基于磁化率测量平遥古城古砖的烧制温度

古砖的烧制温度决定了其物理力学性质。本研究提出基于磁化率来确定古砖烧制温度的方法。通过对古砖重新加温,测量不同温度下古砖的磁化率,得到磁化率差值的平方-温度曲线图。图中第一个较大的偏差对应的横坐标即为古砖的烧制温度。利用上述方法测得实际烧制温度为700℃、800℃和900℃的黏土砖的烧制温度分别为690℃、810℃和870℃。二者误差较小,认为利用该方法确定砖的烧制温度可行。本研究利用该方法确定了平遥古城10块古砖的烧制温度,发现其烧制温度在650～690℃和850～870℃两个区间范围内。据此推测平遥古城古砖是以秸秆和木柴为燃料烧制而成。本研究实验结果可为古建筑修复和保护提供理论参考。     

How Was Edmond Halley’s Map of Magnetic Declination (1701) Constructed?

Edmond Halley made two scientific voyages in the Atlantic Ocean as captain of the HMS Paramore between 1698 and 1700. Following these voyages he published the first map showing lines of equal magnetic declination in 1701. Halley did not reveal how he constructed the map, however, and it remains unknown. In this study, a construction procedure is hypothesized that uses mathematical tools that were available in his day, namely arithmetical averages and Isaac Newton’s method of divided difference for fitting a polynomial curve to data. To enable his map construction, a method is suggested whereby Halley could have created new data to augment the situations where insufficient data were collected.     

Geophysics of Lager Wick forced labour camp,Grouville, Jersey,Channel Islands

Abstract

Three seasons of fieldwork at the forced labour camp of Lager Wick, Grouville, Jersey (2014–2016) employed resistivity, ground penetrating radar (GPR) and magnetic susceptibility to investigate areas of the camp. Resistivity and magnetic susceptibility produced the most useful results, whilst the GPR survey only revealed a modern pipe. The resistivity survey was undertaken in the south-west corner of the former camp close to the entrance gate posts, whilst the magnetic susceptibility survey was undertaken over the remains of one of the barrack huts along the Gorey Road frontage which had been burnt to the ground in 1943. The resistivity survey produced some high resistance anomalies that appear to resemble a demolition layer or a surface on which the huts were constructed. Magnetic susceptibility results showed zones of burning which appear to relate to the remains of one of the burnt huts; excavation revealed a stone/brick surface.     

地面核磁共振方法在石质文物保护中的应用

石质文物破坏问题不仅在于人为破坏和表面污染,更多来自自然因素对文物的破坏,例如,日晒雨淋、风沙吹蚀、地表水的冲刷、地震、地下水的侵蚀溶蚀。为对第六批全国重点文物保护单位阳华岩摩崖石刻露天石质文物病害进行探查,采用无损探测的地面核磁共振方法和探地雷达方法,直接找水的地面核磁共振方法成功探测出摩崖石刻依附岩体地层含水分布状况。探地雷达方法探测出依附岩山体内岩溶、裂隙的发育状况。两种方法探测结果发现,石刻依附岩体内岩溶、裂隙发育,部分区域岩溶裂隙带已成为地下水汇聚场所或流通通道,对阳华岩摩崖石刻构成了极为严峻的侵蚀威胁。两种方法解释结果互为验证,研究结果为阳华岩摩崖石刻的病害治理和保护提供了宝贵的基础资料。     

Experimental Heating of Moravian Cherts and its Implication for Palaeolithic Chipped Stone Assemblages

The applicability of colour, magnetic susceptibility and remanent magnetization measurements for the identification of heated or accidentally burned Palaeolithic cherts from Moravia (Czech Republic) is tested in this study. We conclude that all these methods are usable. Colour changes are best detectable in materials heated at between 250–350°C, while magnetic susceptibility and remanent magnetization change at higher temperatures, closer to 600°C. This latter temperature, however, is usually destructive for cherts and is probably evidenced by accidentally burned artefacts. With the use of the three methods, we managed to identify three probably heated chert artefacts from two early Upper Palaeolithic assemblages from Moravia.     

Images of buried graves in Bayat,Afyon (Turkey) from high-resolution magnetic data and their comparison with preliminary excavations

Dedemezari necropolis, the site of our study, is located in the west of Turkey near Afyon. Archaeologists think that it belongs to the Middle Bronze age. A high-resolution magnetic survey identified buried material highly accurately. In particular, anomalies, which are transformed by the analytic signal method, clarify the observed magnetic anomalies. Magnetic surveying was applied in three different areas in this study. The map of analytic signal-transformed anomalies presented good results on preliminary excavation in trenches A and B. Two types of graves are found in the study area. One is made of clay and the second is carved in the rocks. Shapes of the buried graves are mainly cylindrical and elliptical. Most of the magnetic anomalies are elliptical and reflect the shape of the buried materials. Future excavations in Dedemezari necropolis will be able to be carried out more easily due to the known locations of the buried graves.     

Archaeological geophysics of a Bronze Age agricultural landscape: the AROURA Project,central mainland Greece

Between 2010 and 2012, the AROURA project conducted magnetometric prospection in the ancient polder around the Late Bronze Age (ca. 1300–1190 b.c.) fortress of Glas, mainland Greece. As had been hypothesized, the anomalies detected were consistent with a system of agricultural fields. This system appears to have been irrigated and drained through previously identified hydraulic mechanisms in and around the polder. Comparison of soil profiles of anomalies with those of background areas, including their magnetic susceptibilities, corroborated magnetometric data. Anomalies were traced from sampled to unsampled areas through corresponding reclassified satellite bandwidths. Constituent sediments of features discovered were dated to the Late Bronze Age through AMS radiocarbon and OSL analyses. The results validated the use of extensive geophysics to detect and investigate ancient agricultural landscapes.     

Marine Magnetic Survey of a Submerged Roman Harbour, Caesarea Maritima, Israel

A marine geophysical survey was conducted at Caesarea Maritima, Israel, to map the buried structure of King Herod's Roman harbour. Magnetic surveys reveal the presence of an extensive hydraulic concrete foundation below the ruined harbour moles. The magnetic anomaly patterns indicate that the concrete foundation was laid out in header fashion along N-S and W-E trending segments to form two large 'artificial islands'. Magnetic lows within the structure identify baffles that were infilled with sand to stabilise the concrete foundation walls.
© 2004 The Nautical Archaeology Society     

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...