Questions tagged [sedimentology]

Sedimentology encompasses the study of modern sediments such as sand, mud, and clay, and the processes that result in their deposition.

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Blueberries, cauliflower, chert, concretions, accretions and diagenetic crystal clusters on Mars, can you help me sort these all out?

Curiosity has actually seen these types of features before, which are called diagenetic crystal clusters. Diagenetic means the recombination or rearrangement of minerals, and these features consist of ...
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What chemical or physical parameters altered during the usage of buffered versus unbuffered extractant for leachability of a soil or sediment?

Toxicity characteristic leaching procedure (TCLP) is an extraction method to simulate a soil or sediment leaching. The method employed two extraction fluids - one is a buffered solution of acetic acid ...
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Is this kind of sediment location sampling on river acceptable?

Yesterday, we performed a sediment sampling along both sides of a river. On various research papers, it seems that they always made it successfully to perform the sampling at both left and right side ...
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Can a braided fluvial create thick relatively continuous siltstone beds?

I am attempting to interpret an outcrop I went to. I suggested it was created by a braided fluvial. The one thing I cannot explain are prominent alternating siltstone beds with the sandstone beds. ...
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Why are the Himalayan rivers highly tortuous in the mountain reaches?

"In the Himalayan reaches, the course of these rivers is highly tortuous, but over the Plains they display a strong meandering tendency and shift their courses frequently." This is what I ...
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Can we separate a sandy, clayey & salt layer on basis of their rheological properties?

Since, given enough compaction, salt is able to behave like a fluid & buoyant too if it's overlain by a higher density rock (it could be fine grained clay or a sandy sequence). But in another case,...
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Is there sand in Antarctica?

There's a song "Blizzard's Never Seen the Desert's Sand". Given Antarctica is a desert, someone questioned the title's validity. BUT is there sand in Antarctica? I'd imagine yes as it's a pretty ...
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What makes sand dunes shaped asymmetrically?

I have been working on a simulation to approximate the formation process of dunes. I understand that their formation is a result of saltation and aeolian processes, but I don't understand the exact ...
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Reconstructing lake level from organic and magnetic sediment data

I would like to understand why any of the following conditions in a layer of a lacustrine sediment core appear to imply that the lake level was low at the relevant time: low C/N ratio low δ13C low ...
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What does the term "founder" in "load and founder structure" mean in sedimentary geology?

In the context of sediment deformation, why are some structures called load and founder structures? I know what a load is, but what is a founder? I read it in Sam Boggs, Jr's Principles of ...
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Large scale structures in the Sahara – what are they?

In Google Earth we can see some very clear lines in the Sahara. In the screenshot below you can clearly see these lines starting at the top going southward, then gently curving westward towards the ...
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Igneous and Sedimentary Rocks' Susceptibility to landslide

Which is more susceptible to landslide based on lithology compared to one another? Granite, Conglomerate, Sandstone, Mudstone I've been tasked to create a hazard map and was given a Geologic Map, ...
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Are carbonated stalactite deposits sedimentary deposits?

Acording to britanica.com: sedimentary rock, rock formed at or near Earth’s surface by the accumulation and lithification of sediment (detrital rock) or by the precipitation from solution at normal ...
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Why is the delta part of Jezero crater higher than the surroundings?

In images of Jezero crater on Mars, it looks like the delta fan is higher than the surrounding crater floor. This indeed seems to be the case with closer-up images from the Perseverance rover taken ...
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Is Radiocarbon dating flawed?

I posted this before on physics stack exchange, but it was deemed off topic, which is understandable, so I hope it won't be here. Recently, I stumbled upon an article by an individual named A.M. ...
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What is the sedimentary form of gabbro/diabase? What would it look like?

Gabbro is an intrusive, mafic, and igneous rock. How would it turn into sedimentary rock?
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Sedimentology (Particle size distribution parameters)

The Inclusive graphic standard deviation (sorting) value of this claystone sample is negative (-1.29). Is this right to be considered as very well sorting ? However, the bivariate plots of ...
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How to tell whether sediment was laid in ocean or on land

What are the features of terrestrial lithographic/clastic sediment that indicate it was deposited into an oceanic as opposed to a terrestrial (e.g. fluvial or lacustrine) environment? How to tell ...
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Are we observing sedimentary rock formation today?

For instance, are we able to see the microscopic accumulation of shale or limestone? Can anyone reference me to sandstone formation observation, that would have to occur more rapidly. I’ve heard it ...
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Is it true that "[sand] grains in the Coconino Sandstone come from the Appalachian Mountains"?

The Creation Museum is a terrifying place for scientists of all stripes. One of their exhibits is the "Flood Geology" exhibit, which purports to explain how a flood of (literally) Biblical proportions ...
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Permeability test

What are the different ways permeability of a core specimen can be determined accurately for fluids with different viscosities and their mixtures?
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Why is coal classified as a sedimentary rock?

Something just clicked in my head today. Rocks, by the definition I was taught, are composed of minerals which in turn are by definition not organic, so they are or were not alive. However. Coal, ...
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SC7 and SC10 Lithology Classifications

I am looking for the full names of the lithology classifications SC7 and SC10. According to the FAO's guidelines for soil description SC3 e.g. refers to silt-, mud-, claystone. What do SC7 and SC10 ...
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What is the oldest sediment?

Sedimentary rocks in Akilia or at Hudson Bay have been proposed as the oldest in the world. My question is not related to rocks, but rather to sediment while still forming sedimentary deposits but ...
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Have we looked for human-like signals in the geological record?

