Chemical and Mineralogical Signatures of Archaeological Features at the Mailhot-Curran Iroquoian Site, Eastern Canada

The St. Lawrence Iroquoians built villages in southwestern Quebec (Canada) along the St. Lawrence River. They left behind longhouses, hearths, middens, and storage pits like those discovered at the Mailhot-Curran archaeological site in Saint-Anicet. Here, we contrast the properties of Iroquoian features with undisturbed soil to define the chemical and mineralogical signature of hearths, middens, and pits. The native soil has a neutral pH and consists of an Ah horizon overlaying a Bm horizon dominated by quartz and feldspars. In the hearths, ashes are characterized by neoformed calcite and apatite with carbonates, higher total P, and enrichment in amorphous inorganic Al, Fe, and Si. The rubified layer of hearths contain poorly crystallized Fe oxides. The mineralogy of the rubified layer is dominated by authigenetic ankerite, an Fe-carbonate mineral identified here for the first time in Iroquoian hearths. Middens have the highest organic matter content and contain more organically complexed Al and Fe than the soil. The storage pits have low pH values and carbonate content and contain high levels of amorphous Si and total P. Our work establishes the pedologic signature of three Iroquoian features despite significant alteration of their properties by post-occupational biogeochemical processes. (C) 2015 Wiley Periodicals, Inc.