Introduction

Formation of Earth

• The Nebular Hypothesis – bodies in our solar

system evolved from an enormous rotating cloud called the solar nebula.

– mostly hydrogen and helium, with some heavier elements.

Differentiation

• As Earth cooled, layers formed through a process called differentiation.

• Denser elements (iron and nickel) sunk to Earth’s core.

• Lighter material migrated outward forming the mantle and crust.

Earth’s Four Spheres

• Solid Earth (Lithosphere)

• Hydrosphere

• Atmosphere

• Biosphere

Solid Earth•Core

–mostly iron and nickel–densest part of Earth–inner core solid

•Mantle–mostly iron and magnesium–liquid

•Crust–mostly silicon and oxygen–rigid outer layer

Earth’s Crust

• The earth’s crust is divided into:

– Continental crust

– Oceanic crust

Hydrosphere1. Ocean (the most prominent

feature of the hydrosphere)

a. Nearly 71% of Earth’s surface

b. About 97% of the earth’s water

2. Fresh water

a. glaciers

b. rivers and lakes

c. groundwater

Atmosphere1. Gaseous envelope surrounding Earth

a. life-giving gasesb. protects organisms from intense heat and radiation from the sun

Biosphere

1. Includes all life

2. Influences the other three spheres

Course Overview

• Lithosphere- Geology

• Water- Oceanography

• Atmosphere- Meteorology

• Space- Astronomy

Branches of Geology

• Paleontology

Branches of Geology

• Volcanology

Branches of Geology

• Glaciology

Branches of Geology

• Seismology

Branches of Geology

• Mineralogy

Branches of Geology

• Sedimentology

Branches of Geology

• Structural Geology

Branches of Geology

• Planetary Geology