THE ROCK CYCLE Key Vocabulary Rock Cycle Mineral

THE ROCK CYCLE Key Vocabulary: -Rock Cycle -Mineral -Igneous -Metamorphic -Sedimentary

What is a rock? Rock: any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet Mineral: a naturally occurring, inorganic solid with an orderly crystalline structure and a definite chemical composition

Rock Cycle - The continuous process that cause rocks to change Magma or lava solidifies Melting Weathering, erosion, deposition Metamorphism Compaction & cementation

How is Sediment Made? Together, weathering and erosion work continuously to wear down the material on Earth’s surface. weathering – process that breaks down rock and other substances of Earth’s surface erosion – removal of rock particles by wind, water, ice or gravity

Weathering acts slowly, but over time will break down the largest and hardest of rocks mechanical weathering – rock is physically broken down into smaller pieces by processes chemical weathering – process that breaks down rocks through chemical changes

Mechanical Weathering Abrasion Rock particles wear away rock Freezing & Thawing Breaks rock by ice wedging Animal actions Ground breaks away by animals burrowing Plant growth Roots grow into cracks of rocks and pry them apart

Chemical Weathering Acid Rain Results from burning fossil fuels causing minerals to wear away rapidly Carbonic Acid Forms from CO 2 dissolving in water then weathers marble and limestone Living Organisms Plants produce weak acid that slowly dissolve rock that surround roots Oxygen Oxidation produces rust on some rocks that have iron

Deposition deposition – the laying down or settling of eroded material

Geologists classify rocks into three major rock groups based on how they form: Sedimentary Metamorphic Igneous

Sedimentary Rock rock material that forms where rocks are broken down into smaller pieces or dissolved in water as rocks erode or the remains of plants and animals are pressed and cemented together

SEDIMENTARY ROCKS sediment – small, solid pieces of material that come from rocks or remains of living things Formed through a series of processes which include: • erosion – form sediment by particles getting carried away from their source by wind and water • deposition – process by which sediment settles out of the water or wind carrying it • compaction – process that presses sediment together growing thick layers that build up over millions of years • cementation – process in which dissolved minerals crystallize and glue particles of sediment together

Metamorphic Rock forms when existing rock is changed by heat, pressure or chemical reactions

METAMORPHIC ROCKS Heat and pressure deep beneath Earth’s surface can change any rock into metamorphic rock. • foliated – metamorphic rocks that have their grains arranged in parallel layers or bands • nonfoliated – mineral grains are arranged randomly

Igneous Rock • created when magma or lava cools and crystallizes

IGNEOUS ROCKS Formation: May form on or beneath Earth’s surface. • Extrusive rocks – igneous rocks formed from lava that erupted onto Earth’s surface • Intrusive rocks – rock that formed when magma hardened beneath Earth’s surface

Final Exam A student observed a rock made up of many small particles of sand arranged in light-colored layers and dark-colored layers. Which of the following statements describes how this type of rock most likely formed? A. Clay was crushed and frozen under a glacier. B. Lava from a volcano cooled quickly in water. C. River sediments were slowly compacted and cemented together. D. Mineral deposits hardened into solid rock in underground caves.