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。     

A Rock‐Magnetic Quest for Possible Ore Sources for the Ancient Iron‐Smelting Industry in the Olkhon Region (Lake Baikal,Siberia)

Rock‐magnetic techniques were used to examine the topsoil layer of Kurma archaeological site (in the Olkhon region, on the north‐western coast of Lake Baikal, Siberia) in an effort to determine the possible sources of iron ores for iron‐smelting centres (at about the bc /ad boundary). Measurements have shown a magnetic enhancement of the topsoil due to magnetite grains resulting from weathering of strongly magnetic crystalline rocks. They have also revealed a preliminary picture of the distribution of strongly magnetic topsoils around the ancient iron‐smelting centres. Perhaps, in addition to traditional sources of raw materials, the ancient metallurgists used black sand talus as an ore deposit.     

高精度磁测在考古勘查中的应用

介绍了考古对象的磁性、磁异常特征及一般工作方法等。例举了在一些地区应用高精度磁测的情况和效果。以具体的实例证明该方法高效率、无损伤等优点的同时,进一步提出该方法在考古应用中应注意研究的问题。     

Magnetic Alteration of Soils by Late Holocene Hunter–Gatherer Groups (Tierra Del Fuego,South America)

The present work aims to analyse the magnetic signature from the Late Holocene open‐air archaeological deposits of hunter–gatherer ephemeral occupations. For this purpose, two profiles were sampled at the Marazzi 2 site in the north‐western Isla Grande de Tierra del Fuego, Chile, in order to carry out studies of magnetic susceptibility, hysteresis cycles, back‐field remanent magnetization, isothermal remanent magnetization and thermal variation of magnetic susceptibility at high and low temperature. Despite short‐term occupations, the P1 profile shows a magnetic peak at a depth of ~30–70 cm due to magnetite, probably formed by anthropogenic activity related to combustion. The P2 profile instead yields an anomalous peak of coercivity (at a depth of 20–40 cm), which could also be anthropogenic, due to the presence of finely dispersed ancient ‘red ochre’. The red ochre is proposed to form anthropogenic thermal alteration of goethite associated with volcanic ash, the remnants of which were found in thin sections from the P2 subsoil.     

Site Identification and Correlation Using Geoarchaeological Methods at the Cabeço do Porto Marinho (CPM) Locality, Rio Maior, Portugal

Several geoarchaeological techniques have been employed in evaluating an open-air site within a uniform sand matrix, near Rio Maior, Portugal. Electrical resistivity data, acquired at the Upper Palaeolithic site complex of Cabeço do Porto Marinho (CPM), delineated an important new occupational locus. This result was confirmed, first by auger testing which recovered subsurface artefacts, and then by direct excavation. In addition, 107 samples were recovered at the site for magnetic susceptibility measurements. Comparisons between magnetic susceptibility profiles from two loci, including the new area at CPM, show distinctive patterns which allow direct correlation between the occupation areas. These methods provide quick and inexpensive means for investigators to evaluate new sites or to correlate between and within sites, without resorting to other more time-consuming and expensive techniques.     

Magnetic imaging and electrical resistivity tomography studies in a Roman military installation found in Satala archaeological site,northeastern Anatolia,Turkey

Satala is one of the last great military centers in the Roman East available for archaeological and historical investigations. This archaeological site is situated on the crossing of two singularly important routes in North-East Asia Minor. Only little archaeological fieldwork in and around Satala has so far been carried out, thus delimiting our knowledge of the site and its role within the Roman military structure of the East. In order to provide further data on the site, we carried out geophysical surveys including the application of magnetic and electrical resistivity techniques in an area north of the Sadak village. The geophysical surveys within this area (supposedly part of the Roman military camp) proceeded in two stages. The first stage saw magnetic gradiometer imaging studies being carried out on 2.1 ha, measured by a Geoscan FM-36 fluxgate gradiometer by using 0.5 × 1 m grid intervals. For the second stage a different geophysical technique was used—resistivity tomography. Resistivity data were collected using a number of combined 2D resistivity pseudosections in the eastern part of the area which contained very regular magnetic anomalies. The 3D data were obtained by the combination of all survey lines collected from 2D data sets, and thereafter the arranged data were processed by using the 3D robust inversion modified from the smoothness-constrained algorithm. Electrical resistivity tomography investigations revealed that the buried archaeological structures might be located near the surface, except for some structures found in the middle of the studied area. The archaeological structures were furthermore determined by realistic model sections and volumetric representations. Magnetic imaging and electrical resistivity tomography surveys show that the combined usage of these techniques advances the understanding of archaeological structures beneath the surface.     

Integrated geophysical surveys for the subsurface mapping of buried structures under and surrounding of the Agios Voukolos Church in İzmir,Turkey

This work presents the results of the integrated usage of geophysics in the Agios Voukolos Church, one of the unique Orthodox constructions in ?zmir. The surveys had two main objectives: to define subsurface characteristics inside and around the church and search for possible structural damage such as cracks and fissures, that may exist in the subfloor of the church. Magnetic gradiometry, ground penetrating radar and electrical resistivity tomography were used in the investigations; this study is the first indoor application of magnetic gradiometry. The studies revealed that several suspicious relics and crypts might have existed under the floor of the church. In addition, investigations of the courtyard area indicated potential buried structures under the settling area of the church. This study demonstrates the importance of the integrated usage of non-destructive geophysical techniques in searching for possible hidden subsurface structures in standing historical buildings. In addition, magnetic gradiometry might be useful in indoor studies, assuming that there are no important magnetic sources near the site.     

Wissenstransfer durch Zentrenbildung. Physikalische Methoden in der Chemie und den Biowissenschaften

From the 1950s to 1970s, physical techniques replaced many classical methods in the chemical and biological sciences. In this development, a novel type of method‐oriented scientists emerged, relying on cooperation with instrument manufacturers and forging close links with science‐funding agencies. Their main engagement was the development of methods and the improvement of instruments, responding to the needs of the chemical and biomedical communities. In the United States, an important institutional locus of such method‐oriented scientists were instrument centers, providing service to regional and national groups of scientific users. This article analyzes the knowledge transfer involved in investigating the Biotechnology Resources Program of the National Institutes of Health, and presenting the example of one of these centers, the Stanford Magnetic Resonance Laboratory.     

Magnetic detection of ship ballast deposits and anchorage sites in King Herod's Roman harbour,Caesarea Maritima,Israel

Ballast stone deposits are a common feature of sediments in ancient harbour basins but are often overlooked as a potential source of archaeological information. Recent geophysical investigations at Caesarea Maritima in Israel have discovered a thick, laterally extensive ballast layer in the area seaward of the 1st c. BC Roman harbour. The ballast deposits were identified by low-relief mounds on the seabed with elevated magnetic intensities. Jet probing and excavation of magnetic anomalies at several locations revealed a 20–60 cm thick rubble layer containing large quantities of Late Roman and Byzantine pottery, local sedimentary boulders (kurkar sandstone, limestone cobbles) and foreign igneous and metamorphic boulders (granite, schist, volcanics; ca. 50%). The foreign boulders and pottery identify the rubble layer as ballast and ships refuse jettisoned by merchant ships outside the harbour. The strong magnetic contrast between the ballast deposits and the natural seabed sediments is attributed to the high magnetic susceptibility (>10⁻³ SI) of crystalline boulders and pottery materials within the ballast rubble.