Rocks !

Rock and Roll! A rock is a solid mixture of crystals of one or more minerals. Uses: Early humans used rock to make tools Buildings (concrete) Science: helps us with the history of the Earth

Rock Types and Magma Igneous Sedimentary Metamorphic Magma is the hot liquid that forms when rock partially or completely melts.

The Rock Cycle The rock cycle is the process by which one rock type changes into another. Weathering Erosion Deposition Compacting Metamorphism Melting Cooling Solidification

Classifying Rocks Composition – the minerals the rock is made of. Texture – sizes, shapes, and positions of the grains of which it is made. Fine grained Medium-grained Coarse-grained

Igneous Rock When magma or lava cools down enough, it solidifies to form igneous rock. Igneous means “fire” in Latin. 3 ways igneous rock can form heat Pressure released Composition change

Igneous rock formations Intrusive Igneous rock forms when magma cools beneath the Earth’s surface. Usually coarse grained. Cools slowly Plutons are large, balloon shaped intrusive formations that result when magma cools slowly at great depths.

Igneous rock formations Extrusive Igneous rocks form on the Earth’s surface. Cools quickly Can form from volcanoes or from fissures (long cracks in the Earth’s surface)

Sedimentary Rock Through weathering and erosion, sediment (rock fragments) is deposited in layers and becomes compacted. Weathering, erosion, deposition, compaction Layered rock – strata Stratification – the layering of sedimentary rock. (tells us a lot about history)

Sedimentary Rock compositon Clastic – made of fragments of other rocks and minerals. (ex. Sandstone) Chemical – made of solutions of minerals and water. (ex. Chemical limestone) Organic – made of remains of animals that once lived in the ocean. (limestone) Fossils are formed in sedimentary rock.

Metamorphic Rock Meta means changed and morphos means shape in Latin. Rock undergoes metamorphism through heat or pressure or both. All 3 types of rocks can change into metamorphic rock.

Types of Metamorphism Contact: when a rock comes in contact with magma. Regional: when enormous pressure builds up in a rock that is deeply buried under other rock formations.

Textures of Metamorphic Rock Foliated – has minerals that are aligned like pages in a book. Nonfoliated – does not have a regular pattern. Usually made of one or a few minerals.