Stability in the South Pacific surface marine C reservoir over the last 750 years. Evidence from American Samoa, the southern Cook Islands and the Marquesas

Although minor climatic and sea-level changes have been documented for the South Pacific during the late Holocene, our understanding of the consequent impact of these changes on the marine ¹⁴C reservoir, and therefore the ¹⁴C content of shellfish, is limited. Ultimately, this has implications for documenting the chronology of human movement and adaptation in this region. In this paper we compare marine reservoir (ΔR) data obtained from tightly controlled archaeological proveniences with known-age, pre-AD 1950 shells from the southern Cook Islands, American Samoa, and Marquesas Islands. Results indicate that there has been no significant change in the near-shore marine reservoir in these three locations over the last ca. 750 years. Furthermore, known-age, pre-AD 1950 shell samples provide more precise ΔR values for use in sample calibration than archaeological paired shell/charcoal samples. This is attributed in part to the limitations of assigning provenance and age to material from archaeological sites. On the basis of these results we conclude that the known-age, pre-AD 1950 shell derived ΔR values can be used to calibrate shell ¹⁴C results from deposits of late Holocene age.     

Historical ecology of late Holocene sea otters (Enhydra lutris) from northern British Columbia: isotopic and zooarchaeological perspectives

We examined the isotopic composition (δ¹³C and δ¹⁵N) of sea otter (Enhydra lutris) bone collagen from ten late Holocene (ca. 5200 years BP–AD 1900) archaeological sites in northern British Columbia (BC), Canada. Because sea otters are now extinct from much of this region and have not fully recolonized their former range (e.g. Haida Gwaii and most of northern BC) these data represent an important first step towards better understanding sea otter foraging ecology in BC. The isotopic data suggest a diet composed primarily of benthic invertebrates, with a very low reliance on epibenthic fish. There is very low isotopic and thus inter-individual dietary variability in Holocene BC sea otters during the late Holocene. Furthermore, zooarchaeological abundance data suggest that otters represented a widespread and significant focus of aboriginal hunting practices on the northern BC coast during the mid- to late-Holocene. The consistent reliance on a small number of low-trophic level prey and limited dietary variability in Holocene BC sea otters may reflect top-down impacts on otter populations by aboriginal peoples. As part of our assessment of sea otter diet, we review trophic discrimination factors (Δ¹³C and Δ¹⁵N) for bone collagen from published literature and find marked variability, with mean values of +3.7 ± 1.6 for Δ¹³C (n = 21) and +3.6 ± 1.3 for Δ¹⁵N (n = 15).     

Diatom-inferred salinity changes in relation to Holocene sea-level fluctuations in estuarine environments of Argentina

Espinosa, M.A., Hassan, G.S. & Isla, F.I., September 2012. Diatom-inferred salinity changes in relation to Holocene sea-level fluctuations in estuarine environments of Argentina. Alcheringa 36, 377–391. ISSN 0311-5518.

The analysis of diatoms from three sedimentary sequences in the Quequén Grande River basin (Buenos Aires province, Argentina) has allowed the reconstruction of local and regional palaeosalinity changes in relation to Holocene sea level fluctuations. An established diatom-based salinity transfer function is used in combination with autecological methods to reveal a maximum sea level between ca 7000 and 6000 ¹⁴C years BP. This marine influence was recorded in deposits exposed 2 km and 12 km upstream, but not 32 km from the mouth. The fossil diatom assemblages are characteristic of an estuarine lagoon with maximum inferred salinities of 15‰. When the Holocene transgression began to flood the former valley (ca 7000 ¹⁴C years BP), brackish lagoons evolved into estuarine settings in the lower valley, but shallow freshwater ponds with salinities <4‰ persisted at 32 km from the mouth.     

Variability in the marine radiocarbon reservoir effect in Muscat (Sultanate of Oman) during the 4th millennium BC: reflection of taphonomy or environment?

