A Multi‐Method Database of the Black and White Marbles of Göktepe (Aphrodisias), Including Isotopic,EPR, Trace and Petrographic Data

A database of the ancient marbles of Göktepe near Aphrodisias is reported, and includes 160 white, black and bichrome samples from 13 quarries and two waste deposits. The quarries are grouped into four districts. Districts 1 and 2, to the north, produced exclusively black or dark grey marbles (nero antico). Districts 3 and 4 produced white statuary marble. Nero antico and a black and white stone were also quarried in district 4, where the black marble surfaces again. The samples were characterized using petrography, isotopic analysis, EPR spectroscopy and trace analysis. The Göktepe white exhibits an unparalleled combination of fine grain, low EPR intensity and high strontium concentration that often allows easy identification. The isotopic values are less distinctive and similar to those for Carrara. In most cases, however, they are tightly grouped and also quite indicative. The black marbles exhibit a much weaker metamorphic overprint. With respect to the white marbles, they show analytical similarities but also notable differences. Therefore, establishing their provenance can be more difficult and may require the support of petrographic analysis. The results suggest that the Göktepe marbles were among the most prized and widespread statuary marbles used in Roman times, particularly from the early second century ad onwards.     

The Asiatic marbles of the Hadrian's Villa at Tivoli

Multi-method provenance studies, including petrographic, isotopic, electron paramagnetic resonance and trace chemical analyses, have been carried out on 20 white, 9 black and 1 red artifacts purposely selected to investigate the use and distribution of sculptural marbles at the Hadrian's Villa. A large fraction of the marbles tested (21 samples, 70%) are shown to be from Asia Minor, mostly originating from the recently discovered site of Göktepe near Aphrodisias (15 or 71%). All the 9 black samples investigated and 6 out of 11 white Asiatic marbles are from Göktepe, the remaining being Docimium marble from Iscehisar (4 samples) and Aphrodisias marble from the city quarries (1 sample). The single red sculpture tested proved to be Carian red marble from the Iasos quarries, whereas non-Asiatic marbles include 3 Carrara and 6 Pentelicon samples. The selection of marbles tested is preliminary and incomplete, but, despite this, the results are noteworthy, especially since the marble of other sculptures from the Villa has already been identified as Göktepe. Together with other published results, the marble distribution at the Hadrian's Villa seems to suggest that the use of sculptural marbles in the Roman world underwent considerable changes around the turn of the 1st and the 2nd century AD. The evidence supporting this hypothesis is briefly summarized in the conclusions.     

Electric field sources in the quiet plasmasphere from whistler observations

Existing evidence for the ionospheric dynamo being the source of quiet time electric fields in the plasmasphere is reviewed. Part of a 24 h set of whistler data recorded continuously at Sanae, Antarctica (L = 4), during quiet magnetic (average K_p = 1) is analysed to obtain westward electric fields in the equatorial plane. These electric fields are examined as a function of L-value in order to infer their source. It is found that for periods of outward flow of plasma during the noon-midnight local time period, the electric fields are consistent with the dominant source being the ionospheric dynamo. There is some evidence that during the evening period of inward flow the electric fields are magnetospheric in origin, although this could also be consistent with a refined dynamo model. The observed whistler duct convection patterns do not fit either of two theoretical models, which invoke a magnetospheric field but not a dynamo field.     

ON THE WHITE AND COLOURED MARBLES OF THE ROMAN TOWN OF CUICUL (DJEMILA,ALGERIA)

This paper reports the results of an archaeometric study of the local and imported marbles found in the Roman town of Cuicul (now Djemila, Algeria), a research project funded by the Sixth Framework Programme of the European Union. Of the few imported coloured lithotypes that have been found, four are of Greek origin and one was imported from Asia Minor. In addition, two other classical Roman coloured stones found on the site are probably of local North African origin (most likely one from Numidia and one from Algeria). With regard to the grey and white marbles employed in the statuary and architecture, petrographic study in thin section and the δ¹³C and δ¹⁸O isotopic data emphasize the frequent use of the local fine‐grained lithotype from Filfila (Skikda) together with imported Greek lithotypes (i.e., Pentelic marble, the dolomitic variety of Thasian marble, and Parian marble from Lakkoi) as well as different varieties of the so‐called ‘greco scritto’, whose provenance in some cases still remains uncertain. In fact, the petrographic and geochemical features of the marbles do not always match those known for the classical ‘greco scritto’ from the quarry of Cap de Garde, near Annaba (Algeria).     

