Transcript Plate Tectonics Theory.

Brainstorm….
 What is the difference between a hypothesis, theory,
and a Law?
Framework!
 A Hypothesis is an educated guess based on research
and observation.
 A Theory is a detailed explanation backed by evidence
that withstands repeated testing.
 A Law is a detailed observation backed by evidence
that withstands repeated testing.
Continental Drift Theory
 The idea that all continents were once together in one
landmass.
 Continents once existed as a supercontinent known as
Pangaea.
Evidence of Continental Drift
• “Jigsaw” of continents.
• Identical fossils are found across the oceans.
• Rock Layers across oceans match up.
• Identical climates across the oceans.
Seafloor Spreading
 Mid Ocean Ridges are mountain ranges in the
middle of the ocean.
 The seafloor spreads apart along both sides of a mid
ocean ridge like a conveyer belt.
Evidence of Seafloor Spreading
 Paleomagneitism is the study of Earth’s magnetic
field shown in rocks.
 The age of the crust gets older the further away it is
from a mid ocean ridge.
Earth’s Plates
 Earth’s lithosphere is broken into separate sections
called plates.
 These pieces of lithosphere float on the asthenosphere
and interact with each other.
Plate Tectonics Theory
 The theory that explains how Earth’s plates move and
change shape is known as The Plate Tectonics
Theory.
 Plate tectonics explains why seafloor spreading and
continental drift occur.