Discrimination of Ceramic Surface Finishing by Vertical Scanning Interferometry

Finishing techniques are significant markers of the technological ‘know‐how’ involved in the production of the traditional, clay‐based ceramic ware. In order to provide a reliable tool to discriminate among two main surface processing techniques—that is, smoothing and burnishing—vertical scanning interferometry (VSI), a recently developed non‐destructive technique for analysing the surface roughness and topography, is applied. The smoothed areas have an obvious roughness expressed by linear structures. The latter are made of parallel ridges and trenches with an average depth of 15–20 μm. Burnishing leads to a lower topography and a lower roughness compared to the smoothed surface section. VSI quantifies the spatial distribution of the surface building blocks, which consist of phyllosilicate aggregates of variable size. The statistical treatment of the roughness data obtained by VSI shows that the surface topography provides significant information on the pottery processing and a clear qualitative and quantitative discrimination between different surfaces. VSI supports the reconstitution of the chaîne opératoire for traditional ceramic pottery and the recognition of the surface finishing techniques.     

Characterization and damage assessment of stones used in the Pasargadae World Heritage Site,Achaemenian period

The architectural remains at Pasargadae were built of three different stones classified according to their colors (beige, dark-gray, and green-gray). The stones show different macroscopic features, such as texture and decay patterns. The aim of this study is to identify the composition of the stones and to evaluate the main decay factors through petrographic studies in order to make conservation decisions more compatible. Petrochemical analyses show that the stones are in fact limestones with different features; two of them have a compact texture (beige and dark-gray stones), while the third has a fairly porous structure (green-gray stone). In some beige stone samples, dolomite was identified. Despite the fact that the presence of salt is a possible decay factor, X-ray diffraction analysis did not report any salt. According to SEM observations, the main reasons for decay in dark-gray and green-gray stones are the dissolution of calcite crystals and the swelling of clay minerals. The main decay factor in the beige stone, by contrast, is dissolution induced by microorganism activity. However, a patina formed by lichens on the surface of the beige stone, although aesthetically detrimental, protects it against further decay.     

Unveiling the Use of Creta in Roman Plasters: Analysis of Clay Wall Paintings From Brixia (Italy)

The paper describes the analysis of a particular kind of plaster from the walls of the Roman Sanctuary (first half of the first century bce ) in the centre of Brixia (now Brescia, Italy), which is an outstanding example of Roman Republican architecture. The walls were plastered and painted with different patterns, imitating marble panels and curtains. Optical microscopy on thin sections, X‐ray diffraction and infrared spectroscopy were performed on several samples of the plaster in order to reveal the execution technique. The palette consisted of glauconite, celadonite, Egyptian blue, and red and yellow ochres. In some cases, an organic compound, possibly a lipidic compound, was present in the external paint layer, as a surface treatment. The plaster contains two superimposed coats: the render coat with lime binder and sandy aggregate; the finish coat with a clay fraction (illite, chlorite, kaolinite), together with calcite from slaked lime and grains of quartz, silicate and carbonate rocks. Although Vitrivius' De architectura reported the use of creta (clay) as daub smeared on reed vaults, the Sanctuary of Brixia represents the first documented use in Roman buildings in a painted plaster laid on a stone masonry wall.     

苏家村遗址烧土样品的过火温度研究

烧土制品作为最早的人工建筑材料,使人类的居住环境得到了根本性的改善。然而,学界关于烧土建筑的成因存在人为烘烤处理、缘自火焚、废弃习俗等多种观点。通过科技手段研究烧土制品的过火温度,有助于科学分析烧土建筑的成因,探讨与之相关的建筑工艺,丰富史前建筑史研究。磁学研究表明,考古遗址中的土壤及其他沉积物在受热后新生成了磁铁矿、磁赤铁矿等强磁性矿物导致磁性显著增强,且矿物成分和磁性几乎不会再发生变化;但当重烧的温度接近或大于原始烧成温度时,样品中原始矿物的破坏或新矿物的生成,会引起矿物磁性的改变。基于这一原理,实验室内分析受热黏土的磁化率随再加热温度的变化特征,可反映烧土制品的过火温度。苏家村遗址是大汶口文化晚期至龙山文化中期早段一处重要的聚落遗址,遗址中第5层为厚约20～40 cm的红烧土层且覆盖整个遗址,推测为房屋倒塌造成的建筑垃圾堆积层或人为堆积层,出土大量烧土块。本研究利用X射线衍射分析法、X射线荧光光谱分析法和磁化率法等对苏家村遗址出土的烧土样品开展了组成及构造特征和样品的过火温度的综合分析。结果表明,苏家村遗址烧土样品中的白灰层中人为地添加了白色陶土原料,土层中有意地添加了植物残骸作...     

