2How Rocks are Formed: Igneous Rocks Lava: liquid rock found above groundMagma: liquid rock found undergroundRocks are formed by cooling of Magma underground or from lava above ground. Rocks formed by the cooling of magma or lava are known as Igneous Rocks. Granite is an igneous rock formed from cooling of magma. Basalt is an igneous rock formed from cooling of lava
3How Rocks Are Formed: Sedimentary Rocks Sedimentary rocks are created by rocks being broken down into small particles or fragments called sediments. When sediments are deposits and compressed, cemented together, and harden forming sedimentary rocks.Types of sedimentary rocks Sandstone, Shale, and Limestone.
4How Rocks are Formed: Metamorphic rocks. Metamorphic rocks are formed by parent rocks under extreme heat, pressure or chemical processes change the form of rock. Metamorphic rock means changed form.Slate, Schist, and Gneiss are examples of a metamorphic rock
7Rock QuestionsHow are igneous rocks formed? Give example of two types of igneous rocks.How are sedimentary rocks formed? Give example of three types of sedimentary rocksHow are metamorphic rocks formed? Give example of three types of metamorphic rocks4. Explain the rock cycle
8Igneous Rocks: Texture Intrusive Igneous Rocks:Rocks formed by magma cooling slowing beneath Earth’s surface over a long period of time.Intrusive Igneous rocks are coarse grained rocksGranite is an example of intrusive rockExtrusive Igneous RocksRocks formed from cooling of lava on the Earth’s surface.Extrusive igneous rocks are fine grained rocks.Basalt is an example of a extrusive igneous rock
9Igneous Rock: Composition Felsic Rocks are formed from magma that contains a large amount of silica.Felsic rocks are light in coloring due to the mineral composition of feldspar and quartzGranite is an example of a felsic igneous rockGranite is coarse grain and quartz or silica is the sparkle found in the rock. This gives the rock a light color.
10Igneous Rock: MaficMafic igneous rocks contain less silica than felsic rocks.Mafic rocks are dark in color because of the iron and/or magnesiumBasalt is an example of a mafic rockBasalt is a dark color mafic rock. It is a fine grain rock.
11Igneous Rocks: Intermediate Intermediate rocks are rocks that have less silica than a felsic rock, but more silica than a mafic rock.Diorite is an example of an intermediate igneous rock.Diorite is an intermediate igneous rock. There is dark and light minerals found in this rock.
12Igneous Rocks Question What is an intrusive Igneous rock give an exampleWhat is an extrusive Igneous rock give an exampleWhat is a felsic igneous rock give an exampleWhat is a mafic igneous rock give an exampleWhat is an intermediate igneous rock give an example.
13Igneous Rock Questions 6. What is the relationship between an intrusive igneous rock and a felsic igneous rock.7. What is the relationship between an extrusive igneous rock and a mafic igneous rock.8. Both Granite and Basalt are igneous rocks, but they are very different types of igneous rocks create a T-chart showing the difference between the two rocks.
14Sedimentary RocksSedimentary rocks are formed from particles of rocks that have been broken down by wind and water. When the little pieces are broken from the rocks, they are washed downstream and settle in the bottom of streams, rivers, and oceans.LimestoneSandstoneShale
15Formation of Sedimentary Rocks Compaction and cementation are the two ways sedimentary rocks are created.Sedimentary rocks are classified by the processes by which the rocks are formed and by the composition of the rockThere are three main classes of Sedimentary Rocks: Chemical, Organic, and Clastic.
16Chemical and Organic Sedimentary Rocks Chemical sedimentary rocks are formed from minerals that were once dissolved in the water.When water evaporates the minerals dissolved in the water are left behind.Rock salt is an example.Organic Sedimentary Rocks are formed from the remains of living things. As sea animals die the shells and bones are deposited on the ocean floor.Limestone is an example.
17Clastic Sedimentary Rocks Clastic Sedimentary rocks are formed from rock fragments that are carried away from the source by wind, water, or ice.The particles are deposited at the bottom of rivers or oceans.Over time the fragments are compacted and cemented to other rock fragments forming a sedimentary rock.