A QUANTITATIVE FABRIC ANALYSIS APPROACH TO THE DISCRIMINATION OF WHITE MARBLES*

Quantitative fabric analysis was applied in order to discriminate better among white marbles from various quarries of archaeological interest. This method provides an effective complementary tool to a characterization based upon petrography, cathodoluminescence microscopy and stable isotopes. Very good discrimination of marbles is achieved with the help of simple variables such as major axis and the shape-specific PARlS-factor. Using quantitative fabric analysis, marbles with similar cathodomicrofacies, as, for example, the Naxian quarries of Apiranthos, Koronos, Flerio and Kinidaros and the quarry of St. Beat (French Pyrenees), can be distinguished from each other. Marbles collected within one quarry may display dissimilar cathodomicrofacies. The common origin of such specimens can be determined with the aid of quantitative fabric analysis, as shown for the quarries of Kinidaros as well as St. Béat.     

POTENTIAL MAGNETIC SUSCEPTIBILITY AND FRACTIONAL CONVERSION STUDIES OF ARCHAEOLOGICAL SOILS AND SEDIMENTS*

Potential magnetic susceptibility (χ_MAX) and, hence, fractional conversion (χ_CONV) are shown to be critical in interpreting low‐frequency mass‐specific magnetic susceptibility (χ_LF) data. Results presented from 29 sites in the UK and one in Hungary encompass six types of investigation: Quaternary sedimentary stratigraphies, archaeological contexts, surveys of old ground surfaces, topsoil surveys of lithic scatter sites, topsoil prospection surveys and ‘natural’ topsoils. The findings highlight the wide range of χ_MAX values that may be encountered; identify factors affecting χ_MAX; demonstrate that χ_CONV provides a measure of enhancement resulting from burning; and identify environments in which χ_LF analysis is likely to be problematic.     

Consideration on the construction process and the sandstone quarries during the Angkor period based on the magnetic susceptibility

Detailed magnetic susceptibility measurement was conducted on the sandstones used for the Angkor monuments constructed in the period spanning the Preah Ko and Angkor Wat styles, and the construction process of the buildings and quarries of the sandstones was considered. Combined with the previous study on the sandstones of the Bayon style [Uchida, E., Cunin, O., Shimoda, I., Suda, C., Nakagawa, T., 2003. The construction process of the Angkor monuments elucidated by the magnetic susceptibility of sandstone, Archaeometry 45, 221–232], the magnetic susceptibility measurement revealed that there were 7 sandstone quarries corresponding to Stages I, II, III, IVa, V, VII and VIIIb during the Angkor period. The sandstones used for the monuments belonging to Stage I show average magnetic susceptibility values ranging from 1.1 to 2.3 × 10⁻³ SI units. In the Bakheng style period (Stage II), the average magnetic susceptibility of the supplied sandstones decreased gradually from around 10 to 1 × 10⁻³ SI units over time. The magnetic susceptibility range of the sandstones used for the monuments of Stage III was from 2.3 to 3.0 × 10⁻³ SI units. In the early Angkor Wat style period (IVb), the average magnetic susceptibility of the supplied sandstones increased over time, reflecting the supply of the sandstones from two different quarries, that is, the quarry corresponding to the Khleang and Baphuon style monuments (Stage IVa), with low average magnetic susceptibilities of 1.1 to 2.4 × 10⁻³ SI units, and the quarry corresponding to the main Angkor Wat style monuments (Stage V), with high average magnetic susceptibilities ranging from 2.8 to more than 4.3 × 10⁻³ SI units. The sandstones of Stage VII show low average magnetic susceptibility around 1 × 10⁻³ SI unit. The sandstones of Stage VId is a mixture of sandstones of Stages V and those of Stage VII. The sandstones with high magnetic susceptibilities are found in the monuments belonging to Stage VIIIb, reflecting the supply from the new sandstone quarry.     

À propos du colloque « The Machine as Model and Metaphor » Max-Planck-Institut für Wissenschaftsgeschichte Berlin,novembre 2006

Sans résumé ? Lève la peau, dissèque: ici commencent les machines. Puis, tu te perds dans une substance inexplicable, étrangère à tout ce que tu sais et qui est pourtant l’essentielle. ? Paul Valéry, Tel quel, Cahier B 1910 Ses recherches portent sur l’épistémologie, l’histoire des sciences et l’histoire de la philosophie à l’age classique (xvi ^e-xvii ^e siècles). Elle a notamment dirigé avec Walter Roy Laird, Mechanics and Natural Philosophy before the Scientific Revolution (Dortrecht/Boston/Londres, Kluwer Academic Publishers, 2007), puis, en collaboration avec Massimo Bucciantini et Michele Camerota, Mechanics and Cosmology in the Medieval and Early Modern Period (Florence, Olschki, 2007).     

