Questions tagged [tectonics]

Tectonics is the application of field geology, petrology, geochemistry, geochronology, geophysics, remote-sensing, modeling and multidisciplinary studies to explains the evolution, structure, and deformation of Earths lithosphere.

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What determines the shape of tectonic plates?

I understand plate tectonics at approximately the level of the Wikipedia entry, but I have not idea what factors determine the particular locations of the plate boundaries. Do we have a model for the ...
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Where are the youngest and oldest subduction zones in the world? Is the dip of the subducting slab proportional with the age of subduction?

I want to learn where the youngest subduction is in the world. Where is the most recently started subduction zone? (The most recent place on Earth that arc magmatism has started) And the oldest ...
Muharrem Yavuz's user avatar
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Is the Pacific Plate composed of smaller plates?

The question, Why are all lower mantle plumes under oceans? has the following diagram which was taken from Wikipedia Commons. About half of the large red dots occur on or near the boundaries of ...
Fred's user avatar
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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?
Andykins 's user avatar
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Formation of Mount Elbrus

Mount Elbrus, in the Caucasus region of Russia, 65 km southwest from Kislovodsk, is a major, isolated volcano in the heart of a continent-continent collision zone. It is not normal for volcanoes to ...
harry.kuril's user avatar
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Speculative Plate Techtonics - Resolving intersecting subductions

I'm working through Artifaxian's (https://www.youtube.com/watch?v=AzD_WVsEIRM) series on using gPlates to make tectonic history. I've run into the place where I have two subduction ridges about to ...
Stephen Rider's user avatar
2 votes
3 answers
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If dinosaurs lived in cities, would we be able to find traces?

Suppose that at least 65m years ago, the dinosaurs (or, for that matter, another species) would have sufficiently developed to build settlements with houses, roads and the like. Would archaeologists ...
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Why are the supposed-to-be results of collision and/or subduction formed in an area where collision and/or subduction didn't happen?

Please correct me if I have said something wrong, as it might be the answer to my question. Also, these are all the things that I've learned through self-studying, so I might have been mislead. ...
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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 ...
Lakhwinder Sidhu's user avatar
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1 answer
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Tectonic plates terminology

I have a very basic doubt regarding what the tectonic plates mean. In Wiki article Subduction is defined as: Subduction is a geological process in which the oceanic lithosphere is recycled into the ...
dark_prince's user avatar
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How to calculate mountain front sinuosity index using DEM?

In tectonic geomorphology the Mountain front sinuosity index is one of the morphometric indexes. Smf = Lmf/Ls I have a DEM, so how do I use it to find the value? According to this diagram do I have ...
Gokul Anand's user avatar
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What will happen to the Indian plate after it slides under the Eurasian Plate?

What will happen if the Indian Plate is done sliding under the Eurasian plate? I hypothesied some possible answers. Tell me the answer and if my hypothesis is not correct. Most likely to least. It ...
Tardy's user avatar
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Learn geological properties of the horizon through density of the rocks

It is possible to evaluate the geological structure of a basin based on gravimetric data. But if one doesn't have gravimetric data, how can one learn the geological structure and properties of a ...
student0434's user avatar
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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 ...
tunar's user avatar
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Understanding certain phrases in the article "Footwall topographic development during continental extension"

I am currently attempting to read the article "Footwall topographic development during continental extension". The article and its abstract can be found here. When reading the abstract, I ...
user2552936's user avatar
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Coloring maps by feature orientation

I live in the SF Bay Area where many, but not all, geological features are oriented parallel to the San Andreas Fault. I was wondering if there’s a type of map where ridges are colored by compass ...
ed94133's user avatar
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Given the movement of the tectonic plates in the past 5,000 years, how can the alignments of megaliths around the planet still be accurate?

Many of the worlds oldest megaliths are aligned with the cardinal points like the Great Pyramid which is said to be within an accuracy of better than four minutes of arc, or one-fifteenth of one ...
William's user avatar
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Where and how big was Sicily between 5 and 1 Ma ago?

