StudySpace: Chemistry 2e.

Animation: Basic Plate Boundaries

Geologists define three types of plate boundary, based simply on the relative motions of the plates on either side of the boundary. These basic types-divergent, convergent, and transform plate boundaries-are shown in the following three-part animation. For more information, see "Identifying Plate Boundaries" starting on p. 89 and Figure 4.6 in your textbook.

Animation: Formation of Ocean Crust

Oceanic crust forms around and above a steady-state magma chamber. As the animation progresses, gabbro forms on the sides, dikes form above, and pillows form at the Earth's surface. Note that although the ridge maintains a consistent size and shape, the sea-floor grows wider. For more information, see "The Formation of Oceanic Crust at a Mid-Ocean Ridge" starting on p. 91 and Figure 4.7 in your textbook.

Animation: The Process of Subduction

At convergent plate boundaries or convergent margins, two plates, at least one of which is oceanic, move toward each other. But rather than butting each other like angry rams, one oceanic plate bends and begins to sink down into the asthenosphere beneath the other plate. This sinking process, termed subduction, is shown in the following animation. For more information, see starting on p. 94 and Figures 4.13, 4.15 and 4.16 in your textbook.

Animation: Transform Faulting

This animation shows the development of a transform fault along a divergent plate boundary. Plates slide past one another along a transform fault without the formation of new plate or the consumption of old plate. As this process occurs, new sea floor forms along the mid ocean ridge. For more information, see Section 4.5 Transform Plate Boundaries starting on p. 100 and Figure 4.17 in your textbook.

Animation: Hot-spot Volcanoes

This animation shows how hot spot volcanoes arise. A mantle plume beneath an oceanic plate creates a hot spot at the base of the lithosphere, and a volcano forms. Because the hot spot remains fixed as the plate moves over it, this volcano eventually becomes extinct and a new one forms. In time, a chain of extinct volcanoes develops, with a live volcano over the hot spot as the last link in the chain. For more information, see "Hot Spots" starting on p. 103 and Figure 4.21 in your textbook.

Animation: The Process of Rifting

Rifting is the process by which a continent splits and separates to form a new divergent boundary. This animation shows the progressive formation and evolution of a continental rift, and the formation of a mid-ocean ridge. For more information, see Section 4.7 How Do Plate Boundaries Form and Die? starting on p. 106 and Figure 4.23 in your textbook.

Zoomable Art: The Theory of Plate Tectonics

The outer portion of the Earth is a relatively rigid layer called the lithosphere. The mantle below the lithosphere is relatively plastic (it can flow) and is called the asthenosphere. According to the theory of plate tectonics, the lithosphere is broken into about twenty plates that move relative to each other. For more information, see the Section 4.8 What Drives Plate Motion? starting on p. 107 and the Featured Painting on pp. 108-9 in your textbook.

Animation: WHAT A GEOLOGIST SEES: Plate Boundaries

A photo from space shows the Sinai Peninsula, separated from Egypt to the west and the Arabian Peninsula to the east by rifts, narrow belts where the crust has stretched and broken apart. A geologist's sketch highlights the plate boundaries. For more information, see Section 4.8 What Drives Plate Motion? starting on p. 107 and Figure 4.24 in your textbook.