Rocks and the Rock Cycle

Three Types of Rocks Rocks are classified by how they form Igneous Sedimentary Metamorphic Rocks can change from one type to another over time Schist

Rock Classification Rocks are classified by: How they form Texture Grain size Mineral composition Conglomerate Sedimentary Rock

Igneous Rocks Igneous rock: forms when molten rock (magma) cools and hardens Melting: when matter phase changes from a solid to a liquid Classified by: Where they form Crystal (grain) size Basalt

Intrusive Igneous Rock Intrusive igneous: cooling takes place slowly beneath Earth’s surface and takes a long time. This process is called crystalization granite

Extrusive Igneous Rock Extrusive igneous: cooling takes place rapidly on Earth’s surface Pumice

Sedimentary Rock Sedimentary rock: forms from the compaction and/or cementation of sediments Sediments are: Rock pieces Mineral grains Shell fragments Limestone

How do sediments form? weathering Sediments form through the processes of weathering and erosion of rocks exposed at Earth’s surface erosion

Sedimentary Rock con’t…. Compaction: after sediments are eroded they then are pushed together from the weight of the sediments on top of them Cementation: after compaction the rock payers are then “glued" together gypsum

Metamorphic Rock Metamorphic rock: forms when any rock type is changed into a different kind of rock Changes due to great heat and/or pressure Gneiss

How does rock change? Rocks are heated, squeezed, folded, or chemically changed by contact with hot fluids. Metamorphic rocks are not melted. They are characterized by banding. marble

The Rock Cycle

The Earth Recycles Rock The rock cycle is an ongoing series of processes inside Earth and on the surface Slowly changes rocks from one kind to another Any type of rock can change into another type

How does this relate to plate tectonics? Plate movement drives the rock cycle Subduction (1 plate pushed under another plate) Re-melts rock into magma Mountain building Folding, faulting, uplift Exposes rock at the surface to be weathered and eroded

Cementation and compaction (lithification) Heat and pressure Weathering, transportation(erosion), and deposition Cooling and solidification Melting

Copy Me

Rocks/Rock Cycle Foldable Your foldable should include the following: Name of each rock type How each rock type formed A brief description of rock type At least 2 examples of each rock type Illustrate 1 example for each rock type

  Based on the processes shown in the diagram, which type of rock is formed at #1?     A. Sedimentary  B. Igneous C. Metamorphic D. Clastic   Because heat and pressure are needed to form #3, it must be what type of rock? A.     Sedimentary B.     Igneous C.     Metamorphic D.     Clastic