Hasil untuk "Prehistoric archaeology"

Anna R. Gallazzi, Stefano Zibetti, Arjen van der Wel et al.

We analyze stellar population properties of 552 galaxies at redshift 0.6<z<0.77 from the LEGA-C spectroscopic survey. This first paper in a series presents the catalog of revised absorption indices for LEGA-C DR3 and inferred physical parameters, and derives benchmark scaling relations for the general massive galaxy population at intermediate redshift. We estimate light-weighted mean ages and stellar metallicities by interpreting key stellar absorption features and rizYJ photometry in a Bayesian framework with a comprehensive library of model spectra based on stochastic star formation and metallicity histories and dust attenuations. We discuss systematic uncertainties within our method and compared to other spectral fitting approaches. We derive volume-weighted scaling relations of light-weighted mean ages and stellar metallicities with stellar mass for the general galaxy population at <z>=0.7 and masses >10^10Msun. The downsizing trends observed locally were already in place 6 Gyr ago. We observe bimodal age distribution as a function of mass, transitioning around 10^11Msun. No bimodality appears in the stellar metallicity-mass relation, which changes from steep to flat across 10^10.8Msun. Similar trends emerge for age and metallicity with velocity dispersion, but with sharper transition from young to old around log(sigma)=2.3. Differences with respect to trens with stellar mass suggest that age primarily depends on velocity dispersion below and above the transition regime, while both stellar mass and velocity dispersion contribute to stellar metallicity. The catalogs of revised absorption index measurements for LEGA-C DR3 and inferred stellar population physical parameters will be released to public repositories. (Abridged)

Jiahao Qiu, Fulian Xiao, Yimin Wang et al.

Recent advances in large language models (LLMs) have led to remarkable progress across domains, yet their capabilities in the humanities, particularly history, remain underexplored. Historical reasoning poses unique challenges for AI, involving multimodal source interpretation, temporal inference, and cross-linguistic analysis. While general-purpose agents perform well on many existing benchmarks, they lack the domain-specific expertise required to engage with historical materials and questions. To address this gap, we introduce HistBench, a new benchmark of 414 high-quality questions designed to evaluate AI's capacity for historical reasoning and authored by more than 40 expert contributors. The tasks span a wide range of historical problems-from factual retrieval based on primary sources to interpretive analysis of manuscripts and images, to interdisciplinary challenges involving archaeology, linguistics, or cultural history. Furthermore, the benchmark dataset spans 29 ancient and modern languages and covers a wide range of historical periods and world regions. Finding the poor performance of LLMs and other agents on HistBench, we further present HistAgent, a history-specific agent equipped with carefully designed tools for OCR, translation, archival search, and image understanding in History. On HistBench, HistAgent based on GPT-4o achieves an accuracy of 27.54% pass@1 and 36.47% pass@2, significantly outperforming LLMs with online search and generalist agents, including GPT-4o (18.60%), DeepSeek-R1(14.49%) and Open Deep Research-smolagents(20.29% pass@1 and 25.12% pass@2). These results highlight the limitations of existing LLMs and generalist agents and demonstrate the advantages of HistAgent for historical reasoning.

Riccardo Vasellini, Gilda Ferrandino, Luisa Sernicola et al.

This study intends to test the hypothesis that, contrary to traditional interpretation, the social structure of the polity of Aksum - especially in its early stages - was not characterized by a vertical hierarchy with highly centralized administrative power, and that the leaders mentioned in the few available inscriptions were predominantly ritual leaders with religious rather than coercive political authority. This hypothesis, suggested by the available archaeological evidence, is grounded in Charles Stanish's model, which posits that pre-state societies could achieve cooperative behavior without the presence of coercive authority. Using agent-based modeling applied to data inspired by the Aksum civilization, we examine the dynamics of cooperation in the presence and absence of a Public Goods Game. Results show that while cooperative behavior can emerge in the short term without coercive power, it may not be sustainable over the long term, suggesting a need for centralized authority to foster stable, complex societies. These findings provide insights into the evolutionary pathways that lead to state formation and complex social structures.

