• What is ground water?
  Ground water is water that seeps slowly through rocks, such as ...

• What are springs?
  Springs occur when ground water flows on to the surface. Springs are ...

• Can the Sun’s heat cause mechanical weathering?
  In hot, dry regions, rocks are heated by the Sun, but they cool at ...

• Can plants change the land?
  Plant roots can break up the rock. When the seed of a tree falls into ...

• What is biological weathering?
  Biological weathering includes the splitting apart of rocks by tree ...

• What are volcanoes made of?
  Some volcanoes are cone-shaped and made of volcanic ash or cinders. ...

• What are trace fossils?
  Trace fossils give information about animals that lived in ancient ...

• What is a dormant volcano?
  Some volcanoes erupt continuously for long periods. But other active ...

• What is amber?
  Amber is a hard substance formed from the sticky resin of trees. Tiny ...

• Do volcanoes do any good?
  Volcanic eruptions cause tremendous damage, but soil formed from ...