Lecture 1 (Intro) And some rin uphill and down dale, Knapping the chucky stones to pieces wi’...
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Transcript of Lecture 1 (Intro) And some rin uphill and down dale, Knapping the chucky stones to pieces wi’...
Lecture 1 (Intro)
And some rin uphill and down dale,Knapping the chucky stones to pieces wi’ hammers,
Like sae mony roadmakers run daft –They say it is to see how the warld was made.
- Sir Walter Raleigh
Of Igneous rocks and volcanoes
Webpage for course (daytime)
Webpage for course (nighttime)
Difference between rocks and minerals
Three types of rocks:
Minerals in igneous rock
Fig. 3.2Minerals distributed randomlyCrystals grow into one another
Continental vs. oceanic crust
Mineral composition of earth crust
Continental crust
Feldspar 58%
Chain silicates 13%
Quartz 11%
Micas (incl. clays)10%
Calcite, Gypsum,
Halite 3%
Olivine 3%
Misc. 2%
Oceanic crust
Olivine 30%
Chain silicates 30%
Plagioclase
feldspars 40%
Types of Igneous environments Volcanic (extrusive)
fine-grained
Plutonic (intrusive)
coarse-grained
Mineral compositions Continental Intermediate Oceanic
Volcan
ic Plu
tonic
Three types of volcanoes
due to mineral characteristics
Continental Composite Oceanic
shield
Three types of volcanoes
pyroclastic composite
< http://www.clas.ufl.edu/users/pciesiel/
gly3150/mt_st_helens2.gif >
< http://upload.wikimedia.org/wikipedia/commons/0/
06/Mauna_Kea_cinder_cone.jpg >
Fig. 3.14b
Fig. 3.15a
obsidian
pumice
History of a volcano
Eroded volcano – volcanic neck
http://www.destination360.com/north-america/us/wyoming/devils-tower-national-monument
Example: Devil’s Tower, Wyoming
Volcanic crater - caldera
http://www.dustydavis.com/longride/2004
Example: Crater Lake, Oregon
“Ring of Fire”
Where do composite volcanoes occur?
Fig. 4.33
Unusual volcanoes - kimberlites
http://volcano.oregonstate.edu/book/export/html/170&usg
Associated with hotspots
Unusual volcanoes - kimberlites
Loper and McCartney hypothesis of dinosaur extinction
http://www.astro.virginia.edu/class/oconnell/astr121/marsImages.html&usg