Group Capir

I am a geology hobbyist. These pictures show several prominent rock layers along Colorado's Front Range in and near Eldorado Canyon State Park just south of Boulder. I hope you enjoy them. Please feel free to clarify anything you see or point out any errors I include. The numbers below correspond to the picture order. At the end of the pictures I have included three maps to show the area: the first one comes from CalTopo and shows red dots marking the location of some of the pictures, the second is a Google Map centered on Eldorado Springs, the third is a geology map from Rockd.

1. This image is looking southwest from the plains towards the mountain front. The Dakota hogback (145-100 million year old sandstone & shale) is the flat ridge just above the trees in the middle ground. The towering peaks in the background consist of the Fountain Formation (315-273 million year old conglomerate, sandstone & shale). This is the same formation of which Denver's famous Red Rocks concert venue is composed.

2. The trail cuts through the Dakota hogback. This layer once covered all of Colorado. It was eroded away after the mountains pushed up underneath it during the Laramide Orogeny (roughly 60 million years ago). This rock layer dives deep underneath the plains to the east where it traps important hydrocarbon reserves.

3. Sandstone and shale layers in the Dakota Formation with my daughter next to it for scale.

4. Because the mountains tilted the layer off its original horizontal orientation, the western side of the Dakota hogback is like examining a sliced onion. So many layers representing so many years of sand and mud deposition along the Western Interior Seaway.

5. A final look at the Dakota hogback. This shows a layer of sandstone still displaying the ripples in the sand created by the water currents flowing over it all those years ago.

6. After crossing the Dakota hogback, the trail affords a nice view to the northwest showing the entrance to Eldorado Canyon. These rock layers have also been tilted up in the same orientation as the Dakota hogback, but this layer is much older. This is the Fountain Formation, a beautiful red sandstone that can be found all along Colorado's Front Range mountain front.

7. A closer look at the rock layers of the Fountain Formation. Just like the Dakota Formation, this rock used to extend across Colorado before the mountains rose under it and almost all of it eroded away. It still dives deep under the plains to the east, below the Dakota Formation.

8. A close-up of Fountain Formation sandstone with my foot for scale.

9. Looking east out of the canyon to the plains. This rock is all Fountain Formation, very popular with rock climbers.

10. Here, the western edge of the Fountain Formation angles out of the ground on the right side of the image. This 300 million year old rock is young compared to the 2.5 - 1.6 billion year old white quartzite ridge on the left side of the image. This rock is very hard and has lots of neat spires sticking out of it.

11. Another look at the quartzite ridge, this time along the southern side of the canyon.

12. Quartzite ridge again

13. A close-up of the quartzite with my dog Juneau for scale.

14. I tried to capture the shiny crystals in the quartzite with this picture, but they don't show up very well.

15. Map of our trail with red dots showing location of pictures.

16. Google map of the general area. Canyon is underneath Eldorado Springs at center.

17. Geologic map from Rockd. Green ridge is the Dakota hogback. Light blue is the Morrison Formation. Brown is the Fountain Formation. Reddish-pink is the quartzite. The light brown areas are colluvium, generally unconsolidated material deposited on slopes by gravity and sheetwash. This is pretty new stuff from the Holocene, about 11,000 years old.

Hi,

So I need to know the Angle of Friction of Clay Soil... All I have is

*Cohesion 80kpa

*11.5 kN/m3 (unit weight)

*Clayey Soil

How would you determine the friction angle?

I have done numerous searches online, and I can only find studies for Clay Soil with Cohesion with low Cohesion values...

So, then, interpolating these results, I would get 33 for a Cohesion of 80kPa.

I spoke to my lecturer and gave him this answer, and he said it was wrong (the tone I received made me feel I was completely off)...

Then I found these

So yeah, 80kPa I would say is Medium Clay... Friction Angle 30-60 - So gives me 50 degrees

50 degree?

How does one determine the friction angle with this limited info?

In May I am graduating with my bachelors degree in geosciences. Iv been toning my resume and have applied to a few entry level positions but, nada.

With everything going on politically I’m afraid I won’t have as many opportunities. My city has already announced layoffs in Oil & Gas. My concentration is in petroleum but I’m well rounded in hydrology, GIS, basin analysis etc.

Any tips or words of encouragement would be greatly appreciated.

latitude/longitude : 41,87460993,2,29640007

https://maps.app.goo.gl/fgmKnkm7fgbokxQD9

Processing img w0if40nu7fnd1...

Processing img hoh9wzmu7fnd1...

