The Grand Staircase II   Leave a comment

In southern Utah, Red Canyon and its colorful rock formations see their first snowfall of the year.

The oldest Grand Staircase’s steps, the Chocolate Cliffs, are mostly Permian in age.  This is the time before dinosaurs, when reptiles and amphibians ruled the world.  But most of the formations in the Staircase were laid down during the Mesozoic Era.  They span the Jurassic and Cretaceous Periods – more than 130 million years!  They are sedimentary in origin, formed in shallow marine and low-lying land environments.  There were river plains, seashores, coral reefs and enormous deserts.  North America was lower in latitude then, and so warmer.  In short, it was during much of this enormous span of time a paradise for the plant and animal life, a time so long before ours that it is impossible to grasp.  

Layers of sandstone are striking as the sun gets lower in the Escalante River country of southern Utah.

And the animals that walked the earth then?  Dinosaurs!  Their fossil bones and tracks are found throughout the Grand Staircase region.  For example you can visit a dinosaur trackway not far from Kanab, just beyond Coral Pink Sand Dunes State Park.  Check at the BLM visitor center for directions.  There are also fossil tracks south of Escalante, off of Hole in the Rock Road.  Drive ~20 miles down the road and turn right on Colette Canyon Road; then look for a large white outcrop (the tracks are on top).  You can get info. at Escalante Outfitters in that town.

Cryptobiotic soil covers the ground in a sandy wash near the Escalante River in Utah.

At the top of the Staircase are the Pink Cliffs, the youngest of the steps.  These rocks date from a time after the dinosaurs went extinct.  Though there are not many fossils from this formation, this was the time when mammals rose to take the place of dinosaurs in all of the ecosystems once dominated by the giants.  So when you stand atop the Paunsaugunt Plateau in Bryce Canyon National Park, looking out and down the Grand Staircase, you are standing at a time when mammals were rising to dominance.

The cross-bedded sandstone in the Vermilion Cliffs National Monument, Utah forms sinuous patterns across the landscape.

 And when you look out to the south and east, down the Staircase, you are looking back in time.  You might think you are merely looking across cliffs and mesas, but you’re actually peering through the immense ages of time when dinosaurs ruled the earth.  Later, at night, look up at the impossibly brilliant stars, and realize you are, again, looking back in time.  The light from the distant stars began its journey across the vastness of space long ago, and so carries evidence of that time through space and time.

The hoodoos (rock towers) in Red Canyon are similar to those exposed in the Pink Cliffs of nearby Bryce Canyon, Utah.

A few little hints on how to recognize the different environments represented in the rocks.  The bold sandstone outcrops that have the angled stripes (layers) are ancient sand dunes.  The striking pattern results when sand grains blow up and over the top of a dune, forming angled layers (cross-bedding) when they tumble down the so-called slip face.  So you are looking at an ancient version of the Sahara.

Hoodoos are a common feature found in the Grand Staircase/Escalante National Monument.

Other sandstone formations of the Grand Staircase also have tilted layers in places but at a much lower angle.  This rock often has thinner platy layers with much silt and clay in between the thicker sandstone beds.  It was laid down by ancient rivers.  Both the ancient dune sands and ancient river sands make rock that is mostly tan in color, but iron oxides can give it a reddish hue, especially on the weathered surfaces.  Thinly layered siltstone and shale often forms vegetated slopes in this arid region, not cliffs.  So these formations are easy to miss.  You can see the small platy pieces in the soil if you look where you’re walking.  These rocks were formed in a shallow marine environment, or in bays close to the coast.  Think mudflats and deltas and you have the idea.

Calf Creek just above its confluence with the Escalante River has numerous potholes from infrequent floods, and which show up during autumn’s low water flows.

 

Limestone, unlike in the Grand Canyon, is not a huge part of the Grand Staircase, but it is here.  It is formed in and near coral reef areas, or further from the coast in deep water.  This rock is often gray in color, though it can often show red on the weathered surface.  What you will notice about limestone in an arid environment is that it is abrasive, like a very coarse sand paper.  Hiking in limestone terrain, every geologist knows, can really chew up a pair of boots.  Occasionally in this region, not often, you’ll notice lava rock.  Basalt is the most common type.  It’s quite dark in color, often has holes in it (from gas bubbles) and contrasts greatly with the light-colored sandstone.

In Grand Staircase National Monument in southern Utah, the first of winter’s storms brews to the west.

This Monument is huge!  It’s tough to decide where to spend your time, especially when that time is limited.  The next post, my last on the Grand Staircase, will cover some basic trip planning and highlight a few worthwhile places to visit.

 

 

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