Geophysical Investigations of an in situ Roman Mosaic floor

in Volubilis, Morocco Ministère de la culture et de la communication A. DEKAYIR1*, N. BOUZOUBAA1, M. ROUAI1, A. LACHHAB2, M. ATKI3, M. ALILOU3, BAKADI1, E.M. BENYASSINE1

1 UR Géoexplorations et Géotechniques, Département de Géologie, BP. 11201, Zitoun, Meknes - Maroc 2 Earth and Environmental Sciences, Susquahanna University, USA 3 Ministère de la Culture et de la Communication , Conservation du site archéologique de Volubilis - Maroc OBJECTIVES An example of Mosaic : Venus Structure of Roman Mosaic

Volubilis (image from Getty) Porte Volubilis located at the NE of Meknes, de Tanger C O R N A Morocco is an archaeological Roman M Porte Nord Palais du Gordien site with many home, public baths,

M . D d M e e . s M s D . fa D N u u y b religious and official buildings v e m a e M D p in s i h . M G F o e e a n s . r l y A m a M v s M. à d u a i o . ’H x n u s A s M d e tr u N u la citerne r a s . e c v é c u a r D V o é e é r le u i t x d s n è decorated with remarkable mosaic e u g s s C M e a . v A a u li e r

F floors. These floors have suffered from M. à o n l’Ephèbe ta in e Thermes Tesselatum du Nord Arc du Tumulus Temple C negligence and a lack of restoration. In Triomphe F o n t M. au a i Chien n e Bedding layer M. order to mitigate these problem, there Desultor

B Temple F a o Temple B s D r u i l i m is a need of exploration of the best q u Nucléus e T

h

e

r m

e Capitol s approach. The goal of this study is to te in e c Huilerie n E d T restituée e h Rudus

e G a r s a m

l a implement electrical resistivity and l e t i e s r Mosaïques échantillonnées n e

F

.

O Monuments religieux M. d’Orphée ultrasonic technics to identify fractures Statumen Thermes et fontaines publics 100 m Monuments politiques and void space, which are the main Maison à mosaiques

Porte cause of deterioration. Sud ESt

RESULTS

Model: Size and characteristics Equipment setup Electrical resistivity Ultrasonic velocity

The geophysical Survey showed that: 1. Areas highly resistive (due to the presence of hallow spaces, existence of joints and fractures) and therefor have low ultrasonic

velocity values. 120 cm 120 2. The less resistive area with high elastic properties and characterized by strong ultrasound velocities

85 cm Case Study: Ephebe in-situ floor Mosaic

Ultrasonic velocity 730 cm 730

730 cm This Mosaic showed a substantial alteration especially The Mosaic floor found at the house of Ephebe which was placed over a near the surface. The small islands characterized by concrete platform was found to witness significant degradation of high velocity values match the highly compacted areas tessellatum mainly due to the oxidation of steel rebars which represent lacunas repaired with cement based CONCLUSION mortar  The implementation of geophysical techniques on Roman Mosaic especially the acoustic method has shown to be effective in the identification of deteriorated areas and allow to map the entirety of the floor revealing areas of urgent needs of restoration.

 The electrical techniques, although destructive has proven to be equally able to identify but can be used on bench model for calibration and experimentation with noninvasive tools