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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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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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 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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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 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 ...
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How do we detect floods?

How do we know that there was a flood at a certain place at a certain time. For example if there was a flood in place A 200 years ago. How could we detect it?
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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 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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In an Earth-like planet with no history of carbon-based life forms, would there be limestone?

The extent of my understanding of limestone is about what Wikipedia says at the very top of the page: Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such ...
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Where can I find papers on the geology of the Wastach Range in Utah

I am looking for papers on the stratigraphy, geochronology and/or compositional make up of the Wastach Range and its formations. I prefer a broad overview paper and I can't seem to find one. Any help ...
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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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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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How are the Scala dei Turchi staircases formed?

The Scala dei Turchi i (Italian: "Stair of the Turks") is a rocky cliff on the coast of Realmonte in Italy: https://en.wikipedia.org/wiki/Scala_dei_Turchi#/media/File:Scala_dei_Turchi_panorama.jpg ...
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How are sand blocks formed?

My son asked me at the beach how are "sand stones" formed. These are the solid (but fragile) sand conglomerates which you can hold in your hand and which crumble to sand once pressed. I tried some ...
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Presence of cross stratified conglomerates in fan deltas

Why are cross stratified conglomerates found in deposits of fan deltas? I know that fan deltas are alluvial fans that deposit directly into the sea, hence they are poorly sorted.But could not ...
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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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What are the differences between alluvial, eluvial and colluvial deposits? [duplicate]

There's always confusion and disagreement when these terms are mentioned. Need to be sure of their exact meanings.
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Inorganic Limestone and Inorganic Gypsum

I read that limestone is made from the compaction of marine animals' bones. But, I am unable to find out why limestone could not have been produced from calcium occurring naturally (5th most abundant ...
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Geology: facies v. formations

Can someone please explain the difference between sedimentary facies and formations?
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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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Are fossil fuels really formed from fossils?

Hydrocarbons have been found in great abundance elsewhere in the solar system where there is unlikely to be evidence for life past or present. No fossils involved. Petroleum and natural gas wells ...
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Formation of petrified trees

In my book, I came across this question: Give reason why formation of petrified tress is considered as a degradation and a sedimentation action of the underground water. My book explains that ...
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The grains of the parabolic dunes

My text book says that parabolic dunes consist of consolidated limestone grains, but I wondered if they have sand grains too, so I googled this issue and found that they consist of sands, but I am ...
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Deposition in epioceanic areas

I found allochthonous (I don´t know the 2 locations) fined grained carbonate sediment in Ammonitico Rosso, which is possibly mudstone in the South Iberian Peninsule, specifically in Carcabuey (Córdoba)...
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A sedimentary rock with only minerals

In my text book I came across this multiple-choice question A sedimentary rock consists of only minerals and lacks fossils, it could be classified as: i) a clastic sedimentary rock ii) a chemical ...
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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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How can we estimate the amount of sediment that traveled downstream during the California flood?

It's amazing how much water traveled down the slopes of California during the first two months of rain/flooding of 2017. Since the amount of water was far greater than anything in recent history, ...
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