Fossils and Faults Activity Background – Stress the Movement of Earth’S Plates Creates Enormous Forces That Squeeze Or Pull the Rock in the Crust

Total Page:16

File Type:pdf, Size:1020Kb

Fossils and Faults Activity Background – Stress the Movement of Earth’S Plates Creates Enormous Forces That Squeeze Or Pull the Rock in the Crust Fossils and Faults Activity Background – Stress The movement of Earth’s plates creates enormous forces that squeeze or pull the rock in the crust. Since the outer part of the Earth crust is relatively cold, when it is stressed it tends to break. Any force that acts on rock to change its shape or volume is called _______________. Stress adds energy to the rock. The energy is stored in the rock until it changes shape or breaks. There are 3 basic types of stress acting upon the Earth’s crust: tension, compression and shearing. ________________pulls on the crust, stretching rock so that it becomes thinner in the middle. *We call this a ___________ boundary when discussing plate tectonics. _____________________ Fault ______________________squeezes rock until it folds or breaks. *We call this a _________________________ boundary when discussing plate tectonics. _____________________ Fault ______________________ pushes a mass of rock in two opposite directions *We call this a _______________boundary when discussing plate tectonics._____________________ Fault Background - Faults When enough stress builds up in rock, the rock breaks, creating a fault. These breaks are called ____________________________. Most faults occur along plate boundaries, where the forces of plate motion push or pull the crust so much that the crust breaks. There are three main types of faults: normal faults, reverse faults, and strike-slip faults. The most obvious result of movement along a fault is an _____________________. Earthquakes tend to happen along the boundaries between plates ________________ causes a normal fault. In a _____________________ ___________, the fault is at an angle, and one block of rock lies above the fault while the other block lies below the fault. The block of rock that lies above is called the _____________________________ The rock that lies below is called the ________________________________. _____________________ causes reverse faults. A ____________________ fault has the same structure as a normal fault, but the blocks move in the opposite direction. ____________________creates strike-slip faults. In a _______________- _______________ fault, the rocks on either side of the fault slip past each sideways, with little up or down motion. Background - Fossils and Superposition The ______________ ______ ______________________ states that in undisturbed rock layers the oldest rock is on the bottom and the youngest is on the top. This makes it simple to determine the relative age of fossils in the different layers of rock. The rock layers, however, are often disturbed (mixed) because of plate motion. Faulting and folding take old rock and push it on top of young rock. Over millions of years, the forces of plate movement can change a flat plain into landforms such as anticlines and synclines, folded mountains, fault-block mountains, and plateaus. A fold in rock that bends upward into an arch is an ________________________. A fold in rock that bends _________________ to form a ________________ is a _________________. Anticlines and synclines are found on many parts of the Earth’s surface where _____________________ forces have folded the crust. Plate movements and stress also create reverse, normal, strike slip and thrust faults. The constantly shifting plates make it difficult to date the age of the Earth’s rocks. A paleontologist (scientist that studies fossils) has to know geology to read the fossil record of life on earth. Directions 1. Color the fossils and faults model according to the color key provided. 2. Cut out the fossils and faults model and form into a box with the surface features on the top. 3. Use the shaded tabs to tape the corners together. 4. Carefully cut the model in half along the dotted line. 5. Cut out and tape the fault face pieces to the open fault face of the two halves. 6. Label the two halves as hanging wall and footwall as shown below. 7. Use the model to answer the questions. .
Recommended publications
  • Strike and Dip Refer to the Orientation Or Attitude of a Geologic Feature. The
    Name__________________________________ 89.325 – Geology for Engineers Faults, Folds, Outcrop Patterns and Geologic Maps I. Properties of Earth Materials When rocks are subjected to differential stress the resulting build-up in strain can cause deformation. Depending on the material properties the result can either be elastic deformation which can ultimately lead to the breaking of the rock material (faults) or ductile deformation which can lead to the development of folds. In this exercise we will look at the various types of deformation and how geologists use geologic maps to understand this deformation. II. Strike and Dip Strike and dip refer to the orientation or attitude of a geologic feature. The strike line of a bed, fault, or other planar feature, is a line representing the intersection of that feature with a horizontal plane. On a geologic map, this is represented with a short straight line segment oriented parallel to the strike line. Strike (or strike angle) can be given as either a quadrant compass bearing of the strike line (N25°E for example) or in terms of east or west of true north or south, a single three digit number representing the azimuth, where the lower number is usually given (where the example of N25°E would simply be 025), or the azimuth number followed by the degree sign (example of N25°E would be 025°). The dip gives the steepest angle of descent of a tilted bed or feature relative to a horizontal plane, and is given by the number (0°-90°) as well as a letter (N, S, E, W) with rough direction in which the bed is dipping.
