Recent Lateral Expansion of Sphagnum Bogs Over Central Fen Areas of Boreal Aapa Mire Complexes

We investigated recent changes in spatial patterning of fen and bog zones in five boreal aapa mire complexes (mixed peatlands with patterned fen and bog parts) in a multiproxy study. Comparison of old (1940–1970s) and new aerial images revealed decrease of flarks (wet hollows) in patterned fens by 33–63% in middle boreal and 16–42% in northern boreal sites, as lawns of bog Sphagnum mosses expanded over fens. Peat core transects across transformed areas were used to verify the remote sensing inference with stratigraphic analyses of macrofossils, hyperspectral imaging, and age-depth profiles derived from 14C AMS dating and pine pollen density. The transect data revealed that the changes observed by remote sensing during past decades originated already from the end of the Little Ice Age (LIA) between 1700–1850 CE in bog zones and later in the flarks of fen zones. The average lateral expansion rate of bogs over fen zones was 0.77 m y−1 (range 0.19–1.66) as estimated by remote sensing, and 0.71 m y−1 (range 0.13–1.76) based on peat transects. The contemporary plant communities conformed to the macrofossil communities, and distinct vegetation zones were recognized as representing recently changed areas. The fen-bog transition increased the apparent carbon accumulation, but it can potentially threaten fen species and habitats. These observations indicate that rapid lateral bog expansion over aapa mires may be in progress, but more research is needed to reveal if ongoing fen-bog transitions are a commonplace phenomenon in northern mires.

Accuracy of the typological classifications of the Late Glacial and Early Holocene osseous projectile points according to the new AMS dates of selected artifacts from Poland

Late Glacial and Early Holocene bone and antler artifacts are recovered from all over the Polish Lowland. Elements of projectile weaponry, in the form of various points made of osseous raw materials, were an important part of hunter-gatherer equipment of that time. We present the results of AMS dating of a unique collection of thirteen artifacts that had previously been chrono-culturally attributed by means of relative dating using typological approaches only. The results obtained are considered alongside current knowledge and typological arrangements for these types of tools in Europe. We also attempt to determine the interpretative potential of the technological studies to which the discussed osseous points were subjected in terms of possibly identifying processing techniques that can be specific to the given periods of the Stone Age. Suggestions made in this respect are verified through the radiocarbon dating results.

An Improved Method for Extracting, Sorting, and AMS Dating of Pollen Concentrates From Lake Sediment

High-resolution chronologies are crucial for paleoenvironmental reconstructions, and are particularly challenging for lacustrine records of terrestrial paleoclimate. Accelerator Mass Spectrometry (AMS) radiocarbon measurement of terrestrial macrofossils is the most common technique for building age models for lake sediment cores, but relies on the presence of terrestrial macrofossils in sediments. In the absence of sufficient macrofossils, pollen concentrates represent a valuable source of dates for building high-resolution chronologies. However, pollen isolation and dating may present several challenges, as has been reported by different authors in previous work over the last few decades. Here we present an improved method for extracting, purifying and radiocarbon-dating pollen concentrates using flow cytometry to improve the extraction efficiency and the purity of the pollen concentrates. Overall, the nature of the sediments and the abundance of the pollen represent major considerations in obtaining enough pollen grains and, consequently, enough carbon to be dated. Further, the complete separation of pollen from other forms of organic matter is required to ensure the accuracy of the dates. We apply the method to surface samples and sediment cores recovered from two contrasting lake basins on the eastern side of the Sierra Nevada (California), and describe the variations that may be used to optimize pollen preparation from a variety of sediments.

From Ore to Metal:Exploitation of the Novotemirsky Mine, Southern Trans-Urals, in the Second Millennium BC

The Novotemirsky mine was the first in the Southeastern Urals to have large areas of the site uncovered. This has yielded new information on the technologies practiced by the first metallurgists in the region and on the evolution of these practices in the second millennium BC. Cultural layers revealed evidence of all stages of Bronze Age metal production. Mining is documented by pits of various forms and adjoining waste dumps. This is the first time that shaft mining has been discovered in the Bronze Age of the Southern Trans-Urals. Metal smelting is evidenced by a copper- smelting furnace with slag. Metal tools were cast in bivalve molds, of which one, made of chloritolite, was used for casting pickaxes. Results of radiocarbon AMS dating indicate three stages of mine exploitation in the Bronze Age, correlating with the chronological sequence of regional cultures. The furnace was built during the Sintashta period (2100–1900 BC). The shaft mine and the adjacent dumps date to the Alakul period (1700–1500 BC). Features dating to the Final Bronze Age (1500–1200 BC) have yet to be identified. It has been demonstrated that the same mines were exploited by people associated with various archaeological cultures in the second millennium BC, implying that a metallurgical center functioned in the Trans-Urals over the entire Late Bronze Age. Given that indicators of metallurgy are quite rare at unfortified sites, and that the technology changed, it can be assumed that smelting and casting became more specialized during the Alakul period: certain operations were performed at mines and/or nearby settlements.

