Investigation of surface laser treatment of ancient calcite: the case of the grave in Torricelle (Naples, Italy)

The laser-cleaning technique has been effectively employed in many areas. Recently it has led to a huge development in art restoration. However, this technique must be optimised to remove contaminations and encrustations from surfaces without generating any physical or chemical changes of the original material.Its use has been considered to clean a 4th century B.C. chamber gravesite in Torricelle, near Nola (Naples). The wall painting could not be seen owing to bioorganic surface layer and resinous material originated from surrounding pinewood. In order to evaluate the technique effectiveness we studied the interaction of the light from a Q-switched Nd: YAG equipped with SHG to work at wavelength of 532 nm.Several characterization techniques have been employed to verify the laser effect on the cleaning of the surface versus the operating parameter configuration and to evaluate the possible damages induced by the beam. In particular, micro X-Ray fluorescence (μXRF) provided information on the chemical composition of the clean surface; X-ray microdiffraction (μXRD) was used to identify the phases and their microstructures. These techniques were effective in assessing the quality of the cleaning process and for following the changes in the microstructure of the sample.Preliminary results suggest a possible influence of the laser on the aragonite–calcite transformation. PACS 61.10.Nz; 33.20.Rm; 42.62.-b; 61.66.Fn; 81.65.Cf     

Study of ancient mortars from the Roman Villa of Pollio Felice in Sorrento (Naples)

The study of ancient mortars is an important aspect of building conservation: the choice of the materials has varied according to historical period, regional habits, and their specific function in the structure. Ancient mortars are composites, comprising hydraulic or aerial binding materials, and aggregates, passive or active, which may react with binding material. Moreover, they were modified during setting, hardening, and aging, according to processes not yet well known. In this paper, we present a study of ancient mortars from the Villa of Pollio Felice of Sorrento (Naples). The analysis has been performed by conventional techniques (grain-size distribution, lime-percentage analysis, optical and electron microscopy, and X-ray diffraction) and by means of a laboratory X-ray microdiffractometer equipped with an image plate detector. This system, applied for the first time to archaeological studies, can reach a spatial resolution of a few tenths of microns and it allows us to obtain separate phase identification of binder and filler particles. PACS 07.85.Nc; 61.10.Nz     

Raman Microspectroscopic study of Iberian pottery from the La Vispesa archaeological site,Spain

Raman microspectroscopy has been employed for the characterization of 16 samples of ancient Iberian pottery. These sherds of vessels were found in the archaeological site of La Vispesa in Tamarite de Litera (Huesca, Spain) and correspond to the Iberian time. The composition of certain mineral phases such as non‐plastic inclusions has been particularly considered with a view to obtaining information on the source materials and their provenance, as well as the technological conditions of ceramic production. Typical minerals such as calcite and quartz were found in most of the samples. The presence of anatase in a group of the samples suggested the use of different clays in the production of the vessels. Furthermore, the absence of rutile in these samples, together with the identification of calcite, is indicative of a mild firing temperature. Hematite was identified in all samples, both in the ceramic body and in the decoration. Differences in the position of the bands and relative intensities characterized hematite in terms of crystallinity and origin. An attempt to assign the samples to different production centers was made according to their chemical composition and morphology. Copyright © 2011 John Wiley & Sons, Ltd.     

Ancient silver extraction in the Montevecchio mine basin (Sardinia, Italy): micro-chemical study of pyrometallurgical materials

Different pyrometallurgical materials such as slags, refractory materials and thermally treated lead ores likely related to smelting and extractive processes and chronologically related to Punic and Roman periods (IV–III BC) have been found at Bocche di Sciria and Conca e Mosu in the Montevecchio mine basin (south western Sardinia, Italy), where archaeological findings and classical authors locate extractive metallurgy activities since pre-Roman times. By means of the combined use of X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDS), selected-area X-ray photoelectron spectroscopy (XPS) and optical microscopy (OM), micro-chemical and micro-structural investigations have been carried out in order to identify the nature of the pyrometallurgical materials, to decipher the processes carried out there and their technological steps and to determine the technological level of competence reached by the ancient metallurgists. The results confirm that the findings can be associated with smelting and extractive processes carried out close to the metal ore deposits first for the argentiferous lead production and, then, for the silver recovery via a cupellation process. Finally, the results disclose the high level of technological competence of the ancient metallurgists able to carry out complex high-temperature processes to treat the argentiferous lead ores and to recover low amounts of silver via high-temperature lead-selective oxidation.     

