Nature of Earth: An Introduction to Geology

Origin of the Universe
1: Origin of the Universe

In the beginning, there was no need for geology because there were no rocks, minerals, or Earth. This lecture takes a "big picture" look at the formation and early evolution of the universe....

31 min
Origin of the Solar System
2: Origin of the Solar System

The planets formed from a disc of cosmic dust rotating around the Sun. The composition of the planets varies. Those nearest the Sun are made of rock, while those most distant are made of gases....

30 min
Continental Drift
3: Continental Drift

Until the 20th century, geologists believed that the size, shape, and location of the continents had been fixed in their present configuration for billions of years. Then the theory of plate tectonics changed everything....

30 min
Plate Tectonics
4: Plate Tectonics

This lecture describes plate tectonics-the rifting of continents and spreading of the sea floor; the force that drives this process; and the cyclic creation, breaking up, and reformation of supercontinents....

30 min
The Formation of Minerals
5: The Formation of Minerals

A full understanding of Earth's origin, the evolution of its surface, and how processes shape the land requires knowledge of minerals, how they form, and their basic classification....

30 min
Classification of Minerals
6: Classification of Minerals

Minerals are classified by their dominant, negatively charged grouping (anion). By far, the major rock-forming minerals are silicates built around the silicate anion. All other minerals are classified as non-silicates....

29 min
The Identification of Minerals
7: The Identification of Minerals

For the average geologist in the field, mineral identification is made based on a series of physical properties. Color streak, cleavage, acid reaction, and hardness are four such tests....

31 min
Kinds of Rocks
8: Kinds of Rocks

Of the three types of rock-igneous, sedimentary, and metamorphic-igneous rocks constitute 80 percent of Earth's crust. They are classified and named based on their texture and mineral composition....

30 min
Sedimentary Rocks
9: Sedimentary Rocks

Sedimentary rocks form from the products of weathering and cover 75 percent of Earth's land surface. As a result, they are the type of rock that is normally seen exposed at Earth's surface....

31 min
Metamorphic Rocks
10: Metamorphic Rocks

A metamorphic rock is any rock that forms from a previously existing rock as the result of heat, pressure, and chemically active fluids. This process takes place only at great depth....

31 min
Volcanic Activity
11: Volcanic Activity

This lecture introduces volcanism, which is associated with three types of sites: convergent plate margins, divergent plate margins, and hot spots. The composition of magma is crucial in determining the intensity of an eruption....

29 min
Phases of Volcanic Activity
12: Phases of Volcanic Activity

The site of an eruption and the type of magma involved govern whether the resulting volcano will be a cinder cone, a shield volcano, or a strato- or composite volcano. Eruptions are further classified based on severity....

30 min
The Hawaiian Islands and Yellowstone Park
13: The Hawaiian Islands and Yellowstone Park

The Hawaiian Islands resulted from the movement of the Pacific plate over a volcanic hot spot. Yellowstone Park also sits over a hot spot that caused violent eruptions in prehistory. Another such eruption is likely....

29 min
Mass Wasting-Gravity at Work
14: Mass Wasting-Gravity at Work

Although mass wasting is one of the most important processes responsible for the evolution of the landscape, most people are unaware of its existence. The driving force of mass wasting is gravity....

29 min
Mass Wasting Processes
15: Mass Wasting Processes

This lecture describes how mass wasting works and where to observe it. Although flows, slides, and falls account for the most dramatic forms of mass wasting, by far the greatest change is achieved by creep....

30 min
Weathering
16: Weathering

Weathering is any process whereby rocks either disintegrate or decompose. The primary agent of physical weathering is the freezing and thawing of water, known as frost wedging....

31 min
Soils and the Clay Minerals
17: Soils and the Clay Minerals

This lecture explores why soils are so critical to sustaining plant life. Clay minerals turn out to be the key component. Different climates have characteristic soil types, some of which are ideal for agriculture....

29 min
Climate and the Type of Soils
18: Climate and the Type of Soils

Soil is the end product of a complex series of factors, the most important of which is climate. The type of soil that forms is controlled by the combination of annual precipitation and temperature....

31 min
Streams-The Major Agent of Erosion
19: Streams-The Major Agent of Erosion

Despite holding only a tiny fraction of the world's fresh water, streams are the major agent of erosion wherever water can exist, including the desert. Streams are either interior (terminating inland) or exterior (ending in the ocean)....

31 min
Sculpting of the Landscape
20: Sculpting of the Landscape

Surprisingly, there is no scientific consensus on the process of landscape evolution. One prominent theory, proposed by William Davis, sees land evolving through three stages of maturity due to stream erosion....

