Archaeological investigations in the Republic of Palau, Micronesia, have produced 409 radiocarbon age determinations from cultural contexts, indicating a range of Palauan occupation from about 3000 yr ago into the modern era. However, these dates are scattered among numerous sources (many difficult to obtain) and are presented in a number of different formats and calibrations. The goal of this paper is to compile a usable, systematic database of all of these Palauan cultural 14C assays. This database will be suitable for developing and evaluating chronological models, an effort being undertaken as a separate paper. Prior to constructing prehistoric colonization and cultural chronologies for Palau, the validity of each assay and the relative adequacy in sample size per cultural and environmental zones must be examined. After systematic recalibration, the reliability of the dates is evaluated in light of sample material, cultural context, and site formation processes. A method for dating monumental earthwork complexes through site formation analysis is presented. Sets of 237 valid and 58 potentially valid 14C dates remain to develop chronological models. The representation of Palau's environmental zones, site types, and regions within the dating pool is examined and compared to ensure meaningfulness in these chronological models. Newly obtained 14C age determinations are also provided.

Dating sediments which have accumulated over the last few hundred years is critical to the calibration of longer-term paleoclimate records with instrumental climate data. We attempted to use wiggle-matched radiocarbon ages to date 2 peat profiles from northern England which have high-resolution records of paleomoisture variability over the last ∼300 yr. A total of 65 14C accelerator mass spectrometry (AMS) measurements were made on 33 macrofossil samples. A number of the age estimates were older than expected and some of the oldest ages occurred in the upper parts of the sequence, which had been dated to the late 19th and early 20th century using other techniques. We suggest that the older 14C ages are the result of contamination by industrial pollution. Based on counts of spheroidal carbonaceous particles (SCPs), the potential aging effect for SCP carbon was calculated and shown to be appreciable for samples from the early 20th century. Ages corrected for this effect were still too old in some cases, which could be a result of fossil CO2 fixation, non-SCP particulate carbon, contamination due to imperfect cleaning of samples, or the “reservoir effect” from fixation of fossil carbon emanating from deeper peat layers. Wiggle matches based on the overall shape of the depth-14C relationship and the 14C minima in the calibration curve could still be identified. These were tested against other age estimates (210Pb, pollen, and SCPs) to provide new age-depth models for the profiles. New approaches are needed to measure the impact of industrially derived carbon on recent sediment ages to provide more secure chronologies over the last few hundred years.

The South Arabian chronology has been problematic for a long time and this is also a true vexata quaestio for the ancient history of South Arabia. Three different chronologies have been suggested for the first literate phase of South Arabian cultures, which may date to the 11th century BC, the late 8th century BC, or the 5th century BC (see de Maigret 1996:157–63; de Maigret and Robin 1989: 276–8; Pirenne 1988; Robin 1997; Figure 1). At the site of Yalâ, potsherds with incised South Arabian inscriptions have been recovered in a stratum dating at least to the 8th century BC, if not earlier, and offer evidence of the existence of South Arabian culture at that time (de Maigret and Robin 1989:288–9).

Radiocarbon dates largely obtained from bulk soil samples in 24 soil profiles in the Teotihuacán Valley, Mexico, are reported insofar as they represent a first step towards developing a sequence of soil formation, erosion, vegetation change, and human impact during the Holocene. Limitations of 14C dating in the area are considered, particularly the absence of charcoal in sediments and poor preservation of pollen. A broad temporal scheme is proposed to guide future research in which 4 periods are defined: ∼5000–2000 BP (relative stability with short, intermittent episodes of erosion); ∼2000–1500 BP (erosion-sedimentation, deforestation, and intensive agriculture); ∼1500–1000 BP (relative stability, depopulation, and partial recovery of the landscape); and ∼1000–500 BP (erosion-sedimentation, deforestation, and intensive agriculture).

A variety of analytical procedures involve breaking open a glass or quartz vessel containing a gaseous sample, and then quantitatively collecting the sample gases for analysis. In order to do this, a variety of “tube crackers” have been used. This paper discusses an alternate tube cracker that offers numerous advantages over those that have been discussed previously in the literature.