Pottery kiln and drying oven from Aventicum (2nd century AD, Ct. Vaud, Switzerland): Raw materials and temperature distribution

Abstract

Fireboxes of two pottery structures, excavated in 2002 at Aventicum (at present Avenches), the capital of Roman Switzerland, were studied to understand their function in the artisan quarter. Twenty-one oriented samples underwent petrographical, mineralogical and chemical analyses to determine the nature of the raw materials and the temperature distribution. Both structures are typologically different and show differing degrees of thermal impacts. Inferred maximum temperatures for kiln Structure 6, as deduced from phase associations, were as high as 1050-1200°C. Such high temperatures are typically recorded in fireboxes of ceramic kilns. Structure 180 is proposed to have been a drying oven, as evidenced by: (1) its phase associations, pointing to maximum firing temperatures of c. 950-1050°C, and (2) its unusual shape. Six out of seven clays from the artisan quarter revealed Ca-rich composition, but the Ca-poor one was preferentially used by Roman potters for bricks and clay binders to build the two structures. Such "refractory" clays are obviously better suited to withstand higher firing temperatures and for a longer period than Ca-rich clays.

Strength of kaolinite-based ceramics: Comparison between limestone- and quartz-tempered bodies

“…In this paper, we report the results obtained from ceramic tests prepared with a clay of the first type, which could be assimilated to earthenwares produced by primary clays (e.g. Smith, 2000;Buxeda I Garrigòs et al, 2003;Eramo and Maggetti, 2013).…”

Discrimination and Provenances of Phoenician Red Slip Ware Using both the Solid State Electrochemistry and Petrographic Analyses

“…The well sorted inclusions suggest sieving procedure and a good selection of the raw material for the Israeli samples. The homogeneous reddish calcareous matrix suggests a very similar production technology for the two archaeological sites with controlled oxidized firing conditions .…”

Clay source and firing temperatures of Roman ceramics: A case study from Plovdiv, Bulgaria

“…In our case, however, there is no archaeological or geological evidence to support a similar assumption. A literature survey revealed that Ca‐poor or noncalcareous clays seem to have been used for the production of Roman brittle ceramics from the Near East and Turkey (Bartl, Schneider, & Bohme, ; İssi, Özçatal, Kara, & Alp, ), amphorae from Italy (Ceccarelli et al, ) or even for bricks and clay binders for pottery kiln in Switzerland (Eramo & Maggetti, ). Such observations can be expected due to the lower thermal expansion coefficient of the noncalcareous clay as compared to the Ca‐rich meaning that the latter are more prone to change in their shape and volume with the increasing temperature (Tite, Kilikoglou, & Vekinis, ).…”