Petrographic characterization and provenance determination of the white marbles used in the Roman sculptures of Forum Sempronii (Fossombrone,Marche, Italy)

The Roman municipium of Forum Sempronii (Fossombrone, Marche) was located along the ‘Via Consolare Flaminia’, in the stretch of road where it ran along the final sector of the valley of the River Metauro (Mataurus). The ancient colony of Forum Sempronii, which is cited by Strabo, Pliny, and Ptolemy, was found in the second century BC, probably on the site of an earlier community and its activity continued until the end of the fifth century AD. During ancient and more recent archaeological excavations, many fragments of coloured stones and marbles, and some white marble sculptures have been unearthed. In this paper, we report the results of the provenance identification of the white marbles used for the sculptures found in the archaeological site of Forum Sempronii and now displayed at the local archaeological museum. The determination of the source origin of the white marbles used for the sculptures has been established by mineralogical-petrographic and geochemical analyses. Microscopic study of thin sections together with carbon and oxygen stable isotope ratios indicate that more than one type of white marbles was used: Pentelikon, Lunense, and Thasian.     

Mössbauer study of archaeological ceramics from Valle del Alto Sinu (Colombia)

A physico-chemical characterization of ceramic samples from the arachaeological sites of El Cabrero, El Gallo, and El Frasquillo (Valle del Alto Sinú) is presented. Extensive use of Mössbauer spectroscopy data reveals that the currently used typological classification scheme of Dolmatoff is related to the production technology of the different artifacts. In addition, a model for firing conditions for “Rojo Sencillo”, “Tierra Impresa”, “Tierra Incisa”, and “Blanco” types of ceramics is proposed.     

Combination of wavelength dispersive X‐ray fluorescence analysis and multivariate statistic for alluvial soils classification: a case study from the Padanian Plain (Northern Italy)

Wavelength dispersive X‐Ray fluorescence analysis, coupled with multivariate statistics, has been used to characterise the alluvial soils of the easternmost Po Plain area. Coarse to fine sediments, which can be related to various depositional environments (paleochannels, interfluvial areas, brackish marsh interdistributary bays and littoral dunes), have been taken into consideration. Through the use of an extensive analytical database and the principal component analysis in combination with factorial analysis, a soil classification method is proposed, which can also help to constrain the depositional environment of the alluvial sediments. This methodology was subsequently validated using other wavelength dispersive X‐Ray fluorescence analyses of soils with different provenance and historical bricks made with alluvial deposits similar to those already studied. By relating the principal component analysis in combination with factorial analysis factors, we therefore provide a useful tool to integrate the classical and well‐established classification of alluvial deposits based on field observation and grain size investigations. Copyright © 2014 John Wiley & Sons, Ltd.     

Provenance and compositional analysis of marbles from the medieval Abbey of San Caprasio, Aulla (Tuscany, Italy)

A compositional study of twenty-two marble artefacts from the medieval Benedictine Abbey of San Caprasio at Aulla (North-western Tuscany, Central Italy) has been carried out. The mineralogical and petrographic analyses, the estimation of the maximum grain size of the calcite crystals, and the determination of carbon and oxygen stable isotopes support a provenance of most marbles from the Apuan Alps quarries (Italy). Only some marbles indicate a probable provenance from the islands of Paros and Thasos in the eastern Mediterranean area.     

Provenance study of obsidians from the archaeological site of La Maná (Ecuador) by electron spin resonance (ESR), SQUID magnetometry and 57Fe Mössbauer spectroscopy

Obsidians from major Ecuadorian sources (outcrops) were analyzed by electron spin resonance, SQUID magnetometry and ⁵⁷Fe Mössbauer spectroscopy. If the last technique allows to discriminate obsidians from the Quiscatola source, an association of ESR with SQUID magnetometry permits to differentiate obsidians from the sources of Cotopaxi volcano, from the Quiscatola and Mullumica-Callejones sources of the Chacana caldera and to infer that the 12 analyzed obsidians from the pre-Hispanic site of La Maná come from the Mullumica-Callejones source.     

Mössbauer,X-rays and SEM analysis of meteorites from the mineralogy museum of the University of Parma (Italy)

Five meteorites, belonging to the private collection of the Mineralogy Museum of the University of Parma have been analyzed by Mössbauer spectroscopy, X-rays diffraction X-rays fluorescence and by scanning electron microscope. Following standard classification they have been assigned to the ordinary chondrites class, L type, with different minor compositions.     

