Earth Science Ch. 1: The Rock CycleEarth Science Ch. 1: The Rock Cycle
G. Lescallette Mt. Ridge HSG. Lescallette Mt. Ridge HS
•Rocks are naturally occurring, solid mixtures of Rocks are naturally occurring, solid mixtures of one or more one or more mineralsminerals and and organicorganic matter. matter.•Rocks are always changing.Rocks are always changing.•New rocks form from New rocks form from
old rocks by a process old rocks by a process known as the known as the Rock CycleRock Cycle..
•Rocks have been used by humans for over Rocks have been used by humans for over 100,000 years for a variety of uses including:100,000 years for a variety of uses including:•ToolsTools•BuildingsBuildings•RoadsRoads•AestheticsAesthetics
Roads and Bridges:Roads and Bridges:
Casselman Bridge, in Garrett County, is on the Casselman Bridge, in Garrett County, is on the right.right.
•Ever since the earth cooled, processes have Ever since the earth cooled, processes have been creating and destroying rock; these been creating and destroying rock; these processes continue on today.processes continue on today.•WeatheringWeathering: the process in which : the process in which water, wind, water, wind, ice, ice, and and heatheat break down rock. The small break down rock. The small fragments that break off are called fragments that break off are called sedimentsediment..•ErosionErosion: the process in which sediment is : the process in which sediment is removed from its source by water, wind, ice, or removed from its source by water, wind, ice, or gravity.gravity.•DepositionDeposition: (root word = : (root word = depositdeposit) the process in ) the process in which sediment is deposited at some distance which sediment is deposited at some distance from its source.from its source.•Erosion and deposition are opposite sides of the Erosion and deposition are opposite sides of the same coin.same coin.
Weathering and Erosion: Monument Valley, Four Weathering and Erosion: Monument Valley, Four Corners RegionCorners Region
Erratic boulder in New York’s Central Park: Erratic boulder in New York’s Central Park: carried for hundreds of miles by continental carried for hundreds of miles by continental
glaciersglaciers
•Heat and Pressure can create Heat and Pressure can create sedimentary rocksedimentary rock from sedimentfrom sediment
•If temperature and pressure are great enough, If temperature and pressure are great enough, metamorphicmetamorphic rock will be formed. rock will be formed.
•Rock can be exposed to the earth’s surface by Rock can be exposed to the earth’s surface by uplift uplift and and erosionerosion..
Rock ClassificationRock Classification•By By typetype: igneous, sedimentary, metamorphic: igneous, sedimentary, metamorphic•By By compositioncomposition: what minerals and other : what minerals and other material are presentmaterial are present•By By texturetexture: the size, shape, and arrangement of : the size, shape, and arrangement of the grains that make up a rockthe grains that make up a rock•Granite is a Granite is a coarse-grained rock coarse-grained rock