This code relates to the Boonma et al. (2019) paper: Lithospheric mantle buoyancy: the role of tectonic convergence and mantle composition.
https://www.nature.com/articles/s41598-019-54374-w
It is my analytical approach to the same problem.
It calculates the evolution of lithospheric bouyancy as a function of convergence rate, and initial density contrast.
Edit parameters in lines 27 to 35. Then run the code clicking the 'play' symbol.
Then watch the results looking at the grapic output (click the top left icon).