ROCKS

CLASSIFICATION

• Rock is classified into 3 groups, igneous, metamorphic, and sedimentary.
• The minerals and organic matter a rock contains determines the composition
• The size, shape,and positions of the grains that make up a rock determine a rock's texture.

IGNEOUS ROCKS

It forms from magma inside the earths mantle or from lava on the crust of the earth.

INTRUSIVE AND EXTRUSIVE

• Intrusive and extrusive are the two types of igneous rocks.
• Intrusive Igneous Rocks: Forms in the mantle- cools slowly- coarse grained. Ex. Diorite
• Extrusive Igneous Rocks: Forms on earth's crust- cools quickly- fine grained. Ex. Basalt

SEDIMENTARY ROCKS

Sedimentary rocks can form in 4 different ways. Erosion, deposition, compaction, and cementation.

SEDIMENTARY ROCKS

• Clastic- form when sediments are buried compacted, and cemented together by calcite or quartz. Ex. Sandstone
• Chemical- form when water, usually seawater, evaporates. Ex. Halite
• Organic- form from the remains or fossils, of once living plants or animals. Ex. Coal

METAMORPHIC ROCKS

As a rock is exposed to high temperature and pressure, the crystal structure of the minerals in the rock change to form new minerals.

METAMORPHIC ROCK

• Foliated- mineral crystals form in bands. Ex. Slate
• Non-Foliated- not banded and do not break into layers. Ex. Marble