Production sequences of ostrich eggshell beads and settlement dynamics in the Geelbek Dunes of the Western Cape, South Africa

The archaeological record attests to the significance of ostrich eggs as a valuable resource for the people of the Later Stone Age. People over a broad geographic range used ostrich eggs to provide nourishment, storage and ornamentation. This paper focuses on the production, use and discard of ostrich eggshell beads recovered from open-air sites in the Geelbek Dunes of the Western Cape, South Africa. We present a comprehensive production chain for analyzing the manufacture of beads and introduce the concept of a heuristic production value for evaluating the degree of completion reflected by an assemblage. The pattern of fabrication and the distribution in size allow for a detailed analysis of the beads that points to specific behavioral patterns involved in their production. This analysis yields information about the duration and intensity of site use, as well as the individual members and cultural affinities of the groups who made the beads. We document the intentional use of fire to blacken the majority of the beads as an aesthetic choice. Combined with the results from AMS radiocarbon dating, the majority of the beads from Geelbek provide insight into the socio-economic identity of their manufacturers: small groups of hunter–gatherers who inhabited and used specific locations on the strandveld near Langebaan Lagoon.     

元代景教石刻的复制工艺

石刻文物的复制工艺较为复杂,尤其是石刻大器,从制作模具到翻制器物均无成规可循。此次复制元代景教石刻,经过多次实验,从材料的选择、配方及工艺流程都取得了新的经验。     

The fire stones carry: Ethnographic records and archaeological expectations for hot-rock cookery in western North America

Ethnographic data from Kalispel elders in the 1930s attest to use of wild root foods, rock-filled earth ovens, steaming and boiling pits, and hot-rock griddles during the 1800s in forested montane regions of the interior Northwest. Cabeza de Vaca’s narrative of his 1528–1536 travels across the Gulf Coastal Plain of Texas and deserts of northern Mexico illustrates the importance of root foods, earth ovens, and stone boiling in aboriginal Southwest North America. These and other accounts, results of actualistic experiments, and knowledge of cooking requirements afford reliable bases for generating archaeological expectations about fire-cracked-rock assemblages representative of diverse cook-stone facilities.     

Methods for calculating brine evaporation rates during salt production

Salt is recognized by archaeologists as an important commodity due to the biological need for sodium and other cultural uses. Numerous studies have described the various techniques used in converting brine to crystallized salt, but few, if any, have attempted to quantify the physical processes of evaporation in pre-industrial societies. Apart from the few areas where salt mining is possible, nearly all forms of salt production require evaporation of water to concentrate brine and ultimately produce salt crystals. This study quantifies three of the most common evaporation techniques and provides insight into the production rates of salt and fuel requirements. Methods of calculation are provided for determining evaporation through (1) direct solar heating of brine, (2) applied external heat to a vessel, and (3) an immersed heated object (e.g., stone). These results provide physical constraints on the evaporation process and provide investigators with techniques for estimating efficiency and total production of prehistoric and historic saltworks.     

Hunting with Howiesons Poort segments: pilot experimental study and the functional interpretation of archaeological tools

For many decades the use of backed pieces from the Howiesons Poort, between about 70 ka and 55 ka ago, in South Africa has been a point of discussion. Recently direct evidence has been provided to associate these tools with Middle Stone Age hunting strategies. Yet, whether they were used to tip hunting weapons or as barbs remained an open question. In this paper we introduce a set of pilot experiments designed to test the effectiveness of Howiesons Poort segments, the type fossils of the industry, hafted in four different configurations as tips for hunting weapons. It is shown that the morphological type can be used successfully in this way. We present the results of a macrofracture analysis conducted on the experimental tools and compare these to results obtained from three Howiesons Poort backed tool samples. By correlating experimental outcomes, macrofracture data and the interpretation of micro-residue distribution patterns, we provide some insight into the functional variables that might be associated with Howiesons Poort segments.     

文物岩石材料劣化两类结垢物质成分 及形成机制的分析与研究

为了探讨文物岩石材料劣化结垢病害的特征和形成机理,以洛阳龙门石窟和北京西黄寺清净化城塔塔基砂岩条石为研究对象,采用全岩化学全分析和X射线衍射测试技术对两类结垢物质的成分和形成过程进行了系统分析和研究。研究结果表明,龙门石窟的结垢物是在水长期渗漏过程中对碳酸盐岩溶蚀改造沉淀后而形成的;而西黄寺清净化城塔塔基砂岩条石上的结垢物来源于砌筑砂浆(其主要物质成分为方解石),白色结垢物的形成机理为,砌缝砂浆在水渗流作用下发生溶蚀,溶蚀形成的溶液流至其下砂岩条石上经沉淀及重结晶形成结垢物。     

