Questions tagged [structural-geology]
The structural-geology tag has no usage guidance.
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How to extend the Wyllie time average equation to multiple constituents
I understand the Wyllie time average equation
How to extend it to multiple constituents ?
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From how deep in the mantle has any rock ever been brought to the surface? Have scientists found anything they believe originated in the outer core?
I wonder if this is even possible to know....
Do geophysicists and geologists have even a 'theoretical' idea about how deep Earth's churning of its layers goes?
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Relay structures in Rupes Recta
Rupes Recta is a 110km long normal fault on the Lunar nearside. It appears to contain features that resemble terrestrial relay ramps. Is this the case or is it something else?
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Mud cracks formation
Are mud cracks formed during rock formation or after the rock is completely formed?
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Displacement-Length scaling relationship on extraterrestrial faults
Faults on Earth share a similar displacement/length ratio of around 0.03 which scales from very small faults to very large faults. Would this apply to faults on other planets and if so, are there any ...
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Representing strike lines in rose diagrams
How can you best represent strike data on a rose diagram? Is it okay to plot only the strike?
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Structural geology book to make an app for first courses students
I want to make a structural geology app for first courses geology and minning students.
I want a book that list the structures as folds and faults to do my own designs with inkscape.
Can you recommend ...
user27958
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Length change of transform fault
Illustration showing the type of transform fault and the length change of transform fault.
Why does the length change of the transition fault between the subduction zones appear as illustrated? I don'...
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Form Lines from Strike and Dip measurements
I am looking to draw form lines on this map based on the strike and dip measurements taken on site. From what I have gathered it is an anticline with a possible second fault to the right hand side. ...
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An approximate, piecewise continuous analytical model for Earth's radial density profile useful for numerical integration?
An intriguing question in Space SE Optimal depth for underground flyby? asks about a theoretical spacecraft trajectory for a "slingshot maneuver" also known as a gravitational assist or &...
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Do any spike-like "cemented fillings of ancient fractures in a sedimentary rock", remotely similar to this one on Mars, occur on Earth?
The SETI Institute recently tweeted the image below, with the text:
#PPOD: Here is another cool rock at Gale crater on Mars! The spikes are most likely the cemented fillings of ancient fractures in a ...
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What is the history behind the present day geology of California? What processes took place that led to the formation of each region as shown in fig?
This is the image showing the different geomorphic provinces of California. What led to the formation of these provinces, and what events took place that resulted in the diverse geological setting of ...
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In Geology - True Dip versus Apparent Dip: When dip is estimated along a line of section, how is that dip determined in relation to true dip?
The map presents a summary example of topography and mapped units X and Y. From the information presented, can someone help me determine or estimate the actual dip along the line of section, A-A'? I ...
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How can smartphones help geologists in the field?
Smartphones have incorporated many sensors and some of them can be helpful for a geologist in the field:
They have GPS, so it is possible to register your route in a Google Maps map. I find this may ...
user20559
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Is there any intuitive and easily understandable way to help students understand the triangular facet of outcropted stratigraphy?
I find it difficult to teach college students about using the triangular facet on remote sensing images to judge the dip direction of sedimentary formations. Is there any intuitive way that can help?
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How can we distinguish fold and cycle of sedimentation on a remote sensing image or in the field?
A fold is composed of stratigraphy that is symmetric and repeated. Cyclic sediments (also called rhythmic sediments) are sequences of sedimentary rocks that are characterised by repetitive patterns of ...
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Terracing in Mahad
my first time here!
I was going down the rabbit hole after watching a video on YouTube that made me want to read about it on Wikipedia.
It led me to this Picture:
(View from Varandha Pass near Mahad ...
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Is there a way to convert from Dip direction to Strike direction?
I have some set of recorded data in dip direction/dip format. I wish to transform then to strike/dip.
I am currently having a hard time imagining how to convert from dip direction to strike direction. ...
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regarding four-way closure in structural geology
I am a little bit confused on the two concepts in structural geology, i.e., what is the relationship of anticline and four-way closure. My understanding is that anticline belongs to four-way closure. ...
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What local formation am I drilling?
I'm having a water well drilled on my property. The drilling crew has been working since Wednesday. They are using an airlift rig with a 6in bore. They are at 300ft and only have 4gpm. I would really ...
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Have cosmic ray muons or solar neutrinos been used to probe inside the Earth?
By looking at the attenuation of cosmic ray muons passing through pyramids as a function of their direction, it seems it is possible to "look inside" by mapping their 3D density distributions.
...
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Why is Venus so cracked?
Wired.com's Space Photos of the Week: Perfectly Safe Celestial Coronas includes radar images of the surface of Venus taken from spacecraft in orbit around it. One of them shown below.
What causes ...
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Could the LA County Museum of Art fall into the LaBrea Tar pit during an earthquake?
LACMA (the Los Angeles County Museum of Art) is built right next to the famous La Brea Tar Pits and that keeps me up at night†.
Question: What is the subsurface structure like adjacent to the Lake ...
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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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How can one find the true dip angle and quadrant when an apparent dip and strike is provided?
I am trying to solve the following question but cannot figure out how:
A layer of limestone has a strike of East to West on a hilltop, and an apparent dip of 40 degrees on the vertical hillside ...
