Rock Shelter Research Articles

Radiocarbon dating and isotopic palaeoecology ofGlossotherium phoenesisfrom the Late Pleistocene of the Santa Elina rock shelter, Central Brazil

AbstractThe Santa Elina rock shelter (Central Brazil) stands out with two human occupation layers with ground sloth fossil remains from the Late Pleistocene. Here, we explore the palaeontological aspect of this site. We update the taxonomic assignment of the ground sloth found in the shelter toGlossotherium phoenesis. Radiocarbon dating performed on bioapatite (14Cbioapatite) from two tooth specimens reveal the minimum ages of 14 944–15 239 cal abp(unit II2) and 22 339–22 534 cal abp(unit III4), which were converted to collagen using a novel approach and presented the calibrated ages of 17 450–17 906 cal abp(14Ccollagen= 14 547 ± 40) and 25 994–26 396 cal abp(14Ccollagen= 22 042 ± 40). We reinforce the chronology of the oldest unit of Santa Elina with material culture in association with megafauna bones to the Last Glacial Maximum. Carbon isotopic signatures suggest a mixed feeding diet for both specimens. The most recent ground sloth presents a higher isotopic value (δ13C = −1.8‰) and narrower niche breadth (BA= 0.50) than the oldest one (δ13C = −3.3‰;BA= 0.74). We conclude thatG. phoenesislived in an arboreal savanna habitat during the phases studied. Slightly different oxygen isotopic values (δ18O = 26.2‰ and 27.9‰) might suggest a decrease in humidity over time. Our results provide insights into the palaeoecology of the tropical PleistoceneG. phoenesisand the palaeoenvironmental setting of Santa Elina when occupied by early humans and megafauna during the Late Pleistocene.

Late Holocene Size Variation of Mytilus californianus Remains from Shelter Cove (CA-HUM-182), Northern California

ABSTRACT Here we evaluate variation in Mytilus californianus size from CA-HUM-182, comparing patterns with those from Punta Gorda Rock Shelter that suggested sustainable resource management. Using a novel equation, we reconstruct the size profile of the assemblage over time and provide a new age-depth chronology. Results indicate no decrease in size over time; instead, increases are observed from initial harvest (∼730 cal BP) to site abandonment (∼260 cal BP), suggestive of sustainable practices and the possibility of conservation.

New evidence of early Holocene naturalistic rock art in Jinsha River valley, southwestern China

More than 70 rock painting sites have been discovered in the Jinsha River valley in northwestern Yunnan Province of southwestern China. These sites are dominated by naturalistic animal paintings and display certain similarities with the oldest hunting–gathering rock art discovered across the world. The Baiyunwan rock shelter is representative of the corpus of the Jinsha rock-art sites, comprising 15 identifiable naturalistic animal paintings in addition to several unidentifiable paintings. However, to date, the age estimation of these precious rock paintings lacks precision. Thus, this study performed U-series dating of carbonate samples (in total, 32 subsamples) to constrain the minimum and maximum ages of the Baiyunwan rock paintings. The U-series ages were corrected with a site-specific value of the initial 230Th/232Th ratio determined by isochron analyses, and the age reliability was evaluated by stratified dating analyses. Moreover, we used Bayesian age modeling to combine the individual age estimates and considered previously published data. The age range of the Baiyunwan rock paintings was determined as 7.09–8.93 ka, with a probability of 95 %. This age estimate corresponds to the late painting phase documented at Wanrendong Cave (∼8.37–8.70 ka), located within the same region, and provides new evidence for early Holocene naturalistic rock paintings in the Jinsha River valley, Yunnan, southwestern China.

The Middle Stone Age Sequence at Klipfonteinrand 1 (KFR1), Western Cape, South Africa