    [Show full text]
  • Faults and Joints
    133 JOINTS Joints (also termed extensional fractures) are planes of separation on which no or undetectable shear displacement has taken place. The two walls of the resulting tiny opening typically remain in tight (matching) contact. Joints may result from regional tectonics (i.e. the compressive stresses in front of a mountain belt), folding (due to curvature of bedding), faulting, or internal stress release during uplift or cooling. They often form under high fluid pressure (i.e. low effective stress), perpendicular to the smallest principal stress. The aperture of a joint is the space between its two walls measured perpendicularly to the mean plane. Apertures can be open (resulting in permeability enhancement) or occluded by mineral cement (resulting in permeability reduction). A joint with a large aperture (> few mm) is a fissure. The mechanical layer thickness of the deforming rock controls joint growth. If present in sufficient number, open joints may provide adequate porosity and permeability such that an otherwise impermeable rock may become a productive fractured reservoir. In quarrying, the largest block size depends on joint frequency; abundant fractures are desirable for quarrying crushed rock and gravel. Joint sets and systems Joints are ubiquitous features of rock exposures and often form families of straight to curviplanar fractures typically perpendicular to the layer boundaries in sedimentary rocks. A set is a group of joints with similar orientation and morphology. Several sets usually occur at the same place with no apparent interaction, giving exposures a blocky or fragmented appearance. Two or more sets of joints present together in an exposure compose a joint system.
    [Show full text]
  • Tectonic Features of the Precambrian Belt Basin and Their Influence on Post-Belt Structures
    ... Tectonic Features of the .., Precambrian Belt Basin and Their Influence on Post-Belt Structures GEOLOGICAL SURVEY PROFESSIONAL PAPER 866 · Tectonic Features of the · Precambrian Belt Basin and Their Influence on Post-Belt Structures By JACK E. HARRISON, ALLAN B. GRIGGS, and JOHN D. WELLS GEOLOGICAL SURVEY PROFESSIONAL PAPER X66 U N IT ED STATES G 0 V ERN M EN T P R I NT I N G 0 F F I C E, \VAS H I N G T 0 N 19 7 4 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog-card No. 74-600111 ) For sale by the Superintendent of Documents, U.S. GO\·ernment Printing Office 'Vashington, D.C. 20402 - Price 65 cents (paper cO\·er) Stock Number 2401-02554 CONTENTS Page Page Abstract................................................. 1 Phanerozoic events-Continued Introduction . 1 Late Mesozoic through early Tertiary-Continued Genesis and filling of the Belt basin . 1 Idaho batholith ................................. 7 Is the Belt basin an aulacogen? . 5 Boulder batholith ............................... 8 Precambrian Z events . 5 Northern Montana disturbed belt ................. 8 Phanerozoic events . 5 Tectonics along the Lewis and Clark line .............. 9 Paleozoic through early Mesozoic . 6 Late Cenozoic block faults ........................... 13 Late Mesozoic through early Tertiary . 6 Conclusions ............................................. 13 Kootenay arc and mobile belt . 6 References cited ......................................... 14 ILLUSTRATIONS Page FIGURES 1-4. Maps: 1. Principal basins of sedimentation along the U.S.-Canadian Cordillera during Precambrian Y time (1,600-800 m.y. ago) ............................................................................................... 2 2. Principal tectonic elements of the Belt basin reentrant as inferred from the sedimentation record ............
    [Show full text]
  • Collision Orogeny
    Downloaded from http://sp.lyellcollection.org/ by guest on October 6, 2021 PROCESSES OF COLLISION OROGENY Downloaded from http://sp.lyellcollection.org/ by guest on October 6, 2021 Downloaded from http://sp.lyellcollection.org/ by guest on October 6, 2021 Shortening of continental lithosphere: the neotectonics of Eastern Anatolia a young collision zone J.F. Dewey, M.R. Hempton, W.S.F. Kidd, F. Saroglu & A.M.C. ~eng6r SUMMARY: We use the tectonics of Eastern Anatolia to exemplify many of the different aspects of collision tectonics, namely the formation of plateaux, thrust belts, foreland flexures, widespread foreland/hinterland deformation zones and orogenic collapse/distension zones. Eastern Anatolia is a 2 km high plateau bounded to the S by the southward-verging Bitlis Thrust Zone and to the N by the Pontide/Minor Caucasus Zone. It has developed as the surface expression of a zone of progressively thickening crust beginning about 12 Ma in the medial Miocene and has resulted from the squeezing and shortening of Eastern Anatolia between the Arabian and European Plates following the Serravallian demise of the last oceanic or quasi- oceanic tract between Arabia and Eurasia. Thickening of the crust to about 52 km has been accompanied by major strike-slip faulting on the rightqateral N Anatolian Transform Fault (NATF) and the left-lateral E Anatolian Transform Fault (EATF) which approximately bound an Anatolian Wedge that is being driven westwards to override the oceanic lithosphere of the Mediterranean along subduction zones from Cephalonia to Crete, and Rhodes to Cyprus. This neotectonic regime began about 12 Ma in Late Serravallian times with uplift from wide- spread littoral/neritic marine conditions to open seasonal wooded savanna with coiluvial, fluvial and limnic environments, and the deposition of the thick Tortonian Kythrean Flysch in the Eastern Mediterranean.
