Radiocarbon Databases

Charcoal from archaeological contexts differs from off-site pollen samples as it is mainly a product of intentional human action. As such, analysis of charcoal from excavations is a valuable addition to studies of past vegetation and the interaction between humans and the environment. In this paper, we use a dataset consisting of 6186 dated tree species samples from 1239 archaeological sites as a proxy to explore parts of the Holocene forest development and human-vegetation dynamics in SouthEastern Norway. From the middle of the Late Neolithic (from c. 2000 BC) throughout the Early Iron Age (to c. AD 550) the region's agriculture is characterized by fields, pastures and fallow. Based on our data, we argue that these practices, combined with forest management, clearly altered the natural distribution of trees and favoured some species of broadleaved trees. The past distribution of hazel (Corylus avellana) is an example of human impact on the vegetation. Today, hazel is not even among the 15 most common tree species, while it is one of the most prevalent species in the archaeological record before AD 550. The data indicate that this species was favoured already by the region's Mesolithic hunter-fisher-gatherers, and that it was among the species that thrived extremely well in the early farming landscape. Secondly, our analysis also indicates that spruce (Picea abies) first formed large stands in the southeastern parts of Norway c. 500 BC, centuries earlier than previously assumed. It is argued that this event, and a further westward expansion of spruce, was partly a consequence of a specific historical event-the first millennium BC farming expansion.

The aim of this paper is to make a critical appraisal of the available 14C dataset from Northwest South
America (Colombia) corresponding to the Pleistocene/Holocene transition (ca. 12,000-8000 14C years
BP). The first step in the study was to assemble from both published and unpublished sources an
exhaustive database of 14C dates (n = 85), recording data regarding the environmental setting and spatial
coordinates of each site, stratigraphic provenance of the dated samples, material used for dating, and 14C
dating method. After the application of different filtering procedures based on outlier detection techniques,
the database was subsequently reduced (n = 77). Using uncalibrated and calibrated dates, some
spatial and temporal trends in data distribution were investigated in order to illustrate both the strengths
and weaknesses of the available database. It is concluded that three main features that characterize the
14C dataset from Northwest South America, namely the very high percentage of 14C measurements made
on charcoal, the almost total disregard of bone as a target sample for dating, and the extremely low
percentage of AMS dates, partially affect both its reliability and comparability. It is suggested that, in
order to use 14C dates as data to make reliable inferences about the timing, pattern, process and tempo of
early exploration and colonization of the study area, work at two different levels would be profitably
carried out. In the short term, it would be advisable to develop an extensive and exhaustive program
aimed at redating, with AMS and new sample selection criteria, the more significant archaeological
assemblages attributable to the Pleistocene/Holocene transition. In the medium to long term, it would be
necessary to implement new research projects specifically aimed at obtaining original information about
early human settlement in different geographical areas of the Colombian territory.