scholarly journals The case for reprecipitation of human bone as an event in a Bronze Age cist burial, Scotland

2014 ◽  
Vol 2 (1) ◽  
Author(s):  
Allan J. Hall ◽  
Lyn Wilson ◽  
Maureen E. Young
Keyword(s):  
Bronze Age ◽  
Organic Molecules ◽  
Human Bone ◽  
Aqueous Geochemistry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Field School ◽  
Landscape Research ◽  
Anoxic Environment ◽  
Archaeological Landscape

A hard whitish precipitate was observed on the lower part of the sandstone sidewalls and as pebble coatings in a Bronze Age cist burial near Forteviot, Strathearn, Scotland. The cist was discovered on excavation of a Neolithic henge in August 2009 during the joint Glasgow and Aberdeen Universities [Strathearn and Environs Royal Forteviot (SERF)] archaeological landscape research project and summer field school. Similar cists have not been found in this area. Scrapings of the precipitate proved on examination by powder X-ray diffraction to be hydroxyapatite. The mamillary material proved on examination by scanning electron microscopy to be calcium carbonate, calcite which had grown as groups of mm-size spheroids consisting of bundles of acicular crystals. Both components of the precipitate were also identified using oil immersion microscopy. Much organic material was preserved in the cist but neither (inorganic) bone nor teeth has been located to date (November 2010). The phosphatic mineral-precipitates provided the first confirmation that there had been bone and therefore an inhumation. Computational aqueous geochemistry using Geochemist’s Workbench confirms that the inorganic calcium phosphate component of human bone is soluble in acidic fluid and demonstrates how it can reprecipitate with change in fluid chemistry. Bone dissolution should be anticipated as being an expected early process when a human body produces an acidic fluid rich in organic molecules as it decays in an essentially closed, but wet, anoxic environment. Any precipitates on grave stonework should be identified as such material could represent human remains and could also provide evidence of environmental processes in the archaeological setting of a burial.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

The conversion of smectite to illite during diagenesis: evidence from some illitic clays from bentonites and sandstones

1985 ◽  
Vol 49 (352) ◽  
pp. 393-400 ◽  
Author(s):  
P. H. Nadeau ◽  
M. J. Wilson ◽  
W. J. McHardy ◽  
J. M. Tait
Keyword(s):  
Organic Molecules ◽  
Thickness Distribution ◽  
Sedimentary Rocks ◽  
Exchangeable Cations ◽  
Diffraction Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Of Burial ◽  
Particle Thickness ◽  
Scanning Electron

AbstractDiagenetic illitic clays from seven North American bentonites of Ordovician, Devonian, and Cretaceous ages and from three subsurface North Sea sandstones of Permian and Jurassic ages have been examined by X-ray diffraction (XRD) and transmission and scanning electron microscopy (TEM and SEM). XRD indicates that the clays from the bentonites are randomly and regularly interstratified illite/smectites (I/S) with 30–90% illite layers, whereas the clays from the Jurassic and Permian sandstones are regularly interstratified I/S, with 80–90% illite layers, and illite respectively. TEM of shadowed materials shows that randomly interstratified I/S consists primarily of mixtures of elementary smectite and ‘illite’ particles (10 and 20Å thick respectively) and that regularly interstratified I/S and illite consist mainly of ‘illite’ particles 20–50 Å thick and > 50 Å thick respectively. Regularly interstratified I/S from bentonites and sandstones are similar with regard to XRD character and particle thickness distribution. These observations can be rationalized if the interstratified XRD character arises from an interparticle diffraction effect, where the smectite interlayers perceived by XRD, result from adsorption of exchangeable cations and water or organic molecules at the interfaces of particles generally < 50Å thick. A neoformation mechanism is proposed by which smectite is converted to illite with increasing depth of burial in sedimentary rocks, based on dissolution of smectite particles and the precipitation/growth of ‘illite’ particles occurring within a population of thin phyllosilicate crystals.

Evolution structurale de la nacrite en fonction de la nature des molécules organiques intercalees

2000 ◽  
Vol 33 (6) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. Ben Haj Amara ◽  
H. Ben Rhaiem ◽  
A. Plançon
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Organic Molecules ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
Intercalation Process

Nacrite has been intercalated with two polar organic molecules: dimethyl sulfoxide (DMSO) andN-methylacetamide (NMA). The homogeneous nacrite complexes have been studied by X-ray diffraction (XRD) and infrared (IR) spectroscopy. The XRD study is based on a comparison between experimental and calculated patterns. The structures of the intercalated compounds have been determined, including the mutual positions of the layers after intercalation and the positions of the intercalated molecules in the interlayer space. It has been shown that the intercalation process causes not only a swelling of the interlayer space but also a shift in the mutual in-plane positions of the layers. This shift depends on the nature of the intercalated molecules and is related to their shape and the hydrogen bonds which are established with the surrounding surfaces. For a given molecule, the intercalation process is the same for the different polytypes of the kaolinite family. These XRD results are consistent with those of IR spectroscopy.

