Geophysical investigation within the Zennare Basin (Venice)
R. Francese, A. Galgaro
Dip. Geologia, Paleontologia e Geofisica,
University of Padova, Padova, Italy
E. Farinatti
A.T.A. Studio Associato di Geologia Tecnica e Geofisica, Rovigo, Italy
M. Putti, P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
F. Rizzetto, L. Tosi
Istituto per lo Studio della Dinamica delle Grandi Masse, CNR, Venezia,
Italy
ABSTRACT
A multi-technique geophysical investigation is performed to map the shallow depositional units in the i
Zennare peat basin nearby the Venetian Lagoon. The detection and resolution capabilities of
Earth Resistivity Tomography, Refraction Seismic, and Ground Probing Radar are compared in a small
test area within the basin, where also additional stratigraphic point information is available.
The results obtained with the different methods prove comparable, but the integration of these
distinct geophysical responses allows for a more precise identification of the subsurface structure.
The Ground Probing Radar survey, because of its cost-effectiveness, has been extended to the entire basin.
Some coherent noise patterns, associated with the frozen ground surface, required a specific
processing sequence to enhance the radar record quality. The radar images outline the main shallow
discontinuities of the basin related to the different depositional framework, allowing for a
detailed reconstruction of peat layers as well as of a series of sand-silty paleo-channels
distributed within the area. Borehole and remote sensing data are used to calibrate
the geophysical interpretation.
