Cool Geology Pictures

[BillTre]

Add more cool geology pictures if you have them.

 

[Ibix]

Columnar basalt.

This is the Giant's Causeway in Ireland, and is not a photo I took. I did take photos of columnar basalt in Iceland (none quite as impressive as this one, I must admit), but I don't know where they are.

Essentially what happens is that solid but still hot rock cools and shrinks, which builds up tensile stress. It can relieve the stress by cracking, and depending on the material properties you can get a lot of T or Y shaped junctions, which ends up yielding fairly regular columnar prisms, most (but not all) hexagonal.

 

[morrobay]

Morro bay This is the core of a volcano and an easy climb to top.

 

[morrobay]

Simalan Islands

 

[morrobay]

Island off Chumphon, Gulf of Thailand

 

[fresh_42]

Impact crater in Germany​

Width: 20-24 km
Area: 350 sqkm
Depth: 100-150 m
Date: -15 million years
Remark: has an inner wall
Asteroid size: 1.5 km
Asteroid speed: 20 km/s
Source: https://de.wikipedia.org/wiki/Nördlinger_Ries

 

[Mark44]

Regarding the K-Pg boundary mentioned in post #1, I had first heard it described as the K-T boundary, apparently its former name. It is the boundary between the Cretaceous and Tertiary Periods. The term cretaceous denotes chalk (Latin creta) and the letter K derives from the German equivalent, Kreide.

The K-Pg boundary is noted for its high concentration of iridium, much higher than normally found on Earth, but present in higher concentrations on asteroids and such. One hypothesized cause for the much higher-than-normal concentrations of iridium throughout the world in the K-Pg layer is the asteroid that created the Chicxulub impact crater on and near the Yucatan Peninsula in Mexico about 66 million years ago.

 

[BillTre]

Here is a smaller piece of geology:

 

[fresh_42]

Not really a single photo, but sintering doesn't have to happen vertically. Here are some nice pictures of the various forms. I considered pasting them all here, but a single click is easier.

I remember that I have seen almost horizontal tiny channels formed by the capillary effect on a TV show, but I couldn't find pictures.

https://gasselhoehle.at/tropfsteine.html
(The site has an English version, but there are more pictures in the German version.)
https://www.showcaves.com/english/explain/Speleothem/Helictite.html

 

[Ibix]

The K-Pg boundary is noted for its high concentration of iridium, much higher than normally found on Earth, but present in higher concentrations on asteroids and such. One hypothesized cause for the much higher-than-normal concentrations of iridium throughout the world in the K-Pg layer is the asteroid that created the Chicxulub impact crater on and near the Yucatan Peninsula in Mexico about 66 million years ago.

A friend had this cartoon on a gag-a-day calendar or something like that:

I cracked up when I saw it, and then had to explain the joke to him.

 

[Ibix]

To drag myself back on topic, another thing I've seen in real life but don't have good photos of:

This is on the north coast of Arran. The things that look like funny tire tracks that the guy is pointing at (if you're on a phone you might need to zoom in a bit) are actually fossilised tracks of a millipede that had its left and right feet about eighteen inches apart.

Wiki article (from whence came the photo above).

 

[difalcojr]

Pine Creek Mine, outside of Bishop, California, in the Sierra Nevada Mountains, elev. 8100 feet at main mine entrance, which is at the higher level road, above the mill, hidden behind the tree on the left in the photo. Tungsten, molybdenum, some copper, very little silver, gold mined. Scheelite is a white, calcium tungstate mineral with the chemical formula CaWO4. It was called Union Carbide's "gold" mine due high W value. Mine and mill employed around 400. Closed in 1982.

Enlarged area of first photo from above.

From: https://pubs.usgs.gov/bul/0931e/report.pdf : the geology:
"A large segment of the septum of metamorphosed sedimentary rocks, called the "Pine Creek pendant" extends from Wheeler Crest south to Horton Creek, This pendant, 5t§- miles long and about 1 mile wide at the maximum, is exposed in the deep trench of Pine Creek down to an elevation of 7,500 feet, more than a mile below its highest points."

tailings ponds unseen from road coming up Pine Creek canyon.

https://www.jsginc.com/2022/01/18/12-little-known-facts-about-the-historic-mine-in-the-sky/
https://bishopvisitor.com/ghost-mine-in-the-sky/ video of mine today is included on this site.