29 min
Stream Erosion in Arid Regions
21: Stream Erosion in Arid Regions

With minor modifications, Davis's theory on the three stages of a stream's life holds true for arid regions as well as humid regions. Nevada is typical of the process of stream erosion in arid regions....

30 min
Ice Sculpts the Final Scene
22: Ice Sculpts the Final Scene

Glaciers are second only to streams as an agent of erosion. In areas such as the Alps and Canadian Rockies, the combined effects of stream and glacial erosion have carved some of the most spectacular scenery on the planet....

31 min
Groundwater
23: Groundwater

Earth's largest readily available source of fresh water is groundwater. This lecture looks at the types of rock most suitable for storing groundwater. Those that produce water most easily are classified as aquifers....

31 min
The Production of Groundwater
24: The Production of Groundwater

Overproduction of an aquifer usually results in the lowering of the water table. Groundwater is not a renewable resource. It may take hundreds of thousands of years to replace a gallon of groundwater with a new gallon....

28 min
Karst Topography
25: Karst Topography

One of the most spectacular results of groundwater in action is karst topography-irregular topography created by the surface and groundwater dissolution of underlying soluble rock, usually limestone....

31 min
Groundwater Contamination
26: Groundwater Contamination

Nearly every human activity, from fertilizing yards to parking cars, has the potential to contaminate groundwater. Poorly designed and built landfills rank high among potential contaminants....

30 min
Rock Deformation
27: Rock Deformation

Deformation is any process in which rock changes in size and/or shape. The three types of deformation are elastic, plastic, and brittle, corresponding to rocks that "bounce back," bend, and break....

30 min
The Geologic Structures
28: The Geologic Structures

Rock structures form as a result of the application of stress beyond the strength of the rock. The three basic rock structures are folds, faults, and joints. This lecture focuses on folds, which are caused by compression....

31 min
Faults and Joints
29: Faults and Joints

Faults and joints comprise the two types of brittle deformation. Rocks move along faults. There is little or no movement along joints. One well-known fault is the San Andreas, a strike-slip fault....

31 min
Earthquakes
30: Earthquakes

Earthquakes occur in the same regions as the most violent volcanoes. Both result from the activity of convergent plate or divergent plate margins. Convergent plate margins produce the most violent of both events....

30 min
Damage from Earthquakes
31: Damage from Earthquakes

The intensity of an earthquake refers to the observed results of the quaking and the amount of damage. An earthquake's magnitude measures the amount of Earth movement. Tsunamis are an earthquake-generated phenomenon....

30 min
Seismology
32: Seismology

Earthquakes have been detected for centuries with simple devices, but the ability to study the full impact of earthquakes awaited the invention of a seismograph that could not only detect but actually measure Earth movement....

31 min
The Formation of Mountains
33: The Formation of Mountains

Mountains are of four types: volcanic, domal, block-fault, and foldbelt. The most impressive are foldbelt mountains such as the Himalayas, which are created by colliding plates at zones of subduction....

30 min
Orogenic Styles
34: Orogenic Styles

Orogeny refers to the processes that create foldbelt mountains. These form under three scenarios: ocean-continent collisions, ocean-island arc-continent collisions, and continent-continent collisions....

31 min
Economic Geology of Coal
35: Economic Geology of Coal

Coal comes from wood that has been preserved in environments where oxygen and microbial activity is low. Coal is ranked by its carbon content, which varies widely in the abundant deposits in the United States....

29 min
Economic Geology of Petroleum
36: Economic Geology of Petroleum

Petroleum is formed when marine material is buried in porous rock capped by an impermeable layer. Predictions about the inevitable decrease and disappearance of oil resources appear to be all too accurate....

32 min
John J. Renton

My goal as a teacher, be it in the classroom or by way of my Great Course, is to have my students develop an understanding and appreciation of the geology that surrounds them every day and wherever they may travel.

ALMA MATER

West Virginia University

INSTITUTION

West Virginia University

About John J. Renton

Dr. John J. Renton is Professor of Geology at West Virginia University where he has been teaching for more than 40 years. He earned his bachelor's degree in Chemistry from Waynesburg College and went on to earn his master's degree and Ph.D. in Geology from West Virginia University. Professor Renton is the recipient of several awards for his success in teaching, including the Outstanding Educator Award from the Eastern Section of the American Association of Petroleum Geologists, the Outstanding Teacher Award from the Eberly College of Arts and Sciences, and the Outstanding Teacher Award from the West Virginia University Foundation. Professor Renton is the author of the textbook, Planet Earth. He has also authored or coauthored 45 papers and has been part of more than $4 million of coal-related research grants.

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