Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Minerals and Weathering

Skip navigational links
Loading
Dictionaries: Our Mapping Systems   The USGS and Science Education   USGS Fact Sheets   Topics   Keywords   Data Dictionary   Metadata Dictionary   Computer Terminology   Digital Formats  
InfoBank Terms: Activity ID   activity overview   crew   digital data   formal metadata   lines   metadata   NGDC   port stops   project/theme   region   ship   stations   time   virtual globe   year  
Data Types: bathymetry   biological   geochemical   gravity   ground penetrating radar   imaging   LIDAR   logs   magnetics   metering equipment   navigation   samples   seismic   total station   definitions disclaimer  
Data Formats: ARC coverage   E00   FGDC metadata   gridded/image   imaging   material   scattered/swath   Shapefile   vector/polygon  
Comment: 09:40 - 10:44 (01:04)
Source: Annenberg/CPB Resources - Earth Revealed - 15. Weathering and Soils
Keywords: "J. Lawford Anderson", granite, weathering, mineral, temperature, quartz, feldspar, "chemical weathering", plagioclase, clay, orthoclase, sediment, rock, "sedimentary rock"

Our transcription: Granite is composed of various minerals formed over a range of temperatures.
Each mineral type responds to weathering differently.
Here's an example of a granite that's fresh, it's unweathered, and as I try as I might, I can't break this rock apart.
We can see the dark gray quartz and the pink orthoclase feldspar, they're in the rock but they haven't weathered.
We'll now turn to another granite that is already begun chemical weathering.
It's starting to fall apart.
And we find that the different minerals are proceeding differently.
Plagioclase is weathering the fastest, and has already turned to clay.
Orthoclase feldspars is starting to weather as well, but the quartz is not weathered at all.
But the basic framework of the rock is beginning to fall apart and now this rock, well you know, I can begin to break this rock apart with my hands -- it is starting to decompose.
And this is how a rock changes to become sediment.
The grains are breaking apart are dislodged and now will fall into the sedimentary system.

Geology School Keywords
Skip footer navigational links

Coastal and Marine Science Centers:  Pacific   St. Petersburg   Woods Hole  
InfoBank   Coastal and Marine Geology Program   Geologic Information   Ask-A-Geologist   USGS Disclaimer  


Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://walrus.wr.usgs.gov/infobank/programs/html/school/moviepage/14.01.09.html
Page Contact Information: InfoBank staff
Page Last Modified: Thu Oct 31 04:26:51 PDT 2013  (chd)