Archive for the ‘sandstone’ Tag

Single-image Sunday: Patterns in Sandstone   5 comments

Since the Foto Talk this week was all about not getting too caught up in the search for abstract patterns in your photography, I thought I’d post an image whose sole aim was to abstract the subject.  But is this really an abstract?  I could have made it more so, for example by moving the camera or otherwise blurring details and color.  Or by getting experimental in post-processing.  But I wanted the close-up features of this dune sandstone to be very clear.

The abstraction is created by simply getting  close with my macro lens and framing so as to exclude the tiny flaws that are scattered through the rock.  I captured this at the famous Wave in southern Utah’s Vermilion Cliffs National Monument.  The sandstone has been worn smooth by water and wind erosion, but up close you can see how rough it is, like sandpaper.

The tiny sand grains are frosted by winds that blew them into dunes during the early Jurassic Period nearly 200 million years ago when this whole region of the American southwest was a vast desert similar to the Sahara of today.

The thin layers (laminae) of alternating color are at an angle to the main sandstone beds.  This is called cross-bedding and is characteristic of dune sands.  The wind blew in grains that had been stained brick-red by iron.  Then it turned around and blew in cleaner, lighter-colored grains from a different source.  These grains would cascade down the steeper lee side of dunes, creating the cross-beds.

The flatter, thicker layers have been eroded into steps, a characteristic of the Wave.  Because of variation in their hardness, their ability to resist erosion, the layers stand out or are recessed.  This differential erosion is caused by variation in the amount and hardness of cement binding the sand grains together.

So what this image shows on a micro-scale is an ancient sand dune in cross-section that is now being sculpted by present-day winds.  In other words, it shows winds in a desert of the distant past, when early dinosaurs roamed the area.  And it shows what the desert of today is doing to those ancient dunes

So an abstract image can tell you something real about the subject.  I believe that’s the best kind of abstract in fact.  I’m hoping the image shows what nature can do, not what me or my camera can do.  Please let me know whether or not I succeeded.  I hope your weekend was a lot of fun.  Thanks for reading.

Undulations

Single-image Sunday: Morning on the Slickrock   4 comments

I’ve mentioned slickrock before on this blog.  It is that sculpted and smooth sandstone that with few exceptions (Cappadocia, Turkey springs to mind) seems to be a unique feature of the American desert southwest. For hiking and mountain biking it can’t be beat.  There’s a freedom you feel on it, no trail, exploring at whim.  Because of its friction, you can walk or bike on crazy steep angles.  On any other surface you would quickly slip and fall on your behind.  If this happened around these parts you just might wind up making a mess thousands of feet below.

So if slickrock is so sticky for sneakers and bike tires, why on earth is it called slickrock?  The name goes back to pioneer days, when white explorers, miners and cowboys first traveled through this canyon country.  Their horses, shod with steel horseshoes, found it nearly impossible to gain any kind of purchase on this rock.  Horses can do much better on it with the hooves Mother Nature gave them, but shod they might as well be on an ice-skating rink.

This image I shot while riding my mountain bike one morning near Moab, Utah.  Moab is well known for its slickrock riding.  The Slickrock Trail is famous around the world, but since I’ve ridden that “trail” on two previous visits, I skipped it this time.  Instead I explored much less crowded slickrock rides a bit further from town.  This one, an area called Tusher, is about 18 miles north of Moab.  I had it to myself.  It’s a great ride, with a bonus: dinosaur bones are weathering out of the rock in the draw on the way up to the slickrock.

I’ve been trying for a picture that gets to the heart of hiking or riding the rollicking roller coaster that is slickrock.  I didn’t want a cyclist or hiker in the shot competing with the stone (easy on this day).  I also wanted to show both the texture and smooth curves of prime slickrock.  I think this image is as close as I’ve come.  Please let me know if you like it or not, and why.  Don’t be shy if you don’t; my skin is thick.

I hope your weekend is going well!

Morning sunlight on slickrock: Utah.  Please click on image for purchase options.  It's not available for free download.

