Erosion can produce heterogeneous distributions of cultural materials of differing densities, weights, and shapes within an archaeological site. A large, provenienced surface collection from a preceramic site in highland Peru is examined for evidence of downslope movement as an explanation for observed heterogeneity in artifact distribution. Statistical methods of spatial analysis are used to define the extent of movements of surface materials in this site. For this particular area of Peru, critical angles for downslope movement will limit the site areas in which analysis of horizontal distributions can be expected to produce culturally significant information.

The function of archaeological mushroom stones has been subject to various speculations. Recently their explanation as ritual objects, associated with the ceremonial consumption of hallucinogenic mushrooms, seems on its way to general acceptance. The subsequent analysis refutes such an interpretation and reveals their real function as potters’ molds.

Some questions concerning the Postclassic Peten can be answered by systematic use of ethnohistoric sources with archaeological data. A review and re-analysis of these data for the Itza capital Tayasal are presented. A plausible argument is formulated for a relocation of the ethnohistoric Tayasal as the archaeologically recognized Postclassic site of Topoxte in Lake Yaxha, Guatemala. It is further argued that a closer correlation of the ethnohistoric data with the archaeological record and a complete re-analysis of other pertinent data may prove useful to the archaeologist when confronted with conflicting interpretations or concepts.

For the past several decades, students of the Central Plains tradition have postulated a south-to-north trend of movement by the bearers of this tradition. Such a pattern should be detectable by means of a trend-surface analysis of the available radiocarbon dates. This paper reports such an analysis. The trend is found to be largely supported by the chronological evidence.

Recent studies have demonstrated that the flaking characteristics of certain siliceous stone materials are enhanced by carefully controlled annealing and that intentional annealing was indeed practiced by prehistoric Native Americans. A note of caution is extended here to investigators who might extend evidence for thermally altered siliceous stone from a site to interpretations that intentional annealing was practiced at the site. The use of fire in quarrying has a long history throughout the world, and much heat-treated material from sites may have been thermally altered unintentionally, the result of quarrying practices.

It has been known since 1972 that Ponce de Leon discovered Yucatan in 1513. New information confirming this is found in the books of Chilam Balam where the Maya record that the Spanish first arrived in their land at that time. The sundry data indicate that 8 July 1513 (N.S.) falls in Tun 13 of Katun 2 Ahau. This relation provides a new test for correlations of the Maya and Christian calendars. The Goodman-Martinez-Thompson correlation passes the test and the Morley-Spinden correlation fails it.

The ceramic assemblage which characterizes the enigmatic Tlatilco burials is duplicated in the stratigraphy of the El Terror phase at Iglesia Vieja, Morelos, where two components have been isolated and defined. The earlier of the two is found to be regional, pre-eminent, and pre-Olmec, rather than Olmec-inspired as previously thought. Radiocarbon dates from charcoal associated with Olmec figurines and vessels are as early as those from the Olmec heartland.

Data from United States General Land Office Surveys are commonly used to create vegetation models for the American Pioneer period. These models are then used as baselines for understanding past biotic change. It should be realized that many of these surveys were made near the end of a climatic episode (the Neo-Boreal or "Little Ice Age") when world temperatures were much lower than at the present time. These baselines therefore do not represent vegetational responses to a climatic regime like that of the present, and the vegetation models must be interpreted accordingly.

The need to teach archaeological field techniques and the obligation to conserve the resources of the past often involve conflicting priorities. On-site instruction ought to be compatible with the accountability of archaeologists under recent provisions for public archaeology and historic preservation. The author presents a viable tested alternative to the indiscriminate exploitation of archaeological sites for the purpose of student practice in field methodology.