Igneous Rocks - Samuel O'Connell

For this week's post, I decided to stay close to home and I traveled (in spirit) to Pike's Peak, near Colorado Springs, CO. As with much of the Colorado Front Range, I observed large amounts of granite in the area. I could tell that the rock was granite from its clear/gray colored quartz grains and the whiteish, block shaped feldspar, as well as the flaky/spotted dark silicates also present. Some of the igneous granite had feldspar crystals that were a couple centimeters big, with smaller sized quartz and amphibole crystals. Since the crystals are large enough to be seen with just my eyes, I gather that the the granite is an intrusive igneous rock (from uplifting and erosion), and cools very slowly due to the magma hardening very deep underground.

I met a fellow traveler on the trail who had a surplus of information about the Rocky Mountain range. He told me that the Rockies began to form over billions of years from the North American plate crust faulting at this area. After lots of erosion, the runoff from glaciers caused many of the various sizes of the rocks we observe at the different elevations.