Users can search the large number of the U.S. Geological Survey's web pages with this engine. In addition to the search box (where a key word or title can be typed), the search is further refined by the incorporation of links to categories of topics. The topics consist of resource types such as Fact Sheets or Maps, subjects such as minerals or water quality, or an organizational search on USGS State ... Full description.

This search tool provides descriptions and availability information for geologic maps of the 50 States, the District of Columbia, and Puerto Rico. These geologic maps are published by a variety of organizations, including State geologic agencies, the U.S. Geological Survey (USGS), universities, and private companies. Title, date, scale, publisher, series (where applicable), and basic ordering information ... Full description.

This site presents a summary of current volcanic eruptions and images and videos of volcanoes on Earth. Discussions of the characteristics of volcanism on other worlds in our solar system are also presented and are accompanied by maps and imagery. Links to volcano observatories, parks, and monuments around the world are also included. Full description.

This collection of images shows geologic features in many of the country's national parks. The collection is searchable by park name, state, year, or by the name of the photograph. Each photo is accompanied by a brief caption that provides the photographer's name, the date, and a description of the photo. Full description.

This is a photograph of the 18 May 1980 explosion of Mount St. Helens. Links to other volcano images and related topics are included. Full description.

This document outlines the development of the theory of contintental drift and how many lines of evidence collected over several decades by various researchers were brought together to explain how the seafloor spreads and the continents move about. Links to additional information are included. Full description.

This site explains how core samples are taken from the ocean floor. Topics include how research cruises are planned, who makes up the crew of a research vessel, and what a cruise track is. Links to additional information are embedded in the text. Full description.

Visitors can read about the characteristics of volcanism on Venus and how it differs from volcanism on Earth. A map showing the locations and types of volcanic structures on the surface of Venus is provided, along with links to other related topics. Full description.

This resource describes what mineral sands are, and discusses the heavy, dark-colored minerals that they contain (rutile, ilmenite, zircon, monazite). A map shows locations of mineral sands deposits in Australia. Full description.

This text explains how glaciers scour and grind the Earth's surface, and about the sorts of deposits they leave behind. Emphasis is on glaciation in the mountains and valleys of Vermont. Links to related topics are included. Full description.