Historical monuments; Archaeological ceramics; Art and Géo- Archaeology
Abstract :
[en] Archaeological ceramics from El Badi Palace, Saadian Tombs and Aghmat historical sites
located in the region of Marrakech were analyzed by a multi-analytical approach based on Xray diffraction, fluorescence and microscopic analyzes to study their physical, chemical and
textural characteristics. Clay samples were also collected from different quarries in the
Marrakesh and Fez region, and then analyzed using the same techniques. The aim is to
determine the manufacturing technology, properties and origin of the raw materials used by
the Almoravide and Saadian dynasties in construction. Experimental cooking tests on ceramic
bodies were also carried out in order to determine the firing temperatures used in traditional
ovens during these times. According to the results obtained, the Saadians used carbonated
clay to make the zellige, one of the key elements of decorative ceramics; the raw material
used comes from the region of Fez. The estimated firing temperature for these materials is
between 700 and 800 °C for the El Badi palace and between 800 and 900 °C for the Saadian
tombs in an oxidizing atmosphere. The glaze is mainly composed of lead and silica, the
coloring agents are conventional, iron (Fe3+) for the yellow glaze, manganese (Mn3+) for the
black glaze, copper (Cu2+) and phosphorus (P) for the blue glaze. The texture of the
glaze/shard interface was studied using optical microscope and cathodoluminescence; results
show that the glaze was applied directly to the ceramic support without slip or intermediate
layer. The utility ceramics (irrigation channels) and structural ceramics (red bricks) were
made from a local clay rich in iron from the Marrakech region, the firing temperature was
around 700 °C for the channels and 900 °C for bricks.
The archaeological ceramics collected at the Aghmat site are composed of fragments of
tiles, bricks, irrigation channels and pottery. The structural ceramic was made from a local
non-carbonated clay rich in iron, fired at a temperature above 900 °C, on the other hand the
utility ceramics come from a carbonated raw material collected in the surroundings of the
village of Aghmat , the estimated cooking temperature for these materials is between 700 °C
and 900 °C.
In order to improve the quality of the materials used in the restoration of the studied
monuments, we have also made experimental briquettes by varying composition of raw
materials and the cooking parameters. The results obtained show that the Benjlikh site clays in
Fez are the most suitable for the restoration of these buildings; the appropriate cooking
temperature is around 850 °C to 950 °C, with a slow firing cycle and a bearing of at least 4
hours. These parameters provide good quality materials which combine strength, durability
and cutting ability.
