La sessione SESSION NEW TECHNOLOGIES FOR ARTIFICIAL CAVITIES, dedicata alla tecnologia nel rilievo delle cavità artificiali, si conclude con l’intervento “Laser scanner survey and tru view applications of the “Grotta della Lucerna” (Ravenna, Italy), a Roman mine
for Lapis Specularis. Santagata Tommaso, Lugli Stefano, Camorani Marco Ennio, Ercolani Massimo”
(1) GSE-Gruppo Speleologico Emiliano, e-mail: tommy.san84@gmail.com
(2) University of Modena and Reggio Emilia, Department of Earth Sciences, Largo S. Eufemia 19,
41100 Modena, Italy, e-mail: stefano.lugli@unimore.it
(3) GST-Gruppo Servizi Topografici s.n.c., via Pistelli 5, Reggio Emilia, Italy, e-mail: geomgst@iol.it
(4) Federazione Speleologica Regionale dell’Emilia Romagna, e-mail: massimoercolani@gmail.com
Abstract
The Grotta della Lucerna (Lamp’s Cave) is a small cavity (about 400 m long and 36 m depth)
located in the Regional Park of Vena del Gesso Romagnola, in Zattaglia (Ravenna, Italy).
This cave represent one of the few documented mining sites of Lapis Specularis in Italy, a particular
type of secondary gypsum (selenite) that was mined in Roman times and worked to obtain thin
transparent clevage sheets used for windows.
Crystal processing traces and artificial changes made to facilitate the exploitation and transport of
the raw material are visible in all areas currently explored. The archeological findings allow to
constrain the period of exploitation between the 1st and the 4st century CE.
We performed a laser scanner survey of the most accessible areas of the cave by carryng out 33
scans inside and 3 outside the cave. The data analysis allowed the costruction of a tridimensional
model, from witch it was possible to draw plans and sections with very high centimetric accuracy.
With the Leica True View applications it was also possible to produce an interactive model wich
permits the navigation inside the point data, with the possibility to move between the scans.
Other operations are also possible such as distance measurements, notes and coordinates input, snap
print directly by photos and points misured with the laser.
This application has been used also for the drawing operations in bi-dimentional mode using the
Cloudworks plug-in that allows to draw line and polyline directly from the True View in Auto-Cad.