This is somewhat of a follow up to some interesting discussion here about using synthetic radioisotopes to define the start of the anthropocene. It is also sort of related to a question asked here, ...
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Have meteorites been found in the oldest sedimentary rocks?

Dropstones sometimes occur in sedimentary rocks. These are foreign rocks and boulders that happened to "drop" into a sediment and were fossilised when the sediment was lithified. (source: ...
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What kind of soil is being worked in this video? [closed]

I have recently stumbled across this video on Youtube, where quite a magnificient building is carved into the soil with simple tools like a shovel and hoe. The location is somewhere in South America, ...
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Mass budget of coastal erosion and ocean deposion

This question made me wonder: how much mass (or volume) of material is eroded by the sea each year? Of this mass, how much is deposited in the oceans? (As Michael pointed out in his answer, part of ...
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How are chenier ridges and strand plains formed at wave dominated coastlines?

In the attached image, we can see chenier ridges and strand plains. How are they formed and what is the involvement of rip and longshore currents in their formation?
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When sediments are deposited, do they sink into the earth?

I was listening to a geology podcast describing how sedimentary rock forms and later turns into metamorphic rock. As a river lays down sediment, the lower layers can eventually be several kilometers ...
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Is there any significance of lacustrine gastropoda fossils regarding paleoenviroment interpretation?

How to interpret lots of gastropoda fossils seen in lacustrine marls? Do they indicate any paleoenvironment conditions? Depth, temperature, chemistry, ph?
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Sandstone Layer Question

I have been exploring the sandstone of southern Utah for many years and I have a question about the area around Sidestep Canyon (near Wahweap, near Page, AZ). There are many amazing hoodoos there and ...
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How much does the weight of urban structures (buildings) affect the compaction (permeability, porosity, density) of alluvial sediments below a city?

I live in Van, Turkey. Van City is situated on an alluvial plain beside Lake Van. General geological structure of the area can be seen on pages 43-44 in this conference book. One of the images is ...
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No sedimentation without water?

I just found a video on sedimentary rock formation, and to my surprise, it stated that this only could occur in water! I always thought that any layer of matter, if buried deep underneath more matter, ...
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How do I plot Troels-Smith lithological symbols in R?

I'm trying to plot lithological data using the Troels-Smith scheme. I have tried psimpoll but as I only have lithological data I cannot create a main input file which is required. I also do not have ...
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How are natural specimens, such as ‘Moqui Marbles’, distinguished from man-made artifacts?

If a particular type of rock specimen is found throughout Earth and is made entirely of natural minerals, but the individual specimens differ minutely from another in size and shape and look to be ...
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How this sedimentary rock is made?

Apologies in advance for a beginners question. Different rock types make me curious and recently went to an area where interesting sedimentary rock is all over. As the area is on the coast, sea has ...
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Geological feature - what is it?

Hello, We were walking in Bundoran in Donegal County, Ireland today and we encountered the geological feature shown in the picture (from above from cliffs and from very close up at beach level). We ...
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What do you call boulders of non sedimentary rock that were lithified into sandstone?

I'm convinced there is a word for this. I was in the Hoodoos at Writing on Stone this weekend and kept noticing what looked like reddish quartzite boulders laying around in the sand, or sometimes ...
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What caused this waterfall to have rounded formations?

This is at Bua Tong Waterfalls in Chiang Mai, Thailand. Tried to find scientific information about this waterfall, but google turns up only travellers' vague guesses, suggesting calcium carbonate ...
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How much does sea level rise due to sediment deposition?

There has been a lot of noise in the news in the last few days because Congressman Mo Brooks from Alabama claimed that erosion played a role in rising sea levels. Quoting from Science magazine: ...
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Waves on sandy beach separating differently-sized rocks?

I recently went to a beach, and I noticed that the sand seemed to have a few distinct regions. I'm wondering what would cause this, and how it works. One region is the part of the beach which is ...
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What are the differences in terms of appearance between sandstone and limestone?

On the field, I find it very difficult to differentiate the two types of rocks just by looking at them.I know that you should do some analysis of the sample before any conclusions. But, for example in ...
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A few questions about the morphology and sediment dynamics of Wissant Bay (France)

Could someone please explain what exactly is shown on the following image? I have a few questions such as: How did the 'Banc à la Ligne' come about? (I know it has something to do with the fact that ...
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What is the difference between Saprolite and Regolith?

Saprolite and Regolith both imply loose material, is one a subset of the other how can I differentiate them ?
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What are these basal rip up clasts in North Dakota?

Ther's an graph that appears that the KT asteroid turned the rocks into rubble 3000 km away, else there was a rain of big rocks from the sky. What are the rip up clasts and what is the way they were ...
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How do you interpret Oxygen Isotope changes?

In a paper I am reading, the authors note "large (5-7%) negative shifts in the oxygen isotopic composition of geologic proxy materials" (Davis 2008, pg. 102) in several regional basins. This is then ...
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Does the existence of limestone nodules in a clay soil horizon indicate a limestone bedrock?

A profile (clay soil) was excavated to a depth of 100 cm in the north of Tunisia. We have found limestone nodules, colluvium and alluvium. What I would like to know is the nature of the bedrock of ...
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Are all natural diamonds made of organic carbon material?

I've read that diamonds are created at a depth of about 180 km. By volcanic activity it comes above. But did plants and trees of 300 million years ago sink so deep? Or is it possible that inorganic ...
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How much climate history can be reconstructed using marine sediment cores?

Today I learnt in college that marine sediments can be used to reconstruct the climate up to 500 million years back. I find that number very strange because in another class we learnt that the ocean ...