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1.
Creating photo‐mosaics and plans of submerged archaeological sites quickly, cost‐effectively and, most importantly, to a high level of geometric accuracy remains a huge challenge in underwater archaeology. This paper describes a system that takes geo‐referenced stereo imagery from a diver‐propelled platform and combines it with mapping techniques widely used in the field of robotic science to create high‐resolution 2D photo‐mosaics and detailed 3D textured models of submerged archaeological features. The system was field tested on the submerged Bronze Age town of Pavlopetri off the coast of Laconia, Greece, in 2010. This paper outlines the equipment used, data collection in the field, image processing and visualization methodology.  相似文献   

2.
We present a new method to assess use‐wear formation processes of pounding tools used to break bones based on a combination of conventional microscopy, optical 3D surface measurements obtained with a confocal microscope and GIS analysis. The method involves 3D alignment and 3D surface change inspection techniques along with a surface morphometric characterization and 2D spatial pattern analysis, to measure the spatital distribution of significant changes in surface topography of pounding tools. Our results show that microscopic changes can be detected in the surfaces of hammers and anvils after bone breakage activities are performed. Use‐wear on the active elements (hammers made on basalt and quartzite) occurred over a larger area than was observed on the passive element (quartzite anvil), but the latter often exhibited deeper modifications. Tool surfaces generally developed smoother topography with increased use, but grain microfracture also appeared with greater frequency over time. This methodology offers highly accurate and statistically robust analyses of microscopic use‐wear traces that can be applied to the analysis of archaeological pounding tools.  相似文献   

3.
This paper presents a detailed elemental analysis of 64 glass beads and pendants dated to the Meroitic period (first–third centuries ad ) and the Nobadian period (fourth–sixth centuries) from burial sites in the Lower Nubian Nile Valley region. Laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) was used to determine the chemical composition of the glass and to gain knowledge about its origin. Four main glass types were identified: low‐alumina soda‐lime glass, high‐alumina glass, plant‐ash soda‐lime glass, and mixed‐alkali glass. Mineral soda‐lime glass (m‐Na‐Ca) of East Mediterranean/Egyptian provenance is dominant within the low‐alumina glass group from Meroitic and Nobadian periods. Mineral soda high‐alumina glass (m‐Na‐Al) appeared in the Nobadian bead assemblages, and the m‐Na‐Al 1 subtype was produced in Sri Lanka/South India. An initial insight into the origin of the glass beads in Nubia from the first to sixth centuries is described, indicating the first evidence for the presence of Asian objects in Nubia. The data obtained for the bead trade in North‐east Africa in this study has allowed a new light to be shed on the westward flow of Asian glass during a time of intensive maritime trade contacts with the wider Indian Ocean world.  相似文献   

4.
J. Cao  W. Hu  X. Wang  D. Zhu  Y. Tang  B. Xiang  M. Wu 《Geofluids》2015,15(3):410-420
In this paper, we attempt to differentiate hydrocarbon‐bearing reservoir horizons of the Junggar Basin of NW China based on the characteristics of diagenesis and associated elemental geochemistry. Reservoirs at this site have varying levels of oil saturation that correlate with the degree of dissolution in minerals (e.g., calcite and feldspar). Four different horizons with varying diagenetic mineral assemblages were observed, including (i) kaolinite‐rich, oil‐dominated horizons, (ii) kaolinite–pyrite–hematite‐rich, oil–water‐dominated horizons, (iii) siderite–chlorite‐rich, water‐dominated horizons, and (iv) chlorite‐rich horizons with negligible hydrocarbon production. The mean MnO content of the representative diagenetic mineral (e.g., calcite) in each of the above horizons is >2.5, 2.0–2.5, 1.5–2.0, and <1.0 wt%, respectively. We propose that the above methodology can be used for the identification of reservoir hydrocarbon‐bearing horizons. We argue that the indicators presented here can be applied in oil exploration across the Junggar Basin.  相似文献   

