Coastal & Marine Geology InfoBank

Home FACS Activities Atlas Geology School Related Sites More

USGS CMG InfoBank: Composition of the Ocean Crust

Skip navigational links
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: 11:57 - 12:43 (00:46)
Source: Annenberg/CPB Resources - Earth Revealed - 7. Mountain Building
Keywords: crust, magmatism, mantle, basalt, "igneous rock", metamorphism, sedimentation, deformation, melting, mountain, orogeny, deposition, basin, "proto-ocean crust", granite, "Jason Saleeby"

Our transcription: Oceanic crust represents material, which has come to the Earth's surface directly by magmatism out of the Earth's mantle.
As the most common type of magma to come out of the Earth's mantle, it comes out as a composition of basalt, which is a silica magnesium rich rock.
The continents represent material that has been recycled numerous times by igneous activity, metamorphism, sedimentation, deformation, melted, mountain building, deposition into basins, and recycled recycled.
It basically came from proto-oceanic crust, but it has undergone many different changes through these processes through time to make it distinct and compositionally much lighter, which is a composition more similar to granite.

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 logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: InfoBank staff
Page Last Modified: Thu Oct 31 04:25:56 PDT 2013  (chd)