Colorado’s Rocky Mountains boast spectacular views of numerous plutonic (intrusive) rocks. These rocks were formed long ago as magma rose from deep sources and solidified before making it all of the way to the surface. As this magma rose, in many places, it brought with it precious minerals such as gold, silver, lead, and molybdenum (used in hardening steel).
After millions of years, erosional processes stripped off the overlying rocks, exposing them as we see today.
Please explore Colorado’s Plutonic Rocks by using the menu on the left side of the page to learn about alkalic complexes, batholiths, dikes, kimberlite diatremes, plugs, sills, and stocks.
Rounded weathering of rocks such as these are often a clue that you have found granitic rock – in this case a 1.7-billion-year-old pluton near Parlin
Distribution of granitic batholiths in Colorado.