Ask-a-Geologist: Rock Types

Question: What are the three big groups of rocks?

Answer: The three basic rock types are Igneous, Metamorphic and Sedimentary. See the article titled Geology is All Around You in the “Dig Into Geology” section of our website for more information on these rock types.

Look at this photo.  Do you see the white rocks that look like they cut through the gray rock?  These are igneous rocks that were probably injected from a magma source underground into the gray rock above, likely through cracks in the rocks.  Rock formations can tell you a great deal of information about he history of an area.

Leave a Reply

You must be logged in to post a comment.