5.
M. Wojcieszak  L. Wadley 《Archaeometry》2018,60(5):1062-1076
Micro‐residue analysis of stone tools is generally performed with optical light microscopy and the visual observations are then compared with experimental, replicated pieces. This paper complements such archaeological research by providing physico‐chemical evidence. Raman spectroscopy and scanning electron microscopy have been used to confirm the presence of hematite on red‐stained medial and proximal parts of 71 000‐year‐old Still Bay bifacial tools from Sibudu Cave. Our results confirm the conclusion from optical light microscopy that the tools were hafted with an ochre‐loaded adhesive. However, we point to some instances when hematite residues are incidental or may be inclusions in the rock used to make the stone tools.  相似文献   

6.
High‐sulfidation vein gold deposits such as El Indio, Chile, formed in fracture arrays <1000 m beneath paleo‐solfatara in volcanic terranes. Stable isotope data have confirmed a predominance of magmatic vapor during the deposition of arsenic‐rich sulfide–sulfosalt assemblages in this deposit. These provide a unique opportunity to analyze the processes and products of high‐temperature volcanic gas expansion in fractures that form the otherwise inaccessible infrastructure deep inside equivalent present‐day fumaroles. We provide field emission scanning electron microscope and LA‐ICP‐MS micro‐analytical data for the wide range of heavy, semi‐metals and metalloids (arsenic, antimony, bismuth, tin, silver, gold, tellurium and selenium) in the complex pyrite‐enargite‐Fe‐tennantite assemblages from Copper Stage mineralization in the El Indio deposit. These data document the progressive fractionation of antimony and other heavy metals, such as bismuth, during crystallization from a sulfosalt melt that condensed from expanding vapor at about 15 MPa (150 bars) and >650°C following higher temperature vapor deposition of crystalline pyrite and enargite. The sulfosalt melt aggressively corroded the earlier enargite and pyrite and hosts clusters of distinctive euhedral quartz crystals. The crystallizing sulfosalt melt also trapped an abundance of vugs within which heavy metal sulfide and sulfosalt crystals grew together with K‐Al silicates and fluorapatite. These data and their geologic context suggest that, in high‐temperature fumaroles on modern active volcanoes, over 90% of the arsenic content of the primary magmatic vapor (perhaps 2000 mg kg?1) was precipitated subsurface as sulfosalt. Subsurface fractionation may also account for the range of exotic Pb‐Sn‐Bi‐Se sulfosalts observed in fumarole sublimates on active volcanoes such as Vulcano, Italy, as well as on extra‐terrestrial volcanoes such as Maxwell Montes, Venus.  相似文献   

7.
This paper addresses the technological choices observed in Mallorca (Spain) for the production of hand‐made pottery during the Late Bronze and Iron Age. We have conducted a diachronic analysis of the ceramic assemblages recovered from two archaeological sites placed in the same territory by means of X‐ray fluorescence and optical microscopy by thin‐section analysis. The archaeometric characterization of the hand‐made vessels allows us to establish several compositional groups related to the use of different raw materials and certain paste recipes associated with the archaeological sites and periods considered. Thus, this study evidences different productive strategies in each site and across time in the same geographical area.  相似文献   