The rock shelter site Klipfonteinrand 1 (KFR1), located on the edge of southern Africa’s Fynbos biome, was initially excavated by John Parkington in 1969. Due to difficulties resolving the stratigraphic sequence, the lack of age estimates, and generally poor organic preservation, the Middle Stone Age (MSA) components of the site have received limited attention. In this paper we report on the re-excavation, dating, palaeoecology, and cultural sequence recovered from a trench placed adjacent to Parkington’s original excavation. The refined sequence includes three stratigraphically distinct MSA components: a Howiesons Poort component dating to ~69 ka, and two earlier MSA components dating to ~85 ka and ~156 ka. These are overlain by two younger components dated to the late Pleistocene and early Holocene. Bedrock morphology at the site is complex, and the oldest component appears to be restricted to a small area of relatively deep (1.9 m) sediment accumulation towards the centre of the sheltered area. Phytoliths suggest limited change in floral communities near the site across the lowest three units—which include parts of marine isotope stages (MIS) 6, 5, and 4—reflecting the characteristic stability of the Fynbos biome. The stone artefacts in the oldest MSA component include large blades that are absent from the overlying strata, and that may be a distinct element of late MIS 6 technology in the area. Interestingly, neither the early MSA nor early Holocene components we describe here were encountered in the rear trench at the site, 3 m away, which instead produced a sequence dominated by marine isotope stage 2 occupation. KFR1 presents new insights into the archaeology of the earlier MSA in southern Africa, while also providing a cautionary note on the discontinuous and spatially variable nature of rock shelter occupation in the region.

Archaeological obsidians of the Zoque region of Tabasco, Mexico: Chronological sequence of procurement

This research examines obsidian artifacts of the Zoque culture, which spanned from the Preclassic-Protoclassic (1200 BCE-200 CE) to Late-Terminal-Classic Periods (600–900 CE) and Late-Postclassic Period (1200–1521 CE). Artifacts collected from three archaeological sites, including a rock shelter and two larger habitation sites with evidence of ritual and ceremonial architecture were analyzed in order to investigate potential interactions between Zoque people and other cultural groups. Analysis using Instrumental Neutron Activation revealed a wide range of geochemical sources, such as El Chayal, San Martin Jilotepeque, Guadalupe Victoria, Pico de Orizaba, Sierra de Pachuca, Ucareo, and Zaragoza. The diversity of sources suggests that the Zoque people procured raw materials from various locations and traded over long distances throughout different historical and cultural periods. This suggests that the Zoque people not only had strong connections within their local and regional environment but also had a broad commercial and cultural sphere.

First Data from the Prehistoric Site Complex of Cueva del Arco (Murcia, Spain)

The southern Iberian Peninsula is a key area for understanding the timing and patterns of the Middle-to-Upper Palaeolithic transition. Recently, the excavation and study of new sites have provided new insights on this topic. The aim of this paper is to introduce Cueva del Arco, a site complex featuring distinct caves and rock shelters. Cueva del Arco is located at a short distance from the Almadenes gorge (Cieza, Spain) and preserves both Middle and Upper Palaeolithic deposits and assemblages, as well as rock art. Despite being known since the 1990s for its Palaeolithic rock art, systematic fieldwork was never undertaken at the site until recently. We here report the first results of a research programme that includes the systematic excavation of several cavities belonging to the Cueva del Arco complex, focusing on the location and context of the site, its stratigraphy and chronology, and site formation. Research at the site is still ongoing, but preliminary results suggest that the data from Cueva del Arco will provide new clues to the current debate on the transition from Neanderthals to anatomically modern humans in southern Europe.

Raw Material Surveys and Their Behavioral Implications in Highland Lesotho

Archaeologists have long considered climate change a primary mechanism behind human behavioral adaptations. The Lesotho highlands’ Afromontane and climatically extreme environments offer a unique opportunity to examine proposed correlations between topography, climate, and human behavior. Previous studies suggest that warmer temperatures allowed humans to expand their diet breadth and foraging range, whereas colder temperatures restricted humans to resources in riverine corridors. These studies used faunal and floral change as proxies to track changes in forager mobility but did not consider how differential access to stone resources affected human behaviors. To account for this gap, we conducted a survey for knappable rocks around the Sehonghong rock shelter in eastern Lesotho, recording the materials present and their size and shape in the modern environment. We compared the survey results to later Pleistocene (~ 22–11 ka cal. BP) lithic assemblages at Sehonghong to better understand whether archaeological patterns match modern knappable rock availability. Contrary to previous hypotheses, we find that past peoples at Sehonghong were not limited to exclusively riverine resources during colder conditions. We then used flake-to-core and noncortical-to-cortical flake ratios to track changes in mobility and knappable rock procurement patterns. The ratios remain constant up until the Late Glacial, ca. 14 ka cal. BP, when we see an increase in both flake-to-core and noncortical-to-cortical ratios, suggesting increased movement of stone out of Sehonghong. These conclusions show that resource procurement and mobility patterns are not solely dependent on climate change but may be driven by more complicated causal mechanisms such as increased interaction and the formation of social networks across the Lesotho highlands and beyond.

