Igneous Rock - Geological Significance

Geological Significance

Igneous and metamorphic rocks make up 90-95% of the top 16 km of the Earth's crust by volume.

Igneous rocks are geologically important because:

  • their minerals and global chemistry give information about the composition of the mantle, from which some igneous rocks are extracted, and the temperature and pressure conditions that allowed this extraction, and/or of other pre-existing rock that melted;
  • their absolute ages can be obtained from various forms of radiometric dating and thus can be compared to adjacent geological strata, allowing a time sequence of events;
  • their features are usually characteristic of a specific tectonic environment, allowing tectonic reconstitutions (see plate tectonics);
  • in some special circumstances they host important mineral deposits (ores): for example, tungsten, tin, and uranium are commonly associated with granites and diorites, whereas ores of chromium and platinum are commonly associated with gabbros.

Read more about this topic:  Igneous Rock

Famous quotes containing the words geological and/or significance:

    The crystal sphere of thought is as concentrical as the geological structure of the globe. As our soils and rocks lie in strata, concentric strata, so do all men’s thinkings run laterally, never vertically.
    Ralph Waldo Emerson (1803–1882)

    It is necessary not to be Christian to appreciate the beauty and significance of the life of Christ.
    Henry David Thoreau (1817–1862)