Davide Adamo, Marco Corneli, Manon Vuillien et al.

Due to its invariance to rigid transformations such as rotations and reflections, Procrustes-Wasserstein (PW) was introduced in the literature as an optimal transport (OT) distance, alternative to Wasserstein and more suited to tasks such as the alignment and comparison of point clouds. Having that application in mind, we carefully build a space of discrete probability measures and show that over that space PW actually is a distance. Algorithms to solve the PW problems already exist, however we extend the PW framework by discussing and testing several initialization strategies. We then introduce the notion of PW barycenter and detail an algorithm to estimate it from the data. The result is a new method to compute representative shapes from a collection of point clouds. We benchmark our method against existing OT approaches, demonstrating superior performance in scenarios requiring precise alignment and shape preservation. We finally show the usefulness of the PW barycenters in an archaeological context. Our results highlight the potential of PW in boosting 2D and 3D point cloud analysis for machine learning and computational geometry applications.

Junzo Uchiyama, Mitsuhiro Kuwahata, Felix Riede et al.

Japan’s rich archaeological record, supported by well-established chronological and typological frameworks, offers valuable opportunities to investigate prehistoric socio-cultural responses to climate change, although comprehensive studies remain limited. This exploratory paper examines the impact of climatic disruptions—particularly the 8.2 ka event—on Jomon foragers in Kyushu, aiming to develop an analytical framework and identify future research directions. The 8.2 ka event is situated within a longer socio-ecological trajectory extending from the onset of the Holocene (11.7 ka) to the Kikai-Akahoya (K-Ah) super-eruption (7.3 ka). Early Holocene Kyushu is typically characterised by the emergence of large, village-based foraging communities, whose abrupt decline has been attributed to the K-Ah eruption, often considered a cultural and demographic watershed. However, this study reconsiders that narrative by comparing environmental changes with archaeological trends in population, settlement, and subsistence. Methods include (a) reviewing environmental history literature; (b) assessing demographic patterns through settlement data and technological trends; and (c) analysing lithic tools and faunal remains at key sites. Our findings suggest a more complex sequence structured by three tempos of environmental change: (1) the gradual postglacial northward move of nut-bearing deciduous forests; (2) short-term climatic downturns, including the 8.2 ka event and other Bond Events; and (3) abrupt volcanic impacts. Each phase appears to have triggered cumulative and adaptive socio-cultural responses. We tentatively conclude that the 8.2 ka event impacted communities already undergoing long-term adaptation to dynamic and unstable ecological conditions, shaped by both environmental constraints and opportunities. These groups responded in cyclical ways to different tempos of change. Ultimately, we argue that the 8.2 ka event in Kyushu should be examined as part of a broader trajectory of socio-ecological transformation, rather than as an isolated moment of major disruption.

L. Timbrell, L. Timbrell, J. Blinkhorn et al.

<p>Both proxies and models provide key resources to explore how palaeoenvironmental changes may have impacted diverse biotic communities and cultural processes. While proxies are thought to provide the “gold standard” in reconstructing the local environment, they only provide point estimates for a limited number of locations. On the other hand, models have the potential to afford more extensive and standardized geographic coverage of multiple bioclimatic variables. A key decision when using model output is the appropriate geographic resolution to adopt; models are coarse scale, in the order of several arc degrees, and so their outputs are usually downscaled to a higher resolution. Most publicly available model time series have been downscaled to 30 or 60 arcmin, but it is unclear whether such resolution is sufficient for certain applications like species distribution models or whether this may homogenize environments and mask the spatial variability that is often the primary subject of analysis. Here, we explore the impact of increasing the resolution of model output from 30 to 5 arcmin using the delta-downscaling method, which interpolates and applies the long-term difference between past and present model datasets to a higher-resolution grid of observed present-day climate. We seek to determine to what extent further downscaling captures climatic trends at the site level through direct comparison with proxy reconstructions, evaluating different versions of the output from the HadCM3 Global Circulation model for annual temperature, mean temperature of July, and annual precipitation against a large empirical dataset of pollen-based reconstructions from across the Northern Hemisphere. Our results demonstrate that models tend to provide broadly similar accounts of past climate to that obtained from proxy reconstructions, with coherence tending to decline with age and at higher altitudes. However, our results imply that using the delta method to downscale to a very fine resolution has a minimal net effect on the coherence of model output with pollen records in most cases. Optimal spatial resolution is therefore likely to be highly dependent on specific research contexts and questions, with careful consideration required regarding the trade-off between highlighting local-scale variations and increasing potential error via unreliable interpolation.</p>

