INVESTIGATING SEASONALITY AND SEASON OF BIRTH IN PAST HERDS: A REFERENCE SET OF SHEEP ENAMEL STABLE OXYGEN ISOTOPE RATIOS

Intra‐tooth sequential analysis of enamel δ¹⁸O is currently used to investigate birth seasonality in past animal populations, offering new insights into seasonal availability of animal resources, herd management and seasonality of site occupation. Reference data sets are still required to address two major difficulties: (1) that inter‐individual variability in the record of the seasonal cycle is affected by tooth size; and (2) that the season of birth cannot be directly estimated from the timing of tooth growth, because of a delay in enamel mineralization. We present a data set acquired on the lower second molar of 10 modern sheep from Rousay (Orkney) born within a few weeks of each other in April/May and submitted to the same environmental conditions until death. All sheep have recorded a sinusoidal pattern of δ¹⁸O variation spanning approximately a year. From the difference between the expected and the measured time sequence, the delay of enamel mineralization is estimated to be 5–6 months. The data set is then described using a model mainly based on a cosine function. The period, corresponding to the length of the M2 crown formed over a year, averaged 35.8 mm. A very slight variation of tooth growth rate with time and no attenuation of the isotopic signal towards the cervical margin of the crown could be detected in this data set. The lowest δ¹⁸O values, corresponding to the sheep's first winter, were tracked at a distance from the enamel/root junction that varied between 23.0 and 30.3 mm (x_min mean = 27.6 mm); the highest δ¹⁸O values, corresponding to the sheep's second summer, were between 6.3 and 11.6 mm (x_max mean = 9.9 mm). Most of the variability can be attributed to tooth size. When normalized on the period, x_min and x_max are 0.28 (± 0.05) and 0.78 (± 0.05) on average, meaning that the Rousay sheep have recorded the minimum and maximum δ¹⁸O values on average at 78% and 28%, respectively, of the end of the periodic cycle recorded in the second molar.     

A COMBINED MULTI‐ANALYTICAL APPROACH FOR THE STUDY OF ROMAN GLASS FROM SOUTH‐WEST IBERIA: SYNCHROTRON μ‐XRF,EXTERNAL‐PIXE/PIGE AND BSEM–EDS

An integrated, multi‐analytical approach combining the high sensitivity of SR‐μXRF, the light element capability of PIXE/PIGE under a helium flux and the spatial resolution of BSEM + EDS was used to characterize chemical composition and corrosion of glass samples (first to fourth centuries ad ) from an important, but scarcely investigated, Roman region of south‐west Iberia (southern Portugal). The geochemical trends and associations of major, minor and trace elements were investigated to shed light on production techniques, the provenance of raw materials and decay mechanisms. The results, while confirming a production technique common to Roman glasses throughout the Empire—that is, a silica‐soda‐lime low‐Mg, low‐K composition, with glass additives as colouring and/or decolouring agents (Fe, Cu, Mn, Sb)—show at one site high Zr–Ti contents, suggesting a more precise dating for these glasses to the second half of the fourth century. The Ti–Fe–Zr–Nb geochemical correlations in the pristine glass indicate the presence of minerals such as ilmenite, zircon, Ti‐rich Fe oxides and columbite in the sands used as raw materials for the glass former: these minerals are typical of granitic‐type source rocks. The unusually high K content in the corrosion layers is consistent with burial conditions in K‐rich soils derived from the alteration of 2:1 clays in K‐bearing rock sequences.     

SELECTION AND HEATING OF COLOURING MATERIALS IN THE MOUSTERIAN LEVEL OF ES‐SKHUL (c. 100 000 YEARS BP,MOUNT CARMEL,ISRAEL)

The transformation of yellow goethite into red hematite by heating has long been assumed for Palaeolithic red artefacts excavated close to fireplaces. However, this transformation is extremely rare. Using SEM–FEG–EDX, PIXE–PIGE, TEM and μXRD, we characterized the mineralogical and chemical compositions of four microsamples of colouring materials from the Mousterian layer B in the es‐Skhul rock‐shelter, from about 100 kya ago. For some colouring materials, the Mousterian people of es‐Skhul chose to gather remote yellow lumps for heating. Their significant transport distance provides evidence of the possible high cultural value of these colouring materials for transformation into red pigments.     