TREE-RING-RADIOCARBON DATING AT A LATE CONTACT PERIOD KITKAHAHKI PAWNEE SITE ON THE CENTRAL GREAT PLAINS, USA

ABSTRACT This study obtained calendar dates by radiocarbon accelerator mass spectrometry (14C AMS) dating sequential tree-rings of wooden support posts from the buried remains of traditional Kitkahahki Pawnee earthlodges preserved at an archaeological site on the Central Great Plains, USA. The tree-ring segments from the site were dendrochronologically analyzed prior to this study, but the cross-matched site chronology could not be definitively cross-dated and was thus “floating” in time. Our study represents the first floating tree-ring chronology from the Great Plains to be anchored in time by means of independent radiocarbon analysis. Three specimens were analyzed and dated to 1724–1774 CE (82.0% probability), 1774–1794 CE (95.4% probability), and 1800–1820 CE (95.4% probability). These dates correspond to the hypothetical timing of Kitkahahki ethnogensis, the main phase of village growth in the area, and a later reoccupation during a turbulent period in regional history. The results of this study conform to a scenario in which chaotic social conditions correspond to an increase in residential mobility between the core of Pawnee territory and a southern frontier in the Republican River valley.

CULTURE, PERIOD OR STYLE? RECONSIDERATION OF EARLY AND MIDDLE COPPER AGE CHRONOLOGY OF THE GREAT HUNGARIAN PLAIN

ABSTRACT The main goal of our research project was to date the Early and Middle Copper Age (4500/4450–3800 cal BC) of the Great Hungarian Plain more precisely. In our project, we took samples for accelerator mass spectrometry (AMS) dating from both settlement features and burials, and the data were analyzed using Bayesian modeling. We examined the Early and Middle Copper Age finds of the Great Hungarian Plain on several levels (site, microregional, and regional levels) using a bottom-up approach. The AMS measurements were supplemented by statistics-based pottery analysis in order to make our understanding of the relationship between the Tiszapolgár and Bodrogkeresztúr cultures more detailed. As a result, we can see a significant, 130 (68.2%) 230 years overlap between the two types of find assemblages, which contradicts to the earlier accepted chronological sequences created by the traditional culture-historical approach. According to the stylistic analyzes, the two ceramic styles are not clearly distinguishable.

Obsidian from the Site of Piano dei Cardoni, Ustica (Palermo, Italy): Preliminary Results on the First Occupation of the Island

New investigations on Ustica (Palermo, Sicily) originated from the need to improve our knowledge of the island’s archaeological and environmental heritage. Through field surveys, particular attention was paid to human occupation in the Neolithic phases and focused on the less investigated southern side of the island. The systematic survey of the area of Piano dei Cardoni in 2018 brought to light a new Middle/Late Neolithic site, already partially documented in the literature. The island was settled for the first time during these phases, as also testified from the area of Punta Spalmatore. The presence of Serra d’Alto, incised dark burnished, and Diana styles suggests that the site and the archaeological assemblage dates from the mid to late 5th millennium BC, as confirmed by AMS dating. In addition to pottery, obsidian artifacts were also recovered, and a preliminary study of these materials is presented here. Portable XRF analyses on a sample of 41 obsidian artifacts, representing a high percentage of the lithic assemblage compared to chert tools, show that the provenance of the raw material is Gabellotto Gorge (Lipari) and Balata dei Turchi (Pantelleria). These results provide new insight into broader regional debates about obsidian technology and its exchange during the Neolithic and open an important consideration for sites that are far from the raw material sources.

