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In some of the world's continental regions, layer after layer of basalt lava erupted at various times in the earth's history to form extensive accumulations of thick lava flows. These features are called flood basalts (or plateau basalts). In many cases, flood basalts were generated as the continents were torn apart to form ocean basins during the processes of continental drift and seafloor spreading.

“Basalt” is the term applied to dark, iron-rich volcanic rocks that occur everywhere on the ocean floors, as oceanic islands, and in certain areas on continents. It is the parent material from which nearly any other igneous rock can be generated by various natural processes.

The Cascade mountain range extends from Northern California through western Oregon and Washington into British Columbia in Canada. The loftiest peaks of this range are stratovolcanoes, the highest being 4,392-meter Mount Rainier in Washington. The history of the Cascades goes back about 25 million years, but the periodic eruption of once-dormant volcanoes such as Mount St. Helens shows that the range is still evolving.

Europa is one of the four largest satellites of the planet Jupiter, known as the Galilean satellites after their discoverer, Galileo Galilei. In order of their distance from Jupiter, they are Io, Europa, Ganymede, and Callisto. Jupiter has at least sixty-three satellites, but only the Galilean satellites are large enough to be observed from Earth through small telescopes. With a diameter of 3,138 kilometers, Europa, the smallest Galilean satellite, is slightly smaller than Earth’s Moon of 3,476 kilometers. By contrast, the largest Galilean satellite, Ganymede, measures 5,260 kilometers in diameter, larger than the planet Mercury (4,878 kilometers). Thus, if the Galilean satellites orbited the Sun instead of Jupiter, they would be considered full-fledged planets. Despite its relatively small size compared to its Galilean companions, Europa is nevertheless the sixth-largest planetary satellite in the solar system. It is about 780 million kilometers from the Sun, about 5.2 times the distance from the Earth to the Sun.

Phosphate is mined in Florida and North Carolina (more than 85 percent of US output), as well as Idaho and Utah. Major world producers include China, followed by the United States, Morocco and the Western Sahara, Russia, Tunisia, and Brazil.

Anorthosites are coarse-grained, intrusive igneous rocks composed principally of plagioclase feldspar. They are useful for what they reveal about the early crustal evolution of the earth, and they are the source of several economic commodities.

Plutonic rocks (from Pluto, Roman god of the underworld) form by slow crystallization of molten silicate magma intruded below the Earth’s surface. Subsequent erosion may expose “plutons” that have the area of a large house or huge granitic “batholiths” that encompass thousands of square kilometers. Many plutons are sources of valuable industrial and metallic mineral deposits, including granite building stone, gold, copper, molybdenum, chromium, and other metals. Plutonic bodies occur on all the major continents of the Earth. They are common in Precambrian shield areas, the ancient cores of continents composed of rocks formed billions of years ago, such as the Canadian Shield of North America. They also occur in younger mountain ranges such as the Rockies and the Appalachian Mountains of North America.

Planets in the solar system move around the sun in elliptical orbits. Those whose orbits are closest to the sun move more rapidly than those that are farther away. These simple, universally accepted observations form the basis of the knowledge of planetary motions. Gravity—the force that causes apples to fall from trees and keeps humans firmly planted on Earth’s surface—plays the central role in the mechanics of planetary motions.

All planets in the solar system have at least one satellite except Mercury and Venus. There are hundreds of known satellites in the solar system, ranging from about fifteen to more than fifty-two hundred kilometers in diameter. Each year, this number grows as spacecraft and telescopic observations discover more relatively tiny satellites around the gas giants, particularly Jupiter and Saturn. Although the largest satellites of the solar system’s eight planets have been identified, a table of known satellites would become outdated within months as more are constantly discovered. Satellites are essential for the scientific clues they provide concerning their parent planets' origin and the solar system.

Igneous rocks are created by the crystallization and solidification of hot, molten silicate magma. magma consists of silicate liquid (the major component is the silica molecule SiO4 -4), solid crystals, rock fragments, dissolved gases such as carbon dioxide, water, and various sulfurous oxides. Familiar examples of igneous rocks are granite (an “intrusive” or “ plutonic” rock that is crystallized at depth) and basalt (as in dark “extrusive” lava flows, such as those in Hawaii). Igneous rocks are found worldwide on all continents, on oceanic islands, and on the ocean floors. They are particularly common in mountain ranges or other areas where the Earth has undergone tectonic activity. Oceanic islands, such as Hawaii and Iceland, are nearly exclusively igneous in origin, and the world’s oceans are floored by basalt lava flows.

All but two of the planets in the solar system have one or more smaller bodies in orbit around them. These satellites are important for what they tell scientists about the origins of the main planets and the evolution of the solar system.

Plutonic rocks crystallize from molten magma that is intruded deep below the earth’s surface. Exposed at the surface by erosion, they occur mainly in mountain belts and ancient “shield” areas of continents. Many of the world’s principal ore deposits are associated with plutonic rock bodies; the rocks themselves may be also exploited economically, as in the production of granite for building stone.