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Study guide for - WHAT TO KNOW LIST GEOLOGY 100 EXAM I WEDNESDAY February 6 INTRODUCTORY MATERIAL Scientific Method explain the data observations

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WHAT TO KNOW LIST, GEOLOGY 100 EXAM I – WEDNESDAY, February 6 INTRODUCTORY MATERIAL Scientific Method- explain the data/ observations with a hypothesis, test the hypothesis, confirm by making predictions COSMOLOGY Nebulas- Remnant of supernova ex) Crab Nebula in Taurus Supernovas- •Explosion of a dying star •Nuclear reactions create elements heavier than iron •Eject large quantities of matter that form new nebulae Planetesimals- Dust particles collide and stick together from a nebula Supernova to nebula to solar system Formation of the solar system The nebula condenses into a swirling disc, with a central ball surrounded by rings. The ball at the center grows dense and hot enough for fusion reactions to begin. It becomes the Sun. Dust (solid particles) condenses in the rings. Dust particles collide and stick together, forming planetesimals . Gravity reshapes the proto-Earth into a sphere. The interior of the Earth separates into a core and mantle. Forming the planets from planetesimals: Planetesimals grow by continuous collisions. Gradually, an irregularly shaped proto-Earth develops. The interior heats up and becomes soft. Soon after Earth forms, a small planet collides with it, blasting debris that forms a ring around the Earth. The Moon forms from the ring of debris. Eventually, the atmosphere develops from volcanic gases. When the Earth becomes cool enough, moisture condenses and rains to create the oceans •Estimated age of the Earth is 4.57 billion years EARTH'S INTERIOR Differentiation of the Earth •Denser materials moved to the center and lighter materials rose to the top •Gases escaped from the interior, forming the early ocean and atmosphere Types of igneous silicate rocks •Silicic Rocks – high silica, low iron & magnesium; Granite •Intermediate Rocks •Mafic Rocks – low silica, high iron and magnesium; Basalt and Gabbro •Ultramafic Rocks – very low silica, very high iron and magnesium; Peridotite •Continental crust •Variety of rock types, but overall is silicic - intermediate •35 – 40 km thick •Oceanic crust •Mafic •7 – 10 km thick •Denser than continental crust Structure of Earth's interior (crust, mantle, lithosphere, asthenosphere, Moho, core, etc.) See graph P Waves (Primary Waves) – travel through solids and liquids S Waves (Secondary Waves) – travel through solids but NOT liquids; travel slower than P waves P waves bend at the core-mantle boundary because wave velocities slow down P waves reflect off a boundary within the core S waves don’t pass through the core at all The outer core must be liquid See graph 2 Earth's magnetic field – how it is generated, paleomagnetism, apparent polar-wander paths, magnetic reversals
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This note was uploaded on 03/31/2008 for the course GEO 100 taught by Professor Cervato during the Spring '07 term at Iowa State.

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Study guide for - WHAT TO KNOW LIST GEOLOGY 100 EXAM I WEDNESDAY February 6 INTRODUCTORY MATERIAL Scientific Method explain the data observations

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