Obj 2 changes rocks undergo over timePresentation Transcript
Rocks: Mineral Mixtures
Understanding Rock Rock-a solid mixture of crystals of one or more minerals. -Rocks are very useful.
RockCycle-The process by which one rock type changes into another.
The Rock Cycle
The Rock Cycle Cont.
Rock Classification Composition-the minerals a rock is made of. Texture-determined by the sizes, shapes, and positions of the grains of which it is made.
Igneous Rock Igneous comes from the Latin word for “fire”. It is made by Temperature, Pressure, and Composition.
Intrusive Igneous Rock When magma cools beneath the Earth’s surface. It has a coarse- grained texture.
Extrusive Igneous Rock Igneous Rock that forms on the Earth’s surface.
Sedimentary Rock Wind, water, ice, sunlight, and gravity all cause rock to weather into fragments. Erosion is the process when rocks fragments are moved.
Layers of sediment become compressed and cemented over time. Dissolved minerals separate out of the water and form a natural glue that will bind the sediments together. Sedimentary rocks are formed near the Earth’s surface, with little heat and pressure.
Categories of Sedimentary Rocks Clastic-whenrock or mineral fragments, called clasts, stick together.
Chemical-forms when minerals crystallize out of a solution (sea water) and become rock.
Organic-form from the remains of animals.
Metamorphic Rock Rockthat forms when the texture and composition of pre-existing rock changes due to heat and pressure.
Origins of Metamorphic Rock The texture can change when the surroundings change. Most change by pressure that occurs at depths greater than 2 km (about 6000 ft.) The temperature range is 50 C to 1000 C (122 to 1832 F)
Metamorphism-when the rock Contact comes in contact with magma. Metamorphism-when a lot of Regional pressure builds up in rocks buried in the Earth or when large pieces of the Earth’s crust collide with each other.
Textures of Metamorphic Rock Foliated Metamorphic Rock-contains mineral grains that are aligned by pressure.
Non-foliatedMetamorphic Rock-the texture of metamorphic rock which mineral grains show no alignment.