Petrographic and Geochemical Constraints on the Provenance of Sanidine‐Bearing Temper in Ceramic Potsherds, Four Corners Region, Southwest USA

Abstract

Previous researchers proposed that trachybasalt temper with “poikilitic” sanidine, found in pottery from the Mesa Verde region of the American Southwest, was procured along the eastern Chuska Mountains. This served as one line of evidence that Chaco Canyon was a regional trade center linked to the Chuska Mountains in the ninth to thirteenth centuries. Recent geologic studies, however, revealed other potential sources for the trachybasalt temper. A comparison of petrographic features and geochemical signatures of poikilitic sanidine in rock samples and potsherds shows no definitive correlation of temper materials and a specific geologic source. Several outcrops of trachybasalt are identified as less viable prospects, but the results do not support the idea that the sanidine‐rich temper was exclusively gathered in the Chuska Mountains. This conclusion opens up the possibility that raw materials were gathered from local sources that were more accessible, reducing the dependence on a regional trade center.