Incipient Maya Burnt-Lime Technology: Characterization and Chronological Variations in Preclassic Plaster, Stucco and Mortar at Nakbe, Guatemala

1996 ◽  
Vol 462 ◽  
Author(s):  
Eric F. Hansen ◽  
Carlos Rodriguez-Navarro ◽  
Richard D. Hansen
Keyword(s):  
Critical Time ◽  
Cultural Development ◽  
Power Structures ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
Burnt Lime ◽  
Construction Methods ◽  
Random Aggregate ◽  
Middle Preclassic ◽  
Maya Site

ABSTRACTPatterned technological behaviors in the production and use of burnt-lime products can be characterized using optical microscopy and image analysis of pétrographie thin-sections to determine the texture (supplemented by X-ray diffraction analysis). Variations in technological styles have been identified in 21 samples from the ancient Maya site of Nakbe, Petén, Guatemala dating to the Middle Preclassic (1,000 B. C. - 300 B. C.) and Late Preclassic (300 B. C. - 150 A. D.) periods. Middle Preclassic floors exhibit a chaotic texture with a highly random aggregate particle size. Late Preclassic modeled stucco or painted fragments have a well-sorted texture with a low acid-insoluble content (<2%). Load -bearing mortar dating from the early Late Preclassic has a matrix with a high acid insoluble content (>15%), the major phases being quartz (-10%) and clays (∼5%). The variations correlate both with the time of occurrence and the function of the end-product. These issues of construction methods and levels of technology contribute data to aid our understanding of cultural development in this area at a critical time when the Maya were formulating power structures.

Chemical modification of the bacterial wall to determine sites of metal deposition

1978 ◽  
Vol 36 (2) ◽  
pp. 350-351
Author(s):  
T. J. Beveridge
Keyword(s):  
Electron Scattering ◽  
Metal Salt ◽  
Metal Deposition ◽  
Suitable Model ◽  
X Ray Diffraction ◽  
Subtilis Cell ◽  
Thin Sections ◽  
X Ray ◽  
Section Data ◽  
Metal Impregnation

The Bacillus subtilis cell wall provides a protective sacculus about the vital constituents of the bacterium and consists of a collection of anionic hetero- and homopolymers which are mainly polysaccharidic. We recently demonstrated that unfixed walls were able to trap and retain substantial amounts of metal when suspended in aqueous metal salt solutions. These walls were briefly mixed with low concentration metal solutions (5mM for 10 min at 22°C), were well washed with deionized distilled water, and the quantity of metal uptake (atomic absorption and X-ray fluorescence), the type of staining response (electron scattering profile of thin-sections), and the crystallinity of the deposition product (X-ray diffraction of embedded specimens) determined.Since most biological material possesses little electron scattering ability electron microscopists have been forced to depend on heavy metal impregnation of the specimen before obtaining thin-section data. Our experience with these walls suggested that they may provide a suitable model system with which to study the sites of reaction for this metal deposition.

Fabric Description of Archaeological Ceramics

2016 ◽  
pp. 199-216 ◽  
Author(s):  
Ian Whitbread
Keyword(s):  
Quantitative Data ◽  
Raw Materials ◽  
Thin Sections ◽  
Archaeological Ceramics ◽  
Qualitative And Quantitative ◽  
Rock Fragments ◽  
Construction Methods ◽  
Hand Specimen ◽  
Technological Analysis

Fabric description is fundamental to the characterization, technological analysis and provenance determination of archaeological ceramics. It encompasses description of the arrangement, size, shape, frequency and composition of ceramic material constituents. These properties are used to identify the raw materials, their processing, vessel construction methods, and firing conditions. The process of description should, so far as possible, be an objective record of observed fabric properties that is independent of interpretations concerning technology and provenance. Fabric descriptions are made of ceramics in hand specimen and of samples prepared as thin sections for examination under a polarizing microscope. Rapid evaluation of fabric properties in the field is achieved by studying hand specimens using a magnifying glass or stereomicroscope. Laboratory-based analysis of thin sections provides more accurate and comprehensive identification of fabric properties, especially mineral and rock fragments in coarse fabrics, in terms of qualitative and quantitative data.

scholarly journals Ceramic Micropalaeontology

2016 ◽  
pp. 265-287
Author(s):  
Ian Wilkinson ◽  
Patrick Quinn ◽  
Mark Williams ◽  
Jeremy Taylor ◽  
Ian Whitbread
Keyword(s):  
Organic Compounds ◽  
Depositional Environment ◽  
Local Environment ◽  
Integrated Analysis ◽  
Thin Sections ◽  
Archaeological Ceramics ◽  
Construction Methods ◽  
Individual Grains ◽  
Transportation Routes ◽  
Source Materials