Radiocarbon (¹⁴C) dating of archaeological coastal sites in arid areas is challenging because of the relative rarity of datable terrestrial artefacts. Marine artefacts provide an abundant source of carbon, which is technically easy to date but radiocarbon dates need to be corrected for local variations from the global average marine ¹⁴C reservoir age (ΔR). In archaeological sites, this is usually done by the comparison of the ¹⁴C age measured between coeval pairs of terrestrial and marine samples that have no inbuilt age. Here, we present the results of a study that aims to determine the local ¹⁴C marine reservoir effect (MRE) along the Eastern coast of the Arabic Peninsula during the 4th millennium BC, a period of important cultural, demographic and social changes in this region. Previous estimates of the MRE based on associated shells and charcoal vary by about 400 ¹⁴C yr and this is a serious limitation to the establishment of a precise chronology in the area based on marine material. In order to maximize the chances to obtain contemporaneous terrestrial–marine pairs for a new assessment of the MRE in this region we dated charcoal, shells, fish and turtle bones as well as human bones found in three recently and carefully excavated graves from Ra’s al-Hamra RH5. A large variability was found between charcoals (up to 240 ¹⁴C yr) and marine specimens (up to 785 ¹⁴C yr) present in the same grave. This variability was attributed to inbuilt ages, diagenesis and possibly environmental factors although taphonomic processes cannot be excluded. We discarded the oldest charcoals and used the ¹⁴C ages obtained on human apatite as a cut-off value to remove the marine outliers. Two out of the three graves provided terrestrial and marine assemblages which did not differ statistically and were used to calculate an average MRE of 645 ± 40 ¹⁴C yr (ΔR = 255 ± 55 ¹⁴C yr). This value is consistent with previous estimates based on the ¹⁴C dating of marine sediments off Pakistan and suggests stability of the MRE in the Arabian Sea since the 4^th millennium BC.     

Lapa das boleiras rockshelter: stratigraphy and formation processes at a paleoamerican site in Central Brazil

Lapa das Boleiras rockshelter, a Paleoamerican archaeological site in Central Brazil, was intensely occupied by humans from 10,000 ¹⁴C BP (11.8 cal kyr BP), until approximately 7500 ¹⁴C BP (8.4 cal kyr BP). In this paper we present some interpretations about the formation processes operating on the site. One of our main conclusions is that the bulk of accumulated sediments at the site is of anthropogenic origin: they are constituted by volumetrically significant quantities of plant ash remains, what is somewhat unexpectedly in view of prevailing models about the lifestyle of Paleoamerican hunter–gatherers in South America. The evidence we discuss below is also consistent with paleoenvironmental data that suggest a dry period during the mid-Holocene in the region, probably leading to a decrease in human occupation [Araujo, A.G.M., Neves, W., Piló, L.B., Atui, J.P., 2005. Holocene dryness and human occupation in Brazil during the ‘Archaic Gap’. Quaternary Research 64, 298–307]. We surmise that both factors underpin a surprising reduction in sediment accumulation at the site during the mid-Holocene.     

The antiquity of Olivella shell beads at CA-ORA-64: AMS radiocarbon dated between 9420 and 7780 cal BP

Investigations in the 1960s and 1970s showed the Irvine site (CA-ORA-64) to be among the oldest shell middens known from the Pacific Coast of North America. The site chronology, based on conventional analysis of mixed shell samples collected from heavily bioturbated soils, extended back to ca. 8440 RYBP. Recent work at the site provided an opportunity to refine the CA-ORA-64 chronology via AMS ¹⁴C dating of single shell fragments, including 14 Olivella beads. Long considered to be one of the earliest ornament types made by Pacific Coast peoples, such spire-removed Olivella beads were used through much of the Holocene and generally are not good chronological indicators. AMS analysis of the CA-ORA-64 specimens, however, produced a consistent series of Early Holocene dates that includes some of the oldest securely dated shell beads in North America. Along with obsidian from interior sources, Olivella beads played an important role in early exchange networks between coastal and interior peoples. Methodologically, our research demonstrates the utility of AMS ¹⁴C dating in determining the age of key artifact types found in multicomponent sites with assemblages affected by stratigraphic mixing.     