Seasonality and mobility of Epipaleolithic groups in the north-east of the Iberian Peninsula: tooth wear analysis of ungulates from Balma del Gai

The aim of this work is to provide evidence about the mobility of hunter-gatherer groups from the north-east of the Iberian Peninsula during the Epipaleolithic, more specifically, those from the Balma del Gai site (Moià, Barcelona, Spain). To do so, a study of the dental meso- and microwear of ungulates hunted by the groups that occupied the Balma del Gai site during the Epipaleolithic was carried out with two main objectives. First, we aimed to determine the diet of the hunted ungulates to reconstruct the habitat in which they lived in the areas near the site through the comparison of the dental microwear patterns with those of extant populations of directly related taxa that inhabited different regions. Second, we aimed to study the variability in the diet of the hunted ungulates to determine the durations of the occupations, and therefore, to characterize the mobility model (forager vs. collector) of the hunter-gatherer groups at Balma del Gai during the Epipaleolithic. The results indicate that the rock shelter was occupied on a seasonal basis. The browsing dietary traits of the red deer at the time of death combined with archaeological evidence suggest that the occupation took place during late summer and especially autumn. This points to a forager mobility pattern for the hunter-gatherer groups of Balma del Gai that could have been present throughout other contemporary human groups of the Mediterranean coast and pre-coastal area.

Last Interglacial–Glacial sequence of palaeosols and calcareous slope deposits at Verteuil (Charente, southwest France)

ABSTRACTThe 12 m thick sequence of calcareous slope deposits and palaeosols exposed in a quarry at Verteuil (southwest France) has been studied and dated by optically stimulated luminescence. Emphasis was given to the identification and characterisation of palaeosols through geochemistry and micromorphology. The main clastic units, separated by major unconformities, were dated to MIS 6, MIS 5–4 and MIS 3–2. Stratified deposits (‘grèzes litées’), consisting of alternating diamictic and matrix‐free clastic beds and attributed to stacked stone‐banked solifluction lobes, developed mainly after ca. 40 ka, i.e. during late MIS 3 and MIS 2. MIS 3 is recorded as a palaeosol complex including two humic A horizons overlying a chromic cambisol associated with burrows of ground squirrels, while MIS 5 corresponds to a reworked rubified chromic cambisol. Overall, this sequence shows similarities with the clastic deposits found in regional cave porches and rock shelters, strongly suggesting that anthropogenic activities did not significantly modify the climate‐driven sedimentary and soil‐forming processes at the Palaeolithic sites.

Does size matter? Bat diversity and the use of rock shelters in Brazil

A positive correlation between cave size and bat diversity has been recorded by some authors for different cave areas in South America. We analyzed published and otherwise available data from three Brazilian karst areas and phytogeography domains, including NE and SE Atlantic Forest and Cerrado (savannah-like vegetation), encompassing a wide range of cave sizes. We found no such correlation, as expected in view of previous observations by researchers and speleologists. We discuss the ecological implications of different ways to measure bat diversity, i.e. the accumulative number of species (sequential use of caves) vs. the number of species at a given occasion (species in actual cohabitation) vs. bat abundance (numbers of individuals), as well as speleological topics related to the concept of caves (based on an anthropomorphic definition, not applicable to other species), the problems of estimating topographic variables such as cave area and volume, and the value of including cave temperatures in the analyses. Multiple interacting variables may influence the composition of cave bat communities and bat species richness and abundance. The most important ones would be the density of caves in a given area (related to lithology – calcareous vs. siliciclastic caves), regional climates, and degree of preservation of epigean habitat. Cave morphology, number and size of entrances, and presence of water bodies, as well as interactions with other species, must also be considered. In conclusion, as a general statement for tropical and subtropical bats, cave size (in the human sense) by itself does not matter, except perhaps for one-off situations. Finally, a brief overview of the diversity of cave bats in Brazil is presented.

