Presentation on theme: "Chapter 4 - Rocks What can be learned by studying rocks… We can learn mo better about earth. So what is a rock??? Its a mixture of 1 or more minerals."— Presentation transcript:
Chapter 4 - Rocks What can be learned by studying rocks… We can learn mo better about earth. So what is a rock??? Its a mixture of 1 or more minerals. Easy.
The Rock Cycle Shows how any rock may be transformed from one type into another. Its a continuous process that causes rocks to change.
Vocab terms Magma – underground molten rock Lava – above ground molten rock Crystallization – formation of minerals from cooling magma/lava Weathering – any process that breaks down rocks into smaller pieces (sediment)
Vocab terms Erosion – transportation of sediment Deposition – accumulation of sediment Metamorphism – changing one type of rock into another by heat/pressure/chemicals Lithification – compaction and cementation of sediment
Igneous Rocks…from fire 2 main types –Intrusive (large crystals) From magma Underground Cools and forms slowly –Extrusive (small crystals) From lava Above ground Cools and forms quickly
Igneous Rocks Classification 2 ways to classify igneous rocks 1 = Texture 2 = composition 1. Texture (3 types) a)Coarse grained – slow cooling, large crystals b)Fine grained – fast cooling, small crystals c)Glassy – super fast cooling, glassy Porphyritic – slow and fast cooling, has both large and small crystals
2. Composition Granitic (felsic) –High in silica (SiO 4 ), light colored, lower density Basaltic (mafic) –Low in silica, dark colored, high in iron and magnesium higher density Andesitic (intermediate) Ultramafic
Sedimentary Rocks Your teacher rocks!
Sedimentary Rocks From (Latin) sedimentum = settling Made from sediments of any type 4 agents of erosion (transportation) 1.Water 2.Wind 3.Glaciers 4.Gravity
3 Types Sedimentary Rock 1.Clastic = formed from sediment 2.Chemical = formed from precipitation or evaporation…dried up soda on a table 3.Biochemical (organic) = formed from remains of once living organisms
2) Chemical Sedimentary Rocks Crystalline limestone – precipitates from ocean water Gypsum – precipitates from oceans, too Travertine – precipitates in caves Chert/flint – quartz Rock salt – evaporated salt water
Metamorphic Rocks Means to change form 2 types of metamorphism 1. Contact - small areas from toughing hot magma 2. Regional - large areas from the pressures of mountain building
Agents of Metamorphism 1.Heat (temperature) 2.Pressure (stress) 3.Reactions in hot solutions (chemicals)
Metamorphic Rock Classification 2 textures 1.Foliated - layered 2.Nonfoliated – not layered
1. Foliated Metamorphic Rx A) Slate – very thin layers from shale B)Phyllite – thin layers, sheen, wavy, from slate C)Schist – medium layers,shiny, micas, from phyllite D)Gneiss – distinct black & white layers, from schist or granite
2. Nonfoliated Metamorphic RX A)Marble – shiny, fizzes in acid, H = 3, from limestone B)Quartzite – shiny, wont fizz, H = 6 – 7, from sandstone C)Anthracite coal – shiny, black, from bituminous coal The carbon cycle…see page 85