Presentation on theme: "Rocks and the Rock Cycle. A rock is a mixture of minerals, rock fragments, volcanic glass, organic matter, or other natural materials. What do you."— Presentation transcript:
Rocks and the Rock Cycle
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? Just what are rocks?
What 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.
Let’s Compare… Must be inorganic Made of elements or compounds and must be chemically bonded Naturally occurring Made of elements Solid Can be made of lava/ magma Have crystals Can be formed from solutions Can be made from organic materials Mixtures made of minerals Can be man made
Rock Classifications Igneous Sedimentary Metamorphic
Igneous Rock Igneous is Greek and means ‘ born of fire ’ Igneous rock forms when magma, hot molten rock, cools and hardens Igneous rock can be intrusive or extrusive
Intrusive Igneous Rock Formed from magma cooled below the Earth’s surface Cools very slowly Forms mineral grains large enough to see with the unaided eye
Extrusive Igneous Rock Formed as lava cools on the surface of the Earth Cools quickly Exposed to air and water which can result in holes in the rock material Forms very fine (small) mineral grains.
Extrusive Igneous Rock Includes Volcanic Glass Lave cools very very quickly Few or no minerals grains form Atoms are not arranged in an orderly pattern
Sedimentary Rock Forms when sediments are pressed and cemented together Forms when minerals form from solutions Often form layers If undisturbed by nature, the oldest and first layer is the bottom layer
Sedimentary Rock Sediments 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 erosion Compaction – 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
Metamorphic Rock Metamorphosis – to change Rocks that have changed their chemical composition due to the presence of extreme heat and pressure or Rocks that have been subjected to hot watery fluids
Metamorphic Rock Can form from igneous, sedimentary or other metamorphic rock Can be foliated - mineral grains appear in parallel layers Can be nonfoliated – mineral grains do not align in layers
To 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. The What?...The Rock Cycle
Rock Cycle RocksNatural Processes The Rock Cycle explains how Rocks and Natural Processes are related weathering melting p r e s s u r e, h e a t Sedimentary Metamorphic Igneous
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. What is the law(principle) of conservation of matter?
Let’s Have Some Fun!!
(Study Jams – really great site) More Fun with the Rock Cycle
Prepared just for YOU, my 6 th Grade Earth Science classes! Ms. Houston Austin Road Middle School