文物真三维数字建模技术在秦始皇兵马俑博物馆中的应用——以一号坑陶俑为例

随着高新技术的发展,文保应用研究中引入了三维扫描技术。通过对秦兵马俑一号坑陶俑的扫描实例,介绍了一套利用三维激光扫描技术建立文物真三维模型的基本流程及方法,并通过文物真三维数据管理系统对模型进行展示、分析与研究。文物真三维数据模型的建立,使全面观察研究、再现和重建遗迹及文物成为可能,为文物的数字化展示、数字博物馆的建立、文物鉴赏以及文化遗产的保存提供了新思路。     

Large-scale 2nd to 3rd century AD bloomery iron smelting in Korea

Iron production in Korea has traditionally been seen in the shadow of developments in cast iron technology in China, with limited indication for a northern influence via Russia’s Maritime Province. The possibility of the existence of bloomery iron production in ancient Korea has been little explored, and relevant discussion is fraught with speculations based primarily on the early use of cast iron. The recent excavation of a site in South Korea recovered substantial amounts of slag providing direct evidence of bloomery smelting. The accelerator mass spectrometric dating of burnt wood from inside one of the slag pieces showed that the site was in use in the early 3rd century AD or earlier, which is in agreement with the assessment based on ceramic typology. The traits of a bloomery process evident in the slags’ microstructure, shape, composition and excavation context are discussed along with the implications for historical iron technology in Korea, where cast iron and the influence from China have been overly emphasised.     

Estimating original flake mass from 3D scans of platform area

This study confirms the increased capacity to predict flake mass that arises from more accurately measuring surface area in three dimensions using a digital scanner. We also reveal the existence of significantly different relationships between platform area and flake mass for flakes with different platform types and ventral and dorsal morphologies. These different relationships between platform surface area and mass have not been previously identified, and reveal the complexity of platform/mass relationships. Using multivariate regression of 3D platform surface area and external platform angle we improve the accuracy of predictions of original flake mass. We propose a method for studying reduction intensity on retouched flakes, based on comparing predictions of the initial mass of the flake with measurements of the mass following retouching to estimate the amount of mass removed through retouching. We name this approach the Initial-/Terminal-Mass Comparison, or ITMC. Our experiments demonstrate that the capacity of the 3D platform scans to predict flake mass, and by implication the capacity of the ITMC to estimate mass loss, rivals or exceeds the capacity demonstrated for existing reduction measures.     

