Tuesday, September 24, 2013

Arches NP, UT - 09/24/13


Tuesday – September 24, 2013
Arches National Park – Moab, Utah

Wonderful weather has returned, here at Ken’s Lake Campground, 10 miles south of Moab, Utah. The rainy weather has departed the area, along with the strong winds. Clear blue skies greeted us on Monday morning and again this morning, with warmer weather. The temperature is forecast to be in the mid-70’s to low 80’s for the rest of the week, along with sunny weather. This is our second day exploring Arches National Park.

We departed our campground for Arches National Park at 10:30 a.m. It is only a 15-mile drive from our campground. Our Golden Age Pass allows us to enter the park free of charge. On Monday, we stopped at the Visitor Center, watched a very nice orientation film on the park and picked up some literature. So, today we continue our journey through the park.

The park lies atop an underground salt bed that is responsible for the arches, spires, balanced rocks, sandstone fins, and eroded monoliths. Thousands of feet thick in places, this salt bed was deposited 300 million years ago when a sea flowed into the region and eventually evaporated. Over millions of years, residue from floods, winds, and the oceans that came and went blanketed the salt bed. The debris was compressed as rock, at one time possibly a mile thick.

Salt under pressure is unstable, and the salt bed lying below Arches was no match for the weight of this thick cover of rock. The salt layer shifted, buckled, liquefied, and repositioned itself, thrusting the rock layers upward as domes, and whole sections fell into the cavities.

Faults deep in the Earth made the surface even more unstable. Fault-caused vertical cracks later contributed to the development of arches. As the salt’s subsurface shifting shaped the Earth, surface erosion stripped off younger rock layers. Over time water seeped into superficial cracks, joints, and folds. Ice formed in the fissures, expanding and pressuring the rock, breaking off bits and pieces. Wind later cleaned out the loose particles, leaving a series of free-standing fins. Wind and water then attacked these fins until the cementing material in some gave way and chunks of rock tumbled out. Many of these damaged fins collapsed. Others, hard enough and balanced, survived despite missing sections. These became the famous arches. Pothole arches are formed by chemical weathering as water collects in natural depressions and then eventually cuts through to the layer below. This is the geologic story of Arches National Park.

The sheer grandeur of the Arches National Park is simply breathtaking. To comprehend how the forces of nature, over millions of years, created these variety of marvelous rock formations, defies the imagination. A paved, two-lane, winding road takes the visitor on an 18-mile journey back in time. The journey begins from the Visitor Center, at an altitude of 4,085 feet. The steep, winding, entry point road then climbs to an elevation of perhaps 5,000 feet. The remainder of the route traverses a winding road through lower and higher elevations.

Around each turn in the road the visitor is exposed to yet another scenic delight. Here are just a few highlights of nature’s wonders we observed:

Park Avenue
A magnificent view of a valley filled with light green vegetation, dark green Utah Juniper and Pinyon Pine evergreen trees, surrounded by massive bare rock formations towering above it. One of the striking features was a huge boulder, perfectly flat on the bottom, precipitously balanced upon one of the rock formations, with an equally perfectly flat surface.

Balanced Rock
This was an incredible sight! A massive rock balanced upon another rock formation.

Mother nature exhibits her finest works of art! Over 2,000 cataloged arches range in size from a three-foot opening, the minimum considered an arch, to the longest, Landscape Arch, measuring 306 feet to base.

Tomorrow another adventure begins.

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