1. Historical shoreline evolution and the Roman
Harbour in the Como urban area: results from
stratigraphic and geotechnical analyses
Ferrario M.F., Brunamonte F., Castelletti L., Livio F., Martinelli
E., Michetti A.M. & Motella S.
Università dell’Insubria, Dipartimento di Scienza e Alta Tecnologia
Via Valleggio 11, Como
Francesca.ferrario@uninsubria.it

2. Medolo Group
(pelagic
limestones, Early
Jurassic)
Gonfolite Group
(conglomerates
and
sandstones, Oligo
Gonfolite
Backthrust

3. Stratigraphic database
Piazza Verdi
Piazza Verdi drillings
- 2 boreholes (65 – 70 m)
- Physical parameters
- Shear tests, triaxial tests
- Permeability tests
- Macroremains and
palynological analyses
- Gamma-Ray analysis
- Carbon dating

4. Subsidence
• Natural: soft sediments (few mm/y)
• Anthropic: ground water overexploitation (up to cm/y)
• Increased risk of inundation
• Building damages
Photo by Valerio Comerci

5. LGM - Maximum extension of Adda glacier
and water outflow
Modified after
Bini et al., 1993

6. Lateglacial
270 m asl
220 m asl

7. 1st appearance organic substance
ca. 18 kyr BP
215 - 220 m asl

8. Coastline (18.000 BP)
Delta progradation
Proto-historic settlements

9. Shoreline
I century BC
City walls (I century BC)
Archaeological
findings: Roman
quay
Archaeological
findings: ship remains
(Piazza Mazzini)
Prehistorical drainage network
Drainage modified by the Romans

10. Archaeological findings
In 1964, in Piazza Mazzini a
marble block and ship
remains were discovered at
4,60 m below the ground
surface.

11. Shoreline
1858
1722
1871
2013
I century BC
City walls (I century BC)
City walls (IV-V century AD)
Historical coastline position

12. Catasto Teresiano, 1858
Catasto Teresiano, 1898
Piazza Cavour

13. 1997 campaign
- 10 drillings (60 m deep)
- 5 CPTU
- lab tests
2013 campaign
- 3 drillings (30 – 40 m deep)
- 2 drillings (10 m deep)
- 10 DPSH
- cross-hole seismic tests
- In progress: radiocarbon
dating, plant macroremains and
diatoms analyses

14. Pile-dwellings
Gas-emission features
Leather tiers (depth: 13 m)

15. The cross-disciplinary integration of the various
datasets enables to:
- Identify an organic silty layer ca. 2-4 m
thick, with very poor mechanical
properties, related to a closed low-energy
environment, such as a sheltered harbour or a
dock;
- Sparse reworked bricks fragments suggest an
historical age;
- Reconstruct the isopachs of this layer

17. Geologic section

18. SW NE
wn = 60 – 90 %
LL = 55 – 70 %
Qc = 0,2 – 0,5 MPa

19. SE NW
Man-made fillings
Organic siltsAlluvial sands
Organic clayey silts

20. Conclusions
A multidisciplinary approach, involving data
coming from both geology and
archaeology, can lead to a more accurate
knowledge of an area, thus allowing to
understand present-day natural and
anthropic dynamics and to better plan
future urban development.

21. Thank you
This research was realized in
collaboration with Comune di
Como and Georicerche srl