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How Fast Is the Ocean Floor Moving? / I .tAUSTAL EVOLUTION EDUCATION PROJECT U.S. DEPARTMENT OF EDUCATION NATIONAL INSTITUTE OF EDUCATION ED CATIONAL RESOURCES INFORMATION CENTER (ERIC) 1'Nes document has been reproduced as received (torn the person or organrzabon onginabng t Who, changes have been made to improve reproducbon Quality Pots of new or optnions Stated rn rho docu "PERMISSION TO REPRODUCE THIS men( do not necesSanty represent officer ME MATERIAL IN MICROFICHE ONLY poster or pohcy HAS BEEN GRANTED BY TO THE EDUCATIONAL RESOURCES INFORMATION CENTER (ERIC) How Fast Is The Ocean tea Floor Moving? TEACHER'SGUIDE . Catalog No. 34W1013 For use with Student Investigation 34W1113 Ciasi time: two to three 45-minute periods 0 Developed by THE NATIONAL ASSOCIATION OF GEOLOGYTEACHERS Produced and Distributed by Ward's Natural Science Establishment, Inc.Rochester, NY Mopterey, CA 2 111TM 4tRU STA L. EVOLUTION EDUCATION PROJECT U.S. DEPARTMENT OF EDUCATION NATIONAL INSTITUTE OF EDUCATION E0 CATIONAL RESOURCES INFORMATION CENTER (ERIC) The document has been reproduced as received from the person or organdation Originating it Minor changes have been made to improve reproduCbon quality Fo.nts of v.w Or Opink/nS stated in this doco "PERMISSION TO REPRODUCE THIS thent do not neCeSSanry represent otIttet NIE MATERIAL INMICROFICHE ONLY POSiteth or pofev HAS BEEN GRANTED BY TO THE EDUCATIONAL RESOURCES INFORMATION CENTER (ERIC) How Fast Is The Ocean 73 FloorMoving? TEACHER'S GUIDE . Catalog No. 34W1013 .c6 For use with Student Investigation 34W1113 Class time: two to throe 45-minute periods IP Developed by . THE NATIONAL ASSOCIATION OFGEOLOGY TEACHERS Produced and Distributed by Ward's Natural Science Establishment, Inc.Rochester, NY Mopterey, CA * 2 v. NAGT Crustal Evolution Education Project Edward C. Stoever, Jr., Project Director Welcome to the exciting world of current research Teachers and students alike have a unique into tne composition history and processes of the opportunity throwgh CEEP modules to share in the eartri s crust and the applNation of this knowledge unfolding of these educationally important and to man 's activities The earth sciences are exciting advances CEEP modules are designed currently experiencing a dramatic revolution in to provide students with appealing firsthand Our understanding of the way in which the earth investigative experiences with concepts which are wr,rks CEEP modules are designed to bring into at or close to the frontiers of scientific inquiry into assroom the methods and results of these plate tectonics Furthermore, the CEEP modules investigations The Crustal Evolution are designed to be used by teachers with little or El,,,anon Project began work in 1974 under no previous background in the modern, theories -tr auspices of the National Association of of sea-floor spreading, continental drift and plate -Ge.-yogy Teachers CEEP materials have been tectonics developed by team,s of science educators We know that you will enjoj, using CEEP c-assroorn teachers and scientists Prior to modules to your classroom Read on and be o-nlication the materials were field tested by prepared to experience a renewed enthusiasm for fh-,r,-1 than UV tkcriers and over 12,000 students teaching as you learn more about the hying earth C :,rustal evolutioN research is a breaking In this and other CEEP modules st:Jr, that students are living through today About CEEP Modules ... CEEP ---locules consist of two bocAlets a ,crying quantities according to the method of Teach ,s Guide and a Student Iriiestigation The presentation Read over the module before' Teacner s G sde contains all the information scheduling its use in class and refer to the list of ,arvi :1 ustrat,ons in the Student Investigation ',1ATERIALS in the module P'us sect,ons printed in color, intended only for tne Each module is individual and self-contained in teacPer as Nell as answers to the questions that content but some are divided into two or more are ^c'uder in the Student Investigation Darts for convenience The recommendll length In some module,s there are illustrations that of time tor each module.is indicated Some modules `a;_-)pear only in the Teachb.r s Guide and these are require prerequisite knowledge of some aspects lewpated ni figure letters instead of the number of basic earto science this. is noted ire the see; ,ence used ;n the Student Investigation Teacher s Guide Fr_-,r some modules maps, rulers and other nom on classroom materials ,are needed and in The material was prepared with the A, support of National Science Foundat6n Grant Nos SED 75-20151 SED 77-'08539, and SED 78-25104 However, any opinions findings conclusions or recommendations fi expressed herein are those of tne author(s) arid do not necessarily reflect the views of NSF, , -in owei tp comply with U S Public Caw ?'94-86 -every school district in the U S A istng :rese materials agrees to make