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1.
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.  相似文献   

2.
Abstract We report preliminary results of our provenance study of marble from the Telephos Frieze of the Pergamon altar. The emphasis here is on the stable isotope geochemistry of marble. The obtained δ(13)C values (2.4 to 3.5‰) vary insignificantly. However, the δ(18)O values give two clusters. The isotopically light marbles (close to -9.5‰) derive from panels 1-8 and the heavy marbles (-3.5 to -1.0‰) derive from panels 11-50. Mineralogical, petrographic and geochemical investigations (accessory minerals, grain size distribution, rare earth elements) further refined the marble characteristics. In spite of certain differences observed (grain size distributions, isotopy and contents of certain elements) for the two marble groups, the present data support a common provenance. So far, east Aegean islands and the Marmara region are favored.  相似文献   

3.
ESR spectroscopy is one of the physicochemical techniques used to characterize archaeological white marbles and obtain information about their quarries of provenance. This is done by measuring selected spectral features of the Mn(2+) impurity ubiquitously present in marbles and developing a statistical classification rule from the variable vectors measured for a significant number of samples of known provenance (the quarry database). Now we show that the overall variability exhibited by the same spectroscopic features decreases rapidly with the linear dimensions of the sampled block and can be used to distinguish fragments belonging to the same piece of stone from those simply originating from the same quarry. Application of the method to the seven marble panels of the Donatello pulpit in Prato (Tuscany) shows that they have all been cut from the same single block and their different degradation must be ascribed to differential weathering and to the different conservation treatments undergone in the past. The limits and possible drawbacks of the method are also discussed.  相似文献   

4.
High surface finish quality of the produced slabs is generally desirable in the stone processing industry. This paper presents the results of an experimental investigation into the effects of mineralogical‐petrographical and chemical variables on the surface roughness and glossiness of some selected ornamental marbles subjected to grinding–polishing processes. For this purpose, a series of grinding–polishing procedures were performed on the slabs of three distinct marble types. Roughness and brightness measurements were carried out on predetermined surfaces of marble samples using a stylus profilometer and a glossmeter, respectively. Thin sections were examined by a polarizing microscope for mineralogical‐petrographical characterization of the studied marbles. Scanning electron microscopy was used to aid in the identification and characterization of the slab surface morphologies at each polishing stage. X‐ray diffraction and scanning electron microscopy with energy‐dispersive X‐ray spectroscopy were used for the determination of mineralogical and chemical compositions of the samples. Mainly because of the differences in textural and chemical compositions, different levels of microroughness and gloss values were observed for the studied marble varieties. The presence of different mineral phases such as the grain (i.e. calcite to calcite) and phase contacts (i.e. calcite to epidote) greatly affected the heterogeneity of the marbles, resulting with different removal mechanisms under the action of abrasive grits. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

5.
For the last 70 years, the authenticity of disputable marble objects has been tested by using a black light lamp. According to empirical observations “fresh marbles are purple while ancient ones are blue under the lamp”. This discrimination lacks scientific basis but is very popular because sculptured stone dating is impossible. This work aims to test the reliability of the “UV method” by studying the laser excited photoluminescence (PL) of marble surfaces. An argon ion laser beam was focused through a microscope objective onto the sample, offering a PL spatial resolution of 3 μm. Newly-cut marbles show an intense emission at 610 nm ascribed to Mn2+ and a less intense one at 390 nm. Excavated surfaces show the 610 nm emission and a broadband (380–530 nm) one. Similar broadband emissions due to humic (HAs) and fulvic acids (FAs) are typical in soil PL spectra and were observed in the spectra of samples taken from the soil surrounding the excavated surfaces. Additionally, electron paramagnetic resonance (EPR) spectra of excavated surfaces show a peak at g=2.0045, typical in calcite doped with humic acids. We presume that the 380–550 nm emission originates from HA and FA salts existing in the infiltrated soil or the recrystallised calcite developed in marble patinas. Finally, the application of the “UV method” on twelve ancient and modern surfaces proved that the technique is only partly reliable and should be used together with other analytical techniques. PACS 78.55.-m; 78.55.Hx; 81.70.Fy; 87.64.Hd  相似文献   

