Afternoon at Zion
November 28th, 2020
Just around the corner from yesterday’s plain view, the road to Zion National Park descends into a canyon while the surrounding landscape protrudes suddenly in sedimentary peaks.
The geology of Zion spans up to 270 million years, connecting with Bryce Canyon to the north and the Grand Canyon to the south. While researching this, I finally came across the origin of the regional term “Grand Staircase” as explained perfectly on the park website:
“Zion National Park is located along the edge of a region known as the Colorado Plateau. The rock layers have been uplifted, tilted, and eroded, forming a feature called the Grand Staircase, a series of colorful cliffs stretching between Bryce Canyon and the Grand Canyon. The bottom layer of rock at Bryce Canyon is the top layer at Zion, and the bottom layer at Zion is the top layer at the Grand Canyon.”
The park website also describes how this sedimentary landscape formed:
“Zion was a relatively flat basin near sea level 240 million years ago. As sands, gravels, and muds eroded from surrounding mountains, streams carried these materials into the basin and deposited them in layers. The sheer weight of these accumulated layers caused the basin to sink, so that the top surface always remained near sea level. As the land rose and fell and as the climate changed, the depositional environment fluctuated from shallow seas to coastal plains to a desert of massive windblown sand. This process of sedimentation continued until over 10,000 feet of material accumulated.”
One of the most memorable things about the drive into Zion is Mount Carmel Tunnel. Completed in 1930, the tunnel is more than a mile long with several “windows” through the north wall that let in light and air from the valley. The tunnel is monitored, around the clock, to alert park officials of any danger of collapse even though its sandstone walls have been reinforced.
We spent an afternoon at Zion — an immeasurably brief moment relative to the last 270 million years which created the park we see today. We hopped on our bikes, rode to the Narrows on Floor of the Valley Road and stopped to explore along the way. In the end, the Narrows proved too narrow for us — too many people on a skinny trail in the time Covid — so we returned to our bikes and coasted back out of the park.
Tomorrow we’ll stop alongside the road to meet a wild resident of Zion.
Post of the Day: Adding a bit of light to the darkness as we get through the pandemic together. This series features travel photos from my archives, shared with you while staying close to home.