View allAll Photos Tagged Geologic
sent to me by friend hiking across Somerset, England
very good info ougs.org/southwest/event-reports/380/west-somerset-coast-...
OK, Flickr Friends! How well have I trained you? What is this feature? (Answer posted in a day or two!)
Autumn in the desert--Cottonwoods in a watercourse, along the road (Hwy 211) to the Needles section of Canyonlands National Park. These trees grow in areas of perennial water. When the climate changes and water isn't available for many years, the trees die. So they are an indicator of current rainfall conditions on a time scale of decades or centuries. The current shape of the spire above (North Six Shooter Peak) reflects a far longer time period of erosion, on the scale of a million years or a bit less. In turn, the rock strata in the pyramid formed over a still longer time frame, many millions of years.
Note the well stratified nature of the Paleozoic carbonate rock units/formations, and how the lines of trees commonly follow certain rock layers extending across the mountain slopes.
C. J.R. Devaney
This rock is a hard, metamorphosed sandstone (quartzite), with thin beds (layers) showing internal lamination (cross-bedding is well defined in the lowest of the three beds, and subtle in the middle bed). It was probably sourced from a Late Precambrian quartzite formation, a rock type which can be seen today exposed in the Canadian Rocky Mountains (to the west of Calgary).
This well rounded boulder was likely transported by high-energy river flows. During transport it collided with other boulders, and this energetic 'banging together' produced impact marks ("percussion marks"), the dark arcuate (curving, crescentic) marks present (scale: up to approx. 2 cm long). These marks are dark because they are recessively weathered and it looks like they probably contain dirt and lichen. Note how the arcuate fracture marks cross-cut the older lamination in the rock.
In more recent times, someone collected this and other boulders and placed them on a front lawn in my Calgary neighbourhood as part of an ornamental wall. So this is a piece of building stone that reveals multiple stages of its geological history (to those of us who know how to 'read' such clues).
C. J.R.Devaney
Clast-supported polymict conglomerate, with two of my fingers for scale.
Part of a natural boulder in an artificial (man-made) deposit of boulders that has been used to protect the shoreline of the Bow River (in central Calgary) from erosion.
C. J.R. Devaney
Mattawa River, Ontario, 26 Aug 2021
A teacher's geology field trip on the Mattawa River. The Mattawa here runs through a glacial meltwater canyon which is cut into the Canadian Shield. The Shield at this point is fractured along faults created by the suturing of two pre-Cambrian continents.
More simple fashion again today. When I saw this beautiful party dress from ALT on Flickr I knew I just had to have it, and especially in this stunning gold version (though they call it yellow!). I played around with what hair would look best, and the new Catwa hairbase and hair from Tableau Vivant at Kustom9 fitted the bell, especially when combined with this cheeky old pose from DARE
at Point Arena, January 2020 -- such fascinating linear rock forms, where the San Andreas fault goes out to sea...
The back of the fantastic little beach near Penzance. My rock fascination was working on overdrive here, and it was actually a very misty day. The variety of colour and shape was really appealing and warranted using the 6x6 back on my Mamiya RZ67 Proii film camera with some Fuji Velvia 50 film. I am glad I took two shots of this, as the other had a huge light leak coming in from the top of the frame. This one escaped. Sorted the problem now with some new foam sealant.
Glacier National Park
If you look closely you will see two waterfalls and a off to the far right a tunnel carved through the rock--that takes cars along the spectacular Going to the Sun Road that traverses Glacier National Park.
Have you ever wondered how the brightly-colored geologic formations of the Southwestern USA came about? They seem so artistic and surreal. A discovery that I have made has revealed the secret behind these multi-colored wonders. They are elaborate artworks of an ancient race of cosmic beings, of course. The proof, you ask? I have stumbled upon the palette of colored material that these powerful entities used to create such masterpieces as the nearby Bryce Canyon and Zion National Parks. If you are still skeptical of my claim, I present this photo taken at a remote canyon in Utah as verification.
Yes, I admit that I have a long history of odd scientific discoveries and that many so-called experts have labeled me a whacko and charlatan. However, I am certain that this time my soiled reputation will at last be redeemed!
This photo was taken by an Asahi Pentax 6 X 7 medium format film camera and Super-Multi-Coated Takumar/6X7 1:4.5/75mm lens with a Zenza Bronica 82mm L-1A filter using Fuji 160NS [220] film, the negative scanned by an Epson Perfection V600 and digitally rendered with Photoshop.
I drew two lines to show the folding of the rock layers (and hope that geologists would approve).
Ich zeichnete zwei Linien, die verdeutlichen sollen wie sich die Gesteinsschichten falten (und hoffe, dass Geologen mir zustimmen).