    [Show full text]
  • Faults and Earthquakes Lesson Plans and Activities
    Faults and Earthquakes Lesson Plans and Activities Targeted Age: MATERIALS NEEDED Elementary to High School • Colored pencils or crayons Activity Structure: Individual assignment • Scissors • Tape Indiana Standards and Objectives: 3.PS.1, 4.ESS.2, 7.ESS.3, 7.ESS.4, • Printed copies of fault block activity ES.6.7, ES.5.6, ES.6.5, ES.6.7 Introduction In this lesson, students will create three-dimensional (3-D) blocks out of paper to learn about the types of faulting that occur at the Earth’s surface and its interior. Students will manipulate three fault blocks to demonstrate a normal fault, reverse fault, and strike- slip fault, and explain how movement along a fault generates earthquakes because of the sudden release of energy in the Earth’s crust. Background Information The outer crust of the Earth is divided into huge plates, much like a cracked eggshell. Driven by convection currents that permit heat to escape from the Earth’s interior, the plates move at a rate of about a ½ inch to 4 inches per year, displacing continental land masses and ocean floor alike. The forces that move the plates create stresses within the Earth’s crust, and can cause the crust to suddenly fracture. The area of contact between the two fractured crustal masses is called a fault. Earthquakes result from sudden movements along faults, creating a release of energy. Movement along a fault can be horizontal, vertical, or both. Studies show that the crust under the central United States was torn apart, or rifted, about 600 million years ago.
    [Show full text]
  • 2 Review of Stress, Linear Strain and Elastic Stress- Strain Relations
    2 Review of Stress, Linear Strain and Elastic Stress- Strain Relations 2.1 Introduction In metal forming and machining processes, the work piece is subjected to external forces in order to achieve a certain desired shape. Under the action of these forces, the work piece undergoes displacements and deformation and develops internal forces. A measure of deformation is defined as strain. The intensity of internal forces is called as stress. The displacements, strains and stresses in a deformable body are interlinked. Additionally, they all depend on the geometry and material of the work piece, external forces and supports. Therefore, to estimate the external forces required for achieving the desired shape, one needs to determine the displacements, strains and stresses in the work piece. This involves solving the following set of governing equations : (i) strain-displacement relations, (ii) stress- strain relations and (iii) equations of motion. In this chapter, we develop the governing equations for the case of small deformation of linearly elastic materials. While developing these equations, we disregard the molecular structure of the material and assume the body to be a continuum. This enables us to define the displacements, strains and stresses at every point of the body. We begin our discussion on governing equations with the concept of stress at a point. Then, we carry out the analysis of stress at a point to develop the ideas of stress invariants, principal stresses, maximum shear stress, octahedral stresses and the hydrostatic and deviatoric parts of stress. These ideas will be used in the next chapter to develop the theory of plasticity.
    [Show full text]
  • 4. Deep-Tow Observations at the East Pacific Rise, 8°45N, and Some Interpretations
    4. DEEP-TOW OBSERVATIONS AT THE EAST PACIFIC RISE, 8°45N, AND SOME INTERPRETATIONS Peter Lonsdale and F. N. Spiess, University of California, San Diego, Marine Physical Laboratory, Scripps Institution of Oceanography, La Jolla, California ABSTRACT A near-bottom survey of a 24-km length of the East Pacific Rise (EPR) crest near the Leg 54 drill sites has established that the axial ridge is a 12- to 15-km-wide lava plateau, bounded by steep 300-meter-high slopes that in places are large outward-facing fault scarps. The plateau is bisected asymmetrically by a 1- to 2-km-wide crestal rift zone, with summit grabens, pillow walls, and axial peaks, which is the locus of dike injection and fissure eruption. About 900 sets of bottom photos of this rift zone and adjacent parts of the plateau show that the upper oceanic crust is composed of several dif- ferent types of pillow and sheet lava. Sheet lava is more abundant at this rise crest than on slow-spreading ridges or on some other fast- spreading rises. Beyond 2 km from the axis, most of the plateau has a patchy veneer of sediment, and its surface is increasingly broken by extensional faults and fissures. At the plateau's margins, secondary volcanism builds subcircular peaks and partly buries the fault scarps formed on the plateau and at its boundaries. Another deep-tow survey of a patch of young abyssal hills 20 to 30 km east of the spreading axis mapped a highly lineated terrain of inactive horsts and grabens. They were created by extension on inward- and outward- facing normal faults, in a zone 12 to 20 km from the axis.