Variety of Black and White Limestone Tesserae Used in Ancient Mosaics in Slovenia

This study concerns the microfacies characterization of white and black limestone tesserae from selected Roman floor mosaics in Slovenia, with the aim of defining their provenance. We investigated 42 tesserae from 15 different mosaics from the archaeological sites of Ljubljana, Izola, Mo?nje, Ptuj, ?rnomelj and ?entpavel, dated from the first century bc to the fifth century ad . Among the studied tesserae, 13 different microfacies were identified: eight black and five white. The most common were mudstones with ostracods (65% of black tesserae) and wacke‐packstones with miliolids (85% of white tesserae). The majority of the identified facies can be found in the Cretaceous successions of the Dinaric Carbonate Platform in south‐western Slovenia, north‐eastern Italy and south‐eastern Croatia, suggesting a regional or imported origin of the tesserae.     

Cultural Heritage Documentation and Conservation: Three-Dimensional (3D) Laser Scanning and Geographical Information System (GIS) Techniques for Thematic Mapping of Facade Stonework of St. Nicholas Church (Pisa,Italy)

This article reports the mapping of the stones, including marbles and brick masonry, used for building the facade of the medieval Church of St. Nicholas (XI century ad), one of the most interesting churches in Pisa, due also to the nearby famous octagonal bell tower. Mapping of stone materials was performed using a computer-aided design (CAD)/geographical information system (GIS) software package for storing and processing spatial information of the ashlars, obtained using three-dimensional (3D) laser-scanning data, combined with high-resolution images, and stone-to-stone observations. Based on collected data, the facade of the Church of St. Nicholas appeared mostly composed of rocks belonging to the metamorphic Tuscan sequence, quartzites, and marbles from Mt. Pisano area. Other types of rocks were also observed, as black limestones quarried at some kilometers northwest from Pisa in the Monti d’Oltre Serchio area, white Apuan marbles and Macigno sandstones. Conversely, intarsia appeared mainly made up of serpentinite and, subordinately, red limestones laid in white Apuan and Mt. Pisano marbles.     

Interpretation of optical substorm onset observations

The ionospheric location of substorm onset is generally found to be at the most equatorward arc in the poleward portion of the diffuse aurora. The observation that most activity occurs in this region provides a reference from which the source region in the magnetotail may be assessed. This reference can be examined in two ways. First, magnetic field mappings of these onset locations to the equatorial plane suggest that the onset is associated with processes quite near the Earth. For example, for 14 cases the average GSM X value was found to be ≈ −7.8 R_E. However, this identification is based on a static magnetic field model and while these results are consistent with some earlier findings there is not sufficient confidence in this technique to discriminate between topological regions in the magnetotail. A second way to examine the ionospheric onset location is in relation to the open/closed field line boundary. It is evident from Viking satellite images that optical substorm expansions can occur well equatorward of the poleward extent of emissions, both during quiet and active periods. There is no reason to suspect that this poleward region of emissions is not on closed field lines and that the onset location is therefore unrelated to the open/closed field line boundary, a result consistent with some (but not all) near-Earth mechanisms but only under some conditions with the distant tail boundary layer theory.     

Marble Pieces in the Romanesque Portal of Glory of the Santiago de Compostela Cathedral. New Data through a Multi-Analytical Approach

ABSTRACT

Probably the most important Romanesque artwork in Spain, the Portal of Glory of Santiago de Compostela is essentially made in granite, the most abundant stone in the NW of Iberia, with the only exception of five marble pieces. Different hypothesis on the origin of these marbles have previously been proposed based on visual assessment or by directly assuming a local source. To shed light on their quarry provenance, a multi-analytical study was performed combining polarized-light optical microscopy, cathodoluminescence microscopy, XRPD, SEM-EDS and stable C and O isotopes. The comparison of the results with the available databases reveals the use of marbles from the Estremoz Anticline (Portugal) in the three exquisitely carved columns strategically placed in the central arcade, whereas the other two pieces are local marbles, illustrating a more complex consumption of this noble material than that initially expected.     

