Showing posts with label Chinle formation. Show all posts
Showing posts with label Chinle formation. Show all posts

Saturday, May 12, 2018

Zion National Park, Part 1

Saturday, April 14th, 2018 to Monday, 14th May; Zion National Park.


C1667
“Desert Spring Morning”
(near Zion National Park, Utah)
Oil Study on Pannelli Telati fine Cotton Panel
5” x 7”

Sold


This is my view every morning that I have camped north of the Eagle Crags Trailhead.  It has been delightful to watch the changing light as the mornings progressed, and also the cactus blooms coming into their own as the days passed by.  When I arrived I was not sure whether the little knobs on the Prickly Pears were new pads or flower buds … pretty much the latter.  The mountain in the distance is Johnson Mountain, I believe, which is in the southern part of Zion National Park.  Between here and there lies the East Virgin River; just below Springdale it flows into the Virgin River, which is that which flows through the Canyon of Zion proper.


Pigments used in the painting:

Imprimatura: W&N Venetian Red;

Drawing: W&N Cobalt & Ultramarine Deep Blues;

Pigments: W&N Cerulean, Cobalt and Ultramarine Deep Blues, Cadmiums Orange & Yellow Pale, Permanent Rose;

Rublev: Ercolano Red, Purple Ochre, Blue Ridge Yellow Ochre, Italian Burnt Sienna, Orange Molybdate & Lead White #2, Ceruse.


(Take Note: for those of you who have signed up to be notified by email of new postings to this blog, you have been receiving not just a notification, but an actual copy of the new blog posting as the email.  As this does not show the images of the paintings in the best possible light, you should click on the title of the latest blog posting at the top of the post, and not the title of the painting itself; this will open up the actual blog itself, and you may then enjoy the paintings at their best.)


My camp just south of Zion National Park is at the end of a steep desperate road below Eagle Crags, not far past the trailhead for the Crags; 4-wheel drive and high clearance a necessity.  Here at 4300', several small wildflowers are in bloom, and the prickly pear cacti are showing new growths; whether flower buds or new pads I’m not yet sure.  In Zion all the Cottonwoods are fully clothed in leaves, whereas a week ago in Cottonwood Canyon, they were only just opening their buds, except for those in sheltered spots, but then Cottonwood is 2000' higher.  It’s so interesting to see how these different situations affect the natural world, and even more so to observe the micro-climates that may be found within them. 

Here at Zion the geology is younger than the youngest formations at the top of the Grand Canyon, but older than those at Bryce.  The major rock formation on the canyon walls at Zion, sometimes as much as two thousand feet, is the Navajo Sandstone, first encountered at Arches National Park, in the form of petrified dunes, and which also formed the canyon walls on my second walk through the slot canyon in Cottonwood Wash several days ago.  I would also point out that back in Dinosaur National Monument the Nugget Sandstone there, is equivalent to these Navajo formations.


Take heed.

The western end of Zion National Park.


And there it is … the hanging valley.

Still in Kolob Canyons.


A Big Pondie.


To reach my camp, near the Eagle Crags Trailhead, is a very steep climb, on a very rutted, rocky road.  As one ascends you pass through the chocolate coloured Moenkopi Formation of early Triassic times, then over the ledge of the Shinarump Conglomerate Member of the Chinle Formation, also of Triassic age.  The Triassic was when the Dinosaurs were beginning to establish their hold on the world, but there were still some nasty amphibians about, they had to keep a watchful eye out for.  The Moenkopi Formation is composed of mud and silt sediments along a coastal mudflat environment, being distributed lugubriously by lazy streams and rivers and tidal channels.  Later more continental conditions took over the landscape, and coarse sands and small pebbles were deposited by braided river channels, forming the Shinarump Conglomerate Member of the Chinle Formation.


My first afternoon …

… & evening views of Zion …

… from my camp.

New Moon & Venus.


So, my present camp lies above that, within later members of the Triassic Chinle Formation.  If I walk north a few yards I can trace these formations (Moenkopi & Shinarump), across the valley towards Zion National Park, dipping slightly down towards the northeast and disappearing beneath the present surface somewhere in Springdale, the town just south of the Park entrance [An aside: the Chinle is what makes up the coloured layers of the Petrified Forest, I passed through back in mid-February].  Above them l can see the slope forming Chinle, the cliffs and slopes of the Jurassic Kayenta Sandstone, and finally the massive cliffs of the Navajo Sandstone (also Jurassic), the latter up to 2000’ in thickness; interesting to think that these Navajo Sandstones were once part of a vast dune field stretching from Arizona into Wyoming.  Here and there are bits of the Temple Cap Formation above the Navajo Sandstone … I can see West Temple, easily, which can also be seen from within the Park itself, from various places.