Geoarchaeology of Ancient Aulis (Boeotia,Central Greece): human occupation and Holocene landscape changes

This article presents the results of a coring operation which brought to light new evidence for the evolution of the coastal plain of Aulis (Boeotia, Central Greece) in the Holocene. Thanks to Homer, Aulis is best known as the gathering point of the Achaean fleet before it sailed to Troy and a sanctuary of the goddess Artemis. Ancient sources and archaeological evidence suggest the presence of an ancient marine bay, potentially used as a harbor. In the course of investigation, we drilled two cores, to a maximum depth of 4.20 m in the marshy lowlands and performed mollusc and micro-paleontological identifications, laser grain size analyses, and magnetic susceptibility measurements in order to reveal the facies evolution of the area. We obtained a chronostratigraphy sequence through a series of seven AMS ¹⁴C radiocarbon dates. Our study shows that the area was affected by a shallow marine incursion from the first half of the 6th millennium BC and gradually turned into a succession of shallow marine/lagoon environments from ca. 5000 cal. BC to the 2nd Century AD, and into a confined lagoon environment during the Roman and Byzantine periods.     

Spatial–temporal distribution and geographic context of Neolithic cultural sites in the Hanjiang River Basin,Southern Shaanxi,China

Understanding how to live successfully within our environment is among the most pressing challenges facing contemporary society. This paper probes the problem based on comparative analysis and discusses the relationship between the spatial–temporal distribution of the Neolithic cultural sites and the geographic context in the Hanjiang River Basin in the south of Shaanxi Province, China. Archaeological studies have identified 175 Neolithic cultural sites in the study area, with a sequence of Laoguantai (¹⁴C age 8–7 ka BP), Yangshao (¹⁴C age 7–5 ka BP) and the late period of the Neolithic Age (¹⁴C age 5–4 ka BP). The total number of archaeological sites, the distribution area and the density all showed an early ascending and later descending trend, but the proportion of the number of archaeological sites in the study area to the corresponding value of the entire Shaanxi Province declined sharply. Spatially, these sites were concentrated on the terraces of the Hanjiang River and its main tributaries with an altitude of 400–800 m. Multiple data were integrated to clarify the critical effects of tectonic and geomorphologic conditions on the distribution of the Neolithic sites. Further comparisons revealed the correlation of Holocene climate change and environmental evolution with the Neolithic cultural succession in the study area that ameliorated conditions to generally promote the development of the primitive culture while degeneration coincided with the culture's transition or interruption. The discussion on the origin of the primitive culture and the temporal–spatial distribution corresponding to the regional culture differentiation sheds light on the complex and dynamic human–nature interaction system during the Neolithic Age, thus emphasising the wider field-based investigation and high-resolution reconstruction works of the palaeoclimate and palaeoenvironment in the future.     

Composite hunting technologies from the Terminal Pleistocene and Early Holocene,Niah Cave,Borneo

Renewed archaeological investigation of the West Mouth of Niah Cave, Borneo has demonstrated that even within lowland equatorial environments depositional conditions do exist where organic remains of late glacial and early post-glacial age can be preserved. Excavations by the Niah Cave Research Project (NCP) (2000–2003) towards the rear of the archaeological reserve produced several bone points and worked stingray spines, which exhibit evidence of hafting mastic and fibrous binding still adhering to their shafts. The position of both gives strong indication of how these cartilaginous points were hafted and gives insight into their potential function. These artefacts were recovered from secure and ¹⁴C dated stratigraphic horizons. The results of this study have implications for our understanding the function of the Terminal Pleistocene and Early Holocene bone tools recovered from other regions of Island Southeast Asia. They demonstrate that by the end the Pleistocene rainforest foragers in Borneo were producing composite technologies that probably included fishing leisters and potentially the bow and arrow.     

Cultural and trade practices in Sincu Bara (Senegal): a multi-proxy investigation

The Sincu Bara site in Senegal is one of the most famous archeological sites in Western Africa. Here we present the results of a multi-proxy study that combined microscopic analyses, carbon content, stable carbon isotope (δ¹³C) and radiocarbon (¹⁴C) measurements. This investigation exhibits a chronological framework in two phases: from 400 yr AD to 650 yr AD and 650 yr AD to 900 yr AD. Furthermore, it shows that besides basic potteries, some potsherds are notable for a temper exclusively made with human-harvested C4 plants. Finally, the ¹⁴C analysis performed on the organic slip strongly indicates the use of bitumen or bitumen-derived products for red slip preparation. This suggests the establishment of trade relationships with Nigerian and/or Trans-Saharan populations as early as 400 yr AD.     

