Earth Tectonics & Science

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What is the ø of the earth?

8,000 miles
What is the ø of the sun?

800,000 miles
What is the earth circumference?

24,000 miles
Describe Earth's 3 distinct, concentric layers:
- Iron Core
- Mantle
- Crust
Describe 2 types of the Earth's Crust:
- Oceanic → Mafic → Basalt
- Continental → Felsic → Granitic
Describe 3 sources of Earth's residual Heat:
- Gravitational energy
- Kinetic energy → planetesimal collisions
- Meteor impacts
Heat from within the Earth is continually generated by:

Radioactive decay
What is a Lithosphere and where is located?

Rigid outer layer containing "crust" & frozen part of the upper mantle
What is the Asthenosphere and where is located?
- Partially melted upper mantle
- has plastic-like
What is the Lower Mantle and where is located?
- Mesosphere
- Solid layer of rocks
- between the asthenosphere iron core
What are the components of Earth's core and where are they located?
- Liquid Core
- Solid Iron Core
What happened to most of the hydrogen and helium that accumulated with Earth's mass?
- Escaped
- Earth did not have enough gravity
How much free oxygen was available very early in Earth's history?

Almost none
What does the presence of pyrite grains in early sedimentary rocks imply?

Back then was no free oxygen because pyrite was not oxidized like in today's atmosphere.
Describe the occurrence of "Banded Iron Formations" during early Earth times?
(2.5 - 2 billion yrs)
- BIF require abundant oxygen
- Therefore, during that time there must have been more free oxygen
- Became thick + cover vast areas
Which ancient life forms were present at least 3.5 billion years ago that began creating Earth's fee oxygen?

Bacteria + Algae

Author

Anonymous

242515

Card Set

Earth Tectonics & Science

Description

Unit 4

Updated

2013-10-24T02:44:49Z

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