Questions tagged [structural-geology]

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2answers
118 views

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,...
3
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0answers
511 views

How to differentiate between normal and reverse fault, given a stress tensor?

I want to generate synthetic fault slip data using a known stress tensor. I am using a rotation matrix to get the orientation of the principal stress axes, and rotating the tensor [1 0 0, 0 phi 0, 0 ...
2
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0answers
63 views

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 ...
2
votes
1answer
84 views

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. ...
2
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0answers
15 views

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, ...
2
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0answers
86 views

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/...
2
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0answers
1k views

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 ...
2
votes
0answers
306 views

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 ...
1
vote
0answers
815 views

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. ...
1
vote
0answers
43 views

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 ...
1
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0answers
24 views

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 ...
1
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0answers
204 views

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 ...
0
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0answers
35 views

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 ...