JOURACA_SP_2017

Assessing Firing Characteristics of Locally
Sourced Clays and Their Potential for Use in
Pottery and Ceramics
Mary Cave
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
vessels and other 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 firing temperatures, shrinkage,
texture and color were concerned.
Modern clay bodies that are available commercially
are manufactured to meet industrial
standards with respect to these properties
and for the most part, this is welcomed by
ceramists that desire consistency with respect
to working and firing. However, for
many artists, especially those 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 Weeks Bay
and the Mobile River Delta, as well as clayrich
intervals of the Citronelle Formation
(Pliocene), the Bucatunna Clay Member of
the Byram Formation (Oligocene) and other
undifferentiated Miocene units, all within
160 km of Mobile, Alabama. Each sample
Department of Earth Sciences
Earth Sciences
Mentor: Dr. Douglas W. Haywick
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 (c. 1000°C), medium fire (c. 1200°
C) and high fire (c 1300°C) 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.
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