geologic cycle

  • Earth’s balance of chemical elements

  • formation of rocks

    TITLE: rock (geology): Rock cycle
    SECTION: Rock cycle
    Geologic materials—mineral crystals and their host rock types—are cycled through various forms. The process depends on temperature, pressure, time, and changes in environmental conditions in the Earth’s crust and at its surface. The rock cycle illustrated in Figure 1 reflects the basic relationships among igneous, metamorphic, and sedimentary rocks. Erosion includes weathering (the...
  • significance in geochronology

    TITLE: geochronology: James Hutton’s recognition of the geologic cycle
    SECTION: James Hutton’s recognition of the geologic cycle
    In the late 1780s the Scottish scientist James Hutton launched an attack on much of the geologic dogma that had its basis in either Werner’s Neptunist approach or its corollary that the prevailing configuration of the Earth’s surface is largely the result of past catastrophic events which have no modern counterparts. Perhaps the quintessential spokesman for the application of the scientific...