Study guide 2

_______   _______ was a hypothesis proposed by Alfred Wegener, where Pangaea broke apart roughly ~200 Ma and shifted to the current position.

• Tectonic Plate Theory
• Global Warming Theory
• Continental Drift

• Earthquake Theory

What is Pangaea?

• Pangaea was a planet
• Pangaea was a type of dinosaur
• Pangaea was a famous explorer
• Supercontinent (continents fused together)

What was the evidence that supported continental drift hypothesis?

• Alignment of the planets
• Discovery of new continents
• Analysis of ocean currents
• •Fit of the continents

  Distribution of climate belts (glacier & swamp)

  Distribution of fossils

  Matching geologic units& mountain ranges

Why was continental drift hypothesis eventually discarded?

• Didn’t provide a valid mechanism

• There was no evidence to support the hypothesis
• Scientists lost interest in the topic
• The hypothesis was proven to be entirely false

What is the concept of seafloor spreading?

• Seafloor spreading involves the movement of tectonic plates towards each other
• Harry Hess (American Professor)

  Stretching apart at mid-ocean ridge forms new seafloor by volcanic eruptions.

  Old seafloor is subducted at seafloor trenches.

  To maintain Earth’s volume, amount of seafloor created at spreading centers must equal amount of seafloor destroyed at trenches in subduction zones.

• Seafloor spreading is the process of the Earth's crust sinking into the mantle
• Seafloor spreading occurs due to the cooling of the Earth's core

Define Plate Tectonics Theory.

• Plate Tectonics Theory explains the formation of clouds in the atmosphere.
• Plate Tectonics Theory is related to the study of marine biology.
• Plate Tectonics Theory focuses on the behavior of celestial bodies in space.
• Lithosphere is broken into a series of plates that move

  relative to each other

  Move over underlying asthenosphere

What are the three types of plate boundaries?

• Divergent boundaries, convergent boundaries, and transform boundaries.
• Collision boundaries, sliding boundaries, and rift boundaries.
• Subduction boundaries, lateral boundaries, and sliding boundaries.
• Tectonic boundaries, sliding boundaries, and fault boundaries.

What is the lithosphere?

• The lithosphere is the layer of the atmosphere closest to the Earth's surface.
• Earth’s rigid outer shell (crust and uppermost mantle)

• The lithosphere is the molten core of the Earth.
• The lithosphere is the layer of the Earth where living organisms reside.

What is the asthenosphere?

• Solid outer layer of the Earth's mantle
• Hotter and weaker rocks of the mantle

  Beneath the lithosphere

  Allows for gradual motion, slow flow

• Liquid layer of the Earth's core
• Rigid layer of the Earth's lithosphere

_________ plate boundaries are constructive margins, where

two plates move apart, and the mantle material upwells to

create new seafloor.

• Transform
• Subduction
• Divergent
• Convergent