Morning Sun on Slickrock: Utah. Please click on image for purchase options. It’s copyrighted & not available for free download.

Travel Theme: Flow   6 comments

A small creek in Oregon's Columbia River Gorge rolls through a mossy forest.

A small creek in Oregon’s Columbia River Gorge flows in a rolling way through a mossy forest.

I don’t usually go for the theme post, at least those invented by other bloggers.  I figure it’s sorta cheating, letting other people decide what you will blog about because you don’t have any ideas of your own.  Or something like that.

Since I want to avoid being dogmatic about it, occasionally I’ll go along with the crowd, join the party, however you want to phrase it.  But only when the theme intrigues me.  This time it is the concept of flow, Ailsa’s idea on her great blog Where’s My Backpack.  I love flowing water of course, but that’s an easy approach.  Hmm…

If you’re interested in any of these images, just click on them.  You will be taken to the high-res. version where you can view price options by clicking “Purchase Options”.  The images are copyrighted and not available for download without my permission, sorry.  Please contact me if you have any questions.  Thanks for looking!

Spring melting at Bryce Canyon National Park in Utah brings a heavy sediment-laden slurry down from the red rocks.

Spring melting at Bryce Canyon National Park in Utah brings a heavy sediment-laden slurry flowing down through the snow from the red rocks above.

 

The upper reaches of East Fork Hood River in Oregon tumbles down Mount Hood's slopes.

The East Fork Hood River in Oregon tumbles down through its canyon near Mount Hood Oregon as a spring flows out of its banks to feed it.

 

Sand dunes in Death Valley National Park, California forms textured shadows as the wind blows hard and the sand flows over the surface.

Sand dunes in Death Valley National Park, California forms textured shadows as the wind blows hard and the sand flows over the surface.

 

This flowing rock in southern Utah's Coyote Buttes area was originally formed into enormous dunes, now solidified into rock.

This flowing rock in southern Utah’s Coyote Buttes area was originally formed into enormous dunes, now solidified into rock.

 

 

A close-up view of sandstone strata in the slickrock country of southern Utah, very near the location called "the wave".

A close-up view of sandstone strata in southern Utah, very near the location called “the wave”.  The sandstone appears to flow on different scales, though it is solid rock.  Originally of course, it was formed by flowing currents.

A small stream deep in Oregon's Columbia River Gorge flows through a green-lined channel.

A small stream deep in Oregon’s Columbia River Gorge flows through a green-lined channel.

 

One of the easiest ways to get into a "flow", that feeling of timeless, effortless doing, is cross-country skiing.

One of the easiest ways to get into a “flow”, that feeling of timeless, effortless doing, is cross-country skiing.

 

The clouds rapidly flow out of the basin containing Mowich Lake as night comes on and temperatures drop, revealing Mount Rainier standing above.

The clouds rapidly flow out of the basin containing Mowich Lake as night comes on and temperatures drop, revealing Mount Rainier standing above.

 

The Sandy River flows and eddies, throwing golden reflections from the setting sun back up at Steelhead fishermen.

The Sandy River in NW Oregon flows and eddies, throwing golden reflections from the setting sun back up at Steelhead fishermen.

 

The upper Columbia River in Washington flows smoothly but powerfully during spring's high flows.  On the opposite bank lie giant current ripples, formed during an ice age flood bigger than any we know about in earth history.

The upper Columbia River in Washington flows smoothly but powerfully during spring’s high flows. On the opposite bank lie giant current ripples, formed during an ice age flood bigger than any we know about in earth history.

 

 

Standing atop the columns of a basalt flow, cooled and hardened millions of years ago, in Washington's Channeled Scablands.

Standing atop the columns of a basalt flow, cooled and hardened millions of years ago, in Washington’s Channeled Scablands.

 

Golden light from a setting sun is reflected from the churning, flowing surf at Cape Kiwanda on the Oregon Coast.

Golden light from a setting sun is reflected from the churning, flowing surf at Cape Kiwanda on the Oregon Coast.

 

 

 

 

 

 

 

 

 

 

 

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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