Coalition in Action

• 
  

  	Geologists analyze and sample geologic materials at the Earth’s surface to better understand the geologic history of an area. These are glacial deposits in a stream valley in central Illinois.
  	Glacial deposits are sampled deep underground by drilling (Lake County, Illinois). Geologists analyze sediments to determine physical characteristics, such as the capacity to hold and transmit water or ability to accept a load from a building or bridge.
  	Geophysical surveys at the land surface help scientists explore the subsurface geology. Here geologists collect geophysical data using geophones. In the resulting geophysical profile, colors highlight key horizons.