明代石拱桥永昌桥的加固修缮技术研究

为明晰明代石拱桥的结构性能,并提出适宜的加固修缮方法,以典型的明代石拱桥永昌桥为例进行研究。首先对其进行精确测绘,获得其准确可靠的几何信息;然后对其建筑形制、构造工艺及残损状况进行研究,为结构性能分析提供依据;接着利用ANSYS软件建立永昌桥主体结构的有限元模型,进行包括荷载影响分析、重要度分析和裂缝分析的结构性能研究;最后基于现状分析和结构性能研究,通过对比拱背套钢筋混凝土拱加固法和拱背粘贴碳纤维布加固法对石拱桥的结构性能的影响,提出了明代石拱桥永昌桥的加固修缮方法。研究成果可为同类型石拱桥的加固修缮提供参考。     

New research on the Holocene settlement and environment of the Chad Basin in Nigeria

Recent investigations of three archaeological sites in the Nigerian part of the Chad Basin during the Holocene reveal key stages in the cultural development and environmental history of that region. At Dufuna, a dugout boat was dated to around 6000 BC, making it the oldest known boat in Africa and one of the oldest in the world. Boats may thus have contributed to the mobility of the population of the southern edge of the Sahara 8000 years ago and, thereby, to the cultural homogeneity of this period. The pottery site at Konduga is around a thousand years younger than Dufuna but still belongs to the time of Mega-Chad. The site is on the Bama Ridge, an old shoreline. Its pottery, decorated in the Saharan tradition, belongs to the earliest ceramic phase of the West African Later Stone Age, long before the beginnings of food production. Although this site was probably settled by pioneers advancing into a largely flooded landscape along the slightly raised shoreline, the human occupation of the area previously covered by Mega-Chad began along a broad front around 2000 BC. Archaeological and palaeoecological finds from two settlement mounds at Gajiganna are described as case studies for this phase, which predates the well-known site of Daima.

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Résumé Les résultats présentés proviennent de recherches récentes sur trois sites archéologiques, dont chacun représente un épisode clé du développement culturel et de l'histoire environnementale du Bassin nigérian du Tchad au cours de l'Holocène. A Dufuna, la découverte d'une pirogue monoxyle, datée d'environ 6000 ans BC, constitue le témoignage le plus ancien d'une embarcation en Afrique et l'un des plus ancien dans le monde. Ce moyen de transport indique la mobilité des populations de la marge sud du Sahara à l'Holocène inférieur et moyen; ce qui a dû contribuer à l'homogénéité culturelle de cette période. Le site à poterie de Konduga est le plus jeune d'un millénaire que Dufuna, mais appartient à l'époque du Méga-Tchad. Le site est installé sur une ancienne ligne de rivage, la Bama Ridge. Sa poterie, décorée selon la tradition saharienne, appartient à la plus ancienne phase à céramique du Later Stone Age ouest-africain, bien avant le début d'une production alimentaire. Vu que ce site ne devait étre occupé que par des pionniers aventurés dans un paysage largement amphibie à la faveur d'un mince cordon émergé, la colonisation de l'espace antérieurement couvert par le Méga-Tchad, débute le long d'un large front vers 2000 ans BC.Les trouvailles archéologiques et paléoécologiques de deux tertres anthropiques à Gajiganna sont décrites commes études de cas illustrant cette phase, qui précède celle du célèbre site de Daima.

     

The Pleistocene Later Stone Age south of the Limpopo River

The earliest Later Stone Age (LSA) industries from southern Africa are microlithic and unstandardized and include the bipolar technique. The dating of these industries is controversial and the earliest microlithic industry is said to occur at Border Cave at about 39,000 B.P. By 18,000 B.P. a bladelet tradition was established and this was replaced in many parts of southern Africa, at about 12,000 B.P., by a widespread and prolific nonmicrolithic industry, characterized by side-struck flakes. The late Pleistocene environment was colder than present, with particularly harsh conditions during the Last Glacial Maximum (LGM), between about 20,000 and 18,000 B.P. Populations may have been isolated because archaeological visibility is low during the LGM and decreases further after the LGM. After 13,000 B.P. there is a dramatic increase in sites and this implies that there may have been widespread colonization of territory previously unoccupied for tens of thousands of years. By the end of the late Pleistocene there was a change in hunting patterns, in parts of southern Africa, from an emphasis on the capture of large, gregarious grazers to an emphasis on small, solitary browsers. Social complexity increased during the late Pleistocene, and by 12,000 B.P. it seems possible that Stone Age people were observing some social practices recorded historically among Bushmen (San).     

石质文物表面墨迹的保护作用

在许多不可移动石质文物,尤其是石刻文字表面,因历代文人墨客的拓片留下了大量墨迹。这些墨迹是否对文物本体岩石有害?一直是保护工作者希望了解的问题之一。为此本研究开展了一系列调研和实验研究。通过对各地保存较完好的石刻表面的观察,可以发现石刻表面残留的墨迹具有某种保护作用;对模拟样块的SO2腐蚀实验结果表明,岩石表面的墨迹具有一定的阻止空气中腐蚀性气体侵蚀岩石的作用;盐迁移破坏实验也发现墨迹在某种程度上具有减小可溶盐结晶破坏岩石的作用。吸水率实验和电镜观察等结果显示,墨迹缓解岩石风化的机理主要是墨迹对岩石微裂隙具有填充和加固作用,使岩石的吸水系数降低,部分阻挡了可溶盐的入侵和聚集结晶。