Download 3/15 Lesson 15 Investigating plate movement and faults pg

Lesson 15 Investigating plate movement and faults
Homework
Colliding, Sliding and Separating Plates Pg. 174-175
1. What happens when plates slide?
When plates slide no new land forms. Energy is built up as the
plates rub up against each other. When the rock breaks, fractures
or slips this energy is released in the form of an earthquake.
2. What happens when plates collide?
When two continental plates collide the ground crumples
upward forming mountains, such as the Himalayan mts.
When an oceanic plates collides with a continental plates the more
dense oceanic plates slides under the continental plate forming an
ocean trench. The end of the oceanic plate melts. The magma
then rises through the continental plate forming volcanic
mountains.
3. What happens when plates separate?
In this case magma rises up to form a mountain ridge. (midatlantic ridge)
Lesson 15: Investigating Plate Movement and Faults
Homework
Earth’s Moving Plates: A Look Back, pages186-189
1. Explain the theory of Continental Drift. Provide evidence to
support this theory.
According to this theory proposed in 1912 by the German
scientist Alfred Wegener,. He believed that Pangaea broke
apart and the continents drifted the continents were once
united in one “supercontinent” that Wegener named Pangaea
to their present loc+ation over time. His theory was
supported by the following evidence:
a. The shorelines of continents seemed to match like
pieces of a puzzle.
b. Mountains of similar age and structure were located on
separated continents.
c. The same plant and animal fossils were found on
different continents.
d. Continents that are currently in the tropics were once
covered with glaciers.
2. Explain the theory of sea floor spreading. Provide evidence
to support this theory.
Evidence shows that the sea floor closer to a mid-ocean ridge
is younger than parts of the sea floor located near trenches.
This would suggest that as the sea floor spreads, magma rises
forming new land where the plates separate. The older sea
floor slides under continental crust forming ocean trenches.
3. What is the theory of Plate Tectonics?
This theory states that plates move away from mid-ocean ridges
causing new land to form, and old land moves toward ocean
trenches and sinks into the earth. Mountain chains of volcanic
islands, such as Japan, form along trenches, where events such as
earthquakes and volcanoes occur. The theory of plate tectonics
explains how continental drift occurred and how sea floor
spreading takes place.--