Presentation on theme: "Rocks and the Rock Cycle"— Presentation transcript:
1Rocks and the Rock Cycle It Rocks!Rocks and the Rock Cycle
2Just what are rocks?A rock is a mixture of minerals, rock fragments, volcanic glass, organic matter, or other natural materials.What do you see in this sample of pink granite?
3What is the difference between a rock & a mineral? Minerals are solid, naturally occurring, inorganic, have a fixed composition and are made of one or more elements.Rocks are made of one or more minerals.
4Let’s Compare… Solid Made of elements Must be inorganic Can be made from organic materialsMust be inorganicSolidCan be made of lava/ magmaMixtures made of mineralsMade of elements or compounds and must be chemically bondedNaturally occurringHave crystalsCan be man madeCan be formed from solutions
6Igneous Rock Igneous is Greek and means ‘born of fire’ Igneous rock forms when magma, hot molten rock, cools and hardensIgneous rock can be intrusive or extrusive
7Intrusive Igneous Rock Formed from magma cooled below the Earth’s surfaceCools very slowlyForms mineral grains large enough to see with the unaided eye
8Extrusive Igneous Rock Formed as lava cools on the surface of the EarthCools quicklyExposed to air and water which can result in holes in the rock materialForms very fine (small) mineral grains.
9Extrusive Igneous Rock Includes Volcanic GlassLave cools very very quicklyFew or no minerals grains formAtoms are not arranged in an orderly pattern
10Sedimentary RockForms when sediments are pressed and cemented togetherForms when minerals form from solutionsOften form layersIf undisturbed by nature, the oldest and first layer is the bottom layer
11Sedimentary RockSediments are loose rock fragments, minerals grains, and bits of shell that have been moved by the wind, water, ice or gravity.Sediments form from the processes of weathering and erosionCompaction – occurs when pressure on the uppers layers of the sedimentary rock pushes down on the lower layers.Cementation – the process by which water and dissolved minerals move through open spaces and form a glue-like substance
12Metamorphic Rock Metamorphosis – to change Rocks that have changed their chemical composition due to the presence of extreme heat and pressure orRocks that have been subjected to hot watery fluids
13Metamorphic RockCan form from igneous, sedimentary or other metamorphic rockCan be foliated - mineral grains appear in parallel layersCan be nonfoliated – mineral grains do not align in layers
14The What?...The Rock CycleTo show how rocks slowly change through time, scientists have created a model called the rock cycle.It shows the processes that form and change rocks.The rock cycle shows the three classifications of rock— igneous, metamorphic, and sedimentary—and the processes that form them.
15The Rock Cycle explains how Rocks and Natural Processes are related weatheringSedimentaryMetamorphicIs the rock cycle really this simple, neat and colorful?(NO)Created October 2, 2000, revised September 2001meltingpressure, heatIgneous
16What is the law(principle) of conservation of matter? Law of conservation of matter states that matter cannot be created or destroyed.The changes that take place in the rock cycle never destroy or create matter.The elements are just redistributed in other forms.