NEW RESULTS OF DIRECT RADIOCARBON AMS DATING OF THE POTTERY FROM THE BUH-DNISTER SUB-NEOLITHIC СULTURE

Traditional ideas about the origin of the Buh-Dnister Culture (BDC) and its synchronisation with the Neolithic cultures of the Danube-Carpathian region were questioned by series of radiocarbon dates measured on bones at the Kyiv laboratory in the 1998—2004. To start addressing this problem, 11 AMS dates on organic inclusions in the ceramic paste and charred residues on the surface of vessels were obtained at the Tokyo University laboratory. The set of new dates has given a wide scatter of their values within the entire period outlined by the previous BDC dates. Moreover, the two results of the second quarter of the 7th millennium BC for the Hlynske 1 and Bazkiv Ostriv site are beyond it and may potentially be the oldest dates of the culture. However, analysis of the samples in terms of carbon content, their susceptibility to the influence of the freshwater reservoir effect, correspondence to the stratigraphy of the sites and typology of materials detected only six more credible dates. Their order on the timeline coincides with generally accepted ideas about the sequence of existence of the different BDC pottery types. The youngest is the vessel of the Savran type from Shumyliv-Cherniatka has yielded two dates falling into the range of 4723—4491 cal BC, when the Trypillia culture bearers already populat the region. Two vessels of the Samchyntsi type from Bazkiv Ostriv yield three dates within the range of 5288—4847 cal BC, which corresponds to their finding next to fragments of fine «music-note» bowls of the Linear Band Pottery Culture. The Skybyntsi type vessel from Bazkiv Ostriv yield the oldest plausible date of 5621—5514 cal BC, which corresponds to the age of the Criş monuments in Moldova. Unfortunately, the new dates did not shed light on the issues of the time and direction of the first pottery spreading in the region. Thus, this needs further research including reliably direct radiocarbon dating on pottery.

ERRONEOUSLY OLD RADIOCARBON AGES FROM TERRESTRIAL POLLEN CONCENTRATES IN YELLOWSTONE LAKE, WYOMING, USA

ABSTRACT Accelerator mass spectrometry (AMS) dating of pollen concentrates is often used in lake sediment records where large, terrestrial plant remains are unavailable. Ages produced from chemically concentrated pollen as well as manually picked Pinaceae grains in Yellowstone Lake (Wyoming) sediments were consistently 1700–4300 cal years older than ages established by terrestrial plant remains, tephrochronology, and the age of the sediment-water interface. Previous studies have successfully utilized the same laboratory space and methods, suggesting the source of old-carbon contamination is specific to these samples. Manually picking pollen grains precludes admixture of non-pollen materials. Furthermore, no clear source of old pollen grains occurs on the deglaciated landscape, making reworking of old pollen grains unlikely. High volumes of CO2 are degassed in the Yellowstone Caldera, potentially introducing old carbon to pollen. While uptake of old CO2 through photosynthesis is minor (F14C approximately 0.99), old-carbon contamination may still take place in the water column or in surficial lake sediments. It remains unclear, however, what mechanism allows for the erroneous ages of highly refractory pollen grains while terrestrial plant remains were unaffected. In the absence of a satisfactory explanation for erroneously old radiocarbon ages from pollen concentrates, we propose steps for further study.

RADIOCARBON DATING APPLIED TO PREHISPANIC TERRITORIAL DYNAMICS AT EL MAYE, IXMIQUILPAN, HIDALGO, MEXICO

ABSTRACTEl Maye is a community located in the municipality of Ixmiquilpan, Hidalgo, in the central region of Mexico. During the late Postclassic period (1350–1521 AD), the Aztecs controlled the area through the establishment of a dual-headed system, one part belonging to the Aztec government and the other to the local government. El Maye was the local government center for the Ixmiquilpan territory under the Aztec domain. The residential units of El Maye archaeological site were constructed in 6 different occupational phases, with the presence of large rooms, stucco floors and walls, offerings, and a variety of ceramics belonging to the late Aztec III ceramic period (1400–1520 AD). The Axis Project of the Mezquital Valley (PEVM-ENAH) and the Accelerator Mass Spectrometry Laboratory (LEMA-UNAM) have undertaken a collaborative study of the El Maye site by performing absolute radiocarbon accelerator mass spectrometry (14C AMS) dating. For a better understanding of the emergence and development of El Maye, a series of AMS 14C dates of charcoal and bone samples recovered from different stratigraphic levels, was performed. This allowed us to locate the occupation of the site between 1320 and 1625 cal AD.