6.
The so-called sugaring of marble is a very common degradation phenomenon, affecting both historical monuments and modern buildings, which is originated by environmental temperature fluctuations. Thermal cycles are indeed responsible for micro-cracks formation at the boundaries between calcite grains, so that marble is subjected to granular disintegration and can be reduced to a sugar-like powder of isolated calcite grains by just the pressure of a finger. Since no effective, compatible and durable treatment for sugaring marble consolidation is currently available, in this paper a novel consolidating treatment recently proposed for limestone, based on the formation of hydroxyapatite inside the stone, was investigated for weathered marble. To test the new treatment on suitably decayed marble samples, some naturally sugaring marbles from the Monumental Cemetery in Bologna (Italy, nineteenth century) were firstly characterized by scanning electron microscope (SEM), mercury intrusion porosimetry (MIP) and ultrasonic pulse velocity (UPV) measurement. Then, artificially weathered samples were produced by heating fresh Carrara marble samples at 400 °C for 1 h. The effects of artificial weathering were characterized using the same techniques as above, and a very good agreement was found between microstructure and mechanical features of naturally and artificially weathered samples. Then, the hydroxyapatite-based treatment was tested on the so-obtained artificially weathered samples, and the treatment effects were characterized by UPV, MIP and SEM equipped with energy dispersive spectrometry and Fourier transform infrared spectroscopy. The hydroxyapatite-based treatment exhibited a remarkable ability of restoring marble cohesion and a good compatibility in terms of modifications in pore size distribution, which leads to regard this treatment as a very promising consolidant for weathered marble.  相似文献   

7.
We present laser-induced breakdown spectroscopic studies of variety of marbles extracted from Quetta region of Boluchistan, Pakistan using a Nd:YAG laser (532 nm) in conjunction with LIBS 2000 detection system. The emission spectra of Onyx (white spot) and Quetta Green Marble samples have been recorded as a function of laser irradiance. The elemental composition and their relative abundance in each sample are fond to be quite different. In Onyx (white spot), calcium dominates while in the Quetta Green marble magnesium is the dominant element. In addition the effect of the laser irradiance on the emission intensity, width and shift of the transition lines have been studied.  相似文献   

8.
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.  相似文献   

9.
An integrated microchemical–petrographic approach is here proposed to discriminate the provenance of archaeological pottery artefacts from distinct production centres. Our study focuses on a statistically significant sampling (n=186) of volcanic temper-bearing potteries representative of the manufacturing and dispersion among the islands of the Aeolian Archipelago during the Bronze Age. The widespread establishment of new settlements and the abundant recovery of Aeolian-made ceramic in southern Italy attest for the increased vitality of the Archipelago during the Capo Graziano culture (Early Bronze Age–Middle Bronze Age 2; 2300–1430 BC). Potteries from three of the main known ancient communities (Lipari, Filicudi and Stromboli) have been studied integrating old collections and newly excavated material. Volcanic tempers have been first investigated through multivariate analyses of relative abundances of mineral and rock clasts along with petrographic characters. In addition, we performed in-situ mineral chemistry microanalyses by Electron Microprobe and Laser Ablation—Inductively Coupled Plasma Mass Spectrometry to assess major and trace element composition of the most common mineral phases. Four Temper Compositional Reference Units have been recognised based on compositional trends. Two units (AI and AX) are unequivocally distinct by their peculiar trace element enrichment and petrographic composition; they mostly contain samples from the sites of Lipari and Stromboli, respectively. Units AIV and AVIII, restricted to the sites of Filicudi and Stromboli, show distinct petrographic characters but overlapped geochemical fingerprints.  相似文献   

10.
Concerning the transparent blue calcite crystals of blue marble from Madagascar, this work suggests that their cavities, accessorial quartz, and marble stress textures do not provide unambiguous characterization of the blue color compared to other white marbles. It is suggested that the presence of stronium (~850 ppm), barium (~18 ppm), vanadium (~10 ppm), and nickel (~2 ppm) might be considered influential chromophores for the blue color. Blue marble aliquots were characterized to determine their mineralogical, textural, and chemical composition to elucidate luminescence spectra and the causes of the blue color by use of different techniques.  相似文献   

