Weathering of hydroxyapatite, Ca5(PO4)3(OH) in bone probably is initiated by organic and carbonic acids formed by the microbial decomposition of collagen. This weathering, independent of soil properties, is caused by protons replacing Ca from hydroxyapatite. As collagen is depleted, proton production decreases and weathering may either continue if protons are available from the soil or be arrested if Ca from the soil displaces the protons previously added to the hydroxyapatite. The theoretical Ca/P weight ratio of unweathered bones is 2.15. Weathered bones that have been stabilized by Ca may have this ratio or a higher one if extra Ca has been added. A group of weathered bones from one site with a slightly acid soil had an average ratio of 1.67, which probably promotes further weathering, while bone at the same site with an average ratio of 4.09 was less weathered and apparently stabilized.

Recent archaeological work at Colha and at other localities in the geographically restricted chert-bearing zone of northern Belize has revealed large-scale exploitation of chert for stone tool production. Workshops dated during the Late Preclassic period signal the beginning of craft specialization in chert working that continued in the Late Classic and into the Early Postclassic periods. Secular items such as large oval bifaces, tranchet bit tools and prismatic blades, as well as nonsecular eccentrics and stemmed macroblade artifacts are distinctive of the Late Preclassic and Late Classic workshops. The distribution sphere of Preclassic and Classic period chert tools has been traced to several contemporaneous sites that lie beyond the chert-bearing zone to the north. Colha has been identified as the primary production and distribution center during the Late Preclassic period; although it remained a production center in the Late Classic period, the main center for distribution may have shifted to Altun Ha.

The obsidian hydration dating technique has been refined since its invention in 1960. The hydration process slows down as it proceeds and appears to follow the relation: hydration thickness is proportional to the square root of time. The variables that influence the hydration rate are mainly the temperature experienced by the object to be dated and its chemical composition.

Methods of estimating effective integrated field temperatures and composition variables of obsidians are discussed.

In the lowlands of Central Veracruz, as in various locations across the base of the Yucatan peninsula, Prehispanic agriculturalists sought out wetlands with a limited fluctuation in water level for adaptation to intensive cultivation. Vestiges of canals and raised fields show through the dry season pastures of many ranches. The rectilinear remains of the earlier incursion show considerable accordance, from wetland to wetland, in their astronomical orientation: about 15 degrees clockwise of our own cardinal directions. It may be hypothesized that this orientation was imposed from Teotihuacan and that the majority of the raised field vestiges seen in the wetlands of Central Veracruz date back at least to a time between A.D. 100 and 600.

For the determination of provenience of obsidian artifacts, precise and accurate measurements of composition patterns of the geologic sources are necessary for definitive and cost-effective assignments. Inter-comparison of data from different laboratories is often difficult. Suggestions for maximizing the usefulness of data already in the literature are made, contributions to a useful data bank of source composition patterns are recorded, and provenience determinations of 30 artifacts excavated in Quirigua, Guatemala are presented to exemplify the technique.

During observational fieldwork in undisturbed ranges of free-roaming bison and moose, I have identified approximately 8% of surface bones as spirally or green-fractured due to documented carnivore activity, and 5% as spirally or green-fractured due to trampling or dust wallowing by bison. The bones of smaller species suffer up to 50% breakage. Bone modifications by wild wolves and bears are briefly described, as are characteristics of fractures caused by trampling and wallowing.

Refinements and extensions to the permutation test for assessing the intrasite patterning of artifact distributions in an archaeological space are presented. Specifically, a Pearson type III distribution is employed to approximate the sampling distribution of the test statistic, an improved weighting is introduced to increase the efficiency of the test, and a method is presented to permit the inclusion of unclassified artifacts in the spatial analysis.

It is argued that the reliability of archaeological inferences based upon artifactual assemblages is in part a function of the methods used to quantify the assemblages. Using ethnoarchaeological data, this proposition is tested by comparing associated artifactual assemblages with the presence or absence of specialists in individual households. Assemblages are quantified in terms of absolute frequency, diversity, and proportional frequency. The correlation between each measure and the presence or absence of specialists is assessed. The analysis reveals assemblage diversity to be one of the strongest and most consistent indicators of specialization and further reveals an inherent flaw characteristic of proportional frequencies.