In the land of the apu: Cerro Llamocca as a sacred mountain and central place in the pre-Columbian Andes of southern Peru

Cerro Llamocca is a mountain with a summit elevation of 4,487 m asl in the southern Peruvian Andes. This paper presents a first overview of recent archaeological and paleoenvironmental research in its vicinity, and introduces new results from archaeological surveys and strontium isotope analyses. Our survey data show how the wider Cerro Llamocca area comprises an extensive complex of archaeological sites, composed of different sectors with public, domestic, and funerary architecture and rock shelters, occupied throughout the pre-Columbian period from the Early Archaic to the European invasion in 1532. Despite the extreme living conditions of this high-elevation environment, Cerro Llamocca includes the oldest archaeological site hitherto recorded in the larger region: a rock shelter (PAP-969) on its south-eastern slope with evidence of human occupation in the Early Archaic period ∼ 8000 BCE. Human activity in the Cerro Llamocca area reached its zenith in the Middle Horizon (CE 600–1000), at a time of a dry climate and when an expansive Wari state incorporated the worship of mountain deities into an imperial strategy to dominate local people. Our strontium isotope analyses of archaeological human dental enamel from a funerary rock shelter (PAP-942), alongside modern plants as reference data, indicate that the people buried here originated in the adjacent highlands. At a broader level, we study the roles of Cerro Llamocca as a sacred mountain or apu and central place over a long-term perspective, and how these functions integrated and focused religious, ritual, social, political, and economic activities over this high-altitude complex. Its central place function was linked to its sacredness, but also to its topography, provision of shelter, and geographical proximity to a range of critical resources such as water, creating resource dependencies that shaped socio-economic cooperation and exploitation. Although Cerro Llamocca has progressively lost many of these roles since the beginning of the colonial period, local communities continue to revere it as a sacred mountain today.

Multi-Analytical Techniques to Define the Mineralogical and Petrophysical Characteristics and Provenance of Siliceous Lithic Findings: The Case Study of La Calvera Rock Shelter (Cantabria, Spain)

This archaeometric study aims at characterizing the archaeological finds belonging to the lithic industry from La Calvera rock shelter (Camaleño, Cantabria) and at hypothesizing the possible provenance of each material. The site, located in the mountainous area of Picos de Europa National Park (more than 1000 m a.s.l.) close to the megalithic complex of Peña Oviedo, is characterized by the presence of hearths and charcoal remains, ancient pottery, and a rich lithic assemblage composed of siliceous rocks dating back to >8000 BP and linked to the first Holocene occupations of the Cantabrian Mountains. For the study of the rock shelter’s lithic assemblage, a multi-analytical approach was used: SEM-EDS and XRD analyses were performed to define the microtextural characteristics of samples and to identify the amorphous/crystalline phases; physical and mechanical tests were conducted to define the petrophysical properties (density, porosity, imbibition and saturation indexes, mechanical strength) of the samples. Preliminary data of chemical compositions, obtained by portable XRF, are also presented. The results show that the different siliceous materials (quartzite, cherts, hyaline quartz) can be distinguished through the basic analytical techniques used here. In addition, most of the archaeological samples have mineralogical and petrographic features similar to the natural samples coming from nearby outcrops, corroborating the hypothesis of a local material supply. The presence of local sources of useful raw materials could have favoured the site’s occupation. Finally, the diverse compositional and textural feature of the analysed materials result in different mechanical properties (porosity, density, hardness, workability), so they likely had different uses and technical functions.

Another non-anthropic leporid accumulation in Southwestern Iberia? The case of a leporid sample from Morgado superior (Tomar, Portugal)

ABSTRACT The Morgado Superior Rock Shelter is located near the city of Tomar, in Central Portugal. This site presents important funerary contexts that according to published information encompass the Neolithic, Chalcolithic and Bronze Age. Other non-funerary uses have not yet been characterised but were briefly suggested. A faunal sample of the 1988 and 2012 interventions is analysed from a zooarchaeological and taphonomical perspective, focusing on the leporid remains that largely dominate the assemblage. Clear indicators of a human origin are absent, while a configurational approach allows the description of exogenous and intrusive origins. The characteristics of the registered consumption taphonomical indicators are suggestive of scat and non-ingested accumulation by foxes. Furthermore, this study allows us to discuss some aspects of the formation of the stratigraphy of this important cave necropolis, while also serving as an example of the expected results of foxes’ action on leporid remains in an archaeological site.