NMR as a new tool for cultural heritage application: The provenance of ancient white marbles

Identifying the origin of marble used in antiquity brings back to light details of the economic, social and political organization of classical societies, and characterizing in depth the chemistry of marble is key to discovering its provenance. Beyond X‐ray diffraction, which could reveal the presence of discriminant secondary crystalline phases and the quantification of accessory minerals combined with a multivariate analysis approach, solid‐state nuclear magnetic resonance (NMR) enables one to recognize the local structure arrangement of both crystalline and amorphous materials by looking at one or more selected atoms. In present paper targets the ¹³C nuclide, and thus the major component of marble, calcium carbonate. Whatever their geological origin, marbles ¹³C‐NMR spectra present only one resonance corresponding to the carboxyl function whose intensity and line width vary from one marble to another. If the variation of the NMR signal intensity observed is the result of great T1 variations (from 220 to 5300 s) and is linked to iron content, the line width reflects defects in the calcite crystal in which calcium has been replaced by another element such as magnesium, aluminium or strontium. The specific profile of the NMR signal has been used successfully to help determine the origin of some archaeological items.     

Ionoluminescence and Cathodoluminescence in Marbles of Historic and Architectural Interest

Ion beam induced luminescence (IBIL) was applied, along with cathodoluminescence (CL), on seven samples of marbles of historic and architectural interest. The CL colours, observed in a cold cathode device, have been related to the IBIL spectra. Moreover, a detailed analysis of the IBIL spectral features has made it possible to disclose the influence of the chemical composition and to emphasize the crystal‐chemical role of the Mn²⁺. Beyond the chemical information and the crystal‐chemical interpretation, the spectra are recognized as being valuable in the field of archaeological studies for their significance as fingerprints of marbles, giving information on their nature and origin.     

WHITE,VEINED MARBLE FROM ROMAN AMMAIA (PORTUGAL): PROVENANCE AND USE

A multimethod approach using petrography and strontium (Sr) isotopic analysis was applied to determine the geological source of 17 marble artefacts from the Roman town of Ammaia (Portugal). All samples are calcitic, with dolomite, quartz and muscovite as accessory minerals. The marbles are characteristically medium‐grained with a maximum grain size (MGS) between 0.98 mm and 1.82 mm, have a heteroblastic texture, and have curved to embayed calcite grain boundaries. ⁸⁷Sr/⁸⁶Sr values of marble leachates range from 0.708488 to 0.708639. Comparison with Hispanic and Mediterranean marbles suggests the Estremoz Anticline as the most likely source for the Ammaia marble, especially for architectural marble. This hypothesis is supported by the geographical proximity of the Estremoz marble district and the long and expensive overland transport required for other marbles to reach Ammaia.     

Factors Determining Magnetic Enhancement of Burnt Clay from Archaeological Sites

The magnetic susceptibility of a collection of 212 archaeological samples of burnt clay of different origin (burnt soil, ovens and bricks) taken from 60 archaeological sites from Bulgaria, were studied in order to determine factors which may have affected their magnetic enhancement. The highest magentic susceptibility values were obtained for bricks, and the lowest for burnt soils, suggesting that the firing temperature and the duration of burning are important conditions for determining magnetic enhancement. Specific spatial pattern of the low-field magnetic susceptibility was also observed, characterized by separation of sites situated in northern and southern parts of the country, divided by the west-east trending mountain chain Stara Planina. Maximum susceptibility values are obtained for burnt soils in southern Bulgaria and minima in northern Bulgaria. In contrast, burnt clay plasters and bricks show the opposite picture. It is supposed that the observed pattern is due to differences in the outcropped geological formations and variable climate conditions between the two regions which determine different iron-supply during burning of initial clay material. Results from the thermomagnetic analyses show that the dominant ferrimagnetic mineral in all burnt clay materials studied, is magnetite/titanomagnetite with low Ti content and different grain-sizes. High values of frequency-dependent magnetic susceptibility indicate the presence of significant amount of fine-grained (d<0·015 μm) superparamagnetic magnetite.     

THE PROPERTIES AND IDENTIFICATION OF MARBLE FROM PROCONNESOS (MARMARA ISLAND,TURKEY): A NEW DATABASE INCLUDING ISOTOPIC,EPR AND PETROGRAPHIC DATA*

This paper reports an updated and enlarged archaeometric database of Proconnesos marbles with the aim of attaining more reliable inter‐ and intra‐site identification. Quarry and artefact samples (n = 397) from 23 different quarrying areas were characterized using petrographic, isotopic and EPR results. The most distinct property of Proconnesos marbles is their extremely weak EPR intensity, associated with the low concentration of Mn²⁺impurities. This feature, supported by the contribution of other important isotopic and petrographic variables, forms the basis for the correct identification of Proconnesos marbles. Within the site the distribution of properties is relatively homogeneous; only limited intra‐site discrimination is possible. All the experimental results, as well as the quarry samples are made available to other researchers willing to measure additional experimental properties, thus increasing the rate of within the site discrimination. Extensive survey has proved that, although about 10% of the samples exhibit maximum grain size below 1.0 mm, no locations exist where fine grained marbles could be intentionally quarried. The historical aspects of Proconnesos marble quarrying and usage are also discussed.     