基于视觉的明清古家具数字文化档案高精度三维重建

文物是人类在社会活动中遗留的具有历史、艺术、科学价值的遗物和遗迹。优秀物质文化遗产的体系庞大、内容繁杂,数字化三维重建是保存、管理文物的一种切实可行的方案,对文化传承意义深远。相比于三维激光扫描、结构光技术等在成本和效率方面都有待改进的现有方法,数字近景摄影测量在确保低成本、高效率的同时,还能够满足数据的精度要求和详细程度。如何应用摄影测量技术对文物进行高效三维重建,实现纹理、部件、结构的精细化描述,并综合管理文物以便线上欣赏、未来修复与辅助断代,对优秀物质文化遗产的保护与传承至关重要。 本研究提出了基于视觉的三维建模方案,分为明清家具分层管理体系构建、高效率数据采集与精细化三维重建、高精度三维数字文化档案建设三步。首先针对明清家具的文化特点,从类别、纹饰、部件出发进行分层分类管理,构建独特编码体系;其次基于数字近景摄影测量技术,提出了对明清家具进行非接触数据采集的低成本高效率方法,进行高精度三维重建;再次从三维信息中提取家具纹饰、部件、结构特征,以编码为依据建立索引,为三维数字文化档案的建设提供信息基础;最后设计分层索引结构,建设高精度数字文化档案,搭建互联网共享平台进行展示。 以100套明清古家具袖珍模型为实例进行精细化数字建模,基于数字近景摄影测量技术,将模型精度控制在毫米级别,完成了文物要素提取、分类体系搭建、属性信息管理与索引结构设计,构建了历史文化和三维模型融合的数字文化档案。研究结果表明,基于视觉的非接触视觉处理算法能够实现高精度三维重建,提出的技术方案能够保留模型的细节程度,并且降低了成本、提升了效率,对文物类别、部件、纹饰的属性管理与索引架构能有效管理文化信息,数字文化档案兼具科技、人文与传统美学,满足文物保护需求。明清家具三维数字文化档案可用于古家具的研究,有利于中国古代家具工艺的传承,而其中对于家具的历史年代的介绍鉴别能够辅助断代。下一步将考虑运用人工智能对家具纹饰和部件进行元素组合,生成个性化定制家具。同时将完善技术方案,应用范围拓展至小型文物,支撑数字博物馆建设。     

The 4th-century B.C. shipwreck at Mazotos,Cyprus: New techniques and methodologies in the 3D mapping of shipwreck excavations

Abstract

Well preserved ancient shipwrecks are rare in the archaeological record, but when discovered, they can provide valuable information on a wide range of research issues if analyzed and documented properly. In this paper we discuss the significance, potential, and constraints of mapping methods applied during the underwater excavation of shipwreck sites with special emphasis on stratigraphy, documentation of finds, and reconstruction of site formation processes. As a case study, we present the digital photogrammetry and computer vision software programs used in the excavation of the 4th-century b.c. shipwreck at Mazotos, Cyprus. Our goal is to develop a targeted documentation and mapping method of ongoing shipwreck excavations so that others can address complex research questions concerning this unique discipline of archaeology.     

The Tel Akko Total Archaeology Project (Akko,Israel): Assessing the suitability of multi-scale 3D field recording in archaeology

Abstract

Archaeology is a destructive discipline, and, unfortunately, the majority of methods employed by archaeologists to record and preserve the archaeological record consist of two-dimensional representations of three-dimensional (3D) subjects. Recent breakthroughs in 3D technology, however, have the potential to revolutionize the discipline. In recent years, multiple software suites capable of generating spatially accurate, photorealistic 3D models with a series of digital photographs have become available. Following a successful season of field testing in 2011, the Tel Akko Total Archaeology Project (Akko, Israel) expanded the use of Agisoft’s PhotoScan Pro—one of the commercially available software suites—to test the accuracy and suitability of the program for archaeological applications at multiple scales. After two years of field testing, it is clear that the implementation of PhotoScan Pro in archaeology facilitates unprecedented accuracy in field recording and digital heritage management, and provides a new outlet for the dissemination of archaeological data.     

Measuring core reduction using 3D flake scar density: a test case of changing core reduction at Klasies River Mouth,South Africa

A new core reduction index is presented, calculated as the ratio of flake scar number to 3D surface area (SDI). The index is tested experimentally on five types of core (blade, discoid, Levallois, biface and multiplatform cores) and then applied to the core assemblages from five sub-stages of the Middle Stone Age at Klasies River Mouth, South Africa. Preliminary results indicate that the SDI possesses the desirable attributes of a successful reduction index and is a significant improvement on traditional proxy measures of core reduction. The results of the archaeological case study confirm previous untested observations that cores from the Howiesons Poort and MSAIII sub-stages are more heavily reduced than preceding and following stages, and that local and exotic raw materials as well as different types of cores are all more heavily reduced during these periods. The SDI fills a significant lacuna in available core reduction measures.