Danny Horta, Ricardo P. Schiavon

Stellar halos of galaxies retain crucial clues to their mass assembly history. It is in these galactic components that the remains of cannibalised galactic building blocks are deposited. For the case of the Milky Way, the opportunity to analyse the stellar halo's structure on a star-by-star basis in a multi-faceted approach provides a basis from which to infer its past and assembly history in unrivalled detail. Moreover, the insights that can be gained about the formation of the Galaxy not only help constrain the evolution of our Milky Way, but may also help place constraints on the formation of other disc galaxies in the Universe. This paper includes a summary of work undertaken during a PhD thesis aiming to make progress toward answering the most fundamental question in the field of Galactic archaeology: "How did the Milky Way form?" Through the effort to answer this question, we summarise new insights into aspects of the history of assembly and evolution of our Galaxy and measurements of the structure of various of its Galactic components.

Douglas I. Kelley, Hiromitsu Sato, Michaela Ecker et al.

Abstract The refugia hypothesis, often used to explain Amazonia’s high biodiversity, initially received ample support but has garnered increasing criticism over time. Palynological, phylogenetic, and vegetation model reconstruction studies have been invoked to support the opposing arguments of extensive fragmentation versus a stable Amazonian Forest during Pleistocene glacial maxima. Here, we test the past existence of forest fragments and savanna connectivity by bias-correcting vegetation distributions from a Dynamic Vegetation Model (DVM) driven by paleoclimate simulations for South America during the Last Glacial Maximum (LGM). We find evidence for fragmented forests akin to refugia with extensive tropical humid forests to the west and forest islands in central/southern Amazonia. Drier ecosystems of Northern Llanos, Caatinga and Cerrado may have merged into continuous savanna/grasslands that dominated the continent. However, our reconstructions suggest taller, dense woodland/tropical savanna vegetation and areas of similar bioclimate connected disparate forest fragments across Amazonia. This ecotonal biome may have acted as a corridor for generalist forest and savanna species, creating connectivity that allows for range expansion during glacial periods. Simultaneously, it could have served as a barrier for specialists, inducing diversification through the formation of ‘semi-refugia’.

Deke Xu, Houyuan Lu, G. Chu et al.

Prehistoric human activities were likely influenced by cyclic monsoon climate changes in East Asia. Here we report a decadal-resolution Holocene pollen record from an annually-laminated Maar Lake in Northeast China, a proxy of monsoon climate, together with a compilation of 627 radiocarbon dates from archeological sites in Northeast China which is a proxy of human activity. The results reveal synchronous ~500-year quasi-periodic changes over the last 8000 years. The warm-humid/cold-dry phases of monsoon cycles correspond closely to the intensification/weakening of human activity and the flourishing/decline of prehistoric cultures. Six prosperous phases of prehistoric cultures, with one exception, correspond approximately to warm-humid phases caused by a strengthened monsoon. This ~500-year cyclicity in the monsoon and thus environmental change triggered the development of prehistoric cultures in Northeast China. The cyclicity is apparently linked to the El Niño-Southern Oscillation, against the background of long-term Holocene climatic evolution. These findings reveal a pronounced relationship between prehistoric human activity and cyclical climate change. Long-term climate cycles can potentially influence population dynamics, including those of humans. Here, the authors combine climate and archaeological records from Northeast China over the past 8000 years and demonstrate ~500 year cycles in both the monsoon and human activity.

