Only a few specific studies exist on the Orzinuovi Source and on the 
seismicity of the area. Nevertheless, information on the location, geometry and 
recent activity of the source, possible causative fault of the Me=5.6 1802 
Soncino earthquake, can be obtained from several papers dealing with 
geomorphology of the drainage system of this part of the Po Plain and subsurface 
geology.

Cassano et al. (1986)
These workers provide a comprehensive summary of subsurface and surface 
geophysical and geological data along several transects crossing the Po Plain 
from the Southwest to the Northeast. The interpretation of their Section 6 shows 
the presence of several low-angle, S-verging blind thrusts in the subsurface of 
the Alps homocline. More in detail they image a crustal blind thrust that 
deforms Upper-Middle Pliocene sediments, South of the Oglio River.

Marchetti (1990)
This investigator focuses on the hydrology of the main rivers of the 
northern sector of the central Po Plain, analysing the geometrical 
characteristics of their meander belts and reconstructing the environmental 
evolution of this part of the plain during the past 15,000 years. He shows that 
the Oglio River and the Casalmorano-Annico paleo-channel, as well as other main 
rivers, have the characteristics of an underfit stream, with average length and 
radius of curvature of the abandoned meanders five times larger than the present 
ones. Following empirical relationships these characteristics would be 
indicative of water discharges 15 to 20 times larger than the present, that 
were typical during and at the end of the last glacial maximum. During this 
period the rivers formed the "Superficie fondamentale" of the plain, a large 
aggradational paleosurface found north of the Po River, now deeply incised by 
the present drainage system. According to the author the erosional stage 
started when large amount of sediments were no longer available due to the 
formation of the large lakes at the Alps piedmont, and to major climatic 
changes; its age of inception can be constrained by means of archeological 
findings, as well as of analyses of buried paleosoils. The author propose that 
hydrological conditions similar to the present were found in this area starting 
from the "Atlantic" period (6 kyr B.P.); this hypothesis seems to be confirmed 
by the finding of neolitic settlements along the valleys cut into the 
"superficie fondamentale". The author also points out that the analysis 
performed shows that the Casalmorano-Annico paleo-channel, which according to 
previous writers was formed by the Adda River (Romani [1928], De Chaurand 
[1932]) but morphologically seems to be connected to the Oglio River, had 
paleo water discharges larger than both rivers, but more similar to those of the 
paleo Oglio.

Boschi et al. (1997)
This catalogue describes the major effects of the 12 May 1802 Me=5.9 Soncino 
earthquake; among the other effect they report the opening of ground cracks in 
the epicentral area, and the temporary stop of the water flow of the Oglio 
River.

Burrato et al. (1999)
These workers use a geomorphological approach to locate and characterise active 
potentially seimogenic faults in the Po Plain. They first analyze the drainage 
system of the plain and identify several areas where significant fluvial 
anomalies (e.g., river diversions and shifts in channel patterns) are suggestive 
of the presence of active blind thrust or reverse faults. As second step of 
their approach the authors compare the position of the drainage anomalies with 
the location of known buried anticlines, to corroborate the hypothesis of their 
tectonic nature. Following the further observation that some of these anomalies 
are associated also with historical earthquakes, they propose that the blind 
thrusts responsible for the river anomalies may be potential sources of rather 
infrequent large earthquakes beneath the Po Plain. Burrato et al. hypothesise 
that the anomaly shown by the Oglio River South of Orzinuovi, can be explained 
by the presence of an active EW-striking, S-verging blind thrust, that produces 
uplift in the area of the Casalmorano-Annico paleo-channel, and make the river 
diverge south-eastward. They point out that their hypothesis is corroborated by 
the presence of several blind thrusts imaged in exploratory seismic profiles, 
and also that the occurrence of the Me=5.6 12 May 1802 earthquake is evidence 
that the tectonic structure is not only active but also seismogenic. Besides 
their solution is in good agreement with that obtained using the method 
developed by Gasperini et al. (1999), which analyses only intensity data.

Burrato et al. (2001)
This paper discusses the location of the source associated with the 1802 
earthquake (Orzinuovi Source) in the framework of a detailed analysis of 
drainage anomalies in the lower Oglio Valley. The source is hypotesised to be 
located a few km to the south of the earthquake epicenter and can explain both 
changes in the river behaviour and changes in the river pattern occurring 5 km 
northeast of Soresina, where the river exhibits a significant diversion.