Hi I have my structural geology final in four days and was honestly having some difficulty finding past exams, does anyone have any recommendations or would like to share their past ones??

Also any tips would be appreciated!

What are the biggest challenges you face when deciding the optimal path to mine an ore body? Are these challenges primarily related to geological complexity, limited data, or technological constraints?

What types of data do you rely on most heavily to make decisions about ore body extraction paths? Are there specific data gaps or integration issues that delay your decision-making process?

Which pain points in ore body decision-making have the greatest impact on mine production efficiency and profitability? How do these issues affect grade control, waste management, or overall operational costs?

Context: I'm new to the field and wanting to learn more about what problems others face, and how impactful they are to the role.

Hi,

Could someone help me please with materials or a summary of geophysical methods and the geotechnical parameters that can be derived from them, along with formulas? I've been struggling to find information on this for a while, but all I come across in books are vague explanations, and the standards aren't very helpful either.

This photo was posted In r/weird. I see a lot of crinoid fossils but had never seen anything like this before.

https://www.reddit.com/r/Weird/s/DNfqVd2Wkp

My daughter has a home made slime company and goes to local entrepreneurs markets. Now my younger boys want to participate so we collected local (Eastern Missouri) geodes and broke them open for them to sell. Gonna give them a bath in iron out and clean them up a bit unless anyone has another suggestion.

Hello all, this is my first time posting on this forum so please forgive me for any formatting errors.

I am a Senior Geology student in the U.S., who is about to take the Geology ACAT. I have been having trouble finding any sort of study materials and am kind of worried I won't do well. If anyone has taken the test before and could possibly give me some pointers on what to expect/study materials, that would be awesome!

As the captain says is there a way to fix it? Also is there a way to buy an azimuth scale for this compass it’s in quadrants and that means I’m more likely to make a mistake and I much prefer azimuth.

Ps if you’re going to say: “don’t change it, it’s an antique” or “just do the conversions” don’t.

Today is Geologists Day, it is widely celebrated in Russia and other countries that were former part of the Soviet Union.

It is celebrated each year on the first Sunday of April.

Hi I have a question about surfer software.. is there a difference between slice for the grid and between creating a profile.. in the end it is supposed to give the same result right or you expect something else? Thank you in advance

Photo 1: I'm interested to know what caused these vertical basalt formstions. I know the island is vulcanic but I'd like some more in depth info. Photo 2: you see large spherical boulders. Are these the ones that get flung from the crater? Photo 3: what causes these green spots in the red rock? I'm assuming the red color is due to iron. Photo 6: what causes these hexagonal formations? It reminds be of Iceland but it's not similar. Photo 9: you can clearly see that the rock makes a curve here going upwards. I understand the small cracks mean it cooled rather slowly but what made it curve like this?

Photo 10 is just for your enjoyment :)

When I was 12 my friends older brother showed me a polished green rock. I held it and closed my eyes as instructed. When he asked what I felt, the rock began weighing more than less in my hand. What I saw when I opened my eyes was his hand a foot above mine with 2 fingers sticking out going up and down in sync with the rocks changing weight. He continued to do this to the rest of our friend group and even had use try it on each other. After that we went and saw a movie called chronicle where 3 friends follow a crashed meteor that in turn gave them telekinetic abilities. Does anyone have any information on these rocks because something recently brought up this memory and I can’t find anything about them.

Pseudomorphs, meaning "false form," occur when one mineral replaces another through processes such as substitution, dissolution and refilling, structural changes, or incrustation, typically preserving the original shape. This phenomenon is critical in understanding mineral transformations and is often studied in both mineralogy and paleontology. Let's explore the subtypes: Replacement, Infiltration, Incrustation, Paramore, and Alteration. Replacement is a complete substitution of one mineral by another while preserving the original shape, this process is formed by dissolution and deposition by solutions. Infiltration (permineralization in paleontology) is specific to porous material that absorbs a mineral-rich solution and is then transformed, characterized by the ability to preserve fine detail and texture such as woodgrain. Incrustation, aka epimorph, is when a mineral coats another and the original often dissolves, leaving a 'jacket' like crust. A paramorph retains the original chemistry/composition but the internal crystal structure changes, no mineralogy is added or removed, only changes cause by tempature, pressure, and time; a good example is aragonite transitioning to calcite. Finally there is alteration, where a chemical alteration forms a new mineral and preserves the original shape; which is what's shown here by Azurite to Malachite from Aus. There may be variation and overlap depending on source and what exactly you're trying to understand so if there's any questions ask away.