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Mineral Mania
The Rock Factory A Pre-Visit Information Guide for Teachers Meets Next Generation Science Standards: 5-PS1-3; MS LS4-1,2; MS ESS1-4; MS-ESS2-1 How does our Earth create so many different types of rocks? Learn about the different processes that form and reform rocks as you identify many types of rocks, minerals and fossils. Students will learn to think like geologists as they move through interactive investigation stations packed with specimens from the Museum’s collections. OBJECTIVES The Rock Cycle: Students will examine the three types of rocks - igneous, metamorphic and sedimentary – and discover the processes that create them. Tracing the connections between shale and slate, limestone and marble, students will discover how the rock cycle changes the very ground beneath our feet! Characteristics of Rocks Students will learn how to observe and identify rocks through their unique characteristics, looking for telling clues such as layering, crystal size, fossils, magnetism, and more. Students will practice their observational skills as they describe the Museum’s unique rock and mineral specimens. Investigation Stations: Students will explore Museum geology specimens up close at investigation stations to answer such questions as: “Why do fossils form only in certain rocks?” “How do rocks form from volcanic eruptions?” “How can I recognize different types of rocks?”. ACTIVITIES Teachers are encouraged to conduct pre-visit and post-visit classroom discussions and activities with their classes to make the most of their experience. Encourage your students to start a classroom rock collection, and create an exhibit with the rocks organized by type – igneous, sedimentary and metamorphic. -
Geologic Boulder Map of Campus Has Been Created As an Educational Educational an As Created Been Has Campus of Map Boulder Geologic The
Adam Larsen, Kevin Ansdell and Tim Prokopiuk Tim and Ansdell Kevin Larsen, Adam What is Geology? Igneous Geo-walk ing of marine creatures when the limestone was deposited. It also contains by edited and Written Geology is the study of the Earth, from the highest mountains to the core of The root of “igneous” is from the Latin word ignis meaning fire. Outlined in red, numerous fossils including gastropods, brachiopods, receptaculita and rugose the planet, and has traditionally been divided into physical geology and his- this path takes you across campus looking at these ancient “fire” rocks, some coral. The best example of these are in the Geology Building where the stone torical geology. Physical geology concentrates on the materials that compose of which may have been formed at great depths in the Earth’s crust. Created was hand-picked for its fossil display. Campus of the Earth and the natural processes that take place within the earth to shape by the cooling of magma or lava, they can widely vary in both grain size and Granite is another common building stone used on campus. When compa- its surface. Historical geology focuses on Earth history from its fiery begin- mineral composition. This walk stops at examples showing this variety to help nies sell granite, they do not use the same classification system as geologists. nings to the present. Geology also explores the interactions between the you understand what the change in circumstances will do to the appearance Granite is sold in many different colours and mineral compositions that a Map Boulder Geologic lithosphere (the solid Earth), the atmosphere, the biosphere (plants, animals of the rock. -
Exploring Origins of Pitted/Vesicular Rocks in Perseverance Valley, Endeavour Crater
50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132) 2327.pdf EXPLORING ORIGINS OF PITTED/VESICULAR ROCKS IN PERSEVERANCE VALLEY, ENDEAVOUR CRATER. A. W. Tait1*, C. Schröder1, W. H Farrand2, J. W. Ashley3, B. A. Cohen4, R. Gellert5, J. Rice6, L. C. Crumpler7, B. Jolliff8, 1Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, UK ([email protected]), 2Space Science Institute, Boulder, CO, USA, 3Jet Propulsion Laboratory, California In- stitute of Technology, Pasadena, CA, USA, 4NASA Goddard Space Flight Centre, Greenbelt, MD, USA, 5Department of Physics, University of Guelph, Ontario, Canada, 6Planetary Science Institute, Tucson, AZ, USA, 7NM Museum of Natural History & Science, Albuquerque, NM, USA, 8Washington University in St. Louis, MO, USA. Introduction: Since sol 4780, the NASA Mars Ex- ploration Rover (MER) Opportunity has been traversing down Perseverance Valley (PV), a linear, negative-re- lief feature trending perpendicular to the western flank of Endeavour crater. The goal of the current investiga- tion is to understand PVs geomorphology and chemical composition to determine its mode of formation and ap- proximate age. Formation hypotheses include debris or fluid flow, and wind sculpting, all while intersecting possible Noachian lithologies [1]. Rover observations confirms orbital data that there exists a dextral off-set, indicating a structural origin to the valleys formation [2]. This faulting may have allowed for fluids to interact with the rocks [3]. On sol ~5000 Opportunity started to investigate a train of dark pitted/vesicular rocks with an unusual morphology, texture, and composition enriched in Al and Si. Here we describe the rock facies, and ex- plore preliminary formation/alteration hypotheses. -
