Download Grade 6 Chapter 1 Study Guide

Grade 6 Chapter 1 Plate Tectonics Study Guide
*Section 1 Earth’s Interior: Be able to define the following terms:
 crust
 mantle
 lithosphere
 asthenosphere
 outer core
 inner core
 basalt
 granite
 seismic waves
 Know the geologists use two main types of evidence to learn about Earth’s
interior: 1. direct evidence from rock samples and 2. indirect evidence from
seismic waves.
 Be able explain the different compositions of earth’s layers (i.e. the crust,
mantle, outer core, and inner core) and be able to label the different layers of
our planet on a diagram.
 Understand the difference between continental crust and oceanic crust and
the rock types that each mainly consist of.
 Know that earth’s core is composed of the metals nickel and iron and that
movements in the liquid outer core are believed to be responsible for the
magnetic field.
 Realize that temperature and pressure increase as you travel towards the
center of the earth’s core.
*Section 2 Convection and the Mantle: Be able to define the following terms:
 radiation
 conduction
 convection
 density
 convection current
 Know the differences between the three types of heat transfer (radiation,
conduction, and convection).
 Understand the heating and cooling of a fluid, changes in the fluid’s
density, and the force of gravity combine to cause convection currents in the
mantle.
 Know that heat from the core and the mantle itself cause convection
currents to rise and sink in the mantle.
*Section 3 Drifting Continents: Be able to define the following terms:
 continental drift
 Pangea
 fossil
 Know that in Alfred Wegner’s hypothesis of continental drift, he thought
that all the continents were once joined together in one single landmass and
since drifted apart.
 Be able to list the evidence he gathered to support his continental drift
hypothesis (i.e. land features, fossils, and evidence of climate change).
 Be able to explain why other scientists rejected Alfred Wegner’s
hypothesis.
 Know that the supercontinent Pangea existed approximately 225 million
years ago and have since moved to their current locations of today.
*Section 4 Sea-Floor Spreading: Be able to define the following terms:
 mid-ocean ridge
 sonar
 sea-floor spreading
 deep-ocean trench
 subduction
 Know that scientist use sonar devices that bounce sound waves off
underwater objects to map the bottom of the ocean.
 Know that Henry Hess proposed the idea of sea-floor spreading to provide
a mechanism to Alfred Wegner’s continental drift hypothesis.
 Understand that in the sea-floor spreading theory, the sea floor
continuously spreads apart on both sides of a mid-ocean ridge as new crust is
added from molten material coming up from the mantle, and this is what
moves the continents.
 Be able to list the three sources of evidence that Henry Hess used to
support his sea-floor spreading theory (i.e. eruptions of molten material,
magnetic stripes in the rock of the ocean floor, and the ages of the rocks
themselves).
 Know that oceanic crust along the mid-ocean ridge is eventually destroyed
at a deep-ocean trench and this keeps a balance of new ocean floor being
created while older crust is subducted into the mantle.
 Know that the sea-floor spreads at an average rate of between 2-10
centimeters a year and that the ocean floor is renewed about every 200 million
years.
*Section 5 The Theory of Plate Tectonics: Be able to define the following terms:
 plate tectonics
 scientific theory
 fault
 rift valley
 divergent boundary
 convergent boundary
 transform boundary
 Know that another scientist named J. Tuzo Wilson proposed that the
lithosphere was broken into many sections he called plates and these plates fit
together along cracks in the lithosphere.
 Be able to explain the difference between a hypothesis and a theory.
 Know that the plate tectonics theory explains the formation, movement,
and subduction of Earth’s lithosphere plates.
 Be able to explain how convection currents in the mantle, gravity, and
density differences between continental crust and oceanic crust provide the
mechanism for the plates to move in relation to one another.
 Be able to define and explain the differences between the three types of
plate boundaries (i.e. transform, divergent, and convergent) as well as the
geologic features that exist at each.