Unraveling the Core of The Gran Pirámide From Cholula, Puebla. A Compositional and Microstructural Analysis of the Adobe

2015 ◽  
Vol 1656 ◽  
pp. 41-50
Author(s):  
N. A. Pérez ◽  
L. Bucio ◽  
E. Lima ◽  
C. Cedillo ◽  
D. M. Grimaldi
Keyword(s):  
Amorphous Materials ◽  
Microstructural Analysis ◽  
Magic Angle Spin ◽  
Clay Fraction ◽  
Archaeological Site ◽  
Conservation Strategies ◽  
Magic Angle ◽  
X Ray ◽  
Mural Paintings ◽  
Starting Point

ABSTRACTThe Gran Pirámide, a Mexican cultural heritage site, is located at the archaeological site of Cholula, Puebla, Mexico. At the base of its platform this pyramid is the largest in the world. It was built in layers from 800 to 1100 AD by the Cholultecan pre-Hispanic culture. The archaeological site is famous by its great mural paintings that have been well-studied. The pyramid was built with earthen construction, a system of multiple bulding episodes with layers of adobe. The building material, adobe, has not been well studied. Due to its fragile condition, a more extensive study was conducted to understand the behavior of the building and the mural paintings substrate, in order to propose conservation strategies.Geological context of the area was the starting point to propose the relevant materials used in its construction. That was a fundamental key for the interpretation of the experimental techniques used that include X-ray Diffraction (XRD), Particle-Induced X-ray Emission (PIXE), 29Si and 27Al Nuclear-Magnetic Resonance with Magic-Angle Spin (NMR-MAS), Thermal Analysis, Optical and Scanning Electron Microscopy (SEM) and colorimetric measurements.The results obtained from the original adobes have been compared with fresh soils from horizons related with pre-Hispanic activity. The results indicate presence of amorphous materials and neo-mineral formation besides feldspars and opal. The amorphous phases have been identified by NMR-MAS and SEM.Differences were found in the composition from the adobe used for the joints, mainly in the clay fraction, that can be distinguished by color and that guided to group the information acquired.These results provide new information on the composition and microstructure of adobes from the Gran Pirámide of Cholula. Further studies will involve soil physics methods and erosion tests to complete the task of having a comprehensive knowledge of the earth architecture of the pyramid.

scholarly journals Characterization of Roman and Arabic Mural Paintings of the Archaeological Site of Cercadilla (Cordoba, Spain)

Scanning ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Andrea Gil-Torrano ◽  
Auxiliadora Gómez-Morón ◽  
José María Martín ◽  
Rocío Ortiz ◽  
Mª del Camino Fuertes Santos ◽  
...  
Keyword(s):  
Archaeological Site ◽  
Mural Painting ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mural Paintings ◽  
Thermal Zone ◽  
Chronological Sequence ◽  
Ft Ir ◽  
Materials Used

The archaeological site of Cercadilla (Cordoba, Spain) includes a complete chronological sequence from the 3rd to 12th centuries. The most relevant monument is a Roman palace dated between the end of the 3rd century and the beginning of the 4th century AD. It is believed that it was the headquarters of the Emperor Maximiano Herculeo. A bathtub with mural paintings has been found in the thermal zone of the palace. Regarding the occupation of the archaeological site in the medieval period, it should be pointed out that two houses with mural paintings were found; these belong to the Caliphal era (10th-11th centuries). During the Caliphal era, the archaeological site was mostly occupied by one of the large suburbs surrounding the walled city. Cercadilla was gradually abandoned; this process starts at the beginning of the 11th century. This study is focused on the analysis of pigments and preparatory layers of red and white mural paintings of the Roman period in the bath zone and on the analysis of pigments in mural paintings in two houses of the Caliphal era. In the thermal zone, the walls have a white mural painting with vertical and horizontal red bands, while the walls in the two Caliphal houses present the red mural painting decorated with white stripes. Techniques such as Optical Microscopy (OM), Scanning Electron Microscopy in combination with Energy Dispersive X-ray Microanalysis (SEM-EDX), X-ray Diffraction (XRD), micro X-ray Diffraction (μ-XRD), Wavelength Dispersive X-ray Fluorescence (WD-XRF), and Fourier Transform-Infrared Spectroscopy (FT-IR) have been used to study the mural paintings of this archaeological site. The results allowed to determine the composition of the materials used and to understand the differences between the technologies employed in Roman and Caliphal remains studied.

