...to Geog 111 Main Page and Course Description
...to Geog 111 Syllabus
...to Geog 111 Course Schedule and Lecture Outlines
...to Geog 111 Course Project

Introduction

To understand landforms

• have to understand basics of the atmosphere and hydrosphere

• both contain major forces that shape landforms

The Earth's atmosphere

• Composition, Vertical Structure, Weather and Climate

The Earth's hydrosphere

• the unique characteristics of water
  • processes which cause it to change from one state to another
    
  • sublimation, evaporation/condensation, freezing/melting

• the Hydrologic Cycle: seven vital components:
  • Surface to Air Water Movement
    
  • Air to Surface Water Movement
    
  • Movement on and Beneath Earth's Surface
    
  • The Oceans
    
  • Permanent Ice
    
  • Surface Waters
    
  • Underground Water

Next: An Introduction to Landform Study

Landforms shaped by

• external forces: atmosphere and hydrosphere (and biosphere)

• internal forces: processes occurring below the surface of the earth

1. Earth and its Interior

Physical geographers focus on the surface of the earth: part of the lithosphere

Geologists: more concern with the interior of the earth and related processes

• OWU Geology courses

What we know about the interior of the Earth

• limited amount of direct experience
  • examples

  
  
  

• what we do know is based on indirect evidence
  • example

McKnight Fig 13.1: Earth and its Interior

The earth's crust: diverse mix of different rock types

• variations in thickness

At the base of the crust is a narrow zone of material: Moho

• Mohorovicic discontinuity: what is it

The earth's mantle

• where and how deep

• size in relation to other layers

McKnight Fig. 13.2: Earth's Mantle

Zones in Earth's mantle: more spheres!

• outer zone: lithosphere: characteristics

• next zone: asthenosphere: characteristics

• next zone: mesosphere: characteristics

McKnight Fig 13.1: Earth and its Interior

The outer core

• characteristics

The inner core

• characteristics

2. Composition of the Earth's Crust

90+ chemical elements in the crust

Most are bonded together with other elements to form compounds we call minerals

• minerals: solid substances having characteristic crystal structure

Rock: aggregated mineral particles

McKnight Fig 13.4 Bedrock

• outcrop:

• bedrock:

• regolith:

2a. Igneous Rocks

Origins

Common characteristic: crystalline structure

• example) Granite and characteristics
  

  
  

  example) Rhyolite and characteristics

  

One way to distinguish igneous rocks is by the conditions under which they solidified

McKnight Fig 13.5a: Igneous Rocks

extrusive igneous rocks: characteristics

• McKnight Fig 13.6 Basalt

• example) basalt and characteristics
  

  
  

  example) obsidian and characteristics

  

intrusive igneous rocks: cool beneath Earth's surface at a slow rate

• exposed (erosion) or pushed up as part of Earth's surface

• McKnight Fig 13.7 Granite: characteristics

All rocks started out as igneous: but transformed by physical processes into two other major types of rock: sedimentary and metamorphic

2b. Sedimentary Rocks

Various physical processes (chemical or mechanical) break up rocks into fragments

Sediment: small particles of rock and organic material deposited by water, wind, or ice

Two factors are involved in turning sediments into sedimentary rock:

• weight (pressure) and cementation

McKnight Fig 13.8: Pressure and Cementation

Weight (pressure) on sediments and effects

Cementation: cementing agents (silica, calcium carbonate, iron oxide) and effects

Variations in sedimentary depositing: leads to layering

Stratification: horizontal layering: characteristic of sedimentary rocks

Types of sedimentary rock: based on how they formed

• mechanical: how formed
  • example) conglomerate and characteristics

    

    
    

  • example) shale and characteristics

    

    
    

  • example) sandstone and characteristics

    

    
    

• chemical: how formed
  • McKnight Fig 13.9a Limestone Cliff (large component of calcium carbonate)

  • McKnight Fig 13.9b Limestone specimen

  • example) limestone (stromatolitic)