THE CHRONOSTRATIGRAPHY AND GEOARCHAEOLOGICAL SIGNIFICANCE OF AN ALLUVIAL GEOARCHIVE: COMPARATIVE OSL AND AMS 14C DATING FROM GREECE*

The Basin of Phlious in southern Greece is known for its thick colluvial and alluvial deposits from the Holocene. It offers a good opportunity to reconstruct the history of Holocene soil erosion and its interaction with historical farming activities. In this study, we present new results based on optically stimulated luminescence (OSL) dating from the Basin of Phlious. The comparison between OSL and ¹⁴C AMS ages shows good agreement, and demonstrates the need for the detection of insufficiently bleached OSL samples in order to obtain accurate results. The discovery of a Neolithic site, buried under thick alluvial deposits, confirms the hitherto postulated Neolithic human impact on the landscape.     

New radiocarbon dating of the transition from the Middle to the Upper Paleolithic in Kebara Cave,Israel

The Middle to Upper Paleolithic transition (MP-UP transition) is considered a major technological and cultural threshold, at the time when modern humans spread “out of Africa”, expanded from the Levant into Europe and possibly into central and northern Asia. The dating of this techno-cultural transition has proved to be extremely difficult because it occurred sometime before 40,000 radiocarbon years before present (¹⁴C years BP), which is close to the end of the effective dating range of radiocarbon. Other dating methods such as Thermoluminescence (TL) or Electron Spin Resonance (ESR) are not sufficiently precise to date the recorded archaeological MP-UP transition in the Levant. Here we report a consistent set of stratified radiocarbon ages on freshly excavated charcoal from Kebara Cave, Mt. Carmel (Israel), that span the late Middle Paleolithic (MP) and Early Upper Paleolithic (EUP) This study applied novel strategies to improve sample preparation techniques and data analysis to obtain high-resolution radiocarbon models. From this study it is proposed that the MP-UP transition for this site can be placed immediately after 45,200 ± 700 ¹⁴C years BP and before 43,600 ± 600 ¹⁴C years BP or from 49/48 to 47/46 radiocarbon calibrated years before present (years Cal BP).     

Isotopic values of diet of Blastocerus dichotomus (marsh deer) in Paraná Basin,South America

The marsh deer (Blastocerus dichotomus, Illiger, 1815) is the largest contemporary South American deer, and its habitat includes the floodplains and wetlands of eastern South America. Throughout the Holocene these deer were widely used by indigenous societies, from the southern banks of the Amazon River to the Río de la Plata River, and from the Andean foothills to the Atlantic Ocean. However, despite the enormous ecological and archaeological importance of this ungulate in the region, our knowledge of the isotopic values of their diet is almost nonexistent. This paper is the first systematic approach to the study of the isotopic values of this mammal's diet, using archaeological and present-day samples from interconnected watersheds of the Paraná and Uruguay rivers in east-central Argentina. The results obtained from 24 measurements indicate an average value of ?21.09 ± 1.46‰ in δ¹³C collagen, with a low coefficient of variation (6.92%). The data indicate a marked preference for consumption of plants with a C₃ photosynthetic pathway. Most of the observed variability in the isotopic values corresponds to the period 900–1430 ¹⁴C years BP, a time range during which the values show higher consumption of C₄ plants. This it could be related with a period where temperature and associated humidity increased, synchronous in the area with the Medieval Climate Anomaly.     

The Use of Hunting and Herding Spaces: Stable Isotope Analysis of Late Archaic and Early Formative Camelids in the Tulan Transect (Puna de Atacama,Chile)

We present the results of analysing stable carbon and nitrogen isotopes in camelid remains found at the Late Archaic site TU‐52 (ca. 5000–3800 bp ), the Tarajne Phase site TU‐94 and the Early Formative sites TU‐54, TU‐85 and TU‐122 (ca. 3100–2400 bp ). All of the sites are located in the Puna de Atacama (Northern Chile) along the 14 km Tulan transect, between the head of Tulan ravine (ca. 3000 m.a.s.l.) and the border of the Salar de Atacama (2317 m.a.s.l.). Our aim is to understand how the space was used by hunter‐gatherers and early herders from the beginning of camelid domestication to the consolidation of herding practices. Isotopic analyses were complemented with osteometric data in order to correlate changes in animal size and isotopic values with the initiation of animal husbandry. Isotopic and osteometric results show less variability of δ¹³C and δ¹⁵N values during the Late Archaic and Tarajne Phase, whereas variability is higher during the Early Formative. We postulate that during the latter period, there was more widespread use of hunting and herding spaces along the Tulan ravine, including areas above 3000 m.a.s.l. as result of more consolidated herding practices, while the highlands were used as a complementary space to hold livestock near ritual sites and residential settlements. Copyright © 2017 John Wiley & Sons, Ltd.     

