I believe
Buzamiento is a word related to geology, if it is, in this case, you can use
dip of the stratum or simply
dip
This is what I found
Dip of a
stratum (Geol.), its greatest angle of inclination to the horizon, or that of a line perpendicular to its direction or strike...
http://dictionary.reference.com/brow...0the%20horizon
Dip: The downward inclination of a rock stratum or vein in reference to the plane of the horizon.
...
www.thefreedictionary.com/dip - 45k