|What is a Maar?
What is a Maar? The second most common volcanic landscape feature on Earth.
Dowsing is a method used to find underground water that is rejected by most geologists.
Rocks Galleries of igneous, sedimentary and metamorphic rock photos with descriptions.
||Rare Earth Elements
REEs Special metals used in cell phones, DVDs, batteries, magnets & many other products.
Methane Hydrate deposits contain more fuel value than all other fossil fuels combined.
||What are Glaciers?
What are Glaciers? Learn how glaciers form, flow, advance, retreat, and change over time.
||What Geologists Do
What Does a Geologist Do? Information and two videos about the relevance of geology today.
Yosemite Glaciers There are two active glaciers in Yosemite - but they are slowly melting away.
|Yosemite Rock Fall
Yosemite Rock Fall Photos A photo sequence of a rockfall and debris avalanche by Herb Dunn.
||Geologic Time Scale
Divisions of Geologic Time USGS periodically revises rock unit names and age estimates.
||What Are Minerals?
Minerals are the building blocks of our society. We use items made with them every day.
Plate Tectonics Articles, theory, plate diagrams, plate maps and teaching ideas.
|What Is Earth Science?
What Is Earth Science? The study of Earth and its neighbors in space. Learn more!
Bear Attacks Knowing how to react to a bear encounter and attack could save your life.
||Gold History and Uses
Gold A history of gold uses, mining and prospecting over thousands of years.
||Maps Of Pangaea
Pangaea Maps A sequence of maps shows how a large supercontinent fragmented.
Sliding Rocks - Racetrack Playa How these rocks slide across a dry lake bed is a mystery.
||Great Rift Valley
The East Africa Rift System Learn about the complex East Africa Rift Valley system.
How Old is the Grand Canyon? Wayne Ranney explores the age of the Grand Canyon.
Volcanos Articles about volcanoes, volcanic hazards and eruptions past and present.
|What is a Geyser?
What is a Geyser? Photos of geysers from around the world. Causes, height and more.
Roadside Geology Guides Learn about the Geology of your favorite state as seen from the road.
||San Andreas Fault
What is the San Andreas Fault? Map, photos and description of the fault by Dr. David Lynch.
Landslides A USGS fact sheet about landslides and events that trigger them.
The Geology of Bottled Water It costs 1000x as much as tap water. What are you getting?
||Diamonds from Coal?
Diamonds from Coal? They form under several conditions that rarely involve coal.
Geology Tools Available are pick, chisel and crack hammers, rock chisels, goggles and more.
Salt Domes are columns of salt that move upwards because of the salt\'s low specific gravity.
|Air Bubbles in Amber
Bubbles in Amber Cretaceous oxygen levels determed from air bubbles trapped in amber.
Rock Glaciers - Masses of ice, snow, rock, mud and water that slowly flow down slope.
Salt Glaciers are masses of salt that flow downslope under their own weight.
Stream Gaging Stations Used by hydrologists to monitor streams or other water bodies.
The Selenga River delivers most of the water to Lake Baikal, the largest lake in the world.
||Cell Phone Photos
Take Great Cell Phone Photos - Low-cost, easy-to-use lenses will improve your photos.
Troglobites are creatures that have adapted to a permanent life in the darkness of a cave.
||What is a Hydrograph?
What is a Hydrograph? Charts that display the change of a hydrologic variable over time.
|Green River Fossils
Spectacular Fossils of the Green River Formation. Some of the world\'s best fossil fish.
Homeowner\'s Insurance and Geologic Hazards Most policies do not cover geologic hazards.