ASSESSING FIRING CHARACTERISTICS OF LOCALLY SOURCED CLAYS AND THEIR POTENTIAL FOR USE IN POTTERY AND CERAMICS

Clay has been used to manufacture pottery for approximately 20,000 years. Over that time, all major cultures learned which clays and other ingredients were best for producing ceramic products. Because these basic ingredients were locally sourced, there was significant variation in the nature of the clay bodies as far as plasticity, refractory temperatures, shrinkage, texture and color were concerned. Modern clay bodies that are available commercially are manufactured to meet standards with respect to these properties and for the most part, this is welcomed by ceramists that desire consistency during working and firing. However, for artists that specialize in atmospheric firings, the character of the clay body is as important as the consistency. A locally sourced clay used in a wood-fired kiln using locally sourced wood adds "local flavor" to their pieces. The Gulf Coast is enriched with modern clay-dominated depositional environments and clay-bearing Cenozoic geological units. This study seeks to assess the ceramic potential of some of these materials. We have sampled a variety of modern clay materials from estuaries and deltas, as well as clay-rich intervals of the Citronelle Formation (Pliocene), the Bucatunna Clay Member (Oligocene) and other undifferentiated Miocene units, all within 160 km of Mobile, Alabama. Each sample will be geologically assessed (clay mineral composition, carbon and carbonate content, grain size etc.) before being worked into clay bodies for test firing. Firing will be done under controlled conditions in a kiln at low fire, medium fire and high fire settings as well as in a wood fired kiln. The quality of the fired ceramics will then be evaluated by ceramic artists. It is rare to find a naturally occurring clay body that can suit all requirements of all ceramists (especially for high temperature firings), but studies such as ours will provide important information about the quality of the materials that are locally available to artists.