Education

Basics of Geology

By Andrew Alden, About.com Guide

Many ways lead to geology, whether it's the rocks along the road, the threat of climate change or the sights from your vacation. Here are the major avenues.

Rocks
Minerals and Gemstones
Earth Resources
Geologic Processes
Geologic Hazards
Landforms
Geologic Time
Fossils

Evolution and Extinction
Parts of the Earth
Plate Tectonics
Geology of Other Planets
Teaching and Learning Geology
References for Advanced Students
Explore Geology: Activities & Fun

Rocks

Rocks are what the Earth is made of. The first thing geologists learn is how to observe, describe and classify rocks.

Minerals and Gemstones

Minerals are the ingredients of rocks. Just a few important minerals account for the majority of rocks and for the soil, mud and sand of the Earth's surface. Many of the most beautiful minerals are treasured as gemstones.

Earth Resources

Many rocks and minerals are important for civilization. They are products we take from the Earth. Learn more about their geology.

Geologic Processes

Geology is not just rocks and minerals, but also the things that happen to them in the great Earth cycle.

Geologic Hazards

Hazards are ordinary geologic processes that interfere with human life. Here are introductions to the major geologic hazards. For news and background about current hazard events, see the Quakes, Volcanoes Etc tab.

Landforms

The hills, valleys and other features of a landscape are signs of the area's underlying structure and clues to its history.

Geologic Time

All of human history is the briefest moment at the end of four billion years of geologic time. How do geologists measure and order the milestones in Earth's long history?

Fossils

Fossils are precious gifts from the geologic past: signs and remains of ancient living things that help explain how life has coexisted with Earth. Fossils are an important line of evidence showing how life has evolved since its still-mysterious beginnings.

Evolution and Extinction

The consistent parade of fossil species through geologic time shows that life has been evolving since its remote beginning. Modern genetics tells the same story. Geology also shows that species have gone extinct.

Parts of the Earth

Beneath the stony crust lie the rocky mantle and, at Earth's heart, the iron core. All are areas of active research and competing theories.

Plate Tectonics

Plate tectonics is the first theory that explains the mechanics of the Earth's surface in depth, in detail and in a scientifically fruitful way.

Geology of Other Planets

The space program has revolutionized geology by giving us other examples of planets besides our own: they include Mercury, Venus, the Moon, Mars, the asteroids and the larger planetary satellites.

Teaching and Learning Geology

Charles Darwin once wrote, "Geology is a capital science to begin, as it requires nothing but a little reading, thinking, and hammering." Whether you study for pleasure at home or stand in a classroom and teach, I can help.

References for Advanced Students

A compendium of handy lists, tools and photo galleries. Even the experts don't keep it all in their heads.

Explore Geology: Activities & Fun

Go beyond the basics and start getting geology into your life.

Geology