Mitochondrial DNA haplotypes of Devensian hyaenas from Creswell Crags,England

Spotted hyaena (Crocuta crocuta) remains have been recovered from British Middle and Upper Pleistocene sites at intervals within the period 700–730 ka BP. Morphological studies have suggested that hyaenas of the Last Interglacial sensu stricto (Ipswichian: Marine Isotope Stage [MIS] 5e, 130–115 ka BP) and Last Glacial (Devensian: MIS 3, 61–24 ka BP) were two distinct populations, the Ipswichian hyaenas becoming extinct in Britain during MIS 5 and the Devensian ones arriving via a subsequent migration from continental Europe. However, the apparent presence of hyaenas in later MIS 5 deposits has led to the alternative suggestion that there was a southern relict population from which the Devensian hyaenas originated. We obtained ancient DNA (aDNA) sequences from four Devensian hyaena specimens from Creswell Crags, Derbyshire, dated to around 45 ka ¹⁴C BP. Each of these four specimens belonged to the mitochondrial DNA (mtDNA) clade A. This clade is not thought to have been present in Europe until ~360 ka BP, after the initial arrival of hyaenas in Britain. The DNA results, therefore, suggest that there were at least two waves of hyaena dispersals into Britain. The results are consistent with the repeated dispersals into Britain of another Pleistocene social carnivore, Homo sapiens.     

Radiocarbon dating and the “old shell” problem: direct dating of artifacts and cultural chronologies in coastal and other aquatic regions

Archaeologists have long recognized the problem of the “old wood” effect in radiocarbon dating charcoal and wood samples, the age of which may be hundreds of years older than their use by humans. Such problems have resulted in significant changes in how most researchers select wood and charcoal samples for ¹⁴C dating, with many now using relatively short-lived carbonized materials for dating. Despite the significant strides made in our understanding of the potential biases of the “old wood” effect, little emphasis has been placed on the possible impacts of dating “old shell” in archaeological deposits. The use of marine shell for ¹⁴C dating is widespread in coastal areas around the world, including a growing emphasis on the dating of individual shell artifacts via Accelerator Mass Spectrometry (AMS). In dating shell artifacts, we have obtained several dates older than associated ¹⁴C dates for short-lived subsistence remains from the same deposits, including great disparities (>10,000 years) and more subtle differences (≥100 years). These discrepancies appear to be due to the use of old shells by humans to make beads and other artifacts, including shells collected from fossil deposits, older archaeological sites, and beaches. The problems caused by the use of old shells to make beads and other artifacts are surmountable through careful sample selection, analysis of multiple ¹⁴C dates on a variety of materials, and proper calibration procedures.     

New age constraints for hominid footprints found on Jeju Island,South Korea

In 2004 numerous hominid footprints, along with diverse animal footprints, were found in the Late Quaternary strata of Jeju Island, South Korea. However, the age of the sediments in which the footprints were found is still controversial. Previous age estimates included radiocarbon ages of ca. 15,000 yr BP (Late Pleistocene) and quartz optically stimulated luminescence ages of ca. 7000 yr BP (mid-Holocene). In this study we report on 11 AMS ¹⁴C dating results from a new set of samples collected from the footprint-bearing strata and from associated sediments. Despite some variations and age reversal, all samples collected from the footprint-bearing strata yielded ¹⁴C ages of late Pleistocene. These ages are comparable with previous radiocarbon dating results. Furthermore, the presence of the proboscidean footprints attributable to woolly mammoths in the footprint-bearing strata supports the radiocarbon dating results. Based on the new radiocarbon dates and the presence of the alleged mammoth footprints, the age of the hominid footprints found at Jeju Island is thought to be late Pleistocene (about 19,000–25,000 cal yr BP). Therefore, this is the second discovery of hominid footprints dated to the Pleistocene age in Asia, and the first to be discovered in Korea.     

