Fluid control on low‐temperature mineral formation in volcanic rocks of Kahrizak,Iran

The Kahrizak volcanic field, south Tehran, in Iran, is composed dominantly of basalt and basaltic andesite that experienced variable degrees of alteration because of the low‐grade metamorphism (stage I) and hydrothermal activity (stage II). Stage I alteration, which occurred in response to the burial of volcanic rocks and their interaction with heated groundwater, is characterized by the formation of low‐temperature zeolite facies minerals in vesicles consisting mainly of fine‐grained mafic phyllosilicate (smectite, chlorite/smectite mixed layer) and zeolites (thomsonite, chabazite, gonnardite, natrolite, analcime, heulandite, and mordenite). Stage II mineralization occurred because of the activity of hydrothermal fluids that formed large crystals of heulandite, stilbite, mesolite/scolecite, natrolite, and analcime along with quartz and calcite in cavities and fractures. The elements necessary for the formation of alteration minerals (i.e. zeolites and mafic phyllosilicates) in Kahrizak were derived from the hydrolysis of olivine and volcanic glass as well as the alteration of plagioclase. Various mineral assemblages formed during stages I and II reflect changes in temperature, pressure, and fluid composition. The change from mafic phyllosilicates to zeolites species is caused by the decrease in Mg and Fe relative to Ca fluid activities. Zeolite assemblages of stage I, known to be formed at lower temperatures, show the general sequential order from older to younger: chabazite, thomsonite, gonnardite, and natrolite. This sequence is consistent with a hypothetical fluid evolution path with increasing Na⁺ relative to Ca²⁺ activity. The change to stage II, which consists of zeolites species (stilbite, scolecite, natrolite, mesolite, analcime, and heulandite) that formed at higher temperatures, can be attributed to a temperature increase and fluid influx caused by hydrothermal activity related to a later magmatic event in the region.     

再论唐代长江上游地区的荔枝分布北界及其与气温波动的关系

通过对相关文献的全面梳理和研究,本文认为唐代长江上游地区的荔枝分布北界并非此前学界所普遍接受的成都和万州一线,而只到达忠州(今重庆忠县)和涪州乐温县(今重庆长寿区)。唐代该地区的荔枝分布呈现集中于川江两岸峡谷的特点,这种分布格局与川江峡谷地区特殊的区域小气候直接相关,因此不能作为唐代气候较现在温暖湿润的证据。     

The earliest high-fired glazed ceramics in China: the composition of the proto-porcelain from Zhejiang during the Shang and Zhou periods (c. 1700–221 BC)

Bodies and glazes of 54 proto-porcelain sherds and 18 non proto-porcelain samples from Shang and Zhou periods production sites in Deqing, Zhejiang province were analysed by EPMA-WDS. The results indicate that the bodies of all samples were made from local raw material – porcelain stone, with the proto-porcelain samples being made from clay of higher quality. Wood ashes, high in lime and low in potash, were intentionally applied to the proto-porcelain samples, resulting in the formation of lime-rich glazes whose compositions were determined by a temperature-controlled mechanism. In contrast, kiln fragments and furniture show a potash-rich fuel vapour glaze, which formed unintentionally during use of the kiln. The firing temperature for most of the proto-porcelain glazes is around the maturing temperature for typical more recent lime glazes, showing that the potters were already at such an early time able to attain sufficiently high temperature in their kilns.     

Towards a Risk Management and Conservation Plan for the Djin Blocks at the World Heritage Site of Petra,Jordan: The Case of Djin Block No. 9

Cultural heritage is subjected to many pressures and risks. Over the past few years, the use of digital technologies has significantly changed the approaches to cultural heritage documentation for the purpose of condition assessment and conservation. The integration of novel approaches and techniques has permitted a detailed examination and assessment of damage, deterioration due to weathering and erosion, and their mechanisms. This study seeks to contribute to the preservation and conservation of the significant heritage of the so-called Djin Blocks at the World Heritage Site of Petra in Jordan. While these three dimensional cuboid rock-cut monuments have been subject to extensive conservation studies, this is the first time they have been subjected to 3D recording and multispectral photography, with the aim of recording damage caused by the ravages of time.

