Читать книгу Earth Materials - John O'Brien - Страница 16

Earth materials can occur anywhere on or within the geosphere, the portion the Earth from its surface to its center, whose radius is approximately 6370 km (Figure 1.1). In static standard models of the geosphere, Earth is depicted with a number of roughly concentric layers. Some of these layers are distinguished primarily on the basis of differences in composition and others by differences in their state or mechanical properties. These two characteristics by which the internal layers of Earth are distinguished are not totally independent, because differences in chemical, mineralogical and/or rock composition influence mechanical properties.

Figure 1.1 Standard cross‐section model of the geosphere. Major compositional layers are shown on the left: core (red shade), mantle (brown shade), and continental and oceanic crust (blue shades). Major mechanical layers are shown on the right: inner core and outer core (red shades), lithosphere (light brown), mesosphere (dark brown), and asthenosphere (burnt orange).