Gauging the effect of 14C-depleted marine foods on radiocarbon ages requires an accurate assessment of the likely proportion of marine foods in the diet. Several factors must be considered, including region-specific δ13C, δ15N and δ34S... more
Gauging the effect of 14C-depleted marine foods on radiocarbon ages requires an accurate assessment of the likely proportion of marine foods in the diet. Several factors must be considered, including region-specific δ13C, δ15N and δ34S data values (regional stable isotope values can differ from global averages), temporal variations in δ13C which offset values in modern dietary standards by up to 1.5‰, and that modelling which considers only δ13C may overestimate the contribution of various dietary sources. Here, we compare previous calculations by linear interpolation of δ13C and a complex computer simulation of marine contribution to the diet of inhumations from the SAC archaeological site Watom Island, Papua New Guinea, with the ISOSOURCE mixing model and a revised database of regional dietary sources and their isotopic values, to estimate marine diet contributions and radiocarbon offsets for burials from the SAC site. Though different estimates of marine contribution to diet do not significantly alter previous calibrations of radiocarbon ages for the inhumations, the new ISOSOURCE calculations challenge the idea of excessive exploitation of marine resources and support evidence for arboriculture and horticulture being a major component in Lapita diet.Keywords Watom Island; Lapita; marine offsets; calibration; mixing models; dietary standards
ABSTRACT.We present the first radiocarbon dates from previously unrecorded, secondary burials in the Cardamom Mountains,Cambodia. The mortuary ritual incorporates nautical tradeware ceramic jars and log coffins fashioned from locally... more
ABSTRACT.We present the first radiocarbon dates from previously unrecorded, secondary burials in the Cardamom Mountains,Cambodia. The mortuary ritual incorporates nautical tradeware ceramic jars and log coffins fashioned from locally harvested trees as burial containers, which were set out on exposed rock ledges at 10 sites in the eastern Cardamom Massif. The suite of 28 14C ages from 4 of these sites (Khnorng Sroal, Phnom Pel, Damnak Samdech, and Khnang Tathan) provides the first estimation of the overall time depth of the practice. The most reliable calendar date ranges from the 4 sites reveals a highland burial ritual unrelated to lowland Khmer culture that was practiced from cal AD 1395 to 1650. The time period is concurrent with the 15th century decline of Angkor as the capital of the Khmer kingdom and its demise about AD 1432, and the subsequent shift of power to new Mekong trade ports such as Phnom Penh, Udong, and Lovek. We discuss the Cardamom ritual relative to known funerary rituals of the pre- to post-Angkorian periods, and to similar exposed jar and coffin burial rituals in Mainland and Island Southeast Asia
We present the first radiocarbon dates from previously unrecorded, secondary burials in the Cardamom Moun- tains, Cambodia. The mortuary ritual incorporates nautical tradeware ceramic jars and log coffins fashioned from locally har-... more
We present the first radiocarbon dates from previously unrecorded, secondary burials in the Cardamom Moun- tains, Cambodia. The mortuary ritual incorporates nautical tradeware ceramic jars and log coffins fashioned from locally har- vested trees as burial containers, which were set out on exposed rock ledges at 10 sites in the eastern Cardamom Massif. The suite of 28 14C ages from 4 of these sites (Khnorng Sroal, Phnom Pel, Damnak Samdech, and Khnang Tathan) provides the first estimation of the overall time depth of the practice. The most reliable calendar date ranges from the 4 sites reveals a high- land burial ritual unrelated to lowland Khmer culture that was practiced from cal AD 1395 to 1650. The time period is con- current with the 15th century decline of Angkor as the capital of the Khmer kingdom and its demise about AD 1432, and the subsequent shift of power to new Mekong trade ports such as Phnom Penh, Udong, and Lovek. We discuss the Cardamom rit- ual relative to known funerary rituals of the pre- to post-Angkorian periods, and to similar exposed jar and coffin burial rituals in Mainland and Island Southeast Asia.
Least-squares fitted smooth curves to radiocarbon versus tree-ring calibration data for the period AD 1140 to 1950 are compared with climatic warming and cooling of the North Atlantic (Little Ice Age), and with recorded sunspot num- bers... more
Least-squares fitted smooth curves to radiocarbon versus tree-ring calibration data for the period AD 1140 to 1950 are compared with climatic warming and cooling of the North Atlantic (Little Ice Age), and with recorded sunspot num- bers over the period AD 1670 to 1950. Calibration curves from different parts of the globe are not identical, and appear to be determined by a combination of variable solar activity and variable oceanic upwelling of 14C-depleted water, with the variable upwelling itself partly determined by solar activity.
We propose a model for the seismic driving of environmental changes and illustrate it using a case study from New Zealand dated to the 15th Century AD. A "seismic staircase" shows a chronological progression of environmental outcomes that... more
We propose a model for the seismic driving of environmental changes and illustrate it using a case study from New Zealand dated to the 15th Century AD. A "seismic staircase" shows a chronological progression of environmental outcomes that includes tsunami, rock avalanches, vegetation disturbance, rapid coastal dune building, river aggradation, and abandonment of prehistoric coastal settlements. The 15th Century event appears to be unique in the past Millenium and is most notable for its period of rapid coastal dune building. The coincidence of a catastrophic El Niño episode in the mid 15th Century AD may have served to move sediments rapidly through the terrestrial system thus delimiting clearly separate geomorphological after-effects. We contend that seismic driving is a major factor in determining paleoenvironmental change in tectonically active areas during the Holocene and provides the palaeoenvironmental context within which smaller scale events operate.