G. Dong, Ruo Li, Minxia Lu et al.

Exploring prehistoric variation in human–environmental interaction is critical for understanding the historical patterns and mechanisms of long-term human–land evolution. In this paper we review the published radiocarbon and optically stimulated luminescence (OSL) data from Late Paleolithic, Neolithic and Bronze Age sites in China, analyze the spatial–temporal distribution of these sites, and compare it with the results of recent paleoclimatic and archaeological studies. We seek to study the trajectory and influencing factors of human–environmental interactions in late prehistoric China. We detect changing patterns in the relationship between humans and the environment during different phases of the prehistoric era in China. Climate change clearly affected the environment of hunter-gatherer groups between 50,000–10,000 BP (before present, defined as 1950AD), and variation in human population in Neolithic China (∼10,000–4000 BP) was likely influenced primarily by the development of agriculture, in addition to substantial climate events. The spatial scale of human settlements expanded in the Bronze Age (∼4000–2200 BP) in a period of cooling climate. During this time the impact of human activities on the environment increased significantly, primarily caused by technological innovations related to the onset of prehistoric transcontinental cultural exchange in Eurasia.

Elisa Crabu, Federica Pes, Giuseppe Rodriguez et al.

The standard photometric stereo model makes several assumptions that are rarely verified in experimental datasets. In particular, the observed object should behave as a Lambertian reflector and the light sources should be positioned at an infinite distance from it, along a known direction. Even when Lambert's law is approximately fulfilled, an accurate assessment of the relative position between the light source and the target is often unavailable in real situations. The Hayakawa procedure is a computational method for estimating such information directly from the data images. It occasionally breaks down when some of the available images excessively deviate from ideality. This is generally due to observing a non Lambertian surface, or illuminating it from a close distance, or both. Indeed, in narrow shooting scenarios, typical, e.g., of archaeological excavation sites, it is impossible to position a flashlight at a sufficient distance from the observed surface. It is then necessary to understand if a given dataset is reliable and which images should be selected to better reconstruct the target. In this paper, we propose some algorithms to perform this task and explore their effectiveness.

Mehran Tarif, Babak Nouri Moghadam

Oceans, covering 70% of Earth's surface, arelargely unexplored, with about 95% remaining a mystery.Underwater wireless communication is pivotal in various domains,such as real-time aquatic data collection, marine surveillance,disaster prevention, archaeological exploration, andenvironmental monitoring. The Internet of Things has openednew avenues in underwater exploration through the underwaterInternet of Things concept. This innovative technology facilitatessmart ocean research, from small case studies to large-scaleoperations. UIoT networks utilise underwater equipment andsensors to gather and transmit data in aquatic environments.However, the dynamic nature of these environments poseschallenges to the network's structure and communication,necessitating efficient routing solutions. Quality-of-service-awarerouting is vital as it minimises energy usage, extends battery life,and enhances network performance. This paper delves into thechallenges and limitations of UIoT networks, highlighting recentrouting methodologies. It also proposes a comparison frameworkfor routing methods, focusing on the quality of service inunderwater IoT networks, to foster more optimal route selectionand better resource management.

Amandine Doliva-Dolinsky, Nicolas F. Martin, Guillaume F. Thomas et al.

We determine the detection limits of the search for dwarf galaxies in the Pan-Andromeda Archaeological Survey (PAndAS) using the algorithm developed by the PAndAS team. The recovery fractions of artificial dwarf galaxies are, as expected, a strong function of physical size and luminosity and, to a lesser extent, distance. We show that these recovery fractions vary strongly with location in the surveyed area because of varying levels of contamination from both the Milky Way foreground stars and the stellar halo of Andromeda. We therefore provide recovery fractions that are a function of size, luminosity, and location within the survey on a scale of 1 square degree. Overall, the effective surface brightness for a 50-percent detection rate range between 28 and 30 mag per square arcsecond. This is in line with expectations for a search that relies on photometric data that are as deep as the PAndAS survey. The derived detection limits are an essential ingredient on the path to constraining the global properties of Andromeda's system of satellite dwarf galaxies and, more broadly, to provide constraints on dwarf galaxy formation and evolution in a cosmological context.