Micro-chemical and micro-structural investigation of archaeological bronze weapons from the Ayanis fortress (lake Van, Eastern Anatolia, Turkey)

Bronze weapons (VII cen BC) found during the archaeological excavation of the Ayanis fortress (lake Van, eastern Anatolia, Turkey) are investigated in order to determine their chemical composition and metallurgical features as well as to identify the micro-chemical and micro-structural nature of the corrosion products grown during long-term burial. Small fragments were sampled from the artefacts and analysed by means of the combined use of optical microscopy (OM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). The results show that the bronze artefacts have been manufactured by using alloys with a controlled and refined chemical composition demonstrating the high level metallurgical competence and skill of the Urartian craftsmen and artists. Furthermore, the micro-structural and metallurgical investigations evidence the presence of equiaxed grains in the matrix, indicating that the artefact were produced by repeated cycles of mechanical shaping and thermal annealing treatments to restore the alloy ductility. From the degradation point of view, the results show the structures and the chemical composition of the stratified corrosion layers (i.e. the patina) where the copper or tin depletion phenomenon is commonly observed with the surface enrichment of some elements coming from the burial soil, mainly Cl, which is related to the high concentration of chlorides in the Ayanis soil. The results reveal also that another source of degradation is the inter-granular corrosion phenomenon likely increased by the metallurgical features of the alloys caused by the high temperature manufacturing process that induces crystallisation and segregation phenomena along the grain boundaries.     

Application of multivariate statistical methods to classify archaeological pottery from Tel‐Alramad site,Syria, based on x‐ray fluorescence analysis

Radioisotope x‐ray fluorescence (XRF) analysis has been utilized to determine the elemental composition of 55 archaeological pottery samples by the determination of 17 chemical elements. Fifty‐four of them came from the Tel‐Alramad site in Katana town, near Damascus city, Syria, and one sample came from Brazil. The XRF results have been processed using two multivariate statistical methods, cluster and factor analysis, in order to determine similarities and correlation between the selected samples based on their elemental composition. The methodology successfully separates the samples where four distinct chemical groups were identified. Copyright © 2006 John Wiley & Sons, Ltd.     

Volcanic products of Lipari (Aeolian islands,Italy): Multivariate analysis of petrographic and radiometric data

A petrographic and radiometric study, along with statistical multivariate analysis of volcanic products of the island of Lipari (Aeolian islands, Italy) was carried out. The volcanological history of Lipari was reconstructed defining two stages (pre- and post-erosive stages) further on subdivided in four volcanic phases, each of which characterized by products with a particular chemical composition and separated by stratigraphic unconformities. The correlations between petrographic features, determined by X-ray fluorescence, and volcanological history of the island highlight a gradual differentiation with younger rocks showing a more acid chemical composition than the older ones. Radiometric features, and in particular the content of primordial radionuclides ²³⁸U, ²³²Th and ⁴⁰K, have been measured through gamma-ray spectrometry with hyper-pure germanium detector.The different volcanic lithologies, such as basalts, andesites and rhyolites, have been characterized by petrographic diagrams. The calculated dose rate has also been used as an additional classification parameter.Older products show low alkali content than the younger ones. This is related with the increasing of incompatible elements, such as uranium and thorium, in the younger products.Principal components and hierarchical clustering statistical analyses have provided additional information on sample differentiation and similarities.     

Geomagnetic turbulence at L'Aquila (Italy): Preliminary results of a variance analysis

Summary Some preliminary measurements of the geomagnetic turbulence at L'Aquila, in the range of frequency of micropulsations, have been conducted during November 1983. The 60 s variances of the horizontal components show a clear peak around the local noon, while the vertical component is better correlated with the local index of geomagnetic activity which, in the period of interest, has peak values in the afternoon and evening hours. Real-time ?alert? algorithms select the most significant events. These events, which tend to occur in the range of frequency of Pc 2 and Pc 3, perturb mainly the horizontal components and the field fluctuations is often oriented along the averageH. This activity is supported by the Ministero della Pubblica Istruzione (40%) and by the Gruppo Italiano di Fisica Cosmica del C.N.R.     

