Tuesday, February 14, 2012

My Igneous Rock! Lab #4

Diorite

  • intermediate composition between felsic and mafic
  • classically a salt and pepper rock
  • white to light gray plagioclase and black hornblende
  • some diorites contain biotite as well as hornblende, and some contain up to 10% quartz
  • If you have more than 10% quartz, you probably have a granite on your hands. If you clearly have abundant K-feldspar, you probably have a granite on your hands. 
  • Diorite occurs in small bodies such as sills, dikes, stocks, or as more irregular masses associated with gabbro and batholiths of granodiorite and granite.

Tuesday, February 7, 2012

Lab #3, My Minerals

Gypsum is found in nature in mineral and rock form. As a mineral, it can form very pretty, and sometimes extremely large, crystals.
Pumice is a type of extrusive volcanic rock, produced when lava with a very high content of water and gases is extruded from a volcano
Amethyst is a violet variety of quartz
Galena, highly reflective and commonly in cubes.
Halite is the native salt, occurring in massive, granular, compact, or cubic-crystalline forms.
Feldspar, found in abundance on Earth's crust.
   
Amphibole, a variety of hornblende from Faraday Township, Ontario, Canada.
Specimen is approximately 3 inches across.

Wednesday, February 1, 2012

Lab #2, Maps

Proportional Symbol Map

Dot Density Map

Isarithmic Map

Choropleth Map

My Isarithmic Map