Rocket-borne measurements of atmospheric infrared fluxes

In the Energy Budget Campaign two rockets, one from Andøya Rocket Range, Norway, and one from Esrange, Sweden, each carrying a liquid helium cooled infrared spectrometer, were simultaneously launched as part of salvo B. The launches occurred during the recovery phase of the last of four auroral magnetic events after a Joule heating criteria was exceeded. At Andøya, zenith radiance altitude profiles were obtained of nitric oxide (NO) near 5.4μm from 70 to 185 km (rocket apogee), of ozone (O₃) near 9.6 μm from 70 to 105 km (instrument sensitivity) and of carbon dioxide (CO₂) near 15 μm from 70 to 150 km (instrument sensitivity). Measured CO₂ spectra at 72 km are shown to compare favorably to those calculated for local thermodynamic equilibrium conditions and instrument resolution. By comparing Andøya and Esrange CO₂ radiance profiles it is shown that there is evidence for spatial variation in the emission. Further, it is shown that the very disturbed conditions of salvo B prior to and during these launches appears to have significantly changed the O₃ 9.6μm radiance profiles compared to previous rocket measurements in polar disturbed and quiet atmospheres. Using the nitric oxide radiance profiles and spectrum, previous rocket results and computed models it is shown that no radiance increase could be detected from prompt auroral energy deposition. The results support the thesis that the NO density in auroral regions is significantly enhanced over mid-latitude values and that for weak auroras, the reaction NO(v = 0) + O → NO(r = 1) + O is the dominant radiation mechanism.     

About the origin of high energy electrons in the inner radiation belt

A large flux of > 100 MeV electrons were registered in the inner radiation belt on low-altitude satellites. The origin of that flux is discussed. It appears that slow radial diffusion (D_o = 10⁻¹³ 1/s) gives a low probability for penetration of these electrons to small L from the boundary of magnetosphere because of synchrotron radiation energy losses. It is found that they can enter to the inner belt region without such losses after great magnetic storms when high speed radial diffusion sometimes takes place. Two great storms on 8–9 Feb.] 986 and 24 March 1991 are examples when one can directly observe a penetration of energetic electron fluxes into magnetosphere. The assumption about their Jovian origin is discussed.     

Experimental determination of CePO4 and YPO4 solubilities in H2O–NaF at 800°C and 1 GPa: implications for rare earth element transport in high‐grade metamorphic fluids

Monazite (CePO₄) and xenotime (YPO₄) are important accessory minerals in metasediments. They host significant rare earth elements (REE) and are useful for geochronology and geothermometry, so it is essential to understand their behavior during the metasomatic processes that attend high‐grade metamorphism. It has been proposed that F‐bearing fluids enhance solubility and mobility of REE and Y during high‐grade metamorphism. We assessed this possibility by determining the solubility of synthetic CePO₄ and YPO₄ crystals in H₂O–NaF fluids at 800°C and 1 GPa. Experiments used hydrothermal piston‐cylinder and weight‐loss methods. Compared to the low solubilities of CePO₄ and YPO₄ in pure H₂O (0.04 ± 0.04 and 0.25 ± 0.04 millimolal, respectively), our results indicate an enormous increase in the solubility of both phosphates with increasing NaF concentration in H₂O: CePO₄ solubility reaches 0.97 molal in 20 mol.% NaF, and YPO₄ shows an even stronger solubility enhancement to 0.45 molal in only 10 mol.% NaF. The greatest relative solubility increases occur at the lowest NaF concentration. The solubilities of CePO₄ and YPO₄ show similar quadratic dependence on NaF, consistent with possible dissolution reactions of: CePO₄ + 2NaF =  CeF₂⁺ + Na₂PO₄^? and YPO₄ + 2NaF = YF₂⁺ + Na₂PO₄^?. Solubilities of both REE phosphates are significantly greater in NaF than in NaCl at equivalent salt concentration. A fluid with 10 mol.% NaCl and multiply saturated with fluorite, CePO₄, and YPO₄ would contain 1.7 millimolal Ce and 3.3 millimolal Y, values that are respectively 2.1–2.4 times greater than in NaCl‐H₂O alone. The results indicate that Y, and by extension heavy rare earth elements (HREE), can be fractionated from LREE in fluorine‐bearing saline brines which may accompany granulite‐facies metamorphism. The new data support previous indications that REE/Y mobility at these conditions is enhanced by complexing with F in the aqueous phase.