Magma exists at temperatures of 1,100° to 2,400° F (600°  to 1,300° C). Igneous rocks are geologically important because: 1. 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; 2. their features are usually characteristic of a specific tectonic environment (see plate tectonics); 3. in some special circumstances …