Rocks, Weathering, and Processes PDF

THREE MAIN CATEGORIES OF ROCKS 1 IGNEOUS ROCKS Results from volcanic activity in the Earth’s crust and upper mantle 2  IGNEOUS ROCKS 2 Types: Intrusive and Extrusive 1. Intrusive Igneous-formed from magma underground Ex. Diorite, gabbro,...

THREE MAIN CATEGORIES OF ROCKS 1 IGNEOUS ROCKS Results from volcanic activity in the Earth’s crust and upper mantle 2  IGNEOUS ROCKS 2 Types: Intrusive and Extrusive 1. Intrusive Igneous-formed from magma underground Ex. Diorite, gabbro, granite, and pegmatite 3 20XX PRESENTATION TITLE 4  IGNEOUS ROCKS 2 Types: Intrusive and Extrusive 2. Extrusive Igneous-formed from molten rocks above the ground Ex. Andesite, basalt, obsidian, pumice, rhyolite, and scoria 5 20XX PRESENTATION TITLE 6 SEDIMENTARY ROCKS Results from the deposition of materials transported by water wind or ice. 7  SEDIMENTARY ROCKS 3 Types: 1. Clastic Sedimentary Rocks 2. Chemical Sedimentary Rocks 3. Organic Sedimentary Rocks 8  CLASTIC SEDIMENTARY ROCKS Formed from the breakdown material of other rocks eroded. 9 20XX PRESENTATION TITLE 10  CHEMICAL SEDIMENTARY ROCKS Commonly found in the ocean 11 20XX PRESENTATION TITLE 12  ORGANIC SEDIMENTARY ROCKS Formed from fossils of dead organisms such as bones and shells, which are cemented together to form into a rock. 13 20XX PRESENTATION TITLE 14 20XX PRESENTATION TITLE 15 METAMORPHIC ROCKS Produces when pressure and heat cause changes in existing rocks 16  METAMORPHIC ROCKS 4 types: 1. Contact metamorphism 2. Regional metamorphism 3. Foliated metamorphism 4. Non-foliated metamorphism 17 Natural Earth Processes Rosemarie C. Tuto, LPT OBJECTIVES : Describe how rocks undergo weathering Explain how products of weathering are carried away by erosion and deposition Picture Analysis What idea can you infer from the picture? Explain EXOGENIC AND ENDOGENIC PROCESSES EXOGENIC PROCESSES Weathering Breaking up of rocks by such agents as water, ice, chemical, growing plants, and changing temperature. Two kinds of weathering processes A. Mechanical/Physical weathering- breaking up of big rocks into small fragments without changing the mineral content of the rock. This process is also called DISINTEGRATION. B. Chemical weathering- decomposes or decays rocks. Soil, sand, mud, and other fragments are products of weathering. Erosion Process in which rocks that are weathered rocks into smaller fragments and sediments are easily moved from one place into another, by erosion agents such as water, ice, wind, or gravity. Mass wasting Also known as mass movement or slope movement happens when soil, sand, regolith, and rock move downslope typically as a mass. Types of mass movement Soil creep Landslide Flow Slump Fall Soil creep Gravity pulls down slope the soil or rock in different direction over time. Landslide Also called as landslip Rapid movement of a large mass of earth and rocks down a hill or a mountainside when there is heavy rainfall like in areas with less vegetation. Flow Includes avalanches, mudflows, debris flows, earth flows, and lahars. Slump Involves a mass of soil or other material sliding along a curved surface (like spoon) Fall A rock for example, is where the regolith moves down a slope, but volume or viscosity is not sufficient to behave as a flow. Sedimentation This process is the opposite of erosion ENDOGENIC PROCESSES  Activity I. What idea can you infer in the word FOLDS? What idea can you infer in the word FAULTS? 35 Endogenic processes Process that is formed, originated, and located below the surface of the earth. 1. Igneous Processes a. Volcanism-volcanic eruption b. Plutonism-igneous intrusions 2. Tectonic Processes/Diastrophism a. Folding b. Faulting The following are factors that must be met for deformation of rock to occur: Rock material must have the ability to deform under heat and pressure. The higher the temperature of the rock the more plastic it becomes. Pressure must not exceed the internal strength of the rock. If it does-fracturing occurs. Deformation must be applied slowly. Types of Folds 1. Monocline-consisting of two horizontal limbs connected by a shorter inclined limb. 2. Anticline- an arch-like shape and has its oldest beds at its core. 3. Syncline- formed where the rock layers are warped downward as a result of compressional forces. 4. Recumbent- an asymmetrical fold in which the axial plane is inclined. Types of Faults 1. Normal Slip Fault - happen in areas where the rocks are pulling apart so that the rocky crust of an area is able to take up more spaces. 2. Reverse Slip Fault - happen in areas where the rocks are pushed together so that the rocky crust of an area must take up less space. 3. Transform/Strike-Slip Fault -horizontal movement with the block of rock on one side of the fault moving in one direction and the block of rock along the other side of the fault moving in other direction.  Overthrust Fault Combination of fault and a fold in a rock 40