missing? Few impact craters – what does this tell us? No craters less than 3 km (meteoroid ~ 30 m across) Atmospheric filter Magellan image from http: //antwrp. gsfc. nasa. gov/apod/ap 020330. html

Mars n dfldjfkdkfj MOLA image from http: //pds-geosciences. wustl. edu/missions/mgs/mola. html

Olympus Mons TALLEST Volcano in the Solar System 24 km high 550 -600 km across Mauna Loa 9 km high (sea floor) 120 km across (base) Lava flows in last million years? Viking image at http: //photojournal. jpl. nasa. gov/catalog/PIA 02982

Mars LPI image at http: //www. lpi. usra. edu/publications/slidesets/hawaiivolcanoes/slidespages/slide_01. html

LPI image at http: //www. lpi. usra. edu/publications/slidesets/redplanet 2/slide_10. html

Mars n n Olympus Mons Image overlain on topography and vertically exaggerated 10 x MOLA image at http: //photojournal. jpl. nasa. gov/catalog/PIA 02806

Mars Express images from http: //www. esa. int/esa. MI/Mars_Express/SEMKC 2 W 4 QWD_0. html And http: //www. esa. int/esa-mmg/mmg. pl? b=b&keyword=Olympus%20 Mons%203 D&single=y&start=5

On Syrtis Major - Shield Volcano USGS image at http: //wrgis. wr. usgs. gov/fact-sheet/fs 024 -02/ Themis image at http: //themis. la. asu. edu/zoom-20030514 a. html Broken Cinder Cone?

Why Might a Planet Have Ceased Being Volcanically Active?

Hubble

Io NASA Gallileo Image at: http: //www. lpi. usra. edu/publications/slidesets/ss_tour/slide_23. html

Io • • • About the size of our Noon HOT – tidal friction Lots of Sulfur Voyager detected Yellow-brown color Silicate lava – crust is silicate in nature (strong; supports high mountains and deep crevasses; lava flows at temps too high for S) NASA Gallileo Image at: http: //www. lpi. usra. edu/publications/slidesets/ss_tour/slide_23. html

Io Galileo Image Tvashtar Catena NASA Galileo image at: http: //photojournal. jpl. nasa. gov/catalog/PIA 02584

Io Amirani Lava Flow – Galileo Image Largest active flow in solar system (~200 -300 km) Galileo image from http: //photojournal. jpl. nasa. gov/catalog/PIA 03533

• Plumes of sulfur / sulfur dioxide • Long-lived (months) • Geysers • High – lack of atmospheric pressure and low gravity • Old Faithful – 35 km high if on Io Voyager image at http: //photojournal. jpl. nasa. gov/catalog/PIA 01971 Io

New Horizons flew past Io in late February 2007 New Horizons photos at http: //pluto. jhuapl. edu/gallery/mission. Photos/pages/022707_1. htm l