Defining iron-bearing rock sources in compositional data statistical analysis for provenance studies: A case study from South Africa

In iron-bearing rock provenance researches the definition of what is a source vary from an author to another. Issues might occur when the sources are associated with complex weathering profiles. How may the definition of the source influence the results of provenance studies when different types of iron-bearing rocks are encountered within the same weathering profile? In order to deal with this research question, we used a geochemical dataset previously obtained from the study of the ochre geological collection collected around Diepkloof rock shelter, South Africa. We tested the efficiency of Linear Discriminant Analyses (LDA, supervised analysis) and Principal Component Analysis (PCA, non-supervised analysis) in source discrimination and in the attribution of archaeological pieces to the right source. Different assumptions were made: sources were defined by separating or grouping the different lithologies (shale and ferricrete) encountered at the same location. The results show that grouping the different lithologies allows a good attribution of the archaeological pieces to the source it comes from when elements positively correlated with iron are used in the analysis. Separating the different lithologies do not allow a rate of success in archaeological pieces attribution as high as when the lithologies are grouped together. This result might be explained by a highest number of samples that define a source when the different lithologies are grouped together. Further research should be considered in this direction in order to define if this is a general trend.

Portable X-ray Fluorescence Analysis of Levantine and Schematic Art Pigments from the River Vero Shelters (Huesca, NE Spain)

The River Vero canyon (Huesca, Spain) contains an exceptional archaeological legacy with more than sixty rock shelters with cave paintings and forms part of the World Heritage ‘Rock Art of the Mediterranean Basin on the Iberian Peninsula’. This study presents the results of the in situ and non-destructive multi-elemental composition analysis of the pigments used in eight of the main shelters through portable X-ray fluorescence spectroscopy (pXRF). Specifically, the cave paintings of the rock shelters of Chimiachas, Muriecho, and Arpán (Levantine Art); and Mallata, Barfaluy, Quizans, Lecina Superior, and Forau del Cocho (Schematic Art) were investigated. The red pigments, based on iron minerals, were the most abundant in all the River Vero rock shelters, with Fe contents in the 0.51–3.06% range. The iron contents of the paintings of Mallata B1 and I, Muriecho, and Forau del Cocho were higher than those of Arpán, Barfaluy, Lecina, and Chimiachas rock-shelters; and, in turn, these were higher than those of Quizans, pointing to noticeable differences in the degree of conservation. Black pigments, in the absence of manganese, were associated with bone char or carbon black. Through the phosphorus content, evidence is provided of the use of bone phosphates as a component of the paints, either as a filler or as a binder. Geological studies indicate that the detected gypsum is of external origin, probably associated with gypsum-rich atmospheric dust. The reported pXRF analysis of this large set of paintings may serve as a basis for future characterization studies involving other portable chemical analysis techniques.

New data on chert catchment analysis in inland Iberia during the Late Pleistocene

AbstractIn this paper, we present the first results obtained after new fieldwork and laboratory studies of chert catchment sources during the Middle and Upper Palaeolithic in inland Iberia, a region that has been traditionally depicted as marginal and sparsely populated during the last glacial due to its harsh ecological conditions compared to the coastal areas of the Iberian Peninsula. Our main aim is to determine the mobility strategies and social networks of the last Neandertals and first modern humans settled in inland Iberia and neighbouring regions, and eventually test the hypothesis that the last glacial human settlement in the Iberian hinterland was more dense and complex than previously thought. In this study, we focus on the cherts exploited at two archaeological sites: the Peña Cabra and Peña Capón rock shelters. These sites are located in the southeastern foothills of the Central System range, in the province of Guadalajara (Spain), and they have yielded a sequence of human occupations from the Middle and Upper Palaeolithic, respectively. To obtain a detailed picture of the mobility patterns and catchment strategies of the hunter‐gatherers settled at these sites, our fieldwork focussed on identifying chert outcrops that could have been frequented and exploited by them. After two field seasons, 22 chert outcrops from eight geological formations were identified and more than 300 samples were collected and analysed. We conducted textural, micropalaeontological, petrographical and geochemical analyses, with the aim of comprehensively characterising the various rock resources available in the study area. Results have shown that different siliceous varieties were available in the area surrounding the sites and both Neandertals and modern humans could have provisioned there. Also, they suggest the potential existence of a network connecting the Tagus and Ebro valleys, but this is a working hypothesis to be tested with future research.

