EAS 210: Chapter 1

Define Geology

Study of the earth

Define Physical Geology

Study of the earth's materials and properties

Geological Time: Absolute Dating

- How we measure the time of the earth
-Radioactivity can allow for the measurement for the age of rocks
- Age of the earth is 4.567 billion years old

Inner Core

- Innermost part of the Earth
- Contains solid iron

Outer Core

- A layer formed outside of the inner core.
- Mostly contains liquid iron

Mantle

- A layer formed between the Earth's Crust and the Outer Core
- Formed by silicate mineral with Fe and Mg

Crust

- The outermost layer of the Earth
- Formed by silicate minerals with Na, Ca, and Al

What is the difference between the crust and the mantle

The chemical distinction changes between the layers of the Earth

What are the two types of crust

The crust is thin beneath the ocean and thick and beneath the continents

Plate Tectonics

A theory stating that the Earth is comprised plates which shift and move to form our continents

Lithosphere

-Rigid outer layer of the Earth
-150-250 km thick
-Broken into 16 major tectonic plates
-Important geological processes occur at plate boundaries

Asthenosphere

- Soft layer below the lithosphere that behaves as a liquid

Divergent Plate Boundary

-Plates move apart
-Rift valleys and mid-ocean ridges

Convergent Plate Boundary

-Plates move towards each other

Oceanic Plate and Continental Plate Convergent Boundary

-Subduction zone
-The dense ocean crust is pushed under the continental crust
-brings water into the mantle and allows for volcanos to form

Two Continental Plate Convergent Boundary

-Crusts have same density's and create continent-continent collisions
-Crust piles up to form mountains and large plateaus

Transform Plate Boundary

-Plates move against each other

Mid-Ocean Ridge

-Linear mountain range on the seafloor

Subduction Zone

-Contain a line of volcanos
-Offshore is a trench that can be filled with sediment

Transform Faults

-Offset mid-ocean ridges on the seafloor
-linear feature on continents