I have developed a method of dating early medieval Irish buildings using charcoal encased in mortar. Due to the inclement weather over centuries, timbers do not preserve well in these structures, leaving little suitable material for 14C dating. Initially, several buildings of known age were analyzed to verify the mortar charcoal technique. Then, a series of buildings for which no definite architectural-historical dates existed, e.g., churches, houses, oratories and round towers, was successfully tested. I discuss here the results of this dating approach, and provide architectural historians with a firmer understanding of the origin and antiquity of early Irish buildings.

The small but vital role of 14C dating in archaeometric research is clearly shown in the copper project reported herein. The 14C ages place a time perspective on the “Old Copper Culture Complex,” substantiating early Libby dates that had been questioned. The respective roles of INAA, PGE and Pb isotope work are briefly summarized. A long tradition of heat treatment from Paleoindian stone to Archaic copper is suggested.

During the late 1960s, N. J. van der Merwe (1969) obtained 14C measurements on 11 iron pieces, ranging in carbon content from medium carbon (0.22%) wrought iron (1.2 kg used) to high carbon (3.2%) cast iron (30 g), thereby demonstrating the feasibility of the technique for 14C dating iron. In the early 1980s, Sayre et al. (1982) repeated two of van der Merwe's measurements, and carried out two analyses on a recently rediscovered Elizabethan(?) iron bloom. Thirty grams were required of this medium carbon wrought iron to obtain an age using small proportional counters. A number of iron artifacts have recently been analyzed by accelerator mass spectrometry (AMS) at IsoTrace. Samples ranged in size from 3.4 g of a medium carbon (≃0.4%) wrought iron bloom to 274 mg for a high carbon (1.79%) wootz steel fragment. AMS now permits analysis of samples that previously were too small or too valuable to be analyzed. For larger samples, multiple analyses can reveal variations that may aid the evaluation of sample history.

The main problem with dating pottery by radiocarbon is that many different carbon sources, of different radiocarbon age, may contribute to the potsherd carbon content. Also, the process of firing is liable to destroy information that might help separate possible sources. We describe several pottery dating projects in which we have dated separate fractions (such as humics, lipids and classes of residual carbon). Although in some cases consistency between results is sufficient to accept that this approach can give a credible date, in other cases, no date has been possible, and general conclusions are difficult to make.

The beginning of the Bronze Age in the British Isles has traditionally been marked by the appearance, in the archaeological record, of Beaker assemblages, mainly characterized by the Beaker pottery form itself. Ceramic typologies based on this style, which is undoubtedly continental in origin, have been used both for relative dating and as evidence of the social and economic developments of the period. Systematic radiocarbon dating has been attempted for the continental European Beaker material (Lanting, Mook & van der Waals 1973), but no such program has been carried out on British material. An examination of the existing radiocarbon results for the British Beakers showed many to be flawed in some way, particularly in the use of materials, such as mature wood, where there is no a priori reason for assuming a direct relationship between sample death and context. An attempt has been made at the British Museum to test the validity of archaeologically derived chronologies for the Beaker pottery of the British Isles. This involved analysis of a group of carefully selected human bone samples from Beaker burials, where there is a known direct association between ceramic usage and the cessation of carbon exchange. Twenty such samples have been identified and measured. The results presented here, combined with other previously produced determinations, show no obvious relationship between pottery style and calendar date of deposition.

We have radiocarbon dated some Precolumbian artifacts. We have used both conventional beta counting and AMS to date textiles, bamboo from weaving looms, a feather carpet and straw from a clay mask. We discuss the particular problems in sample pretreatment.