This document discusses igneous rocks and provides an example of Mount St. Helens in Washington before its 1980 eruption. It describes how Mount St. Helens was a volcano that had its crater breached by an eruption, as seen in an aerial photograph taken before 1980.

1. 74 Igmeouss Rocks Vilmene rexis ane moks that have on wallind frum lass - Fiyen 45 - d tieler
cuer uat a compenelte velcanu C4.1s Buanew ia the arrial phesograph in ficure 4.8 . Hy if the
erater ham been bexacbet ly a marrew dark. Moumt St. Melens, Wrashington Aerial photo made
bofore 1900 eruption Igneous Rocks it ile iruter has bere breached by a Mount St. Helens,
Washington Aerial photo made before 1960 eruption