This study presents the results of the documentation of the case study Djin Block No. 9. A variety of systematic documentation techniques were used, including 3D recording with terrestrial laser scanning (TLS), close-range photogrammetry, multispectral imaging, and thermography records. In addition, pathological studies of the erosion from various causes and an analysis of the effect of weathering on Djin Block No. 9 are performed. Based on this data, the paper presents recommendations for developing risk management and conservation planning of Djin Block No. 9.     

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.     

On the provenance and manufacture of red-slipped fine ware from ancient Cassope (NW Greece): evidence by X-ray analytical methods

Energy-dispersive X-ray fluorescence spectroscopy was used to characterize red-slipped pottery (2nd–1st century BC) from ancient Cassope, north-western Greece. The compositional data were statistically treated by principal component analysis and chemical groups were established, representing locally produced and imported items. Mineralogical investigation by X-ray diffraction indicated firing temperatures in the range from 850 to 1000 °C for most of the sherds, while one group consisted of over-fired items, possibly in excess of 1050 °C. The morphology and elemental composition of the ceramic bodies and surface slips were examined through scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. The analyses revealed that different pottery groups exhibit surface slips of different nature, in terms of thickness, degree of vitrification and elemental composition. Overall, the diversity in technological characteristics of the examined sherds is indicative of the socio-economic conditions prevailing in Cassopaea during the late Hellenistic period.     

REGIONAL PATTERNS OF TEMPERATURE AND PRECIPITATION FOR NEWFOUNDLAND AND LABRADOR DURING THE PAST CENTURY

We have analyzed the mid-to-late 20th century instrumental record of winter and summer temperatures and precipitation for six stations representative of Newfoundland subregions and of central and coastal Labrador. In addition, these modern records have been extended into the 1800s by using portions of records from Belle Isle and the city of St. John's. For these two lengthier records, several ‘epochs' of alternating relatively high or low characteristic temperatures are distinguished, particularly for the winter season. The modern (post-1940) temperature records show that the mid-century warm period has been succeeded by a significant shift to predominantly colder winters over this entire region since about 1972. A concurrent decline in summer temperatures is restricted to Labrador and north-central parts of the island. With respect to other studies of recent climatic trends over northeastern Canada and the northwest Atlantic, our results demonstrate a significant correlation, at most of our study locations, between mean winter temperature and seasonally averaged values of the North Atlantic Oscillation (NAO) and the Baffin Island-West Atlantic Index (BWI). Comparative examination of the precipitation record for these stations also reveals subregional scale contrasts in the degree of variability and trend for annual and seasonal totals. For St. John's, representative series of total precipitation spanning the past century are analyzed for winter and summer; these series lack significant lengthy trends, although short-term precipitation variability is to some degree associated with the mean temperatures of the defined epochs. Since the 1940s, significant upward trends in total amounts and frequencies characterize the southwestern coast of the island for both winter and summer, and eastern Labrador in summer. The increased winter snowfall observed on the southwest coast during the past three decades is considered to be linked to a greater frequency of onshore synoptic airflow patterns accompanying the trend to predominantly positive winter NAO Index within this period. Nous avons analysé les relevés instrumentaux des températures hivernales et estivales et des précipitations qui ont eu lieu du milieu à la fin du 20^ème siècle dans six stations représentatives des régions de Terre-Neuve ainsi que du Labrador central et côtier. De plus, nous avons pu adapter ces relevés récents au 19^ème siècle en nous servant de relevés de Belle Isle et de la ville de St. John's. Dans ces deux groupes de relevés plus longs, on distingue plusieurs «époques » qui représented des températures caractéristiques (1) relativement hautes et (2) relativement basses - surtout en hiver. Les relevés récents de températures (après 1940) indiquent que la période chaude du milieu de siècle a été suivie par un changement remarquable caractérisé par des hivers plus froids depuis 1972 et dans toute la région. Une baisse simultanée des températures estivales se limite au Labrador et aux régions du centrenord de l'île. En ce qui concerne d'autres études sur les tendances climatiques récentes du nord-est canadien et du nord-ouest atlantique, nos résultats démontrent une corrélation dans la majorité des régions étudiées, entre les températures moyennes hivernales et les valeurs moyennes saisonnières de l'Oscillation Nord Atlantique (ONA) et l'Index île de Baffin-Atlantique Ouest (IBA). L'étude comparative des relevés de précipitations de ces stations révèle aussi des contrastes à l'échelle subrégionale dans le degré de variabilité et dans les tendances des totaux annuels et saisonniers. Pour St. John's, on analyse des séries typiques du total des précipitations hivernales et estivales sur l'ensemble du siècle dernier; on ne trouve aucune tendance significative dans ces séries, même si la variabilitéà court terme des précipitations est associée en partie aux températures moyennes des époques définies. Depuis les années 1940, on remarque que d'importantes augmentations des quantités totales et des fréquences des précipitations caractérisent la côte sud-ouest de l'île pendant l'hiver ainsi qu'en été. Le même phenomène se produit à l'est du Labrador en été. L'augmentation des chutes de neige sur la côte sudouest pendant les trois dernières décennies s'explique par des courants d'air synoptiques venant du large qui accompagnent la tendance positive prédominante hivernale de l'index de l'ONA pendant cette période.     