Advanced Geodynamics: Fourier Transform Methods
Advanced Geodynamics: Fourier Transform Methods David T. Sandwell January 13, 2021 To Susan, Katie, Melissa, Nick, and Cassie Eddie Would Go Preprint for publication by Cambridge University Press, October 16, 2020 Contents 1 Observations Related to Plate Tectonics 7 1.1 Global Maps . .7 1.2 Exercises . .9 2 Fourier Transform Methods in Geophysics 20 2.1 Introduction . 20 2.2 Definitions of Fourier Transforms . 21 2.3 Fourier Sine and Cosine Transforms . 22 2.4 Examples of Fourier Transforms . 23 2.5 Properties of Fourier transforms . 26 2.6 Solving a Linear PDE Using Fourier Methods and the Cauchy Residue Theorem . 29 2.7 Fourier Series . 32 2.8 Exercises . 33 3 Plate Kinematics 36 3.1 Plate Motions on a Flat Earth . 36 3.2 Triple Junction . 37 3.3 Plate Motions on a Sphere . 41 3.4 Velocity Azimuth . 44 3.5 Recipe for Computing Velocity Magnitude . 45 3.6 Triple Junctions on a Sphere . 45 3.7 Hot Spots and Absolute Plate Motions . 46 3.8 Exercises . 46 4 Marine Magnetic Anomalies 48 4.1 Introduction . 48 4.2 Crustal Magnetization at a Spreading Ridge . 48 4.3 Uniformly Magnetized Block . 52 4.4 Anomalies in the Earth’s Magnetic Field . 52 4.5 Magnetic Anomalies Due to Seafloor Spreading . 53 4.6 Discussion . 58 4.7 Exercises . 59 ii CONTENTS iii 5 Cooling of the Oceanic Lithosphere 61 5.1 Introduction . 61 5.2 Temperature versus Depth and Age . 65 5.3 Heat Flow versus Age . 66 5.4 Thermal Subsidence . 68 5.5 The Plate Cooling Model . -
The Way the Earth Works: Plate Tectonics
CHAPTER 2 The Way the Earth Works: Plate Tectonics Marshak_ch02_034-069hr.indd 34 9/18/12 2:58 PM Chapter Objectives By the end of this chapter you should know . > Wegener's evidence for continental drift. > how study of paleomagnetism proves that continents move. > how sea-floor spreading works, and how geologists can prove that it takes place. > that the Earth’s lithosphere is divided into about 20 plates that move relative to one another. > the three kinds of plate boundaries and the basis for recognizing them. > how fast plates move, and how we can measure the rate of movement. We are like a judge confronted by a defendant who declines to answer, and we must determine the truth from the circumstantial evidence. —Alfred Wegener (German scientist, 1880–1930; on the challenge of studying the Earth) 2.1 Introduction In September 1930, fifteen explorers led by a German meteo- rologist, Alfred Wegener, set out across the endless snowfields of Greenland to resupply two weather observers stranded at a remote camp. The observers had been planning to spend the long polar night recording wind speeds and temperatures on Greenland’s polar plateau. At the time, Wegener was well known, not only to researchers studying climate but also to geologists. Some fifteen years earlier, he had published a small book, The Origin of the Con- tinents and Oceans, in which he had dared to challenge geologists’ long-held assumption that the continents had remained fixed in position through all of Earth history. Wegener thought, instead, that the continents once fit together like pieces of a giant jigsaw puzzle, to make one vast supercontinent. -
MAGNITUDE of DRIVING FORCES of PLATE MOTION Since the Plate
J. Phys. Earth, 33, 369-389, 1985 THE MAGNITUDE OF DRIVING FORCES OF PLATE MOTION Shoji SEKIGUCHI Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto, Japan (Received February 22, 1985; Revised July 25, 1985) The absolute magnitudes of a variety of driving forces that could contribute to the plate motion are evaluated, on the condition that all lithospheric plates are in dynamic equilibrium. The method adopted here is to solve the equations of torque balance of these forces for all plates, after having estimated the magnitudes of the ridge push and slab pull forces from known quantities. The former has been estimated from the age of ocean floors, the depth and thickness of oceanic plates and hence lateral density variations, and the latter from the density con- trast between the downgoing slab and the surrounding mantle, and the thickness and length of the slab. The results from the present calculations show that the magnitude of the slab pull forces is about five times larger than that of the ridge push forces, while the North American and South American plates, which have short and shallow slabs but long oceanic ridges, appear to be driven by the ridge push force. The magnitude of the slab pull force exerted on the Pacific plate exceeds to 40 % of the total slab pull forces, and that of the ridge push force working on the Pacific plate is the largest among the ridge push forces exerted on the plates. The high cor- relation that exists between the mantle drag force and the sum of the slab pull and ridge push forces makes it difficult to evaluate the absolute net driving forces. -