11.
Committing stone protection to polymeric materials started in the sixties but the study and knowledge of the complex and multiple interactions between stone and polymers has only been carried out recently. Its important to note that, together with the factors related to the polymeric system itself, intrinsic properties of the stone substrate, like composition, porosity, and crystalline characteristics, play a relevant role. In this paper the issues related to protection of three different Italian marbles have been investigated: Candoglia marble, employed in the building of the Milan Cathedral, Carrara marble, widely used in sculpture and historical architecture, and S. Giuliano marble, used in the building of the Pisa Cathedral and its famous leaning tower. Specimens coming from blocks of the three quarried stones have been characterized, treated with two new partially fluorinated acrylic copolymers, 2,2,2-trifluoroethyl methacrylate/methyl acrylate (TFEMA/MA), and trifluoromethyl-2,2,2-trifluorethyl methacrylate/methyl acrylate (HFIMA/MA), and tested according to UNI-Normal Italian protocol. All the measurements including capillary water absorption, static contact angles, colour variation, water vapour permeability, and SEM morphological analysis have been carried out before and after the polymeric treatment. The aim of this work is to evaluate the protective efficacy of these two new partially fluorinated acrylic copolymers on the three different marbles, and to correlate the different behaviours with the polymers properties and with the stone substrates characteristics. PACS 61.41.+e; 81.05.Lg; 68.08.de; 68.60.wm  相似文献   

12.
Metabolomics is a rapidly developing branch of science that concentrates on identifying biologically active molecules with potential biomarker properties. To define the best biomarkers for diseases, metabolomics uses both models (in vitro, animals) and human, as well as, various techniques such as mass spectroscopy, gas chromatography, liquid chromatography, infrared and UV–VIS spectroscopy and nuclear magnetic resonance. The last one takes advantage of the magnetic properties of certain nuclei, such as 1H, 13C, 31P, 19F, especially their ability to absorb and emit energy, what is crucial for analyzing samples. Among many spectroscopic NMR techniques not only one-dimensional (1D) techniques are known, but for many years two-dimensional (2D, for example, COSY, DOSY, JRES, HETCORE, HMQS), three-dimensional (3D, DART-MS, HRMAS, HSQC, HMBC) and solid-state NMR have been used. In this paper, authors taking apart fundamental division of nuclear magnetic resonance techniques intend to shown their wide application in metabolomic studies, especially in identifying biomarkers.  相似文献   

13.
ABSTRACT

In this paper, the radiation shielding parameters such as linear attenuation coefficients (LAC, µ), mass attenuation coefficients (MAC, µ/ρ), effective atomic numbers (Zeff), effective electron densities (Neff), half value of layers (HVL), mean free paths (MFP) and buildup factors (exposure (EBF) and energy absorption (EABF)) were investigated for cream (M1), pink (M2), white (M3), maroon (M4) and green (M5) marbles. Attenuation coefficients were measured in the energy region 31.18–661.66 keV photon energies. The values of Zeff and Neff were then calculated using these coefficients with logarithmic interpolation method, and HVLs and MFPs were calculated using the values of LAC of marble samples at the same photon energies. The experimental results were compared with the theoretical values obtained from WinXCom program, and good agreements were observed between the experimental and theoretical results. HVLs and MFPs of all marble samples were compared with those of some concretes, glasses and commercial radiation shielding glasses (SCHOTT Co.). The studied marbles were better radiation shielding materials than standard shielding concretes due to lower HVL and MFP values lower than the ordinary concrete. Finally, EBFs and EABFs of the marbles were calculated in the energy region 0.015–1?MeV up to penetration depths of 40 mfps by Geometric Progression method (G-P), and the results were discussed in terms of photon energies and chemical compositions of the marbles.  相似文献   

14.
This interdisciplinary study focuses on a specific type of Roman coarse ware that was widely distributed in Bavaria, Austria and northern Italy during the 1st half of the 1st century AD. Various physical methods were applied to study the provenance of this characteristic marble tempered blackware and to assess its production techniques. The blackware found in large numbers on the Auerberg and at other sites in southern Germany can be identified as imported from East Tyrol, Austria.  相似文献   

