Yesterday we spent the whole day at the south rim of Grand Canyon National Park. As I mentioned in a previous blog entry, the last time I was at the Grand Canyon was 15 years ago but that time we only explored the east side of the south rim. I don’t remember whether we explored the west side of the south rim or not when I came here when I was 9, but in any case, we went al the way west to Hermit’s Rest and all the way east to Desert View this visit. We walked the rim trail as often as we could and took the shuttle bus when we didn’t.
Information on the Grand Canyon is all over the Internet and in many publications already so I won’t give an in-depth geologic history lesson here—just some basic facts.
The Grand Canyon cuts down into the Colorado Plateau that stretches north to Utah, northeast to Colorado, and east to New Mexico. At the south rim, the elevation is 7,000 feet. The Canyon spans almost 2 billion years of time from the basement rocks of the Vishnu Schist to the 270 million year old Kaibab Limestone at the top. Below the Kaibab Limestone is the same Coconino Sandstone and Hermit Shale exposed in the Sedona rocks.
According to the National Park Service pamphlet that is handed out at the entrance, “The Grand Canyon reveals a beautiful sequence of rock layers that serve as windows into time.” The Canyon was carved by the Colorado River 5 or 6 million years ago and is now about a mile deep. Its width varies from 8 miles to 18 miles wide and extends about 280 river miles long. As the river cuts down, the canyon deepens. Tributaries erode into the canyon’s sides and increase its width. Erosion carves faster into the softer rock layers like the shales and undermine the harder layers like the sandstones, creating cliffs, slopes, buttes, and pinnacles.
The views along the rim are inspiring and beautiful. Looking across the Canyon gives you such a feeling of power and beauty at the same time. What nature can create, with the dazzing erosional forms, rock colors, and geologic time is just awesome. Truly a place that every American, every person, should see.
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