An Evidence-Based Approach to Teaching Plate Tectonics in High School
An evidence-based approach to teaching plate tectonics in high school COLIN PRICE ABSTRACT 5. relating the extreme age and stability of a large part of the Australian continent to its plate tectonic This article proposes an evidence-based and engaging history. approach to teaching the mechanisms driving the movement of tectonic plates that should lead high The problem with this list is the fourth elaboration, school students towards the prevalent theories because the idea that convection currents in the used in peer-reviewed science journals and taught mantle drive the movement of tectonic plates is a in universities. The methods presented replace the myth. This convection is presented as whole mantle inaccurate and outdated focus on mantle convection as or whole asthenosphere cells with hot material rising the driving mechanism for plate motion. Students frst under the Earth’s divergent plate boundaries and examine the relationship between the percentages of cooler material sinking at the convergent boundaries plate boundary types of the 14 largest plates with their with the lithosphere dragged along by the horizontal GPS-determined plate speeds to then evaluate the fow of the asthenosphere (Figure 1). This was the three possible driving mechanisms: mantle convection, preferred explanation for plate motion until the ridge push and slab pull. A classroom experiment early 1990s but it does not stand up to a frequent measuring the densities of igneous and metamorphic deduction made by Year 9 students: how can there be rocks associated with subduction zones then provides large-scale mantle convection if hotspots (like Hawaii) a plausible explanation for slab pull as the dominant don’t move? Most science teachers quickly cover driving mechanism. -
Structure of the Earth
And the ROCK CYCLE Structure of the Earth Compositional (Chemical) Layers Crust: Low density High in silicon (Si) and oxygen (O) Moho: Density boundary between crust and mantle Mantle: Higher density High in Magnesium (Mg) and Iron (Fe) Core: High in Nickel (Ni) and Iron (Fe) Heat Flow in the Earth Heat sources: latent heat from the formation of the Earth Radioactive decay in the core and mantle Temperature in the core: 3000- 5000° C Cooling processes: Convection currents: in outer core and asthenosphere transport heat to the surface Plate tectonics releases heat through the crust (volcanoes) Convection cells in the mantle and core transport heat from the interior of earth to the surface and also return cooler material back into the earth. Mechanical (Physical) Layers of the Earth Lithosphere: Crust and upper, solid part of the mantle; “plates” in plate tectonics Asthenosphere: Partially molten part of mantle; location of convection current that drive plates Outer core: Liquid Inner core: Solid Greatest temperatures, solid due to intense pressure Comparing Compositional Layers to Mechanical Layers Moho What is a Rock? A group of minerals bound together Three major groups: 1) Igneous: Solidified Molten Magma 2) Sedimentary: formed by cementing of sediments. Sediments come from the erosion of other rocks. 3) Metamorphic: Heat and pressure change a rock into something new, without melting. Rock Types Igneous: Solidified molten magma 2 types of Igneous: 1) Extrusive (volcanic) = erupted lava Cools more quickly, so only small crystals form. 2) Intrusive (plutonic) = never erupted magma Cools more slowly within the earth, so larger crystals can form. -
The Relation Between Mantle Dynamics and Plate Tectonics
The History and Dynamics of Global Plate Motions, GEOPHYSICAL MONOGRAPH 121, M. Richards, R. Gordon and R. van der Hilst, eds., American Geophysical Union, pp5–46, 2000 The Relation Between Mantle Dynamics and Plate Tectonics: A Primer David Bercovici , Yanick Ricard Laboratoire des Sciences de la Terre, Ecole Normale Superieure´ de Lyon, France Mark A. Richards Department of Geology and Geophysics, University of California, Berkeley Abstract. We present an overview of the relation between mantle dynam- ics and plate tectonics, adopting the perspective that the plates are the surface manifestation, i.e., the top thermal boundary layer, of mantle convection. We review how simple convection pertains to plate formation, regarding the aspect ratio of convection cells; the forces that drive convection; and how internal heating and temperature-dependent viscosity affect convection. We examine how well basic convection explains plate tectonics, arguing that basic plate forces, slab pull and ridge push, are convective forces; that sea-floor struc- ture is characteristic of thermal boundary layers; that slab-like downwellings are common in simple convective flow; and that slab and plume fluxes agree with models of internally heated convection. Temperature-dependent vis- cosity, or an internal resistive boundary (e.g., a viscosity jump and/or phase transition at 660km depth) can also lead to large, plate sized convection cells. Finally, we survey the aspects of plate tectonics that are poorly explained by simple convection theory, and the progress being made in accounting for them. We examine non-convective plate forces; dynamic topography; the deviations of seafloor structure from that of a thermal boundary layer; and abrupt plate- motion changes. -