The foodplant fitness landscape of Hollow Rock Shelter, Western Cape, South Africa

Studying Stone Age foraging behaviours in terms of plant foods is difficult because of preservation, sampling and identification biases. Current foodplant populations, knowledge about their use in recent times, and how they are distributed across the landscape, provide valuable middle-range proxies from which work on archaeological landscapes and material can benefit. With this contribution we provide foodplant lists for three different foraging ranges (radii of ∼ 12.5 km, ∼35 km, and ∼ 70 km) around Hollow Rock Shelter. By comparing data for each of the foraging ranges directly, we discuss proportional increases in foodplant resources when moving further away from the site. We demonstrate that the ∼ 35 km foraging range is the most efficient. This implies that people staying at the site (for shorter or longer periods) may have regularly employed a strategy of temporary camping for a night or two away from the site to forage especially preservable foods that could be brought to the site. Our data highlight potential plant-food staples, and show that under-surface storage organs (USOs) of plants, followed by fruit and leaves are the most abundant edible plant parts available on the Hollow Rock Shelter landscape within all three of the foraging ranges, and that most of these could be eaten raw.

The Diepkloof Rock Shelter foodplant fitness landscape, Western Cape, South Africa

ABSTRACT This paper reports on, and supplies the checklists for, the known foodplant population currently growing around Diepkloof Rock Shelter, South Africa, within radii of ∼12.5 km, ∼35 km and ∼70 km. It demonstrates that many of the species identified from the shelter’s Middle Stone Age charcoal record still grow on the landscape today and that 33 of the ancient charcoal-identified species are historically known as foodplants in southern Africa. With this contribution the current foodplant species that could serve as dietary resources are extended to 81 within a day’s return trip (∼12.5 km) from the site, 158 within the ∼35 km radius and 170 on the greater foraging landscape extending up to ∼ 70 km from Diepkloof. Data are presented that indicate the proportional increases in plant growth forms and edible plant parts by extending foraging ranges. Initial interpretation of the data shows that foragers may have had adequate access to herbs and shrubs from which leafy vegetables and fruits can be collected, as well as hydrophytes (such as waterblommetjies) within a day’s return trip. To increase especially access to energy-rich corms and roots, they may have used additional/other camp sites or home bases to exploit their ∼35 km foraging range. By travelling over longer distances, access to grass grains that also serve as famine foods can be exponentially increased.

A cranial injury from the earliest Gravettian at the Cro-Magnon rock shelter (Vézère Valley, Dordogne, southwest France).

Discovered over 150 years ago, the early Upper Paleolithic human remains from the Cro-Magnon rock shelter have an iconic status, but because of skeletal commingling after discovery, their bio-profiles remain incomplete and contentious. The defect on the frontal bone of the cranium known as Cro-Magnon 2 has been interpreted as both an antemortem injury and a postmortem (i.e., taphonomic) artifact previously. This contribution considers the cranium in order to clarify the status of the defect on the frontal bone and to situate these remains among others of Pleistocene date with similar types of lesions. The diagnostic criteria used to assess the cranium are drawn from recent publications of actualistic experimental studies of cranial trauma and from those associated with cranial trauma due to violence in forensic anthropological and bioarchaeological contexts. The appearance of the defect and comparison with more recent documented cases from the preantibiotic era suggest that the defect is a result of antemortem trauma with survival for a short period. The location of the lesion on the cranium provides growing evidence for interpersonal aggression in these early modern human groups, and the place of burial also provides insight into related mortuary behavior.

A WIGGLE-MATCHED 297-YR TREE-RING OXYGEN ISOTOPE RECORD FROM THAILAND: INVESTIGATING THE 14C OFFSET INDUCED BY AIR MASS TRANSPORT FROM THE INDIAN OCEAN

ABSTRACTRegional offsets from Northern Hemisphere radiocarbon (14C) calibration curves are widely recognized for monsoon Asia and often hinder accurate 14C dating. In this paper, we explore the possible linkage between summer monsoon intensity and 14C offsets using tree-ring δ18O and 14C data from Thailand. We developed a 297-yr floating tree-ring δ18O chronology comprising seven teak log-coffin samples from the Ban Rai rock shelter site, northwestern Thailand. The outermost ring of our chronology was estimated to date from 358–383 CE, within a 95.4% (2σ) probability range, based on a total of 10 14C measurements that were wiggle-matched against a mixed calibration curve evenly weighted from the IntCal20 and SHCal20 curves. Backward trajectory analysis showed that an intensified (weakened) summer monsoon detected in a modern tree-ring δ18O chronology was most likely to be induced by increased (decreased) air mass transport from the tropical Indian Ocean, which is an area of intense upwelling where the 14C concentration is lower than the atmospheric 14C level. However, partly because of the limited sample size and dating uncertainty, the direct linkage between the tree-ring δ18O series and 14C records obtained from our teak log-coffin samples could not be statistically verified.