Characterization of blue decorated Renaissance pottery fragments from Caltagirone (Sicily,Italy)

Renaissance blue decorated pottery fragments from the archaeological site of Caltagirone (Sicily, Italy) were analysed by scanning electron microscopy – energy dispersive X-ray spectrometry (SEM/EDS). The samples were dated back to 16th century AD on the basis of archaeological observations. The micro-chemical analyses were performed on the ceramic body and the surface decorated layer of the samples. Particularly, the investigation was addressed the characterization of the coating blue decorations. The obtained results allowed us to clearly identify smalt as pigment. Also the presence of arsenic (As) was revealed and the Co/As ratio values were calculated and related to the different process used for the pigment preparation. Further spectroscopic analyses, performed through X-ray absorbance spectroscopy (XAS), carried out at the Co K-edge, confirmed the micro-analytical results and permitted us to identify the oxidation form and the local environment of cobalt atoms. PACS  81.05.Mh; 82.80.-d; 68.37.Hk     

材料化学分析的物理方法(Ⅱ)

原子核由一定数量的白旋为1／2的质子和中子组成．其总自旋视原子核的构成而各异自旋的原子核象个小磁体．无外加磁场时．原子核的自旋取向是随机分布的．加上一外磁场，则原子核的自旋取向受磁场的约束出现有规则的分布．以1H^1原子核为例．自旋，：1／2，在磁场下分为自旋为1／2和-1／2的两个分量．能量相差     

X‐ray fluorescence analysis on a group of coins from the ancient roman city of Tridentum (Trento,Italy)

A group of 83 coins, found in the archeological excavations of the ancient Roman city of Tridentum (Trento, Italy), was studied for the determination of their composition, finalized to their classification and cataloging. The coins, mainly made of copper‐based alloys, were minted between the republican period (II century BC) and the last decades of the western empire (V century AD). The X‐Ray Fluorescence archaeometric analysis has allowed a revision of the typological classification of the coins through the identification of six broad groups, each one characterized by a peculiar composition of the coins in the group. A tentative assignation of all the unreadable coins to one of the groups identified was proposed, in a way that could suggest also a possible dating of these coins. Copyright © 2014 John Wiley & Sons, Ltd.     

Investigation of environmental pollution effects on stone monuments in the case of Santa Maria La Blanca, Seville (Spain)

The aim of the study was to characterize specimens submitted to the effects of weathering in an urban atmosphere. Samples investigated were stones covered by crusts and deposits of thickness ranging from micrometers to millimetres due to traffic pollutants and mineral dust. The pieces were collected in the Church of Santa Maria La Blanca in Seville (South Spain). In the Historical Centre of this city, the traffic is the main source of sulphur oxides.     

A Raman spectroscopic study of the Mapungubwe oblates: glass trade beads excavated at an Iron Age archaeological site in South Africa

Oblate seed beads (2–4 mm) excavated on Mapungubwe hill, an Iron Age site in South Africa, were analysed with Raman microscopy and supportive techniques to determine the glass technology and pigments used to produce the beads. The Raman spectra and XRF analysis of the beads classify the glass as a typical soda/lime/potash glass similar to Islamic glass from the 8th century (Ommayad), but with higher levels of aluminium, iron and magnesium. The turquoise, bright green, bright yellow and orange colours were obtained by utilizing a combination of cassiterite (SnO₂) and lead tin yellow type II (PbSn_1−xSi_xO₃). Doping with cobalt and manganese produced dark blue and plum‐coloured beads. The Fe‐S chromophore was detected through its resonance‐enhanced spectrum in the black beads. Corrosion of the black beads was investigated and an organic phase detected on the beads, which might have influenced the corrosion process. This detailed profile of the glass technology used to produce the Mapungubwe oblates might eventually help to determine their provenance. Copyright © 2007 John Wiley & Sons, Ltd.     

Near-threshold equal-loudness contours for harbor seals (Phoca vitulina) derived from reaction times during underwater audiometry: a preliminary study

Equal-loudness functions describe relationships between the frequencies of sounds and their perceived loudness. This pilot study investigated the possibility of deriving equal-loudness contours based on the assumption that sounds of equal perceived loudness elicit equal reaction times (RTs). During a psychoacoustic underwater hearing study, the responses of two young female harbor seals to tonal signals between 0.125 and 100 kHz were filmed. Frame-by-frame analysis was used to quantify RT (the time between the onset of the sound stimulus and the onset of movement of the seal away from the listening station). Near-threshold equal-latency contours, as surrogates for equal-loudness contours, were estimated from RT-level functions fitted to mean RT data. The closer the received sound pressure level was to the 50% detection hearing threshold, the more slowly the animals reacted to the signal (RT range: 188-982 ms). Equal-latency contours were calculated relative to the RTs shown by each seal at sound levels of 0, 10, and 20 dB above the detection threshold at 1 kHz. Fifty percent detection thresholds are obtained with well-trained subjects actively listening for faint familiar sounds. When calculating audibility ranges of sounds for harbor seals in nature, it may be appropriate to consider levels 20 dB above this threshold.