大同华严寺辽代彩绘泥塑颜料与胶结剂的科学剖析

为揭示大同辽代华严寺彩绘泥塑颜料及胶结剂的化学成分及调制应用组合,对华严寺薄伽教藏殿内的典型颜料层样品进行了综合剖析。利用超景深显微镜、扫描电镜-X射线能谱、显微拉曼光谱等对彩绘样品中的颜料部分展开分析。结果表明,红色颜料主要是铅丹(Pb₃O₄)和朱砂(HgS),绿色颜料主要是孔雀石[Cu₂CO₃(OH)₂]和氯铜矿[Cu₂(OH)₃Cl],而且这两种颜色存在着同色系的两种颜料混和使用的情况。蓝色颜料则为蓝铜矿[Cu₃(CO₃)₂(OH)₂],黄色颜料为雌黄(As₂S₃),金色区域则主要是由金(Au)构成;采用红外光谱和甲基衍生化-热裂解-气相色谱串联质谱技术对彩绘样品中的胶结剂成分进行检测。结果表明,金色区域的胶结剂主要是熟桐油和胶蛋白,说明其中存在着“金胶油”的传统贴金工艺;而其他红、绿、蓝、黄等彩色...     

Tracing firing technology through clay properties in Cuzco,Peru

The purpose of this study was to identify changes in firing practices that occurred during a timeframe that saw the introduction of European kiln technology to the Andes (AD 900–1800). Pottery from an excavated context at the archaeological site of Aqnapampa in the southern highlands of Peru was examined for changes in paste recipes that adapted local materials to increased firing temperatures indicative of evolving firing technologies. Sherds (60) and fragments refired to 890 °C from 12 stratigraphic levels were compared by style, surface treatment, paste color, and vitrification structures (ESEM). Four technological phases of the Cuzco pottery sequence emerged and were used to evaluate the trajectory of a single decorative style (Killke). Previously thought to have been produced in pre-Inca times and curated into later periods, the Killke sherds presented evidence that the style was produced using technologies introduced in the Inca and Spanish Colonial Period.     

RHX Dating: measurement of the Activation Energy of Rehydroxylation for Fired‐Clay Ceramics

In rehydroxylation (RHX) dating, the activation energy of the rehydroxylation reaction is required first in the estimate of a material's effective lifetime temperature (ELT), and second to correct the RHX rate constant obtained at a given measurement temperature to that at the ELT. Measurement of the activation energy is thus integral to the RHX methodology. In this paper, we report a temperature‐step method for the measurement of activation energy and develop fully the underlying theoretical basis. In contrast to obtaining the activation energy from a series of separate experiments (each of which requires the sample to be dehydroxylated prior to measuring the RHX rate constant), the temperature‐step method not only requires a single dehydroxylation at 500°C but also eliminates repeated acquisition of Stage I data, which are not required for dating purposes. Since the first temperature step is set to correspond to the temperature at which a dating determination is carried out, the measurement of rate constants at higher temperatures simply becomes an extension of dating. Consequently, the logistics of obtaining the activation energy of rehydroxylation are greatly simplified.     

Weakening processes in thrust faults: insights from the Monte Perdido thrust fault (southern Pyrenees,Spain)

The Monte Perdido thrust fault (southern Pyrenees) consists of a 6‐m‐thick interval of intensely deformed clay‐bearing rocks. The fault zone is affected by a pervasive pressure solution seam and numerous shear surfaces. Calcite extensional‐shear veins are present along the shear surfaces. The angular relationships between the two structures indicate that shear surfaces developed at a high angle (70°) to the local principal maximum stress axis σ₁. Two main stages of deformation are present. The first stage corresponds to the development of calcite shear veins by a combination of shear surface reactivation and extensional mode I rupture. The second stage of deformation corresponds to chlorite precipitation along the previously reactivated shear surfaces. The pore fluid factor λ computed for the two deformation episodes indicates high fluid pressures during the Monte Perdido thrust activity. During the first stage of deformation, the reactivation of the shear surface was facilitated by a suprahydrostatic fluid pressure with a pore fluid factor λ equal to 0.89. For the second stage, the fluid pressure remained still high (with a λ value ranging between 0.77 and 0.84) even with the presence of weak chlorite along the shear surfaces. Furthermore, evidence of hydrostatic fluid pressure during calcite cement precipitation supports that incremental shear surface reactivations are correlated with cyclic fluid pressure fluctuations consistent with a fault‐valve model.     

传统泥质铸型处理技术探源

金属成形加工技术是人类文明的杰出贡献,在中国,传统金属加工技术门类繁多,其中发展最深、应用最广的首推铸造技术。考古发掘与文物研究证明：中国悠远灿烂的青铜文化其基础为铸造技术,而泥质铸型处理技术又是中国传统铸造技术的关键之一。本文拟通过现存传统泥质铸型处理技术的研究、古代文献资料的分析、出土泥质铸型（陶范）的科学测试,对中国传统泥质铸型处理技术的形成作初步探源工作。     

徐州出土"祕府"封泥的封缄方法浅析

1995年 ,在徐州市东郊东甸子西汉一号墓中出土一枚封泥 ,上有阳文隶书“府”。本文对这枚封泥的封缄方法及相关问题进行了研究。