Thickness of Bedding (Stratigraphy)

I imagine a script that could take elevation data (say, a raster derived from DEM) and calculate bedding thickness might be useful.

The workflow would involve:

1. Loading a DEM
2. Overlaying the DEM with remote imagery that has visible bedding
3. Drawing a polygon over bedding where you need to find the approximate thickness
4. Process the elevation data within the polygon to find the bedding thickness
1. This would probably require generating a slope raster, perhaps average slope over the area within the polygon, measuring the various required distances and hope for the best...

Python w/Numpy and GDAL would be utilized.