Extrusive Igneous Rocks- a Rock Formed on the Earth’S Surface
Rocks What is a rock? • Rock- naturally formed, consolidated materials composed of one or more minerals. • There are 3 types of rocks: • Igneous • Sedimentary • Metamorphic Igneous Rocks What are Igneous Rocks? • Magma vs. Lava • Magma- molten rock below the Earth’s surface. • Lava- magma on the Earth’s surface. • Igneous Rock- rocks made from cooling magma or lava. • They can be intrusive or extrusive. Intrusive vs. Extrusive • Intrusive Igneous Rocks- a rock that forms below the Earth’s surface. • Normally made from magma • Extrusive Igneous Rocks- a rock formed on the Earth’s surface. • Normally made from lava. Extrusive rock The white rock is intrusive. Intrusive Igneous Rocks • We cannot see these rocks be formed. • They typically have large crystal minerals. • The rock itself can give you a lot of information about how it was formed. Extrusive Igneous Rocks • You can see them form: • Lava flow • Ash Flow • Lava that cools down very quickly so all you see is ask coming out • Pyroclastic Flow • Clouds flowing downhill like a huge avalanche. • Data from these rocks can be used to interpret ancient volcanic activity. Igneous Rock Textures • The crystal size of the rock is related to the speed of the rock cooling. • Fast gives you small crystals and slow cooling gives you large crystals. • Also the rocks can appear: • Glassy- look like a piece of glass. • From the magma/lava cooling too quickly. • Vesicular- has air bubbles in it. This is vesicular. • From air bubbles getting trapped in the magma/lava. • Fragmental- they look jagged and angular. This is glassy and fragmental. -
Lavas. Understanding Volcanism Provides a Background for Theories
lavas. Understanding volcanism provides a background for theories relating to mountain building, the development and evolution of continental and oceanic crt~st,and how the crust is deformed. Our observations of volcanic activity fit nicely into plate-tectonic theory as described in chapter 11. The May 18, 1980 eruption of Mount St. Helens (box 10.1) was a spectacular release of energy from the earth's interior. The plate-tectonic explanation is that North America, moving weritwa~d,is overriding a portion of the Pacific Ocean Aoor. Melting of previously solid rock takes place at depth, just above the subduction zone. (Thii was described briefly in chapter 1 and more thoroughly in chapter 11.) At least some of the magma (molten rock or liquid that is mostly silica) works its way upward to the earth's surface to erupt. Magma does not always reach the earth's surface before solidifying, but when it does it is called lava. At Mount St. Helens the lava solidified quickly as it was blasted explosively by gases into the air, producing rock frag- ments known as pyrodasw (from the Greekpyro, "fire," and clart, "broken"). Pyroclastic debris is also known as tcphra. Elsewhere in the world (notably Hawaii) lava extrudes out of Flgulr 10.1 fissures in the ground as lava flows. Pyrodastic debris and Volcanic eruptions in Hawaii, 1969. A lava fountain is supply11 rock formed by solidification of lava are collectively regarded the lava cascading over the cliff. as emwive rock, surface rock resulting from volcanic Photo by D A Swanson, US Geolog~calSurvey acrivity. -
Igneous Petrology
IGNEOUS PETROLOGY PRESENTED BY Dr.A.BALUKKARASU Associate Professor Centre for Remote Sensing Bharathidasan University Thiruchirappalli-620 023 India. mail id:[email protected] MTIGT0403: IGNEOUS & METAMORPHIC PETROLOGY 1. Forms and Structures of Igneous rocks - Intrusives and their relation to Geological Structures (Concordant and Discordant forms - Multiple Intrusions – Composite Intrusions) - Composition and Constitution of Magmas - Structure and Texture of Igneous Rocks- Formation of Igneous rocks: Crystallization of Unicomponent Magma -Phase Equilibria studies of Binary and Ternary Silicate system - Crystallisation of Basaltic magma. 12 Hrs. 2. Classification of Igneous rocks – Microtextures and Structures of Igneous rocks and their Petrogenetic Significance - Petrography of Igneous rocks – Tabular Classification - Petrography of Acid-Intermediate - Basic and Ultrabasic rocks - Diversity of Igneous rocks - Reaction Principle - Magmatic Crystallization – Assimilation – Petrographic province and various diagrams - Plate Tectonics and Magmatic Evolution – Fluid Inclusion studies of Igneous rocks. Evolution of Basalts -Petrogenesis of Granites, Pegmatities, Alkaline rocks, Monomineralic rocks, Charnockites and Ultramafics. 14 Hrs. 3. Definition of Metamorphism - Scope of Metamorphism – Controlling factors of Metamorphism - Kinds of Metamorphism and its Products - Classification and Nomenclature - Petrography of Metamorphic rocks (Schists – Gneisses – Granulites) - Metamorphic textures and Microstructures and their relation to Metamorphic