X-ray diffraction analysis of the effect of fluoride on human bone apatite

1963 ◽  
Vol 8 (4) ◽  
pp. 549-570 ◽  
Author(s):  
A.S. Posner ◽  
E.D. Eanes ◽  
R.A. Harper ◽  
I. Zipkin
Keyword(s):  
Diffraction Analysis ◽  
Human Bone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bone Apatite

Scanning electron microscopy and X-ray diffraction studies of human bone oxalosis

1980 ◽  
Vol 30 (1) ◽  
pp. 109-119 ◽  
Author(s):  
H. Jahn ◽  
R. M. Frank ◽  
J. C. Voegel ◽  
D. Schohn
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Bone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

scholarly journals Unique but diverse: some observations on the formation, structure and morphology of halloysite

Clay Minerals ◽  
2016 ◽  
Vol 51 (3) ◽  
pp. 395-416 ◽  
Author(s):  
G. Jock Churchman ◽  
P. Pasbakhsh ◽  
D.J. Lowe ◽  
B.K.G. Theng
Keyword(s):  
Organic Molecules ◽  
Recent Literature ◽  
Low Ph ◽  
X Ray Diffraction ◽  
Octahedral Sheet ◽  
X Ray ◽  
Structure And Morphology ◽  
Fe Content ◽  
Sheet Charge ◽  
Positively Charged

AbstractNew insights from the recent literature are summarized and new data presented concerning the formation, structure and morphology of halloysite. Halloysite formation by weathering always requires the presence of water. Where substantial drying occurs, kaolinite is formed instead. Halloysite formation is favoured by a low pH. The octahedral sheet is positively charged at pH < ∼8, whereas the tetrahedral sheet is negatively charged at pH > ∼2. The opposing sheet charge would facilitate interlayer uptake of H2O molecules. When halloysite intercalates certain polar organic molecules, additional (hkl) reflections appear in the X-ray diffraction pattern, suggesting layer re-arrangement which, however, is dissimilar to that in kaolinite. Associated oxides and oxyhydroxides of Fe and Mn may limit the growth of halloysite particles as does incorporation of Fe into the structure. Particles of different shape and Fe content may occur within a given sample of halloysite.

scholarly journals 14C Dating and Material Analysis of the Lime Burial of Cova de Na Dent (Mallorca, Spain)

Radiocarbon ◽  
2014 ◽  
Vol 56 (2) ◽  
pp. 387-398 ◽  
Author(s):  
Guy De Mulder ◽  
Roald Hayen ◽  
Mathieu Boudin ◽  
Tess Van den Brande ◽  
Louise Decq ◽  
...  
Keyword(s):  
Bronze Age ◽  
Simultaneous Thermal Analysis ◽  
Balearic Islands ◽  
Crushed Rock ◽  
Petrographic Analysis ◽  
X Ray Diffraction ◽  
14C Dating ◽  
X Ray ◽  
Bone Fragments ◽  
The Bronze Age

Lime burials are a characteristic phenomenon of the protohistoric funerary tradition on the Balearic Islands. At Cova de Na Dent, a lime burial has been sampled for analysis. The lime burial was made up of lime and fragmented bones. Six layers were sampled and described in the laboratory according to their color, the consistency of the deposition, and the aspect and quantity of the bone fragments. Bone samples and lime were dated. The lime was analyzed by using petrographic analysis, X-ray diffraction, FTIR spectroscopy, and simultaneous thermal analysis. The results show that the bones were cremated in the presence of crushed rock carbonate. The14C dates on the lime suggest an earlier chronology for this ritual, starting in the Bronze Age, as generally is accepted.

Quantitative Crystal Structure Analysis In The Electron Microscope

1987 ◽  
Vol 45 ◽  
pp. 434-437
Author(s):  
Douglas L. Dorset
Keyword(s):  
Electron Microscope ◽  
Structure Analysis ◽  
Organic Molecules ◽  
Analytical Techniques ◽  
Crystal Structure Analysis ◽  
Linear Polymers ◽  
X Ray Diffraction ◽  
Electron Crystallography ◽  
Small Organic Molecules ◽  
X Ray

Electron crystallography is a term which has emerged in the past few years to describe the quantitative structure analysis of microcrystalline preparations in the electron microscope. The field represents the confluence of two techniques, i.e. the ultramicroscopic capabilities of the electron microscope coupled with analytical techniques long in use by X-ray crystallographers. In the area of organic materials, the most visible success of the technique to date has been in the structure analysis of thin protein microcrystals typically to ca20 Å resolution but sometimes out to e.g. 7 Å and, in this field, there has been considerable effort by an increasing number of laboratories.Although the electron crystallography of small organic molecules and linear polymers has a much longer history than the application to globular proteins, one cannot cite an overwhelming enthusiasm for this technique, despite its promise as a probe for molecules which are not easily crystallized to sample sizes useful for single crystal X-ray diffraction measurements.

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