Petrographic and Qualitative Analysis of Tanque Verde Red-on-brown Sherds from the Northern Tucson Basin and Avra Valley (TR1995-4) (PDF)
Ceramic vessels produced in the prehistoric southwest often contain abundant temper such as sand, disaggregated rock, and crushed sherd. Both sand and disaggregated rock tempers can be used as indicators of the provenance of archaeological ceramics when their geological sources are identified (Arnold 1985; Miksa 1995; Miksa and Heidke 1995; Schaller 1994; Shepard 1936, 1942).
The goal of the present study is to identify the provenance of Tanque Verde Red-on-brown ceramics recovered from a number of sites located in the Northern Tucson Basin and Avra Valley on the basis of the temper found within them. The focus of this study is on sand temper. A sample of wash sands from the project area was collected and analyzed. Those samples supplement the information on geological sources previously compiled by Lombard (1986, 1987a, 198Th, 1987c, 1987d, 1987e, 1989, 1990) and Kamilli (1994).
A collection of 450 Tanque Verde Red-on-brown sherds and 29 sand samples were submitted by Ms. Karen C. Harry to The Center for Desert Archaeology for qualitative and petrographic analysis. Twenty-five of the 450 sherds submitted were selected by James Heidke to be pointcounted, and the point count data was then used to test and refine his temper characterization of the entire collection of sherds. In addition to the qualitative and petrographic analyses of the sherds, “grain boxes,” keys to those boxes, and hand sample descriptions were prepared for each petrofacies, or sand composition zone, relevant to this study.