Igneous Rocks

When magma cools and _______, the result is an ________ rock. There are _____ factors that affect whether a rock will melt or not. ▫Temperature (heating above __________) ▫Pressure ▫And presence of _______ in the rock (adding water).

Partial melting This is the process by which different minerals in a rock melt at different ___________.

The _______ of magma is the reverse of partial melting. Chemicals that have a high ___________, crystallize first. The crystallization and removal of different minerals from the cooling magma is called __________________. ▫They tend to settle at the ______ of magma chamber.

Textures of Igneous Rocks Igneous rocks are classified according to ______ the magma cools and hardens. ▫_______ igneous  Cools deep inside the crust ▫________ igneous  Cools on the earth’s surface

Textures of Igneous Rocks ______-grained ▫Intrusive rocks ▫_____, well developed crystals ▫Have a coarse gained texture ▫Cools slowly _____ grained ▫_____ mineral grains that cannot be seen by eye. ▫cools rapidly ▫Small _______

Other Igneous Rock Texture Glassy ▫Small % percentage of ______ gases. ▫Example ______ Vesicular texture ▫Rapid cooling full of _____ are called vesicles. ▫Example ______ ________ texture ▫Some igneous cools slowly then quickly as it nears the surface. ▫Have a mixture of _____ & ______crystals. ▫Example _______

Composition of Igneous Rocks Determined by chemical ___________. They are divided into _____ families ▫______ Rock  Large proportion on silica, light color  Many common rocks ▫_____ Rock  Contains lower proportions of silica than felsic rock  Rich in _____ and __________ ▫Intermediate Rocks  These types of rocks are in between Felsic and Mafic in their proportions of _______.

Intrusive Rocks They form ________. Intrusions form when ______ intrudes or enters into the rock masses and then cools. ▫______ & stocks ▫Laccoliths ▫_____ and dikes

Extrusive Rocks Igneous rocks that form on the earth’s _______. ▫Lava flows ▫Lava _______ ▫Volcanic necks