LINKING FINISHED CERAMICS TO RAW MATERIALS: OXIDIZED COLOR CROUPS FOR LOWLAND DESERT CLAYS

Abstract

Clays with different concentrations of iron oxides fire to different colors in an oxidizing atmosphere. This pattern has been exploited by archaeologists most frequently in the Puebloan Southwest, where oxidation analysis is used to compare ceramics and clays from sedimentary geologic formations and other contexts. This technique is also useful in the southern U.S. Southwest for evaluating clay sources and characterizing ceramic technology and raw material use.Five oxidized color groups for lowland desert clays are defined here based on 585 ceramic samples and 25 clay samples. Residual clays fire to darker and redder brown colors, whereas alluvial sediments often fire to the lighter and less red buff colors. The two lightest color groups, common in historical-period buff ware and Hohokam Buff Ware, are apparently only produced by leached alluvial sediments from lacustrine and canal deposits and from the Middle Gila River Valley. The darker oxidized paste colors of Hohokam Buff Ware overlap with plain ware paste colors, and similar alluvial clays may have been used for both in some cases.