Problem with sedimentary filling process

ASPECT
1

Hello everyone,

I am a beginner of numerical simulation. I would like to add sediment filling in the process of continental extension. i would like to know is there a built-in procedure within ASPECT? If not, where can I get the relevant sediment filling plugins?

Best wishes,
Chenghui

2

Hi Chengui,

The short answer is that this type of functionality is not currently available in the main branch of ASPECT, but it should be shortly.

There is an open pull request to merge coupling between ASPECT and Fastscape, which includes modifications to ASPECT that allow infilling of sediment. There have been a number of papers published on this by Derek Neuharth, Anne Glerum, Sascha Brune, and others, and the PR (led by Derek) will add this functionality.

It is possible to use this functionality in the versions of ASPECT + Fastscape utilized in the papers above, but my recommendation would be to wait a few weeks and use the version that is integrated into the main branch.

Cheers,
John

3

Hi John,

Thank you very much for your reply. I am very much looking forward to the next ASPECT version, I will read some literature to supplement the relevant knowledge, thanks again!

Best wishes,
Chenghui

4

Hi Chenghui,
The pull request has been merged, so you should be able to use the functionality now. For how to install the coupling see my reply here

For adding sedimentary filling processes and seeing the depositional time, you’d need to add a sediment and sediment_age field. Then, the boundary composition model would need to be setup similar to this:

Fix only top to sediment so any deepening of basement is filled with sediment.

subsection Boundary composition model
set Model name = function
set Fixed composition boundary indicators = top, bottom
set Allow fixed composition on outflow boundaries = true

subsection Function
set Coordinate system = cartesian
set Variable names = x,y,t
set Function expression = if(y>80e3, t/1e6, 0); \ # Sediment_age field
0; \ #non_initial plastic strain
0; \ #plastic_strain
0; \ #viscous_strain
if(y>80e3 && t>0, 1, 0); \ # Sediment field
if(y>80e3 && t==0, 1,0); \ # Upper crust field at surface during initiation
0; \ # lower
0 # mantle_L
end
end

This should fix the top boundary to sediment after initialization so that changes to the surface result in input of the sediment field. These changes will also be given an age from sediment_age depending on when they are deposited, and this name is masked so that it works as a passive field within the model.

You can see an example of this used with fastscape https://github.com/Djneu/fault_analysis_study/blob/master/prmfiles/symmetric-1e-5.prm, though I’d like to note that this used an older version of the coupling so quite a few of the prm parameter names for the fastscape section are outdated.

Best,
Derek.

5

Hi Derek,
Thank you very much for your guidance. I admire and appreciate your work very much. I have now successfully run the fastscape_eroding_box model in cookboos. Thank you again for your work.

Best wishes,
Chenghui