    [Show full text]
  • Deformation of Rocks
    DeformationDeformation ofof RocksRocks Rock Deformation Large scale deformation of the Earth’s crust = Plate Tectonics Smaller scale deformation = structural geology 1 Deformation of rocks Folds and faults are geologic structures Structural geology is the study of the deformation of rocks and the effects of this movement Small-Scale Folds 2 Small-Scale Faults Deformation – Stress vs. Strain Changes in volume or shape of a rock body = strain 3 Stress The force that acts on a rock unit to change its shape and/or its volume Causes strain or deformation Types of directed Stress include Compression Tension Shear Compression Action of coincident oppositely directed forces acting towards each other 4 Tension Action of coincident oppositely directed forces acting away from each other Shear Action of coincident oppositely directed forces acting parallel to each other across a surface Right Lateral Movement Left Lateral Movement 5 Differential stress Strength • Ability of an object to resist deformation •Compressive •Capacity of a material to withstand axially directed pushing forces – when the limit of compressive strength is reached, materials are crushed •Tensile •Measures the force required to pull something such as rope, wire, or a rock to the point where it breaks 6 Strain Any change in original shape or size of an object in response to stress acting on the object Kinds of deformation Elastic vs Plastic Brittle vs Ductile 7 Elastic Deformation Temporary change in shape or size that is recovered when the deforming force is removed
    [Show full text]
  • Focal Mechanism
    Earthquake Source Mechanics Lecture 5 Earthquake Focal Mechanism GNH7/GG09/GEOL4002 EARTHQUAKE SEISMOLOGY AND EARTHQUAKE HAZARD What is Seismotectonics? Study of earthquakes as a tectonic component, divided into three principal areas. 1. Spatial and temporal distribution of seismic activity a) Location of large earthquakes and global earthquake catalogues b) Temporal distribution of seismic activity 2. Earthquake focal mechanisms 3. Physics of the earthquake source through analysis of seismograms GNH7/GG09/GEOL4002 EARTHQUAKE SEISMOLOGY AND EARTHQUAKE HAZARD Location of large earthquakes and the global earthquake catalogues ß Historically of crucial importance in the development of plate tectonics theory a It was the recognition of a continuous belt of seismicity across the North Atlantic (together with profiles measured by marine geophysicists) that allowed Ewing & Heezen to predict the existence of a worldwide system of mid-ocean rifts ß Goter extended this work in the 60’s & 70’s to compile global seismicity maps delineating the plate boundaries a Similar maps at larger scale constructed from regional and local seismic networks allow the tectonics to be studied in much finer detail GNH7/GG09/GEOL4002 EARTHQUAKE SEISMOLOGY AND EARTHQUAKE HAZARD Global seismicity GNH7/GG09/GEOL4002 EARTHQUAKE SEISMOLOGY AND EARTHQUAKE HAZARD Earthquake focal mechanisms ß Using teleseismic earthquake records to determine the earthquake focal mechanism or fault plane solution and deduce the tectonics of a region ß Similar work now done at larger scale for looking at regional and local tectonics - neotectonics GNH7/GG09/GEOL4002 EARTHQUAKE SEISMOLOGY AND EARTHQUAKE HAZARD The Seismic Source ß Shear faulting a Simple model of the seismic source 1. Fracture criterion 2.
