Arches on the way back home

Well, we came home after only three weeks on the road. Everything in front of us was closed. RV parks in the Florida Keys, all RV parks in Moab, all restaurants in New Orleans and the Keys, D.C. museums, all botanical gardens, and on and on. So....what's the point of travelling only to stay in the RV all the time.

It took us 1,200 miles to get back. Four RV parks, one a night. One outside of Price, Utah was nice enough to let us spend the night, even though they'd been told to shut down to all outsiders. Long travel days.

But, we stopped off at Arches National Park outside of Moab and it was, not only open and free, no one was there! We had practically the entire park to ourselves. Kim took about 460 photos! Thank goodness for digital cameras. This is our fourth visit here....never gets old.

We dropped the truck, left the coach in the parking lot and went to see the park.

You can see our coach waaaaay down there in the parking lot.

I'll just post some of the magnificent rock formations we saw...

Closeup

This one is called "The Three Judges".

These are the "Petrified Sand Dunes". They were covered over with sand from the NW over 200 Million years ago, then it all eroded away to leave miles and miles of these dunes.

Good photo with the La Sal Mountains (Salt) in the background and a couple of arches on the far left.

One of the big attractions here...Balanced Rock

Usually you cannot get into the parking lot or on the trail....too many people. Today, no one!

Arches National Park has the densest concentration of natural stone arches in the world. There are over 2,000 documented arches in the park, ranging from sliver-thin cracks to spans greater than 300 feet (97 m). How do they form? See answer at the very end.

So....a few of them...

North and South Window Arches

You can see the scale of how immense the arch is when you see the tiny, tiny people at the base.

Anyway, we got to see the park just in time because I read that, as of the 28th of March...just yesterday, they closed the park entirely.

We're safe and sound back home and are keeping our distance from everyone. Speaking of that, when we were in Carlsbad, New Mexico, I went to the grocery store and it was mobbed! The clerk told me it's that way all the time. Carlsbad is right where all the oil and natural gas fields are located so the town is a 24/7 place. No one seemed that concern about any virus. Oh, I wore latex gloves into the store. No fooling around with this stuff at our age.

Once this crisis all passes...and it will....we'll head back out. In the meantime, we'll probably take 1-2 day trips with our kayak to the local lakes and paddle around.

I'll post some magnificent sunrise and sunset shots some other time.

steve/kim/katie

Katie found a spot to relax on the new kayak

How did so many arches form?

First, you need the right kinds of rock.

Sandstone is made of grains of sand cemented together by minerals, but not all sandstone is the same. The Entrada Sandstone was once a massive desert, full of shifting dunes of fine-grained sand. The grains are nearly spherical so, when packed together, they formed a rock that is very porous (full of tiny spaces).

In contrast, the Carmel layer just beneath the Entrada contains a mix of sand and clay. Clay particles are much smaller than sand grains; a lot of them can pack together and fill in gaps between the sand grains, making the rock denser and less porous than a purer sandstone.

Crack it into parallel lines.

Deep beneath the surface lies a thick layer of salts. Squeezed by the tons of rock above it, the salt flowed and bulged upward, creating long domes. The rock layers covering these domes were forced to crack, like the surface of freshly-baked bread, into a series of more-or-less parallel lines.

Next, add the right amount of rain.

On average, the park receives 8-10 inches (18-23 cm) of precipitation a year. That might not sound like much, but it's enough to keep the engines of erosion working 24 hours a day, 365 days a year.

Drops of rainwater soak into the porous Entrada sandstone easily and then slowly dissolve the calcite bonding the sand together – in other words, rotting the rock from the inside out. Water puddles just above the denser Carmel layer where it erodes a cavity, like food trapped between your teeth. In winter, water trapped between the two layers expands when it freezes and pries the rock apart.

If the park received too much precipitation, the sandstone could erode so quickly that arches might not have time to form. If it never rained here, the engines of erosion would stop.

Make sure your rocks don't rock & roll.

Luckily, earthquakes are rare in this area. If the ground shook often, these massive outdoor rock sculptures would splinter and collapse. The fact that over 2,000 still stand, waiting for visitors to discover them, tells us this area has been rather geologically stable for at least 50,000 years.

Lastly, pick the right time to visit. (You did.)

The rock layers visible in the park today were once buried by over a mile of other rock that had to erode first to expose what lied beneath. Visitors one million years ago might have seen an endless flat plain dotted with vegetation. Imagine a visit 100,000 years in the future, when the Entrada and Carmel layers have fully worn away. What new rock shapes might you discover then?