Create a meshgrid on a 3d plot

Hello,

I have plotted a 3D graph representing a subducting slab. The 3 dimensions are: longitude, latitude and depth.

figure(1) %plot en longitude, latitude, et depth
tri = delaunay(lon,lat);
trimesh(tri,lon,lat,depth);

I'd like to add on it a random triangular mesh grid in black only for specific coordinates : longitude between 273 and 277, latitude between 9 and 12 but most importantly depth from 0 to -50.

Do you have an idea of how I could do that?

Thank you for your help