A gravimetric survey, covering a site 200 m square, was carried out in
order to locate karstic cavities. After eliminating the regional tren
d using a polynomial fit, the residual is modelled by least-squares pr
ediction. Correlated signals for several wavelengths are detected. The
inversion of these anomalies is performed by a global 3D adjustment u
sing spherical bodies as models. The adjustment is repeated in order t
o obtain a stable configuration. The results show the probable presenc
e of a system of cavities and galleries. Data collected from boreholes
and the subsequent appearance of sink-holes are consistent with the r
esults.