The X-ray photoelectron spectroscopy of ancient murals in the tombs at Beni Hasan, Egypt

1987 ◽  
Vol 65 (5) ◽  
pp. 1058-1064 ◽  
Author(s):  
K. M. Wilson-Yang ◽  
George Burns
Keyword(s):  
Photoelectron Spectroscopy ◽  
Archaeological Site ◽  
Photoelectron Spectra ◽  
Surface Layers ◽  
X Ray ◽  
The Past ◽  
Mural Paintings ◽  
Adsorption Of Water ◽  
Aluminium Silicates ◽  
Trace Components

The once colourful mural paintings at the Beni Hasan tombs (ca. 2100 B.C.), an important Egyptian archaeological site, are covered with an obscuring grey deposit. Qualitative observations made over the past 150 years were assembled and correlated with each other by us. Cumulatively, they indicate that recently the development of this layer has accelerated. To study this surface degradation, X-ray photoelectron spectra of fragments from the painted walls have been collected. Empirical XPS sensitivity factors have been employed to treat the data semiquantitatively. Three types of surfaces were identified. The first surface consists of CaCO3 and SiO2 as major constituents, and was the only surface identified previously. Our XPS data indicate that it also contains Al2O3, NaCl, MgO, sulphates, and phosphates as minor and trace components. The second surface consists predominantly of aluminium silicates. The third surface consists mostly of calcium carbonate. A preliminary mechanism for opaque layer formation is proposed herein. It suggests that the principal physicochemical processes are adsorption of water in the presence of carbon dioxide, followed by dissolution of the substrate walls upon which the murals were painted. This mechanism is consistent with our finding that mural deterioration is recent; it also indicates that deterioration is progressive, continuous, and cumulative. Further experiments are designed to verify the proposed mechanism. Two mechanisms proposed earlier are found to be inconsistent with at least some of our findings. Relatively recent efforts in removing obtrusive surface layers with dilute HCl were found to be performed carefully; there was no evidence of excess chlorides on cleaned surfaces. However, this finding does not provide a guarantee that murals were undamaged by HCl below the surface. It does suggest that progressive damage due to the formation of hygroscopic CaCl2 on the surface has been avoided.

Mechanism and Structural Analysis of the Thermal Activation of Coal-Gangue

2011 ◽  
Vol 356-360 ◽  
pp. 1807-1812
Author(s):  
Chi Zhang ◽  
Xiao Yi Yang ◽  
Yong Feng Li
Keyword(s):  
Emission Spectroscopy ◽  
Thermal Activation ◽  
Magic Angle Spin ◽  
Atomic Emission ◽  
Coal Gangue ◽  
Magic Angle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Scanning Electron

This paper presents a study of the thermal activation of coal-gangue. The samples were tested and analyzed using Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Magic Angle Spin Nuclear Magnetic Resonance (MAS NMR), Scanning Electron Microscopy (SEM), and Atomic Emission Spectroscopy (ICP-AES). Results indicate that the degree of coal-gangue activation varies with variations in the phase structure and coordination of aluminum at different temperatures.

Quantification of Crystallinity in Substantially Amorphous Materials by Synchrotron X-ray Powder Diffractometry

2005 ◽  
Vol 22 (11) ◽  
pp. 1942-1953 ◽  
Author(s):  
Cletus Nunes ◽  
Arumugam Mahendrasingam ◽  
Raj Suryanarayanan
Keyword(s):  
Amorphous Materials ◽  
X Ray

scholarly journals Provenance and Sedimentary Context of Clay Mineralogy in an Evolving Forearc Basin, Upper Cretaceous-Paleogene and Eocene Mudstones, San Joaquin Valley, California

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Andrew Hurst ◽  
Michael Wilson ◽  
Antonio Grippa ◽  
Lyudmyla Wilson ◽  
Giuseppe Palladino ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Upper Cretaceous ◽  
Clay Fraction ◽  
Clay Mineralogy ◽  
Bulk Rock ◽  
X Ray Diffraction ◽  
Arc Volcanism ◽  
X Ray ◽  
Magmatic Arc ◽  
Tropical Weathering

Mudstone samples from the Moreno (Upper Cretaceous-Paleocene) and Kreyenhagen (Eocene) formations are analysed using X-ray diffraction (XRD) and X-ray fluorescence (XRF) to determine their mineralogy. Smectite (Reichweite R0) is the predominant phyllosilicate present, 48% to 71.7% bulk rock mineralogy (excluding carbonate cemented and highly bio siliceous samples) and 70% to 98% of the <2 μm clay fraction. Opal CT and less so cristobalite concentrations cause the main deviations from smectite dominance. Opal A is common only in the Upper Kreyenhagen. In the <2 μm fraction, the Moreno Fm is significantly more smectite-rich than the Kreyenhagen Fm. Smectite in the Moreno Fm was derived from the alteration of volcaniclastic debris from contemporaneous rhyolitic-dacitic magmatic arc volcanism. No tuff is preserved. Smectite in the Kreyenhagen Fm was derived from intense sub-tropical weathering of granitoid-dioritic terrane during the hypothermal period in the early to mid-Eocene; the derivation from local volcanism is unlikely. All samples had chemical indices of alteration (CIA) indicative of intense weathering of source terrane. Ferriferous enrichment and the occurrence of locally common kaolinite are contributory evidence for the intensity of weathering. Low concentration (max. 7.5%) of clinoptilolite in the Lower Kreyenhagen is possibly indicative of more open marine conditions than in the Upper Kreyenhagen. There is no evidence of volumetrically significant silicate diagenesis. The main diagenetic mineralisation is restricted to low-temperature silica phase transitions.

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