The foreground slopes are part of the Chinle Formation; beyond that in the left middle distance is a cliff sloping down towards the right … that is the Shinarump Conglomerate Member of the Chinle, above the Moenkopi; the slopes above the Shinarump are of the  Chinle Formation, above which are to be seen the ledgy band of cliffs of the Springdale Sandstone Member of the Kayenta Formation; the slopes above that leading to the high cliffs on the right is the main Kayenta Formation, and those high cliffs on the right are the Navajo Sandstone which once were sand dunes.  This view is on the way to my campsite.


Morning at …

… Zion.

More views of Zion from …

… the Eagle Crags Trail.

The massive Cliffs …

… above the …

… final slopes (Kayenta Formation) …

… are the Navajo Sandstone.

The red formation at the top
 is the Temple Cap Formation.


But here where I am, within the Chinle Formation, I see large slabs and boulders scattered about on the surface, or seemingly erupting out from the earth, at random angles.  My assumption is that the soil surface here is (1) the remnants of eroded Kayenta and Navajo Sandstones, (2) or blown in from elsewhere (3) or probably both, but the slabs and boulders are surely of Kayenta and Navajo origin.  To the southeast are the Eagle Crags, and the shattered spires at the top appear to be the remnants of the Navajo Sandstone layers, the Kayenta being the eroded slopes below that.  It was the slabs and boulders dotted about (I’m sitting in the shade of one as I write), that got me to wondering about why they were there, and so I began to apply my, strictly amateur, geologist eye to the problem.  I have had a crash course in geology over this past Winter, travelling through this geological wonderland that is the Colorado Plateau, centered on the 4-corners (for you British, that’s where Utah, Colorado, New Mexico and Arizona meet).  A year ago, I would not have been able to work this out.



Eagle Crags …

… showing the Slabs …

… & Boulders around my campsite.

And there was rain too!






Cloudscape.

Nocturnal clouds.

Cliff Rose.




Much of my campsite area is covered with these bushes, but they don’t all have flowers.



Three and a half months ago, while camped in the Valley of the Gods, I would watch the brightest star in our heavens, Sirius, pop into view over the canyon rim, not long after sunset.  Now I see it lowering into the southwest about the same length of time after sunset and about the same altitude, and soon to be setting.  These stars of Winter do not remain long in our night sky, whereas the stars of Summer seem to last so much longer.  With Sirius it is its more southerly aspect, and also the days are getting longer, in the Springtime, and so Sirius and the other Winter stars have less night to work with, whereas the Summer stars last long into the Autumn, and some even into early Winter, as the nights get longer at that time of the year; of course the opposite is true if you live down under.  So in a short time Sirius will be gone from the evening sky, just as Orion, for the most part, already is.



Cactus blossoms …

… in the ...

  ... desert.


Friday, May 4, 2018

A Taste of the Grand Staircase Escalante National Monument.

Thursday, April 5th, 2018 to Monday, 9th April; 
Cottonwood Canyon in the Grand Staircase Escalante National Monument.


(Take Note: for those of you who have signed up to be notified by email of new postings to this blog, you have been receiving not just a notification, but an actual copy of the new blog posting as the email.  As this does not show the images of the paintings in the best possible light, you should click on the title of the latest blog posting at the top of the post, and not the title of the painting itself; this will open up the actual blog itself, and you may then enjoy the paintings at their best.)


After five days of not seeing or hearing a vehicle, I left my Buckskin Mountain campsite, and slowly came down from the mountain; slowly being the operative word as that road is a desperate four miles of rocks, and ruts, and ledges and strange angles.  Three miles along the way I spotted an old quarry just off the east side of the road, or so I thought.  It turned out to be Eagle Sink, and is a natural feature, although it looks for all the world like an abandoned quarry.  I never saw it going in last Saturday, as I was concentrating on the road. “Rattlesnake heaven,” according to the lady at the BLM Office down Hwy 89 from there.  I expect they'll be out soon, as it's warming up in these parts.  Just a few miles to the east, after rejoining the highway, there's the road to Paria Township site, and also near the site of the movie set of the small town towards the end of “The Outlaw Josie Wales.”  Nothing there now, except some info signs, a loo, a picnic table, and a lot of interesting geology. 

Eagle Sink …
evidently rattlesnake heaven …
saw not a one.


On the way out from the old movie set.


Farther east over the ridge from Old Paria, is Cottonwood Wash, and yet more interesting geology, and I have a small publication all about it.  Tonight's camp is about 12 miles up the wash, next to a large slab of Jurassic Entrada Sandstone, across a small valley from several hogbacks of Cretaceous Dakota Sandstone, with the stars shining brightly.  On the way in I stopped to gather oysters for my supper, but the oyster-bed turned out to be ninety-some million years old; just a tad past their sell-by date, so I left these petrified suckers be … damn, coulda used some shellfish for me tea!