Microfossils found in archaeological ceramics include representatives of kingdoms Fungi, Protista, Plantae, and Animalia and are composed of calcite, silica, or resistant organic compounds capable of withstanding firing. Methods by which microfossils are isolated for study vary considerably, but the best results involve the disaggregation of potsherds into their individual grains or by cutting petrological thin sections. Microfossils can be related directly to the age and depositional environment of the source materials (clays, temper, and slip) used in the manufacturing process, although the introduction of contaminants at the time of construction must also be recognized. When incorporated into an integrated analysis, the microfossils may demonstrate provenance; contribute to a better understanding of the local environment and landscape; identify transportation routes; contribute to an understanding of the technology used, including construction methods and firing; and elucidate the use to which the vessels were put.

Historical Perspectives of the Concept of Child and Technology Innovation

2011 ◽  
pp. 45-75
Author(s):  
Lee Allen ◽  
Denise L. Winsor ◽  
Sally Blake
Keyword(s):  
Technology Innovation ◽  
Historical Context ◽  
Cultural Development ◽  
Generation Gap ◽  
Power Structures ◽  
Historical Significance ◽  
Technological Advances ◽  
Educational Environments ◽  
The Social ◽  
Relationship Of

Technology has and does influence the social-cultural development of any population. Some see environment, social, cultural, or philosophical factors as the catalyst for the concept of child and technology innovation. Others view the concept of child and technology as the catalyst for change in social-cultural environments. In order to better understand the relationship of child and technology in a historical context, we must first understand the historical significance of technologies’ influence on culture and the development of child as a social influence. Often, as technological advances increase, the generation gap grows, as the concept of child changes to become a driving influence on educational environments. This chapter provides the historical context for the changing educational power structures influenced by technology and how the role of child has evolved from that of a small adult to a major social-cultural influence through the innovations of technology.

The petrology of the Mount Padbury mesosiderite and its achondrite enclaves

1966 ◽  
Vol 36 (276) ◽  
pp. 1029-1060 ◽  
Author(s):  
G. J. H. McCall
Keyword(s):  
Microscopic Analysis ◽  
Host Material ◽  
Refractive Indices ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Wide Range ◽  
Varied Range ◽  
Optical Determination

SummaryThe petrography of the Mount Padbury meteorite, previously briefly recorded, is described in some detail. Both the metalliferous host material of the mesosiderite and the varied range of silicate-rich, virtually metal-free enclaves (including both familiar achondrite material and unfamiliar achondrite material) are described. Eucrite, brecciated eucrite, and a peculiar ‘shocked’ form of eucrite (resembling some terrestrial flaser-gabbros) are the calcium-rich achondrite types represented; hypersthene achondrite (including typical diogenite material and unfamiliar material) and olivine achondrite (granular aggregates of olivine not entirely similar to the unique chassignite and single crystals up to 4 in. in length) are the calcium-poor achondrite types represented. The eucrite displays more or less uniform mineralogy, but the mineral constituents are present in varying proportions, and there is a wide range of textural variations recognized. The silicate grain fragments enclosed in the metallic reticulation to form the mesosiderite host material are, significantly, entirely of minerals seen within the achondrite enclaves—plagioclase, hypersthene, pigeonite, olivine, and tridymite.These results include microscopic analysis of thin sections and polished sections, X-ray diffraction studies, optical determination of refractive indices using mineral grain mounts, and chemical analyses.The wider implications of this new and unique meteorite find are briefly considered.

scholarly journals Parkinson’s disease is a type of amyloidosis featuring accumulation of amyloid fibrils of α-synuclein

2019 ◽  
Vol 116 (36) ◽  
pp. 17963-17969 ◽  
Author(s):  
Katsuya Araki ◽  
Naoto Yagi ◽  
Koki Aoyama ◽  
Chi-Jing Choong ◽  
Hideki Hayakawa ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Amyloid Fibrils ◽  
Lewy Bodies ◽  
X Ray Diffraction ◽  
Thin Sections ◽  
X Ray ◽  
Β Sheet ◽  
The Brain

Many neurodegenerative diseases are characterized by the accumulation of abnormal protein aggregates in the brain. In Parkinson’s disease (PD), α-synuclein (α-syn) forms such aggregates called Lewy bodies (LBs). Recently, it has been reported that aggregates of α-syn with a cross-β structure are capable of propagating within the brain in a prionlike manner. However, the presence of cross-β sheet-rich aggregates in LBs has not been experimentally demonstrated so far. Here, we examined LBs in thin sections of autopsy brains of patients with PD using microbeam X-ray diffraction (XRD) and found that some of them gave a diffraction pattern typical of a cross-β structure. This result confirms that LBs in the brain of PD patients contain amyloid fibrils with a cross-β structure and supports the validity of in vitro propagation experiments using artificially formed amyloid fibrils of α-syn. Notably, our finding supports the concept that PD is a type of amyloidosis, a disease featuring the accumulation of amyloid fibrils of α-syn.