18Clastic Sedimentary Rocks The sedimentary rocks are classified by the size of the fragments found in the rock.A conglomerate sedimentary rock has large particles.A sandstone is made of sand-sized grains that have been cemented together.Quartz is a major component of sandstone because it is such a hard mineral
19Clastic Sedimentary Rocks A third group of clastic sedimentary rock is shale that has clay size grains or very fine grained rock.Shale is compacted into flat layers that will easily split apart.
20Where are Sedimentary Rocks Formed Where sedimentary rocks are formed depends on the size of the particles. Through sorting the larger grained rocks are formed near shoreline or at the mouth of rivers. The larger particles will settle first. (Conglomerates)Along the beaches and near shore sand-size particles settle out of the water and are deposited (sandstone)
21Where are Sedimentary Rocks Formed The finer grained particles stay suspended in the water longer therefore are deposited farther out from the shore where the water’s movement has slowed down. (Shale)The area by the continental shelf where coral reefs and much of the plant and animal life of the ocean is found is the last place for sedimentary rocks to form. The rocks are formed from the shells and skeletons of dead marine life. (Limestone)
23Questions on Sedimentary Rocks How is a sedimentary rock formed?What are two ways a sedimentary rock is created?What are 3 classifications of sedimentary rocks?How are chemical sedimentary rocks formed and give an example of a chemical sedimentary rock.
245. How are organic sedimentary rocks formed and give an example of a chemical sedimentary rock. 6. What are the 3 types of Clastic sedimentary rocks. Describe the difference between each one and give an example.7. Draw the diagram explaining where each of the sedimentary rocks would be deposited. Explain what the diagram is showing.
26Metamorphic Rocks Metamorphism is the alteration of a preexisting rock (the parent rock) due to heat and pressure caused by burial in the earth.The parent rock must adapt to the new conditions and it does so by changing mineral composition and texture. These rocks with new texture and composition are metamorphic rocks.
27Facts about Metamorphic Rocks Classified by texture and composition May react with acidMay have alternate bands of light and dark mineralsMay have layers of visible crystals
28Facts about Metamorphic Rocks May be composed of only one mineral, ex. marble & quartziteUsually made of mineral crystals of different sizesRarely has pores or openingsMay have bent or curved foliation
29Regional Metamorphism Regional metamorphism takes place during mountain building events when very large areas of sedimentary rocks are buried, squeezed, and heated.metamorphic rocks not only tell us the kind of metamorphism, they are also a measure of the intensity of metamorphism. The closer we get to the source of heat and pressure the more altered the rock becomes.
30Contact MetamorphismContact metamorphism occurs in the " country rock" (the rock intruded by and surrounding an igneous intrusion). Rocks are " baked" into a ceramic from heat escaping from intrusives, often enhanced by hot fluids.
31Foliated Metamorphic Rocks The metamorphic texture in which minerals are arranged in planes or bands.Foliated rocks formed in one of two waysExtreme pressure may cause the mineral crystals in the rock to realign or re-grow to form parallel bands.Minerals that have different composition separate and produce a series of alternating dark and light bandsExamples Slate and Gneiss
32Non-foliated Metamorphic Rocks Metamorphic rocks that do not have bands or aligned minerals.The parent rock may contain grains from only one mineralThe grains of the parent rock may be round or square therefore it does not change direction when exposed to pressure in one directionExample Quartzite and Marble
33Foliated/Nonfoliated Metamorphic Rock Foliated RocksComplex composition, many different kinds of minerals.Many new minerals produced with a change in Temp. and/or Pres.Non-foliated RocksSimple composition, only a few minerals such as calcite or quartz.No new minerals form with a change in Temp and/or Pres.
34Foliated/Nonfoliated Metamorphic Rocks Texture is layered, foliated, lineated, banded. Minerals have a preferred orientationMany rocks with diverse compositionsTexture is granular and No preferred orientationFew rocks with simple compositions. Qtz SS - Quartzite Limestone - Marble Dolostone - Dolomitic Marble Shale - Hornfels