Human burials from the cemetery at the Rounala church, northern Sweden, were radiocarbon (14C) dated to shed light on the use of the cemetery. Carbon, nitrogen and sulfur stable isotope analysis of bone collagen from 19 distinct individuals indicated that these individuals had a mixed diet consisting of freshwater, marine and terrestrial resources. Dietary modeling using FRUITS was employed to calculate the contributions of the different resources for each individual. These data were then used to calculate individual ΔR values, taking into account freshwater and multiple marine reservoir effects, the latter caused by Baltic and Atlantic marine dietary inputs, respectively. 14C dating of tissues from modern freshwater fish species demonstrate a lack of a freshwater reservoir effect in the area. Two OxCal models were used to provide endpoint age estimates. The calibrated data suggest that the site’s cemetery was most likely in use already from the 14th century, and perhaps until at least the late 18th century.

On the island of Lolland, southeast Denmark, an area of almost 300 ha is currently under archaeological investigation prior to the planned construction of a tunnel between Denmark and Germany under the Femern belt. The area investigated in the context of the “Femern project” includes a former fjord or lagoon, which was used both as an economic resource and as background for ritual activities in the Neolithic. The wetland conditions give excellent preservation conditions for organic material. A yet unsolved issue, however, is the question of reservoir effects. The local reservoir effect needs to be known for accurate radiocarbon (14C) dating of samples with possible aquatic carbon sources, such as human bones or food residues on pottery. Therefore, this paper attempts to calculate the local reservoir effect for the study area. I will discuss the possibilities and limitations when analyzing 14C dates from a rescue excavation. When applying the estimated reservoir corrections to a hoard of jaws and other bones, an interesting change in ritual activity at ca. 4000 cal BC can be observed. Furthermore, I examined 14C dates on bulk organic sediment and will discuss their implications for building chronologies and for reconstructing the environment of the Stone Age fjord. Finally, I will discuss the pitfalls and uncertainties associated with 14C dates for sea level reconstruction.

Models of late-glacial environmental change in coastal areas are commonly based on radiocarbon ages on marine shell and basal lake sediments, both of which may be compromised by reservoir effects. The magnitude of the oceanic reservoir age in the inland waters of the Georgia Basin and Puget Lowland of northwestern North America is inferred from radiocarbon ages on shell-wood pairs in Saanich Inlet and previously published estimates. The weighted mean oceanic reservoir correction in the early and mid Holocene is −720±90 yr, slightly smaller than, but not significantly different from, the modern value. The correction in late-glacial time is −950±50 yr. Valley-head sites yield higher reservoir values (−1200±130 yr) immediately after deglaciation. The magnitude of the gyttja reservoir effect is inferred from pairs of bulk gyttja and plant macrofossil ages from four lakes in the region. Incorporation of old carbon into basal gyttja yields ages from bulk samples that are initially about 600 yr too old. The reservoir age declines to less than 100 yr after the first millennium of lake development. When these corrections are accounted for, dates of deglaciation and late-glacial sea-level change in the study area are pushed forward in time by more than 500 yr.