Download Rocks and Minerals II

Rocks and Minerals II
http://www.geology.wisc.edu/~maher/air/air14.htm
Rock Types
• Igneous
• Sedimentary
• Metamorphic
Rock Types - Igneous
• Igneous means “formed from fire”
• Rocks formed by cooling and
crystallization of molten material called
magma
• Shows interlocking crystal grains with
sharp edges (some may have to be seen
using a hand lens or microscope)
Rock Types - Igneous
Granite
Gabbro
http://seis.natsci.csulb.edu/basicgeo/GRANITE/Granitic_Minerals.jpeg
http://seis.natsci.csulb.edu/basicgeo/GABBRO/gabbro_handsample_labelle.jpeg
Obsidian
Lunar basalt
http://volcanoes.usgs.gov/Products/Pglossary/obsidian.html
http://www.lpi.usra.edu/expmoon/Apollo15/A15_BasaltFS.gif
Rock Types - Sedimentary
• Rock formed from accumulation of
weathered materials (sediments)
• May contain fossils; may show layering;
may have a conglomerate nature with
rounded particles or cementation evident;
may contain only one mineral as a result
of chemical deposition
• Generally dull in appearance
Rock Types - Sedimentary
fossiliferous rock
http://physics.uwstout.edu/geo/gallery
http://www2.vscc.cc.tn.us/svinson/geo100/sedimentary.html
Andrew Alden
sandstone
conglomerate
Rock Types - Metamorphic
• Term means “changed form”
• Rock formed from pre-existing rocks through the
action of high heat (no melting) and pressure
• May be very hard and may show crystals but
they will be in a linear pattern (foliation) or may
show elongation or folding that results from high
pressure; certain minerals only form in
metamorphic rocks.
Rock Types - Metamorphic
Gneiss
Quartzite
Gneiss
http://www.mii.org/mineral_photos_by_type.htm
http://www2.vscc.cc.tn.us/svinson/geo100/metamorphic.html
Rock Cycle
Rocks can be changed from one
type to another through natural
geological processes.
The series of processes that
comprise these transformations is
called the rock cycle.
http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html