Download File - 7th Grade Science

Warm Up #4
▪ How do natural processes change Earth’s surface over time?
Ch. 14 Earth’s Changing
Surface
Lesson 1: Plate Tectonics
Essential Questions
▪ What is the theory of plate tectonics?
▪ What evidence do scientists use to support the theory of plate
tectonics?
▪ How do the forces created by plate motion change Earth’s surface?
Can you put the pieces together?
▪ Scientists use different types of evidence to show that Earth’s
continents once were joined. How have scientists reconstructed
Gondwana, a large ancient continent that was made of many
continents?
▪ Use a pair of scissors to carefully cut out each landmass along the
outer grey line.
▪ Arrange the puzzle pieces to construct a model of Gondwana.
▪ Once you are sure you are correct glue to pieces down on your piece
of paper.
▪ What do you notice about the land masses?
Plate Motion
▪ Plate tectonics – states that Earth’s crust is broken into rigid plates
that move slowly over Earth’s surface
▪ How do the plates move?
Plate Motion
▪ Plate tectonics – states that Earth’s crust is broken into rigid plates
that move slowly over Earth’s surface
▪ How do the plates move?
▪ Move slowly over Earth’s surface either toward, away from, or sliding past
another plate
▪ Why do you think this is a theory and not just a hypothesis?
▪ This replaced the hypothesis of continental drift (the hypothesis that
continents move)
▪ How much time do you think it would take for the tallest mountains
on Earth to form? Why do you think it will take that long?
Plate Motion
▪ Why do many continents look like puzzle pieces that could fit
together?
▪ What evidence do scientists use to support the theory of plate
tectonics?
Plate Motion
▪ Why do many continents look like puzzle pieces that could fit
together?
▪ The continents were joined at one time but then broke apart and moved away
from each other.
▪ What evidence do scientists use to support the theory of plate
tectonics?
▪ Continental drift
▪ Geological evidence – rocks made of similar substances and mountains formed
at similar times are present on continents that are now far apart
▪ Fossil evidence – the same types of fossils are on continents that are now
separated by vast oceans
Warm Up #2
▪ How does Earth’s mantle move tectonic plates?
How Plates Move
▪ How does Earth’s mantle move tectonic
plates?
▪ Earth’s mantle is so hot that rocks can deform and move without breaking
Tectonic Plate Boundaries
▪ Convergent boundary – 2 plates move toward each other
▪ Denser oceanic plate usually forced down into the mantle
▪ Subduction zone – the area where one plate slide under another
▪ What happens when 2 continents collide at a plate boundary?
▪ Divergent boundary – 2 plates move apart from each other
▪ A rift forms between the 2 plates
▪ Molten rock can erupt from the rift and when it cools it forms new crust
▪ Transform boundary – plates slide horizontally past each other
▪ Move in opposite directions
Movement of Plate Boundaries
▪ Go to Page 520 in Owl book.
▪ Follow the instructions step by step.
▪ Answer all questions on a separate piece of paper with your name on
it.
▪ This will be collected at the end of the period.
▪ For homework: Create a foldable about the types of boundaries
(Page 513 in Owl book)