Between my Pinkie & thumb is a gap of 60 million years
in the strata; this is known as an unconformity.

Petrified Oysters.

Oyster-bed above a seam of coal (where the lower shadow is);
below that is Dakota Sandstone; this series represents a change
from river deposition to swamps, to brackish water,
where the oyster-beds are.

What left these tracks?

Oh!  You did.

Local lounge lizard …
the larger of the two types in this area.


While breakfasting the next morning, I was looking at the sloping strata of the Dakota Sandstone across the valley, and wondering if the oyster-beds were also in evidence there.  After breakfast I drove through Dakota hogbacks and took a look.  Sure enough, there were the oyster-beds at the junction of the Dakota Sandstone and the Tropic Shale (they were also found again two miles back down the road, when I went back for a look at the Geology I had passed by last evening).  Here the strata is steeply sloped to the east, whereas 9.5 miles back down the road where I first encountered them the strata was still level.  Here the rock layers have been bent over the East Kaibab Monocline along an underground fault, much as a tablecloth over the edge of a table, as the Grand Staircase Escalante to the west of this fault line has been uplifted.  Cottonwood Wash, up which I am driving, follows this fault line, and the tilted strata along here has formed a series of hogbacks through erosion, and is known as the Cockscomb for its resemblance to the serrated comb on the head of a chicken.



Entering Hackberry Canyon.

Cross-bedded Navajo Sandstone …
these are ancient dunes.

Some sort of Penstemon.




Much of the time you are walking in the stream, which on this day was half inch deep for the most part, and where slightly deeper easily stepped across.

To the east and west of Cottonwood wash the rock layers lie level, and the tilted layers along the Cockscomb are only a couple of miles or so in width.  I observed this first hand by taking a walk west through Hackberry Canyon for three miles.  At the beginning of the hike the strata is sharply tilted, but by the end of it has leveled out.  By the time I turned around where the Chinle formations were in evidence, I had walked through 60 million years of time, to when the early dinosaurs were inconsequential creatures (225 million years ago), from when they had become the large sauropods and carnivores at the beginning of my walk.  As I retraced my steps back down the canyon, I was now proceeding forwards in time, and at about the 190 million year area, I managed to find the boulder from the Moenave formation, that had some early dinosaur tracks on it.  This beastie who made these tracks was about six feet in height, so I reckon my bear spray might well stop it, should I encounter one next time I use my time machine, once it's repaired.

I brought out the colours in this one,
but with the naked eye and it fluttering along,
it looks black with yellow trimming.

About a mile into the Canyon.

The leaves within the canyon
were further along than those outside of it.

Here the Canyon widens out
at about 1½ miles in.


The lower slopes (in above photo),  are of the Chinle formation and about 60 million years older than the Navajo Sandstone at the canyon entrance.  The Red cliffs above the Chinle slopes are Jurassic Moenave and Kayenta formations, with the whiter Navajo on the skyline.  Note that by the time we reach this point in the Canyon, the strata has leveled out, indicating we have passed through the strata draped over the buried fault that lies beneath Cottonwood Canyon, that I had driven up the day before and where I am now camped.


Small dinosaur tracks in a
Monave formation boulder … my knife about 10”.

Denizen.

Sorry to have bored you silly with all the Geology, but that is much of what the Southwest is all about … you can’t ignore it.  And gaining a bit of knowledge about what I am seeing, whether geology, plants, wildlife, or the ancient ruins I encounter, all enhance these experiences.  That's why I was pleased as punch when I took what little I had learned about the first oyster bed I encountered, and idly wondered if they might be in the same situation near my campsite, and then found that they were!


About a mile to go.





Almost back out of Hackberry Canyon.


But apart from the Geology lesson, the walk through Hackberry Canyon was beautiful; splashing through the shallow streambed (managing to step over those channels that were more than an inch deep); observing my fourth wild flower in bloom this Spring (some variety of red Penstamen); noting that the new leaves on the Cottonwoods were slightly more advanced in the more sheltered, narrow depths of the Canyon, than at either end; spotting black butterflies, with yellow wing edges, that on close inspection through my binoculars, turned out to be not so much black, as a deep purple russet, and as the direction of the light on it changed, there seemed to be a pattern similar to a Small Tortoiseshell Butterfly, I was familiar with in England … but the naked eye impression is of black and yellow.  Yes … it was a good walk.  I returned to my secluded camp of the previous night, only about a half mile from the Hackberry Canyon Trailhead.


View from my campsite … hogbacks are evident.