6LAVA and volcanic eruption! When one plate slides under another, volcanoes formHeat and pressure from the plate sliding under another cause molten rock to make its way out of the earth’s surface…LAVA and volcanic eruption!
17Diversity of ROCKS!Natural forces at work!Combinations of temperature, pressure, and chemical interactions within earth and on its surface gives us a huge diversity of rocks!
18Rocks! Made up of a mineral or a mixture of minerals May also contain sediments and fossil remains of plants and animalsThey are the result of natural forces at work on our planetThe study of rocks is called petrology
19The elements oxygen, silicon, aluminum, iron, magnesium, calcium, potassium, and sodium make up 99 percent of all minerals on Earth.
20The largest topaz crystal was found in Brazil in 1940 The largest topaz crystal was found in Brazil in It weighs 596 pounds. It is on display in the American Museum of Natural History in New York.
26All rocks fall into one of 3 basic groups: Basic Rock TypesAll rocks fall into one of 3 basic groups:1. Igneous2. Sedimentary3. Metamorphic
27Igneous Rocks Form from the cooling of liquid rock Igneous means “fire”Form from the coolingof liquid rock(magma) that came upfrom deep within theearth. It is the meltingand solidification ofmetamorphic rocks!Igneous rock is the mostcommon material of theearth’s crust!
28Igneous Rocks: Often hidden by sedimentary rock Can be intrusive or extrusive igneous rockIf recrystallization and solidification occurred below the earth’s surface (such as the formation of granite), than the rock is intrusiveIf the rock formed on the earth’s surface from cooling of volcanic lava (such as obsidian and basalt), than the rock is extrusive
29Igneous Rocks:If rock formed from a slow cooling, the rock will contain coarse-textured minerals (Example = granite)If rock formed from a fast cooling, the rock will contain fine-textured minerals (Example = basalt)If rock contains a high amount of silica, it will be light in color and weight, and be known as acidicIf rock contains high amounts of iron and magnesium, it will be dark-colored and heavy, and be known as basic
30Most common extrusive and basic igneous rock BasaltMost common extrusive and basic igneous rock
31Most abundant of all igneous rocks GraniteMost abundant of all igneous rocks
35ObsidianLooks like shiny black glass as a result of very fast cooling of volcanic lava
36Porous (has many holes) and floats on water! PumicePorous (has many holes) and floats on water!
37Sedimentary RocksForm from the burial and cementing of layers of sediment broken off of other rock types and deposited in water. Weathering and erosion can be caused by wind, waves, gravity, or water. Rivers carry sediment for long distances.
38Rock formation from years of wind erosion… Sediment that was swept away eventually became sedimentary rocks!
40Conglomerate or Breccia (depends on rounding) Cobble Name of Particle Size Range Loose Sediment Consolidated Rock Boulder >256 mm Gravel Conglomerate or Breccia (depends on rounding) Cobble 64 – 256 mm Pebble mm Sand 1/16 –2 mm Sandstone Silt 1/ /16 mm Siltstone Clay <1/256 mm Claystone, mudstone, and shale
41Compaction from the weight of accumulating sediment results in layers that become hardened and turn to sedimentary rocks!
42Most sedimentary rocks form under water. Most of the earth has been covered by water some time in the past. 70% of the earth is covered by water now. So sedimentary rocks are common all over the world.Sedimentary rocks are often rich in fossils.Many sedimentary rocks may have cross-bedding, mud cracks, worm burrows, raindrop impressions.70% of rocks found on Earth are sedimentary.
43Two Types of Sedimentary Rocks! Rocks formed from sediment (sand, silt, clay, or mud) or clasts (pieces) of rock are known as clastic sedimentary rocksRocks formed from processes known as chemical precipitation or organic activity are known as non-clastic sedimentary rocks
49Peat that gets buried over time and compressed deep into the earth eventually gives us bituminous coal. Bituminous coal is carbon-rich and is an excellent source of energy. Humans burn coal to release that energy in the form of heat.
50GypsumNon-Clastic sedimentary rock that can be scratched with your fingernail!
51Metamorphic RocksForm from pressure and extreme temperatures changing the chemistry of igneous and sedimentary rocks that got buried into the earth over time.
52Metamorphosis Complete change of character, appearance, or condition. Involves heat, pressure, and chemical actionProcess can occur more than onceResults in the recrystallization of original rock (sedimentary or igneous) and a different mineral composition
65Taj Mahul in IndiaBuilt between 1632 and 1654 is made entirely out of marble!
66Up to 100,000 tons of rock a year fall to earth from space Up to 100,000 tons of rock a year fall to earth from space. The largest meteorite in the world lies in the ground in Africa and weighs more than 60 tons.
67A 2. 2 lb rock collected from the moon during the Apollo 16 mission A 2.2 lb rock collected from the moon during the Apollo 16 mission. This rock formed when older moon rocks were fragmented and and then fused back together by a meteorite impact about 3.9 bya. The shiny black material on the side is impact-generated glass.
68The Importance of Rocks and Minerals NameType of RockUseBasaltIgneousUsed in road building materialsCalciteMineralUsed in cements and mortars and the production of limeGraniteUsed for buildings, monuments, and tombstonesMarbleMetamorphicUsed in building, floors, tile in bathroomsObsidianUsed in making arrowheads and knivesPumiceUsed in scouring, scrubbing, and polishing materialsQuartzUsed in making glass, electrical components, and optical lensesSanstoneSedimentaryUsed in the building industry for housesSlateUsed for roofs, chalkboards, and patio walks
69LandformsPart or area of the Earth’s surface that has a distinctive shape or topography
70Weatheringis a series of natural processes, both physical and chemical, that act to change exposed rock into mineral and rock particles and chemical compounds in solution.
71Independent Variable Dependent Variable is the one variable that is changed on purpose in an experiment.Dependent Variableis the outcome that is being measured in an experiment.