L. Reiss, C. Stüwe, T. Einwögerer et al.

<p>Two loess sections from the Upper Palaeolithic site of Kammern-Grubgraben (Lower Austria) were analysed to test geochemical proxies, as well as radiocarbon data of different components, for their reliability and consistency in an archaeological context. Only a reliable basal age (28.9–27.8 ka cal BP) was obtained from charcoal fragments derived from a tundra gley underlying the archaeological horizons and assigned to Greenland Interstadials 3 or 4. Grain size, organic and inorganic geochemistry, and stable isotopes of the fine organic fraction (<span class="inline-formula"><i>δ</i>¹³</span>C<span class="inline-formula">_org</span>) and of rhizoconcretions (<span class="inline-formula"><i>δ</i>¹³</span>C, <span class="inline-formula"><i>δ</i>¹⁸</span>O) were analysed to provide information on palaeoenvironmental conditions. Low-resolution geochemical and sedimentological analyses document a humidity-related variability, while <span class="inline-formula"><i>δ</i>¹³</span>C<span class="inline-formula">_org</span> values indicate predominant C<span class="inline-formula">₃</span> vegetation. High-resolution elemental variations derived from X-ray fluorescence scanning exhibit increasing Ca and decreasing Fe and Ti values, indicating drier conditions towards the top. Secondary pedogenic carbonate concretions provide post-sedimentary (Holocene) ages and are not suitable for assessing climate and environmental changes for the Palaeolithic.</p>

Dheeraj Vagavolu, Akhila Sri Manasa Venigalla, Sridhar Chimalakonda

Despite the growth of online museums for India's cultural heritage data, there is limited increase in terms of visitors. Over the years, online museums adopted many techniques to improve the overall user experience. However, many Indian online museums display artifacts as lists and grids with basic search functionality, making it less visually appealing and difficult to comprehend. Our work aims to enhance the user experience of accessing Indian online museums by utilizing advancements in information visualization. Hence, we propose MuseumViz, a framework which processes data from online museums and visualizes it using four different interactive visualizations: the Network Graph, TreepMap, Polygon Chart and SunBurst Chart. We demonstrate MuseumViz on a total of 723 cultural heritage artifacts present in the Archaeological Survey of India, Goa. Based on our evaluation with 25 users, about 83% of them find it easier and more comprehensible to browse cultural heritage artifacts through MuseumViz.

Marc Tanti, Camille Berruyer, Paul Tafforeau et al.

Propagation Phase Contrast Synchrotron Microtomography (PPC-SR$μ$CT) is the gold standard for non-invasive and non-destructive access to internal structures of archaeological remains. In this analysis, the virtual specimen needs to be segmented to separate different parts or materials, a process that normally requires considerable human effort. In the Automated SEgmentation of Microtomography Imaging (ASEMI) project, we developed a tool to automatically segment these volumetric images, using manually segmented samples to tune and train a machine learning model. For a set of four specimens of ancient Egyptian animal mummies we achieve an overall accuracy of 94-98% when compared with manually segmented slices, approaching the results of off-the-shelf commercial software using deep learning (97-99%) at much lower complexity. A qualitative analysis of the segmented output shows that our results are close in terms of usability to those from deep learning, justifying the use of these techniques.

Rokiah Suriadi, Wan Nurzalia Wan Saelan, Behara Satyanarayana et al.

