The present paper describes obsidian sources and compositional analysis performed on obsidian recovered from natural flows in the upper Maule River basin (central Chile). We compare the composition of this obsidian with that of obsidian artifacts recovered from selected archaeological sites both in the middle and lower valley of the Maule River and in the Argentinian provinces of Mendoza and Neuquén. The results indicate that the collected obsidian samples can be separated into six major groups. Most of the obsidian artifacts are assignable to a particular source area, but there still remain some unknown sources. We conclude that the Laguna del Maule source area was exploited from at least 50 A.D. onward and that the material was distributed to sites located more than 200 km from the source.

Archaeologists have long noted the presence of green obsidian artifacts in a number of Maya sites and have recognized that they were manufactured from the obsidian of the Pachuca source in central Mexico. Viewed as evidence of Teotihuacán influence, these finds were initially explained in economic terms as commodities in an exchange of goods that had a substantial impact on the economies of the Maya and on the development of the obsidian industry in Teotihuacán. However, when the contexts of the finds are examined it becomes clear that the significance of the artifacts was more symbolic than economic. The forms include prismatic blades, bifacially worked points and knives, needles, sequins, and some eccentrics. These are often recovered from ritual contexts, in association with other evidence of Teotihuacán influence. They apparently served to express a variety of relationships with Teotihuacán, ranging from actual Teotihuacanos proclaiming their identity to the attempts of Maya elite to forge some social affiliation with the city. Although most of the finds of green obsidian consist of only one or a few pieces, some contexts, such as the tombs of mounds A and B at Kaminaljuyú, produced more substantial amounts. Nevertheless, despite these occasional impressive finds, green obsidian does not seem to have been a major import, and it is clear that the Teotihuacán obsidian industry had largely attained its Classic-period structure before the Maya demand developed. Although the flow of central Mexican obsidian to the Maya region was not negligible, it could not in itself have had a major effect on either economic system.

Incised pebbles found at the mid-Holocene, Middle Preceramic period Ostra Base Camp site on the Peruvian north coast demonstrate long-distance links to coastal Ecuador, 700 km to the north. The artifacts belong to a northwestern Andean pebble-figurine tradition associated with the tropical coast. Environmental indicators at the Ostra site show a warm-water lagoonal environment, unlike the modern cold-water conditions of northwestern Peru but similar to modern Ecuador. The Ostra site dates between ca. 5500 and 6250 B.P. (3550 and 4300 B.C.), during a hiatus in the coastal Ecuadorian record, so the link to Ecuador provides the earliest evidence of long-distance cultural interaction between these regions. Until contemporary sites are found in Ecuador, the Ostra Base Camp site provides our only example for this time of tropical coastal cultures of the northwestern Andean interaction sphere.

Demographers use mathematical projections to estimate both future and past population in areas where they lack quality data. Such projections may be very useful in archaeological situations. In this analysis, we mathematically project population growth rates from Classic Maya settlement in the Copán Valley, Honduras, from A.D. 650-800 backward to A.D. 450 to estimate valley population levels during the Middle Classic. Projections based on the growth rate (r = .0098) that best describes Late Classic growth yield population estimates that are from 40 to 100 percent higher than the unsmoothed estimates for the Middle Classic calculated by Webster et al. (1992:189). However, they still indicate that Middle Classic Copán was a relatively small polity, with a population of approximately 2,400 by A.D. 550 and 6,400 by A.D. 650. The fact that population growth at Copán from the period A.D. 400-800 conforms well to exponential growth indicates that population growth in the valley was relatively unaffected by episodic events. Each of the three growth rates considered would have been sustainable in a preindustrial agrarian society.

It is commonly assumed in both the public and professional perceptions of Maya archaeology that tombs serve as time capsules, each representing a single event, and that burials of single individuals were the normal interment type, at least during the Late Classic period (A.D. 550-800). The investigation of Caracol Structure A34 provides excellent examples of tomb re-entry as well as of multiple-individual interment in sealed contexts, both of which contradict current assumptions. Analyses of the excavations also embody a true conjunctive approach by utilizing stratigraphy, osteology, artifacts, and epigraphy. When the archaeological data from Structure A34 are placed within a broader context, single-event single-individual tombs are shown to be but one manner of interment at Caracol. Although the large number of multiple-individual burials and the possibility of widespread tomb re-entry at Caracol may appear aberrant when compared with general interment practices at other Maya sites, the inferred funerary rites are well within the bounds of worldwide cultural practices relating to death and burial.