    [Show full text]
  • EPS 116 – Laboratory Structural Geology Lab Exercise #1 Spring 2016
    EPS 116 – Laboratory Structural Geology LAB #1 – Orientation of Structures in Space Familiarize yourself with the following terms. Sketch each feature and include relevant details, e.g., footwall, hanging wall, motion arrows, etc. Also always include at least 3 horizontal layers and an up arrow in the cross sections and a north arrow in each map view. Stress vs. Strain Feature Cross Section Map View compression tension Horst and contraction/shortening Graben extension (Label hanging /foot wall and slip Brittle Deformation direction) joint fault earthquake Thrust Fault thrust/reverse fault (Label hanging / normal fault footwall and slip footwall direction) hanging wall strike-slip fault right lateral or dextral Anticline left lateral (Label hinge axis, or sinistral force direction, dip-slip contact topo lines in map view) oblique-slip Ductile Deformation fold Normal Fault anticline (Label hanging / footwall and slip syncline direction) Map View longitude latitude geographic vs. magnetic north Syncline topography (Label hinge axis, scale force direction, profile contact topo lines in map view) Strike-Slip fault (Label hanging / footwall and slip direction) Lab Exercise #1 Spring 2016 Page 1 of 9 EPS 116 – Laboratory Structural Geology Strike & Dip Strike and dip describe the orientation of a plane in space. Example: the peaked roof of a house: Strike Line Dip Direction Strike is the orientation of the intersection line of the plane in question (roof of a house) with the horizontal plane. If you were to look down on the house from directly above, it would look like this: North Strike Line Strike The angle between the strike line and north is used to describe the strike.
    [Show full text]
  • Safe and Efficient Basement Construction Directly Below Or Near to Existing Structures
    ASUC | Guidelines on SAFE AND EFFICIENT BASEMENT CONSTRUCTION DIRECTLY BELOW OR NEAR TO EXISTING STRUCTURES ASUC Underpinning & Subsidence Repair Techniques | Engineered Foundation Solutions | Retro Fit Basement Construction Kingsley House, Ganders Business Park , Kingsley, Bordon, Hampshire GU35 9LU Tel: +44 (0)1420 471613 www.asuc.org.uk ASUC ASUC is an independent trade association formed by a number of leading contractors to promote professional and technical competence within the underpinning industry. Members offer a comprehensive range of subsidence repair techniques, engineered foundation and retrofit basement construction solutions. It publishes a number of useful documents on underpinning and related activities and a comprehensive directory of members all of which are freely available to download via the website. ASUC members offer 10 or 12 year, depending on the nature of the works, insurance backed latent defects guarantees. Kingsley House, Ganders Business Park, Kingsley, Bordon, Hampshire GU35 9LU Tel: +44 (0)1420 471613 Fax: +44 (0)1420 471611 [email protected] www.asuc.org.uk Part-funded by The Health and Safety This project has been delivered with support from the CITB Executive has been Growth Fund, which aims to ensure that the construction consulted on the contents industry has the right people, with the right skills, in the right of this publication place, at the right time and is equipped to meet the future skills demands of the industry Although care has been taken to ensure, to the best of our knowledge, that all data and information contained in this document is accurate to the extent that it relates to either matters of fact or accepted practice or matters of opinion at the time of publication, neither ASUC, the authors or contributors nor the co-publishers will be liable for any technical, editorial, typographical or other errors or omissions in or misinterpretations of the data and information provided in this document.
    [Show full text]
  • The Earthquake Generating Stresses in the Western Rift Valley of Africa
    J. Phys. Earth, 28, 45-57, 1980 THE EARTHQUAKE GENERATING STRESSES IN THE WESTERN RIFT VALLEY OF AFRICA Kazuo TANAKA,* Shigeki HORIUCHI,** Toshiya SATO,** and Ndontoni ZANA*** *Department of Earth Sciences, University of Hirosaki, Hirosaki, Japan ** Akita Geophysical Observatory , Tohoku University, Akita, Japan *** Centre de Geophysique, Institut de Recherche Scientifique, Bukavu, Zaire (Received June 16, 1978; Revised October 26, 1979) The earthquake generating stress fields of the Western Rift Valley of Africa are discussed in detail from the data obtained by the seismological network of IRS, Zaire, and by the seismological stations in Africa. The present analysis is based on the method of composite mechanism solution using the initial motions of P-waves from earthquakes which occurred during the period from 1958 to 1970. The stress fields are analyzed for ten sub-regions divided on the ground of the characteristics of seismicity. Quite stable solutions are obtained for the sub-regions of Lake Kivu and its vicinities, which are located in the central part of the Western Rift Valley, and shows that the stress fields are of the normal faulting type. The direction of tension axis of each solution is generally perpendicular to the rift system or to the local faults. The per- pendicularity is consistent with the results reported by several authors studying focal mechanisms of earthquakes occurring in the African Rifts and the ocean ridges. In contrast with this general conclusion, the strike-slip type of focal mechanism prevails in sub-regions of the southern part of the Western Rift Valley, and a heterogeneous stress field is suggested in the sub-region of the active volcanoes of Nyiragongo and Nyamuragira.
    [Show full text]