Preclassic Round Structures of the Upper Belize River Valley

2000 ◽  
Vol 11 (1) ◽  
pp. 71-86 ◽  
Author(s):  
James J. Aimers ◽  
Terry G. Powis ◽  
Jaime J. Awe
Keyword(s):  
River Valley ◽  
Architectural Form ◽  
Maya Architecture ◽  
Belize River Valley ◽  
Preclassic Maya ◽  
Preclassic Period ◽  
The World ◽  
Middle Preclassic ◽  
Maya Site

Round structures are considered a rarity in Maya architecture. Four late Middle Preclassic period (650-300 B.C.) round structures excavated at the Maya site of Cahal Pech demonstrate that this was a common architectural form for the Preclassic Maya of the upper Belize River Valley. These open platforms are described, and compared to similar forms in the Belize Valley and elsewhere. An interpretation of their significance is offered that uses information from artifacts, burials, and ethnohistory as well as analogy with round structures in other parts of the world. We suggest that these small round platforms were used for performance related to their role as burial or ancestor shrines.

Preclassic Obsidian Procurement and Utilization at the Maya Site of Colha, Belize

2004 ◽  
Vol 15 (2) ◽  
pp. 222-240 ◽  
Author(s):  
David O. Brown ◽  
Meredith L. Dreiss ◽  
Richard E. Hughes
Keyword(s):  
Classic Period ◽  
Source Distribution ◽  
Broad Distribution ◽  
X Ray ◽  
Edxrf Analysis ◽  
Early Use ◽  
Middle Preclassic ◽  
Maya Site ◽  
San Martín ◽  
Obsidian Source

Abstract This study explores the early use of obsidian at the Maya site of Colha in northern Belize and the implications that variations in source distribution have for the site and its regional connections. Energy dispersive x-ray fluorescence (EDXRF) analysis of 104 specimens of obsidian from Preclassic contexts at the site identified El Chayal obsidian as the most common overall followed closely by that from San Martin Jilotepeque. Ixtepeque obsidian, not common in many Preclassic assemblages, was also strongly represented. The results revealed a Middle Preclassic dependence on San Martin obsidian gradually diminishing through the Preclassic to the Classic period, when San Martin all but disappears from the site. A corresponding increase in El Chayal obsidian use through time at Colha coincides with the rise of Kaminaljuyu in the Guatemalan highlands. Analysis of the obsidian by context indicated that El Chayal obsidian dominated in architectural and ritual deposits while Ixtepeque obsidian was the most common in workshops. San Martin accounted for a slightly greater percentage than El Chayal obsidian in middens, with Ixtepeque materials notably less common. The data indicate that Colha was connected to a broad distribution network from the Middle Preclassic onward, and that obsidian source variability was greater during the Preclassic than the subsequent Classic period.

MORTUARY RITUALS AND CRANIAL MODIFICATIONS AT CEIBAL: FROM THE EARLY MIDDLE PRECLASSIC TO THE TERMINAL CLASSIC PERIOD

2017 ◽  
Vol 28 (1) ◽  
pp. 305-327 ◽  
Author(s):  
Juan Manuel Palomo ◽  
Takeshi Inomata ◽  
Daniela Triadan
Keyword(s):  
Public Spaces ◽  
Skeletal Remains ◽  
Classic Period ◽  
Late Classic ◽  
Terminal Classic ◽  
Ceramic Vessels ◽  
Local Residents ◽  
Middle Preclassic ◽  
Maya Site ◽  
Terminal Classic Period

AbstractSkeletal remains excavated from the lowland Maya site of Ceibal, representing approximately 117 individuals, provide significant data for the study of changes in bodily treatments and mortuary practices from 1000b.c.toa.d.900. The early Middle Preclassic residents of Ceibal apparently did not bury their dead inside residential structures, which represents a burial practice different from those found at contemporaneous Belizean sites. During this time, tabular erect cranial deformations were found among possible local residents. Sacrificial burials were present by the end of this period, but skeletal remains of violent rituals deposited in public spaces increased from the Middle Preclassic to the Late Preclassic. During the Late Preclassic, tabular erect cranial deformations coexisted with tabular oblique shapes. The Classic period witnessed a prevalence of tabular oblique forms, which were probably tied to local residents. The common placement of the dead under house floors and the preference of ceramic vessels as burial goods also indicate Ceibal's strong affinities with other parts of the Maya lowlands during the Late Classic period. During the Terminal Classic period, there was a resurgence in the placement of sacrificial burials in public spaces and tabular erect cranial deformations were found in possible non-local individuals.

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