How to locate a certain element only in the certain side of my model

[Changwan-planet]

Dear GemPy community,
(@javoha)

Hi, Thank you for opening this program.

I have been using your program for my research.
I already had a model of the upper boundary of the basement by using your program (re-aachen/gemgis/discussions/353).

Next step is to add a soft layer above the basement.
The yellow element SOFT2 should be located only in the certain side. But I failed.
I already checked other examples in your homepage, but it is not easy to do that.

I would like to make an new model with my data like this image.

I think I need to change the orientation of elements.
Can you give me some help to the new model like the photo above?

I attached my data and jupyter notebook.
Question3.zip

*ASL (Above Sea Level) is used for GEMGIS to measure the depth.

[javoha]

Hi @Changwan-planet,

thanks for your question. Before suggesting a solution let me ask a couple of questions about your model:

A) In your model the unit "SOFT" (red) has a downslope in the center. In your sketch it looks like this is resembles a fault. Is this supposed to be a fault and if yes, why did you not model it as one?

B) You added another layer called "ASL" (blue) to the top of your model but you do not specify its age relation in the structural frame. By default it is added to the oldest group (comapre screenshot). This does not make sense as it should be in its own (youngest) group. Also note that if this is meant to resemble a topography it is possible to add DEM data to a gempy model.

C) You created orientations strictly facing upwards for each data location. While this is not technically wrong it does not at all fit the data, especially in the sloped areas of unit "SOFT". This might lead to suboptimal interpolation results.

Regarding solutions for your actual problem - It depends a little bit on your answer to question (A) and also what you expect above the units "SOFT" and "SOFT2".

Option 1 (left side of sketch): If you actually want a fault in the center of the model: You need to add the fault as an element - this would also mean to remove some of your current input data points. You could then cap this structure with another layer (or your ASL). Note that you need to move this one down to a point where it removes (erosion) the yellow layer on the right side of your sketch.

Option 2 (right side of sketch). Establish an unconformity relation if you dont want a fault in there. This requires a little bit of a different setup, we recommend going thtough the corresponding video tutorial.

Let me know if this solves your issue.

Cheers,
Jan

[Changwan-planet]

Thanks for your quick reply (@javoha )

A) Yes, it is an active fault. Actually we talked out before about this issue. Back then, I gave up to use the fault because the color of the fault could not be transparent, hiding the deformed structure. However, at this moment, I add another layer (SOFT2) above the basement layer. Probably, I may consider it. 

B) Sorry for my poor bad explanation about the data. ASL means above sea level. The reason I add this data is that I could calculate the depth from the ASL to the certain layer by using GEMGIS. Please look at my work. 

C) Yeah. My final goal is to cap this structure. Before doing that, I would like to make an intermediate result (figure below). But if It is not easy to make an model without capping the structure, I need to add more layers. Plus, I felt that there are normal faults in most examples described in the GemPy homepage. Hard to find the reverse fault model in examples. Subduction zone in example is good for my model?

[javoha]

Making the fault invisible is just a visualization problem and shouldt stop you from using it correctly.

Regarding your sketch: What do you want/expect the rock unit above the yellow line on the left to be?

[Changwan-planet]

Hi, @javoha
It's been a long time to answer your question.
I uploaded my concept for modeling.

I wanna get this kinds of model from GemPy.
UNC means unconfomity. Basement is below UNC.
We interpreted Unit3 and Unit2 are fluvial sediments. Unit2 erodred Unit3, but some Unit3 are still alive on the western part.

I uploaded my scripts and files.
please help me construct the neat model.
Let me know what I am missing.

Miho_Orientations251213_2.csv
Miho_Points.csv
Question3.ipynb

I think that azimuth and dip should be changed.
As you can see, this model includes the fault structure. I will distribute them as a fault in the next step.
Thank you for your attention.

[javoha]

Hello again,

great to see that you are working on the model. Here are a couple of points from looking at your data:

A) Yes, definitely some of your orientations are wrong. I think you need to go through all of them and check if they are actually pointing in the right direction. For the yellow and red layer they should als kind of point upwards, based on your sketch and what I gather from the data.

A') Bonus: If you have only upwards facing orientations you could also remove most of them to speed up computation.

B) I still think you should model your fault as a fault and not a bend surface. This would require you to actual make some of the data fault data and also here not all orientations make sense to me.

C) Make sure to set you structural frame correctly. From your sketch I would guess that all your units need to be in their own structural group with erosive contacts. Adding the fault would require to also set the fault relatiosn correctly - for a quick tutorial how to do this please check our video tutorial series.

Apart from these things I think you are good to go.

Cheers,
Jan

[Changwan-planet]

There is no free lunch. I need more study for my data and GemPy. Many thanks for your feedback, @javoha.

[javoha]

Good luck and let us know when you have more questions!