Area filled on plot to represent a straigraphic column

I need some help with coding up a diagram to represent a stratigraphic coloumn. I have the lithlogies coded as numbers 1 to 4 in one column and bed thicknesses for in the another column. What I want to do is display these on diagram or a plot with the area filled in with a colour for each lithlogy.

Any help would be much apprictaed.