Sicily is a geologically complex island which seems to have been extensively studied geologically and from a tectonically point of view. There are an overwhelming number of papers dealing with the ...
EduardoM's user avatar
3 votes
3 answers
324 views

Formation of Iceland

Iceland sits atop a divergent ocean-ocean boundary. But there are not many islands which are formed along a divergent boundary. Why is it so? Why do not mid ocean ridges often rise above the sea ...
HARVEER RAWAT's user avatar
6 votes
3 answers
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What is the impact of divergent tectonic plates on old mountain ranges?

I found this question, which is similar to what I'm wondering, but my question is slightly different: What happens if a new divergent boundary forms in a way that bisects a mountain range, especially ...
rvg's user avatar
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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, ...
Matheus's user avatar
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Q: Is the crust getting thinner or is the mantle getting smaller

Volcanoes spit out magma onto the surface of the crust or crevices on the surface, but the magma comes (in effect) from the mantle right? If that's the case, isn't the mantle turning into the crust by ...
Nathan's user avatar
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1 answer
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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 ...
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Determining the spatial orientation of a fault given ground acceleration magnitude in different directions

Accelerographs measure ground acceleration in three different components of motion: east-west, north-south, and vertically (up-down). I know that fault orientation is important here, so let's say we ...
Jonathan L.'s user avatar
2 votes
1 answer
426 views

What is diffuse plate rifting?

For example in the Philippine Sea Plate the West Marianas Ridge has formed due to diffuse rifting in the south of the Marianas trough. What does it mean?
Neil's user avatar
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2 answers
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How much change has there been to the shape of plate boundaries over geological time?

This is a question that has bothered me for many years. As a new teacher I was asked this question by a 12 year old in our plate tectonics class. I said I would go away and find out. I would really ...
Mas_geog's user avatar
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1 answer
573 views

Does being under water provide any protection from a asteroid?

Does being under or on water provide any protection from an asteroid hitting the opposite side of the Earth over being in or on land or in air? Why? Will the shock wave follow the curvature of the ...
Muze's user avatar
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3 votes
1 answer
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What structures form due to the melting of subducting plates? [closed]

What structures form from the melting of subducting plates? Plutons, Accretionary wedges, Deep sea trenches, Faults?
Dave's user avatar
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6 votes
1 answer
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What is the metamorphic field gradient useful for?

As I understand it, the metamorphic field gradient is the PT line traced out by the maximum temperature points of a series of PTt paths of rocks from the same metamorphic event. What exactly is this ...
bon's user avatar
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For slab rollback, what allows the subducting plate to begin descending at a steeper incline?

I recently learned about slab rollback, specifically of the Juan de Fuca plate subducting underneath the North American plate. From what I understand, the subducting plate over time begins descending ...
Kristina L's user avatar
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Is the Ethiopian Plateau uplift still ongoing?

The rift zones around the Ethiopian Plateau, Mid Ethiopian Rift, are stil tectonically active since Somalia is separating from Nubia at a rate of 6–7 mm annually[1], and Arabia is rotating counter-...
Crustea's user avatar
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How do tectonic plates move upward? [closed]

And also, can this push continents and land-masses upward as well?I have not been informed of the phenomenon of tectonic plates rising up. I am yet unable to find a satisfactory answer on the internet,...
user8395's user avatar
8 votes
1 answer
354 views

Timeline of Himalayas/Tibetan plateau formation

Note: edited based on helpful comments. In Walking with Cavemen, Robert Winston claims an African rainforest existed 8 mya, but by 4 mya it was gone. He attributes this to newly Himalayas-triggered ...
J.G.'s user avatar
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0 answers
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What happens to the earth after volcanism/tectonics slows?

If we move far enough into the future that the core begins to solidify to the point that volcanism and tectonics are non-existent, what does the surface of the planet begin to look like? Does the ...
SDH's user avatar
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6 votes
2 answers
4k views

What is the difference between nappe and thrust sheet?