them available for inspection by parents or guardians of children engaged in educational; programs or projects of the scbcol district= sq. Copyright 1979 by Southr7s1 Missouri StateUnhsrsity I Air HowFast Is The Ocean Floor Moving? INTRODUCTION In this module students examine data froin sediments on the sea-flow. They determine whether the data support the theory of sea-floor spreading, and calculate the rate of spreading of the East Pacific Rise, usind sediment data. Many earth scientists believe that the continents of Africa and South America were once joined together. What is the evidence for this belief? If it is true, how long has it taken for these two continents to break apart and move to where they are now? Is the earth's surface moving in other places? One way to answer these questrons.is to study samples of sediment taken from the ocean floor Sediment is loose rock, mineral debris, and plant and animal shells which have settled out of the water. -In these activities you will use sediment data, like scientists do, to determine how fast the ocean floor is moving. The deep sea sediments were dbtained by the GlomarChar ranger.TheGlomar Challenger )sa , specially designed drilling ship that can take samples of sediment and rock from the floor df deep ocean basinsIt recovers both sediment and rock ores A core is a cylinder of sediment or rock obtained by using a hollow drillIn many lases, scientists must drill through hundreds of meters of sediment before reaching t rie solid igneous rook of the ocean floor This igneous rock formS by cooling and hardening of Molten rock, material It is the '.'floor" upon which the sediments/settle. r . , PREREQUISITE STUDENT BACKGROUND Students should be familiar with the sea -floor spreading hypothesis in general. The hypothesis states that new ocean crust material is added at the mid-ocean ridge system where the sea floor spreads apart. The students are expected to know how to complete a graph.'Some students may need assistance in converting kilometers to centimeters. OBJECTIVES After You have completed these activities, you should be able to A 1. Make and interpret graphs which show tie 3. Form hypotheses about sea-floor movement relationship between the, thickness of a sediment based on data from sediment cores sample and its distance/from a mid.oCean ridge 4. Calculatethe/ate of movement of the ocean 2. Make and interpret graphs which .show the floor from data on sediment thicknesses,., ages of relationship between the age of deep'eep sea sediments sediment, and locations of the drill sites and their distancato a midocean,ridge... a MATERIALS Map, Pacific Ocean Floor, Natiorial Geog5aphic Society, Educational Services, Department 79, Washington, D.C. 20036one or two per class. Meter stick or metric measuring tape one per group of 3. BACKGROUND INFORMATION The East Pacific Rise is alseS called the East Pacific Ridge. Published literature indicates that prominent scientists use these terms interchange- ably. In this module use of the term East Pacific Rise conforms to historical precedent and popular usage. A The data used in this activity were gathered by the Glomar Challenger on Leg 9 of the Deep Sea Drilling Project. (The section of a cruise between two places is called a leg.) The Glomar Challenger is a specially designed drilling ship which under ideal conditions can take cores of the entire sedimentary sequence and the basaltic rocks of the ocean floor crust. Technological advances allow Figure A. Data from sediment cores have helped scientists to drill cores in the Ocean floor as much to confirm the sea-floor spreading theory. as 4,000 meters below sea level. The drill cores Sediments recovered directly above basement (some are several hundred meters in length) are (igneous ocean crust) nearer the oceanic ridge are studied on board the ship and eventually taken to younger (Y) than those recovered farther from the onshore laboratories for more intensive analysis. ridge (0). Sediments lying on the basaltic ocean floor crust become progressively older with increased distance Sedimentation rites in most parts of the open from the oceanic ridge. in the western Pacific, ocean are slow, ranging from a few millimeters east of the Philippine Islands, the oldest sediments to a centimeter per thousand years (Davis, 1977, recovered from the present ocean floor so far are p. 411). The rates at which sediments accumulate of Jurassic age. This agree with their expected vary with time. The Deep Seathilling'Project has ages calculated from the spading rates. shown there were periods of time when sediments accumulated very slowly or not at all, There are Sediments which cover the ocean floor can either places near the equator where the high production settle out of seawater in the open ocean (pelagic of plants and animals results in rapid accumulation sediments) or come directly from land (terrigenous of sediments.
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