What are some common uses of igneous rocks?
Igneous rocks are geologically important because: their minerals and global chemistry gives information about the composition of the mantle, from where 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; in some special circumstances they host important mineral deposits (ores): for example, tungsten, tin, and uranium, are commonly associated with granites, whereas ores of chromium and platinum are commonly