Panorama interpretation of sunset light on Yampire Peaks near the entrance to the North Unit of Badlands National Park, South Dakota.
Cheers!
Bob G.
The Wheeler Geologic Area was one Colorado’s first National Monuments. It is located in the La Garita Wilderness, a few miles east of Creede, Colorado. Due to its remoteness, there were not many visitors, and its status as a National Monument was withdrawn in the 1950s.
To get there, you drive up state road 149 from South Fork for about 15 miles. Just as the highway crosses over the Rio Grande, take a well-maintained dirt road to the east. This road climbs for about ten miles to the trail head. There is a pit toilet and lots of room for parking.
Because it was Labor Day weekend, there were about 15 cars parked when I arrived in the afternoon. I spent the night there.
From this point you can take the eight mile (one-way) hike over undulating terrain, or you can drive 14 miles over a very difficult 4WD hi-clearance road.
Conventional wisdom is that the drive will take you about as long as the hike.
The next morning, after eating my boiled eggs, I filled my day pack with a poncho, some snacks, and my Sterilite water purifier, and set off on the trail. I took my little Sony Cybershot RX100-iii point-and-shoot camera and a light-weight tripod. It was obvious from the start that it would be a slow walk. At 11,000 feet of elevation, any uphill walking got me out of breath fast. I was passed by several people along the way.
After about 5.5 miles the trail joins the aforementioned road. The road eventually ends in a parking area that is a little less than a mile from the Wheeler area. There were several stands of Aspen with bright yellow leaves along the final path.
After about three and a half hours I reached the viewing area. It was an impressive experience. I spent about an hour taking pictures and then turned around for the eight mile walk back to my truck.
I arrived, exhausted and a bit unsteady, a little before 5 pm. All of the pictures I had taken were during mid-day, when the shadows are not the best for photography. So I got the idea that if I drove fast I would have time for to take the 14-mile drive back to the area and get there before sunset.
I drove like a crazy person (which I was a little bit) and made the trip in an hour and 15 minutes, putting a few scars on the truck body in the process. Just as I arrived, it began to rain, but after a few minutes it abated. I had about 20 minutes to walk up the last part of the trail if I wanted to reach the top before sunset.
I made it! Just as the sun was setting, I hastily set up my little Sony on the tripod and clicked off a few shots. It was darker than you would think from the image here. Thank you, Photoshop!!
I walked back down in the dark to my truck and slept there at the end of the road.
The next morning I made the bumpy 14 mile drive back down to the trailhead. I stopped there to take a break. Actually, as I pulled in, the truck engine quit and so did the radio. It was totally dead. I popped the hood and saw that the battery had bounced out of place and the cable had become unattached. I looked in my toolkit and found everything but what I needed (a crescent wrench). I worked the connector back onto the battery by hand, and that turned out to be good enough. The truck started and I was on my way home.
From left: Atlas (2927m), Piz Segnas (3099m), Piz Sardona (3011m), Sardona Glacier and Piz Dolf (3028m) seen from Fil de Cassons, Flims.
The noticeable line below the peaks is the Glarus Thrust. Geologists are quite fond of it… Wikipedia says: «The Glarus thrust (German: Glarner Hauptüberschiebung) is a major thrust fault in the Alps of eastern Switzerland. Along the thrust the Helvetic nappes were thrusted more than 100 km to the north over the external Aarmassif and Infrahelvetic complex. The thrust forms the contact between older (Helvetic) Permo-Triassic rock layers of the Verrucano group and younger (external) Jurassic and Cretaceous limestones and Paleogene flysch and molasse.
The Glarus thrust crops out over a relatively large area in the cantons Glarus, St. Gallen and Graubünden, due to its horizontal orientation and the high local relief. Famous outcrops include those at Lochsite near Glarus (the town) and in a mountain cliff called Tschingelhörner between Elm and Flims (in the same cliff is a natural hole called the Martinsloch).»
Details from a large block of rock in a Calgary park.
This is a coarse-grained sandstone, with horizontal bedding (layering) across the middle of the photo, and subtle cross-bedding (foreset laminae: layers sloping down to the right) in the upper and lower parts of the photo. In the left half of the photo, near-vertical fracture planes are well defined.
C. J.R. Devaney
This small cliff (about 3 metres high) offers a cross-sectional view of well layered/stratified/bedded sand and gravel (pebbles, cobbles and boulders) deposited by a high-energy braided river during Late Quaternary deglaciation. (This is a common scenario in the recent geological history of Canada, and elsewhere: as the glaciers melted back, they released large quantities of coarse sediment, and the rivers of meltwater transported and deposited gravel and sand in bars and channels.) Location: near the town of Midway and the USA border in southern B.C., western Canada.
C. J.R. Devaney