This study analysed the distribution and abundance of dead and live (Rose Bengal stained) infaunal foraminifera from three short cores taken at three locations in the mangrove swamps of Kemaman-Chukai, Terengganu, Malaysia. Eighteen agglutinated taxa were recorded in assemblages dominated by 'Arenoparrella mexicana', 'Haplophragmoides wilberti' and 'Miliammina fusca'; and of these, only two taxa were recorded as live. The distribution of subsurface and infaunal foraminifera varied from core to core, as did their depth of occurrence. Core 1 (seaward core) was dominated by sandy deposits, relatively high salinity (32 ppt), and extensive crab mounds, displayed very low numbers of dead foraminifera inconsistently throughout the core, while no infaunal foraminifera were observed, indicating intense bioturbation by mangrove crabs. In Core 2 (middle core), even though the numbers of live foraminifera decreased down-core, the number of dead or subsurface foraminifera were inconsistent, indicating taphonomic loss of the tests. Core 3 (landward core) however, displayed ideal foraminiferal distribution patterns required in the palaeo sea-level reconstruction (with less taphonomic loss and decreasing number of infaunal foraminifera downcore). Because of the similarity displayed in the foraminiferal assemblages in the 0–1 cm and 10–11 cm intervals, the surface sample (0–1 cm) should be an acceptable basis for down-core reconstructions in this study. Live (Rose Bengal stained) infaunal foraminifera, though observed at 40–41 cm depth, are not considered abundant enough to influence the dead assemblage in the subsurface sediment and its applicability for palaeoenvironmental and sea-level reconstructions. Therefore, it is possible for palaeo sea-level to be reconstructed based on foraminiferal assemblages preserved in the Kemaman-Chukai mangrove swamps.

Luis Benítez de Lugo Enrich, Andrea Rodríguez-Antón, Juan Palomo Palomo et al.

Los Pedroches es uno de los territorios andaluces más septentrionales, en la frontera con Extremadura y Castilla-La Mancha. Sobre unos suelos poco aptos para el cultivo, pero muy favorables para la explotación ganadera, se encuentran una serie de manifestaciones megalíticas diseminadas, poco conocidas y apenas estudiadas. El estudio de las orientaciones astronómicas de monumentos megalíticos permite verificar su alineación con algunos días particulares del año, como equinoccios o solsticios. Este trabajo presenta un avance del estudio arqueoastronómico de los dólmenes de Las Aguilillas, El Torno, Los Frailes, El Rongil y Torrubia, localizados en Villanueva de Córdoba. Los resultados obtenidos confirman que el diseño de la ubicación de los megalitos incluidos en el presente estudio no es casual. Las orientaciones dadas a estos megalitos resultan consistentes con las orientaciones de otros conjuntos de sepulcros megalíticos en Andalucía y otras regiones de la península ibérica.

Chris U. Carmona, Geoff K. Nicholls

Bayesian statistical inference loses predictive optimality when generative models are misspecified. Working within an existing coherent loss-based generalisation of Bayesian inference, we show existing Modular/Cut-model inference is coherent, and write down a new family of Semi-Modular Inference (SMI) schemes, indexed by an influence parameter, with Bayesian inference and Cut-models as special cases. We give a meta-learning criterion and estimation procedure to choose the inference scheme. This returns Bayesian inference when there is no misspecification. The framework applies naturally to Multi-modular models. Cut-model inference allows directed information flow from well-specified modules to misspecified modules, but not vice versa. An existing alternative power posterior method gives tunable but undirected control of information flow, improving prediction in some settings. In contrast, SMI allows tunable and directed information flow between modules. We illustrate our methods on two standard test cases from the literature and a motivating archaeological data set.

Jordi Guàrdia-Felip

El gran valor estratégico y geopolítico de la ciudad romana de Iulia Libica era que estaba enclavada en el principal paso de los Pirineos Orientales, a más de 1220 m de altura y junto al río Segre, en el límite norte de la Hispania Citerior. Arquitectónicamente destaca el programa decorativo del foro y su templo. De fundación augustea o tiberiana, su época de esplendor hay que situarla durante los siglos I-II d. C.