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How did these dark lenticular features form? (Near Hoganekkal Falls India.)
These photos were taken near Hoganekkal falls in south India. The darker lenses appear to be the same rock type but have varying thickness and do not form a continuous layer. How did this structure ...
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Does fold tightness correlate to deformation intensity?
I'm studying a migmatite with two overprinting fold structures. The first (Dn+1) is tight and the second (Dn+2) is gentle. Would it be fair to assume that, since Dn+1's tightness is, well, tighter, ...
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Calculate normal and shear stresses with fault plane dimensions, slip, orientation and regional stress tensor
I'm trying to verify that some code I have is running correctly when calculating the Coulomb stress change. So for a example I have a fault with :
Length = 70 m,
Slip= 0.004 m,
Orientation(strike/dip/...
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Do earthquakes produce folds on rocks?
Earth rocks are frequently folded at surface.
Folds in alternating layers of limestone and chert in Crete, Greece.
Source: commons.wikimedia
Are earthquakes the main mechanism ...
user12525
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How big were the Siberian Traps originally?
252 million years ago, Siberia was subject to a mass series of flood basalt eruptions, creating a large igneous province called the Siberian Traps. Today, it measures three million square miles (7.77 ...
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What is meant by Massif?
In India, Panchchuli, Kun Nun and Shilong only these mountain are claimed to be massif. Why other mountain formations are not termed as massif...? What are the characteristics of massif..?
Anybody ...
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ALOS Palsar SLC data products for geological mapping
I have some ALOS palsar SLC data products which are downloaded from ESA database and they are processed with ESA ALOS-PALSAR IPF processor which is different from JAXA. Formerly it was not possible to ...
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What did tunnel digging teach us about the formation of chains of mountains?
Since tunnelling is like making a giant horizontal core sample, what did the analysis of the extracted rocks teach us? Is the inside homogeneous or layered, are there "deformations", etc?
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Which type of convergent boundary creates the tallest mountains? [closed]
Which type of convergent boundary creates the tallest mountains?
Continental-Continental
Ocean-Ocean
Ocean-Continental
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Megathrust earthquakes on subduction zones
I am a beginner in geology and earthquake studies, and learning about subduction zones recently.
Question is: do large earthquakes (sometimes referred to as megathrust quakes) occur on any point in ...
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Where can I find information about the basic concepts of sedimentary basins?
There are a lot of papers on the web but they don't explain the concepts, they just mention them, taking for granted that the reader knows the concepts.
I mean piggyback basin, forearc, back arc, ...
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Why should this be a thrust fault?
Why should this figure represent a thrust fault?
I know this might be a stupid question, but I really want to understand. Since thrust faults are reverse faults why in the figure above if we turned ...
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What causes these circular swirls of islands?
I was following the boarder of the US and Canada on Google Maps, because, and found these interesting circular patterns of islands near the Northwest Angle. I have heard of geologic folding but I have ...
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Drawing strike lines when given strike and dip
Map 1 shows a hillside with topographic contours at 50 m intervals. At Locality A a coal seam is exposed at the surface. The strike and dip of the seam is as indicated on the map. Use this information ...
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what is a transverse isotropic rock?
I know isotropic means equal properties in all directions , but the term "transverse" is not making it easy for me to understand.
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measuring fracture length and width using PKN and KGD models for hydraulic fracturing?
I am trying to understand PKN and KGD models for hydraulic fracturing. I am wondering why equations for fracture width and length does not include 'breakdown pressure' (pressure at which fracture ...
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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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Can we determine strike when dip is given? What about the reverse?
In any geological plane, strike gives the direction of a line formed by intersection of horizontal plane and geological plane. And dip shows the orientation of the geological plane. While studying, I ...
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How can oil can escape from a shale source rock into a reservoir rock?
How can oil can escape from a shale source rock into a reservoir rock if the shale itself is impermeable?
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are laccolith, lobolith, dikes and sills formed of porphyritic texture?
Laccolith, lobolith and batholith are shapes of igneous rocks which exist below the surface of the earth, dikes and sills too. And the way they formed by makes me think that they have a porphyritic ...
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Do reverse faults tilt the underlying layers of rocks to form an angular unconformity?
I came across this question while studying in my text book: What does the existence of strata containing a reverse fault and above them parallel strata refer to? I thought that referred to an angular ...
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How to understand Mohr diagram?
Structural geologists use Mohr diagram to evaluate stress on rock's surface, but I find it difficult to understand how this diagram works (Though I am good at math). Where can I find a good ...
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Plotting stereonets in R
Is there a package for R to plot Schmidt nets, like it is done in geology?
So far, I only know software like Stereonet. However I think it would make a lot of sense to handle these data in R, to have ...
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Strange circular structures found on a photo from Mars rover Curiosity at Dingo Gap
What are all these gaps / circular structures found on a photo taken by Mars rover Curiosity at Dingo Gap? Have a look at the image I made to see what gaps I mean.
(I know the quick paint job looks ...
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Structural geology, regarding cross section of two outcrops with similar characteristic but very distinct dip
I found an outcrop of sandstone interbedded with claystone which strike/dip is N 195 E/42. Then, around 4 km at the south of previous outcrop, i found another outcrop with similar characteristic, but ...
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