The effect of charring and burial on the biochemical composition of cereal grains: investigating the integrity of archaeological plant material

Stable isotope analysis of charred archaeobotanical cereal grains has the potential to provide direct evidence of crop growing conditions in the past and to refine palaeodietary predictions. If isotope values of archaeobotanical material are to be considered robust, it is necessary to characterise the compositional changes associated with their charring and burial. This study used a suite of analytical techniques, including FT-IR and solid state ¹³C NMR, to characterise changes in the biochemical composition of modern einkorn grains with heating at 230 °C for 2 h, 4 h, 8 h and 24 h, encompassing conditions that replicate their undistorted ancient counterparts. The biochemical composition of archaeobotanical charred einkorn grains was also investigated by FT-IR and solid state ¹³C NMR in order to assess the changes in composition which occur during burial. Results of FT-IR and solid-state ¹³C NMR show that heating of modern einkorn grains resulted in Maillard reactions between cereal proteins and starch, forming high molecular weight melanoidins, which contain both alkyl and aromatic carbon. Loss of low molecular weight carbon and nitrogen-containing volatiles resulted in a slight but non-systematic increase in the δ¹³C values and a systematic increase of 0.8‰ in the δ¹⁵N values of the charred einkorn grains. Solid-state ¹³C NMR shows that the ancient charred einkorn grains consisted entirely of aromatic carbon and retained a similar proportion of nitrogen to their modern 24 h charred counterparts, despite a significantly lower concentration of amino acids. This indicates that the amino acid nitrogen in the ancient charred grains was retained in the stable melanoidins whose polymeric structure makes them resistant to subsequent degradation.     

ESR and AMS-based 14C Dating of Mousterian Levels at Mujina Pećina,Dalmatia, Croatia

This paper presents the first chronometric dates for sediments that contain a Mousterian industry in Dalmatia (south Croatia). Electron spin resonance (ESR) dating was conducted on two teeth from the Mousterian level E1 at the site of Mujina Pećina. Additionally five bone and one charcoal sample from five different strata of origin at this site were dated by accelerator mass spectrometry (AMS). Assuming 30% moisture for both the gamma and beta dose rate calculations, the mean LU ESR age estimate is 44±5 ka for level E1, which is statistically indistinguishable from the mean EU ESR age estimate of 40±7 ka. A single, uncalibrated ¹⁴C age from the E1/E2 interface yielded an age estimate of 45,170 +2780/−2060 years bp while the mean of the five samples from overlying Mousterian levels is 39±3 ka. The true (calibrated) age of this mean is about 42 ka, which means that the entire stratigraphic profile in Mujina Pećina apparently was very rapidly deposited, and that the ESR age, regardless of uptake model is in good agreement with the calibrated ¹⁴C mean age. Temporally, Mujina Pećina overlaps with Pontinian Mousterian sites in west-central Italy and Vindija level G3 from northwestern Croatia. However, there are notable differences between the Mousterian industry from Mujina Pećina and these other sites. Collectively, the Croatian sites yield important evidence on the adaptation of European Mousterian people.     

Dating of modified femora of extinct dwarf Hippopotamus from Southern Madagascar: Implications for constraining human colonization and vertebrate extinction events

Two significant events in the late Holocene history of Madagascar were (a) the arrival of people, and (b) the loss of nearly two dozen species of land vertebrates in the socalled “subfossil extinctions”. The consensus is that the faunal losses occurred shortly subsequent to human arrival, but the timing of these events is poorly constrained. The minimum age for initial human presence on the island may now be set at approximately 2000 bp, on the basis of AMS ¹⁴C dates for human-modified femora of extinct dwarf hippos from SW Madagascar. Assuming that this date also marks the beginning of deleterious human interactions with the subfossil fauna, and assuming that this fauna became completely extinct by 900 bp, the width of the anthropogenic “extinction window” may have been as long as c. 1000 a. This estimate, nearly twice the length of previous ones, is close to the unadjusted minimum for the duration of the terminal Pleistocene extinction event in the Americas. Whether or not this length of time comports with theoretical expectations of a “blitzkrieg” pattern of losses is uncertain, but greater refinement in dating the end of the subfossil extinctions is unlikely to produce radically shorter estimates of duration.