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Environmental Geology (Geol-102) is a 3-unit college transfer course that
deals with the geological aspects of human interaction with the earth and
satisfies the general education requirement in physical sciences for most baccalaureate programs in North America.

 

Volcanism

 

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Terrestrial and extraterrestrial volcanism:

 
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Extraterrestrial Volcanism

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Basaltic Volcanism on the Terrestrial Planets

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Active Volcanism On Mars

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Volcanism on Mars

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Volcanism on Venus

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Volcanism on the Moon

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Jupiter’s Volcanic Moon
 
bullet Large Igneous Provinces


or LIPs are voluminous emplacements of predominantly mafic extrusive and intrusive rock whose origins lie in processes other than 'normal' seafloor spreading. LIPs include continental flood basalts and associated intrusive rocks, volcanic passive margins, oceanic plateaus, submarine ridges, seamount groups, and ocean basin flood basalts. Click on this map of LIPs, shown below, to read about the research on LIPs.
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Notable LIPs on Land

 The most notable of continental flood basalts and flood basalt provinces are:

 
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Columbia River Basalts (~15 Ma),

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Ethiopian Traps (~38 Na),

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Deccan Traps (~65 Ma),

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Parana/Serra Geral lavas (~135 Ma),

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Karoo/Stromberg, Patagonian and Ferrar lavas (~180 Ma),

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Siberian Traps (~250 Ma), and

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Keweenawan Lavas (~1,250 Ma).
 

 

Explore Volcano World at the URL: http://volcano.und.nodak.edu/vw.html. Also available on-line,at http://adsbit.harvard.edu/books/bvtp/toc.html is the treatise: Basaltic Volcanism on the Terrestrial Planets. For extra-terrestrial volcanism, try the URL: http://pubs.usgs.gov/gip/volc/extraterrestrial.html

  
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Other Kinds of Volcanism:
 
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Spreading Submarine Ridges:
 

Spreading submarine ridges and rises (e.g., Reykjanes/ Mid-Atlantic Ridge, East Pacific Rise, hydrothermal vents) and associated volcanic islands (e.g., Iceland).
 

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Volcanism at the Subduction Zones


 Convergent plate margins  have volcanism towards the edge of the plate that is being subducted (e.g., Cascade Ranges and the Pacific “Ring of Fire”)..

 

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'Hot Spots' and Aseismic Ridges:

 

Intra-plate or “hot-spot” volcanism (e.g., Hawaii-Emperor Seamounts, Yellowstone-Snake River volcanics)
     
The sketch alongside, taken from the URL: http://vulcan.wr.usgs.gov/Glossary/Plate
Tectonics/Maps/map_juan_de_fuca_subduction.html explains the entire cycle of volcanism from Juan de Fuca Ridge to Juan de Fuca subduction (i.e., the Filled Trench) and the Cascades.
     

 

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Volcanic materials/products and rock classification:
 

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Volcanic Rocks:

Increasing order of silica (SiO2) content,
from silica-rich rhyolite at one end and the more common basalt at the other, with the compositionally intermediate andesite denoting crustal contamination of the
magma on its passage through the crust.  

Why andesites on Mars, then?

  
     
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Other products :

 

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Cinder cones/ Pyroclastics (Ash, Cinders, Blocks/Bombs, Lahars)

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Gases and Gas Clouds: Nuees Ardentes, Toxics, Climate Change

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Other materials: Pyroclasts, Volcanic Breccia

 

  
bullet Textures of Volcanic Rocks:
 
bullet Glassy (Obsidian),
bullet Vesicular (Scoria, Pumice),
bullet Aphanitic (Andesite, Basalt, Rhyolite),
bullet Porphyritic (Andesite Porphyry, Basalt Porphyry, and Rhyolite Porphyry).

Visit the USGS volcanoe sites, starting with http://volcanoes.usgs.gov/ and its links

Also try the site: http://interactive2.usgs.gov/learningweb/explorer/topic_rocks_igneous.htm

Basalt

 Andesite

Rhyolite
     
bulletVolcanic Precursors and/or Predictors?
 
bulletSeismicity (Harmonic Tremors?)
bulletBulging or Uptilting?
bullet Exotic Gas Emanations?

Volcanism and Climate

Try http://www.etl.noaa.gov/about/review/aq/post for a comparison of the climate effects of Mt. Pinatubo and El Chichon events.

 

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Is Volcanism Predictable?
 

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Browse USGS Case Study from Kilauea and Mount
St. Helens volcanoes at the URL: http://volcanoes.usgs.gov/edu/predict/

 
American Geophysical Union has an interesting discussion of terrestrial degassing at the URL: http://www.agu.org/sci_soc/eosvarekamp.html.

Also try the URL: http://unr.edu/homepage/fbiondi/BiondiFessenden1999E.pdf
bulletOther Links:
 
bullet WorldWide Volcanism Links
bullet Submarine volcanism home page at the Monterey Bay Aquarius Research Institute
bullet NOAA Ocean Explorer: Submarine Ring of Fire
bullet Flood-Basalt Volcanism
bullet Volcanism and Climate: A Comparison of the Mt. Pinatubo and El Chichon events
bullet USGS Photo Glossary on Volcanic rocks
bullet Minerals, Magmas and Volcanic Rocks
bullet This "USGS Volcano Hazards Program" site leads you to all the information you would need about volcanoes, volcanism and volcanic rocks
 
bulletAccess here the home page of Smithsonian Institution's Global Volcanism Project with links to
 
bullet Catalog of volcanoes active during the last 10,000 years
bullet Smithsonian reports of current activity since 1968
bullet Links to other volcanology resources on the Web

 

bulletTry the following links for interesting presentations on the rock cycle shown alongside:
 
bullet http://www.bbc.co.uk/education/rocks/rockcycle.shtml
bullet http://www.intel.com/education/unitplans/rockcycle/rock.htm
bullet http://www.moorlandschool.co.uk/earth/rockcycle.htm