A phonetic and semantic interpretation of the directional glyphs in Maya inscriptions and codices reveals that they did not refer to the cardinal directions. The glyphs that have been identified previously with north and south can be read phonetically as zenith and nadir, respectively. The glyphs for east and west refer semantically to the rising and setting sun. These data support Clemency Coggins's recent suggestion that Classic Maya directional symbolism was related to the path of the sun across the sky and through the underworld, rather than to the cardinal directions.

Time lapse studies of frost action effects on arctic and subarctic surficial archaeological sites have been conducted from 1973 to the present. Test plots of experimentally produced flakes were constructed in 1973 in the Tangle Lakes Region of the Central Alaska Range and subsequently remapped and photographed in 1974, 1976, and 1980. Similar test plots were laid out in the arctic foothills province of the Brooks Range. Observations made during the study period include: (1) flake displacements of as much as 20 cm/yr; (2) average minimum movement is 4 cm/yr; and (3) upslope movements were observed, suggesting that slope is not the primary factor in flake displacements. Frost heave, needle ice and, possibly, wind appear to be the dominant forces responsible for dispersals. It is argued that these and other natural processes can restructure the archaeological record into patterns that easily can be mistaken for those produced by human activity.

A second amber source has been discovered in Chiapas, which is important for considerations of prehistoric exchange. Source analysis is discussed as a possible means of distinguishing prehistoric amber from the two known sources.

The possibility that prehistoric peoples employed heat treatment of chert and flint as an integral part of their lithic tool production technology is a matter that has long been debated. While previous thermoluminescence (TL) investigations of the heating phenomenon concentrate on finished artifacts, this study investigates the TL stored in biface retouch flakes which are an abundant by-product of the Paleoindian fluted point manufacture. One hundred and seventy-five retouch flakes from three excavated squares at the Parkhill Paleoindian site are examined and compared with their relatively distant geological source. Accidental heating does not satisfactorily explain the fact that the overwhelming majority of the flakes appear to have been heated. We conclude that chert heating at this archaeological site was purposeful.

The Maya text on an all-glyphic stone column now in the Museo del Camino Real in Hecelchakan, Campeche, Mexico, is deciphered. The inscription consists of an unusual truncated Initial Series with an associated Tun-Ahua statement. Arguments are given to justify assigning a Xcalumkin provenance to the monument. The Initial Series is only the third such record known from this site. Other epigraphic highlights include a rare head variant formation of the numeral for 16 by tandem heads for 6 and 10 and a new version of the head variant for 2. A summary of the chronological information available from the site of Xcalumkin is included.

The National Register of Historic Places is important to the preservation of prehistoric sites in ways that are not fully appreciated by archaeologists. The advantages of having a site on the Register are discussed. Archaeologists have a responsibility toward site preservation, and the use of the Register is one means to fulfill that responsibility.

Jade artifacts have been recovered from a wide variety of contexts throughout the Maya Lowlands. Intact artifacts are usually recovered from tombs, burials, and dedicatory offerings. For the most part, the intact jade artifacts from Cerros, a Late Preclassic Maya center in northern Belize, fall within this range. However, the majority of Cerros jades are broken and were recovered from contexts that deviate from the normal Late Preclassic Maya pattern of jade consumption and disposal. In three locations at Cerros, quantities of jade were broken and scattered about. Such activity occurred during the abandonment of masonry and perishable structures and is interpreted here as being a form of termination ritual.

Of the four late Pleistocene and early post-Pleistocene lithic complexes defined by Edward P. Lanning, only one, the Las Vegas complex, is supported by existing evidence from the Santa Elena Peninsula of southwest Ecuador. The Achallan culture, previously defined by Stothert and assigned to the post-Las Vegas period, is now unsupported by satisfactory evidence.

A method of using the Mesoamerican pecked cross as a 365-day or 365 1/4-day calendrical device is proposed. The method consists of placing, removing, and discarding objects in the pecked holes of the arms of the motif in a prescribed sequence. This use does not preclude other uses or meanings of these figures, nor their function in calendrical reckonings more complex than the solar year.