An archaeometric study of the Konya basin metallic ware through FTIR and XRD analysis with chemometrics: Central Anatolian Early Bronze Age ceramics

Fourier-transform infrared, X-ray diffraction and chemometrics were used to characterize the mineralogical composition and firing conditions of 59 Early Bronze Age ceramic sherds from the Konya Plain (Turkey). These include the Konya Basin Metallic Ware (KBMW) and a control group of contemporary local products. The analysis indicates significant differences in mineral inclusions and firing temperatures, with KBMW generally being fired above 800°C and characterized by standardized fabric recipes. Assessed together with other published evidence, these results indicate a high degree of specialization in the production of KBMW ceramic assemblages in central Anatolia during the third millennium BCE.     

Study on the Material and Manufacturing Technology of Different Types of Longquan Ware Imitations from Dapu Kiln of Guangdong Province in the Ming Dynasty of China (ad 1368–1644)

Research on ancient Longquan wares and their imitations has attracted considerable attention. Using a series of experimental methods, including micro X‐ray fluorescence spectroscopy (μ‐XRF), X‐ray diffractometry (XRD), optical microscopy (OM), polarizing microscopy (PLM), dilatometry (DIL) and spectrophotometery, different samples of Longquan imitations from Dapu in Guangdong Province were collected and analysed. The study of different types of celadon from the Dapu kiln factories shows that the pale yellow body had a higher TFe₂O₃ content, and the body material must therefore have been treated differently or have come from a different source. The SiO₂ and Al₂O₃ contents in the body can be used as auxiliary parameters to identify Longquan wares and its imitations. The study also found that both kinds of glaze recipe—including calcium–alkali glaze and alkali–calcium glaze—existed in the Dapu products, which suggested that while imitating Longquan ware, the potters in Dapu also showed innovation in the recipe for the glaze material. Moreover, there were some differences in the TFe₂O₃ content, as well as the size, number and distribution of bubbles in the different types of glaze. Finally, the study revealed that the material of both the saggars and separators were composed of another porcelain clay, different from that of the celadon body. In addition, the white and compact body of the celadon had a higher firing temperature, of 1140–1187 °C, compared with other types of wares, which had a lower firing temperature of 1050–1080 °C.     

博物馆内主要污染气体的检测及其分布状况的研究

采用常用的基准方法对文物具有普遍危害性的 S0_2,NO_2、O_2 进行了测定.研究了适宜检测博物馆内大气污染状况的 TEA 纸片法.运用了 TEA 纸片法对上海博物馆内二氧化硫和二氧化氮的分布状况进行了测定研究.