Shocking! I had no idea, I worked there in 1982 until it closed. The main ore zone inside the mountain, at about 9600 feet up to 11,000 feet, about a mile in length and up to 150 feet wide, is mostly mined out. The inside was a steady 42 degree F., always wet, dripping from snowpack on surface. In ruins now.

 

[morrobay]

Yes ^^ Amazing geography along CA .Hwy 395. Eastern Sierras

 

[FactChecker]

Big Bend has a wide variety

.

 

[difalcojr]

Essentially what happens is that solid but still hot rock cools and shrinks, which builds up tensile stress. It can relieve the stress by cracking, and depending on the material properties you can get a lot of T or Y shaped junctions, which ends up yielding fairly regular columnar prisms, most (but not all) hexagonal.

Devils Postpile, about 20 miles north of the Pine Creek Mine as the crow flies. At location of head waters of the San Joaquin River that goes down into the Central Valley of California. The Eastern Sierra Nevada Mountains are really beautiful.

The formation of the Devils Postpile began with a volcanic eruption that occurred approximately 80,000 to 100,000 years ago in what is now the eastern Sierra Nevada Mountains of California. During this event, basaltic lava flowed from a vent in the Earth's crust, creating a lava lake that reached depths of up to 400 feet. As the lava cooled, it contracted and cracked, forming the distinctive hexagonal columns characteristic of columnar basalt formations."​

 

[fresh_42]

Not far from where I live.

I even remember the controversy some decades ago, when paleontologists had to fight hard to preserve it (Grube Messel, oil shale).

That's their most popular find ...

... a little horse, or what someday became horses. Hundreds of other fossils were discovered, from land and sea, and some with feathers. Have a look at all the pictures:

https://de.wikipedia.org/wiki/Grube_Messel
https://en.wikipedia.org/wiki/Messel_Formation#Messel_pit

 

[difalcojr]

How little is little? Wish there was a (required) ruler underneath to give this.
Never saw oil shale before or in an open pit. Interesting looking. Doesn't look like too big a clean-up mess of it. Was it a clean mine operation? I was stationed in Wildflecken for 9 months. Hessen is really beautiful.

Here's one more from Eastern Sierra Nevada, just out of Bishop, coming from the Long Valley caldera eruption 760,000 years ago. About 10 miles from the Pine Creek Mine down in the Owens Valley.

Photo showing two layers of Bishop tuff, eastern California, United States. This outcrop is exposed in a rock quarry in Chalfant Valley about 25 km southeast of Long Valley Caldera. The two main units of the Bishop Tuff deposit are visible here: (1) the lower 5 m of the section consists of the pumice that fell to the ground (airfall pumice) downwind from the eruption; and (2) the upper 5-6 m of the section consists of the basal part of the pyroclastic flows that swept at hurricane speed away from the eruption. The thin dark "layers" just below the contact between the units are stains from an ancient groundwater table (manganese oxide stains).

 

[fresh_42]

How little is little? Wish there was a (required) ruler underneath to give this.

Early horses were significantly smaller than modern horses, reaching a shoulder height of about 30 to 35 cm. They were roughly the size of a German Shepherd or a cat and weighed approximately 5 to 6.5 kg. These early horses lived in forests around 50 million years ago.

Never saw oil shale before or in an open pit. Interesting looking. Doesn't look like too big a clean-up mess of it.

About 100 acres, if I did the conversion right (40 ha).

Was it a clean mine operation?

Yes, a former oil shale mine. And if I remember correctly, they wanted to use it as a garbage dump.

I was stationed in Wildflecken for 9 months. Hessen is really beautiful.

It is, although Wildflecken is just across the border in Bavaria, but the landscape there is typical for Hessen.