15.
The attenuation of sunlight through different rock surfaces and the thermoluminescence (TL) or Optical stimulated luminescence (OSL) residuals clock resetting derived from sunlight induced eviction of electrons from electron traps, is a prerequisite criterion for potential dating. The modeling of change of residual luminescence as a function of two variables, the solar radiation path length (or depth) and exposure time offers further insight into the dating concept. The double exponential function modeling based on the Lambert-Beer law, valid under certain assumptions, constructed by a quasi-manual equation fails to offer a general and statistically sound expression of the best fit for most rock types. A cumulative log-normal distribution fitting provides a most satisfactory mathematical approximation for marbles, marble schists and granites, where absorption coefficient and residual luminescence parameters are defined per each type of rock or marble quarry. The new model is applied on available data and age determination tests.  相似文献   

16.
A new method involving Doppler spectroscopy with laser techniques is proposed to observe bound-state β-decay of tritium. This process, although theoretically expected to occur, has not yet been observed. The proposed method is, in principle, capable of exposing a finite mass of the neutrino. The low source temperatures and laser spectroscopic resolution necessary for a neutrino mass measurement, although extremely difficult to achieve, appear accessible with conceivable advances of these techniques. The underlying discussions and the writing of a first draft of this paper took place in 1982 during an exciting two-week stay of Solly Cohen at AT&T Bell Laboratories. His enthusiasm for fundamental physics and innovative experimentation encouraged discussions on many interesting problems, of which the present subject and paper are representative. This is the last physics paper bearing Solly's name. It is perhaps fitting that, in this work, Solly returned to the subject of bound-state β-decay on which he wrote one of his first papers, thirty years earlier in 1951. We miss Solly as a wise colleague, teacher and friend. Deceased.  相似文献   

17.
In this paper, a multi‐technique approach, at different scale of observation, is used to characterize a group of decorative stones and to permit to distinguish rocks with similar aspect but coming from different areas. In particular, the samples under study are sedimentary and metamorphic rocks, widely used as building blocks of modern and historical constructions and sculptures. The petrographic and mineralogical features of such rocks were performed by optical microscopy and Raman and Fourier transform infrared absorbance spectroscopies. These techniques permitted to obtain a complete structural, textural, and mineralogical characterization. At elemental level, the investigation was carried out by X‐ray fluorescence (XRF). In particular, XRF and Raman measurements were collected using portable instrumentations, whose advantages for the in situ analysis have been pointed out. The obtained results evidenced the high discriminant capability of the portable XRF for the decorative stones especially when this method is coupled with mineralogical and petrographic information. In this context, we propose to create a database for precious ornamental stones, which could be a starting point for a non‐destructive characterization, even useful for provenance study and/or certification of origin. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

18.
19.
Summary The aim of this paper is to present a high-sensitivity apparatus for measuring the thermal expansion of rocks, minerals and solids in general. The measurement of the magnitude of the linear expansion of a sample at any temperature of its heating-cooling cycle can be obtained with resolution equal to or better than 10 nm. Preliminary results on marble samples having different petrographic features are reported.  相似文献   

20.
Investigations of the provenance and technology of ancient materials are an important part of archaeological research. Studies of the geology of a region combined with petrographic research and chemical analysis may allow one to establish a possible source of raw-materials used. They also enable selection of the materials from currently accessible sources in the process of renovation or reconstruction of buildings [1–3]. Until now, the authors have carried out the studies in order to determine provenance of the raw-materials, the detailed analysis of composition (for the stone materials from Romanesque buildings in South Wielkopolska – Poland, and from ancient ruins in northern Israel and northern Egypt. Petrographic analysis (macro- and microscopic observations), cathodoluminescence (CL), X-raydiffraction (XRD) and stable isotopes analysis have been applied. In the next step, the detailed composition analysis enables, in the case of mortars, selection of suitable samples for dating [4, 9] and to determine the age of a given object, either directly by absolute dating (e.g. 14C of lime mortars) or indirectly, by relative age estimation on the basis of finds and artifacts (their components and characteristic style for a specific period). PACS 07.60 Pb; 78.60 Hk; 91.65 Dt; 91.60.-x; 07.85.Nc  相似文献   

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