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Radiocarbon (14C) dating is widely used to determine the age of organic material in palaeoenvironmental research. Here we compare 14C dates (n=17) resulting from macro-charcoal (>250 μm), short-lived plant macrofossils and pollen-rich residues isolated from two mire environments in eastern Australia. In most samples we found that short-lived plant macrofossils were the youngest organic component, the charcoal samples most often fell into the middle and the pollen-rich residues consistently returned older dates than the other samples. Although pollen-rich residues have been widely used for 14C dating in Australasia we suggest some caution in their use, perhaps because in our fire-prone environments these samples often also contain fine charcoal and other oxidative resistant organic matter that is older than the surrounding sediment matrix. The macro-charcoal samples also often returned older calibrated ages compared to short-lived plant macrofossils from the same depth, although this difference was relatively small (<245 years). Our results demonstrate that 14C dating of short-lived plant macrofossils are likely to yield more accurate chronologies and we advocate their routine use in palaeoenvironmental research when they are available. [ABSTRACT FROM AUTHOR]

This article presents archaeological data critical to our understanding of the pre-colonial past along the northeast coast of New Guinea. Two archaeological sites from coastal and offshore Madang, Papua New Guinea, were excavated to establish the timing of colonization by Bel (Austronesian) speakers, and the subsequent emergence of their trade and exchange networks along the coast leading up to ethnographic accounts. These sites include Nunguri on Bilbil Island, formerly the center of the expansive Madang (Bilbil) pottery exchange network, and Tilu, Malmal village, a pottery consumption area along the coast. Both excavations suggest that initial occupation at these sites by the Bel-speaking groups occurred very recently in the last millennium before present (c. 550-650 cal BP), which is broadly in line with oral history and linguistic evidence. From the start, this occupation involved local red-slipped pottery production and distribution, the exchange of obsidian and sedimentary lithics, and the consumption of nearshore marine resources along with key domesticated animals. In-depth descriptions of these investigations and the archaeological material are presented here. [ABSTRACT FROM AUTHOR]

In the absence of eyewitness reports or clear sedimentary structures, it can be difficult to interpret tsunami deposits or reconstruct tsunami inundation patterns. The emplacement dynamics of two historical tsunami deposits were investigated at seven transects in Okains Bay, New Zealand, using a combined geospatial, geomagnetic and sedimentological approach. The tsunami deposits are present as layers of sand and silt intercalated between soils and become finer and thinner with distance inland. The deposits are attributed to the 1960 and possibly the 1868 tsunamis, based on radiometric dating and correlation with historical records. Measurements of Magnetic Fabric (MF: Anisotropy of Magnetic Susceptibility) and particle size were used to reconstruct the evolution of flow dynamics laterally and vertically. A combination of statistical methods, including spatial autocorrelation testing, Spearman's rank order correlation, Principal Component Analysis (PCA) and K-means cluster analysis, was applied to examine relationships between MF parameters and sediment texture, and infer depositional hydrodynamics. Flow patterns deduced from MF show the estuary channel acted as a conduit for inundation, with flow commonly aligned sub-perpendicular to the estuary bed. MF and sediment data suggest deposition occurred from settling during laminar flow. Evidence of both uprush and backwash deposition, as well as wave reflection from infrastructure, was found. Statistical analysis of data showed significant relationships between grain size parameters and MF parameters associated with flow speed and magnetic fabric type. PCA and cluster analysis differentiated samples into two primary hydrodynamic groups: (1) samples deposited from laminar flow; and (2) samples deposited close to the limit of inundation, which includes samples deposited further inland, those affected by flow convergence, and those in the upper part of tsunami deposits. This approach has potential as a tool for reconstructing hydrodynamic conditions for palaeotsunamis and by combining spatial and statistical analyses, large-scale investigations can be more easily performed. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Stilt structures in the inter-tidal zone or over shallow water on fringing reefs are widely accepted as a feature of settlements of the Lapita cultural complex in Near Oceania. Claims for similar structures in a pre-Lapita context at the Apalo site in the Arawe Islands, New Britain, Papua New Guinea, have been queried on several grounds. Re-evaluation of the Apalo evidence, together with 10 additional AMS radiocarbon dates, establishes human activity associated with some form of structure and possibly with a ground stone axe about 400–500 years before the Lapita pottery occupation. The paucity of occupational refuse suggests a non-residential structure perhaps associated with water transport. Comparisons with the older Dongan midden site in the Sepik-Ramu basin suggest stilt structures were probably used there as well. An apparent shift in depositional processes between the pre-Lapita and Lapita use of Apalo could reflect changed sea conditions arising from increased ENSO activity. [ABSTRACT FROM PUBLISHER]

Bog peat soils have been accumulating at Wellington Plain peatland, Victoria, Australia for the last 3300 years. Now, dried peat soils are common adjacent to bog peats. The 14C basal age of dried peat is not different from the 14C basal age of bog peat, which supports the theory that dried peat formed from bog peat. A novel application of 210Pb dating links the timing of this change with the introduction of livestock to Wellington Plain in the mid-1800s. Physical loss of material appears to have been the dominant process removing material as bog peats drained to form dried peats, as indicated by the mass balances of carbon and lead. This research has implications for the post-fire and post-grazing restoration of bogs in Victoria's Alpine National Park, and the contribution of peat soils to Australia's carbon emissions. [ABSTRACT FROM AUTHOR]