Indurated Sediment Masses (ISMs) from Southern Texas

Author(s): Sean Nash

Year: 2015


Baked-clay nodules are reported at many archaeological sites across southern Texas. These nodules are indurated sediment masses (ISMs) and are found in many contexts. William A. Duffen first found ISMs within a hearth at the Morhiss site in Victoria County. His discovery led researchers to conclude that these were heating elements used in place of stone and analogous to Poverty Point Objects. Ricklis came to the same conclusion about ISMs found in a hearth at 41NU2. The heating element interpretation is convincing when ISMs are found within a hearth. However, most ISMs are not found in hearths but they are still assumed to be heating elements. Contradicting this interpretation, others posit that ISMs are natural concretions, the result of fires used in historic land clearing, or the remains of clay linings from hearths. This paper will show that ISMs from southern Texas sites represent both naturally occurring concretions as well as cultural features and artifacts. A method will be presented to separate the cultural ISMs into types that resulted from incidental formational processes (e.g. field clearing) and those created to be functional tools (e.g. heating elements) and constructions (e.g. clay linings).

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Cite this Record

Indurated Sediment Masses (ISMs) from Southern Texas. Sean Nash. Presented at The 80th Annual Meeting of the Society for American Archaeology, San Francisco, California. 2015 ( tDAR id: 397803)

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Spatial Coverage

min long: -91.274; min lat: 24.847 ; max long: -72.642; max lat: 36.386 ;