The titles of many geology articles contain words like "nappes and thrust sheets". Basically these are rather similar and in certain languages can be denoted with one term. The dictionaries tend to ...
astrsk's user avatar
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22 votes
2 answers
5k views

How high can a mountain possibly get?

Mount Everest is 8,848 metres (29,028 feet) above sea level and is the result of a continental plate smashing into another continental plate. Can a tectonic process build a mountain that's even higher?...
Knob Scratcher's user avatar
9 votes
4 answers
5k views

Do divergent tectonic plates destroy mountains?

Tectonic plates meeting (convergent plates) form mountains. But if those plates change direction (which I am just assuming they can over time, I have no idea if it's true) and start pulling apart (...
Henry Stone's user avatar
8 votes
1 answer
535 views

How do tectonics work on other planets?

What kind of tectonic plate activity exists on other planets in the solar system, or even large moons? Are there any deeper studies of what is needed for a planet or large moon to have tectonic ...
Henry Stone's user avatar
4 votes
0 answers
64 views

Determining rotation of a bending detachment fault system

I would like to obtain the angle of rotation (𝛿θ) of a detachment fault (or oceanic core complex) after X meters of rock displaced during spreading at a mid-ocean ridge. I have a differential ...
JrCaspian's user avatar
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1 answer
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Is "seismic energy released" a regionalized variable and can be analyzed using geostatistics?

In geostatistics, we can assess and analyze regionalized variables. Tectonic stresses releases in seismically active regions by occurring earthquakes. We can calculate and estimate the seismic energy ...
Seyed Naser Hashemi's user avatar
6 votes
1 answer
2k views

Is it coincidence that Antarctica is centered on the south pole?

Looking at a globe, Antarctica looks remarkably centered on the south pole. Has the rotation of the earth had any effect on the position of the landmass?
Nathan Fig's user avatar
7 votes
1 answer
2k views

Himalayas are currently rising. What will be the highest point they can reach?

Himalayas are currently rising about 5 mm/year. What will be the highest point they can reach?
Anixx's user avatar
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3 votes
1 answer
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tectonic faults catalog for plot

I looking for a catalog (ideally in a ASCII file) of the major tectonic faults on earth, in order to plot some of them on a map Any suggestion ?
Covich's user avatar
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4 votes
1 answer
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Relationship between tides and earthquakes

Ide et al. (2016) suggest that earthquakes (especially those of high magnitudes) are more probable during periods of high tidal stress (during full and new moons). While they show a comprehensive ...
arkaia's user avatar
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9 votes
1 answer
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What is the current status of geophysical global cooling theory?

Plate tectonics effectively rubbished the theory of geophysical global cooling as a means of explaining many surface features on the Earth. However, this wiki says that the same process is responsible ...
christopherlovell's user avatar
4 votes
1 answer
479 views

Source of sub-surface ringwoodite water

I was reading about the discovery of vast amounts of water locked up in ringwoodite (see here). The authors of the study seem to suggest that previous ideas, involving water deposits being delivered ...
christopherlovell's user avatar
4 votes
1 answer
87 views

Do the rocks below an active sill go down, or those above go up, or both?

Having read a little about sill formations like the Palisades Sill (eastern USA) and Whin Sill (UK), I understand that strata became separated by the injected layer of magma, with monumental ...
Jimbo's user avatar
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5 votes
1 answer
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Resources on Andean geology

I would like to begin studying the geology of the Andes, with particular respect to the tectonics and paleogeography of the region. I have been searching on-line resources for some time and I would ...
Self-teaching worker's user avatar
7 votes
1 answer
544 views

How is/was continental drift monitored?

I am curious about current technology but I am particularly interested in what techniques were employed prior to the advent of satellite technology.
reddit's user avatar
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8 votes
2 answers
274 views

Explain the Idea of Pangaea and how the continents have reached their current positions

I know Pangaea was a supercontinent that existed 270 million years ago and it started to break apart around 200 million years ago. I'm not clear on whether Pangaea was 1,2, or multiple tectonic plates....
user2988's user avatar