8.
The spatial prediction of point values from areal data of the same attribute is addressed within the general geostatistical framework of change of support; the term support refers to the domain informed by each datum or unknown value. It is demonstrated that the proposed geostatistical framework can explicitly and consistently account for the support differences between the available areal data and the sought‐after point predictions. In particular, it is proved that appropriate modeling of all area‐to‐area and area‐to‐point covariances required by the geostatistical frame‐work yields coherent (mass‐preserving or pycnophylactic) predictions. In other words, the areal average (or areal total) of point predictions within any arbitrary area informed by an areal‐average (or areal‐total) datum is equal to that particular datum. In addition, the proposed geostatistical framework offers the unique advantage of providing a measure of the reliability (standard error) of each point prediction. It is also demonstrated that several existing approaches for area‐to‐point interpolation can be viewed within this geostatistical framework. More precisely, it is shown that (i) the choropleth map case corresponds to the geostatistical solution under the assumption of spatial independence at the point support level; (ii) several forms of kernel smoothing can be regarded as alternative (albeit sometimes incoherent) implementations of the geostatistical approach; and (iii) Tobler's smooth pycnophylactic interpolation, on a quasi‐infinite domain without non‐negativity constraints, corresponds to the geostatistical solution when the semivariogram model adopted at the point support level is identified to the free‐space Green's functions (linear in 1‐D or logarithmic in 2‐D) of Poisson's partial differential equation. In lieu of a formal case study, several 1‐D examples are given to illustrate pertinent concepts.  相似文献   

9.
The aim of this paper is to apply kernel density estimates (KDEs) to the visualization and interpretation of lead isotope data from bronze assemblages found along the northern border of central China, here designated as the Arc. New lead isotope analyses of 30 leaded tin–bronze artefacts from the Wangdahu cemetery (c.500–300 bc ) in the Ningxia Hui Autonomous Region, north‐west China, provide the basis for the discussion. By using multivariate KDEs and the calculated likelihood of the overlap, the present work shows that the Wangdahu objects feature a unique linear array of isotope ratios, representing an important element of overall bronzes from the Arc in the first millennium bc . This characteristic isotope signature is fundamentally different from that of Dajing ores in north‐east China, as well from that of early Qin bronzes in Shaanxi and Gansu provinces. This suggests that a variety of metal resources were utilized by peoples living in the Arc. The KDE approach thus proves effective at presenting and comparing lead isotope data.  相似文献   

10.
This article takes the reader on a journey into the historical writing of the ninth century Muslim historian al‐Dīnawarī (d. 895) and examines the motives behind composing his al‐Akhbār al‐?iwāl. The themes and narrative arrangements of this work give insight into al‐Dīnawarī's historical agenda that demonstrates his interest in royal histories that exemplify the rise and fall of nations, dynasties, and powerful rulers. Al‐Dīnawarī's emphasis on specific episodes and events demonstrates that only certain ethnic groups whose political legitimacy derives from a respectable and prominent origin can bring about political and social stability. By dealing with these sociopolitical concerns, this article also sheds new light on the intellectual discourses and political crises that dominated Islamic society during the eighth and ninth centuries and the way al‐Dīnawarī reacted to these challenges.  相似文献   

11.
Identifying the behavioural patterns of bone collecting animals is a crucial aspect of taphonomic studies. Although many studies have established criteria for identifying animal‐collected or animal‐modified bones, very few papers describe the distinguishing features of fox‐made bone assemblages. The bone assemblage collected in an inactive underground stone mine in Potok‐Senderki (Poland) is diagnostic of a red fox (Vulpes vulpes) den. This site provides an ideal opportunity to develop an understanding of the bone collecting behaviour of red foxes in cave‐like environments. This study showed that bones collected by red foxes are concentrated in clusters. The bones represent a broad spectrum of local fox prey species, with most bones showing the marks of gnawing. Each cluster may contain from <10 to >100 bones. Furthermore, the long axes of the bones in clusters frequently show specific orientation. The analysis of bones at this site might make an important contribution towards the establishment of baseline criteria for the identification and evaluation of fox‐accumulated bone assemblages. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

12.
The Dongsheng uranium deposit, the largest in situ leach uranium mine in the Ordos Basin, geometrically forms a roll‐front type deposit that is hosted in the Middle Jurassic Zhiluo Formation. The genesis of the mineralization, however, has long been a topic of great debate. Regional faults, epigenetic alterations in surface outcrops, natural oil seeps, and experimental findings support a reducing microenvironment during ore genesis. The bulk of the mineralization is coffinite. Based on thin‐section petrography, some of the coffinite is intimately intergrown with authigenic pyrite (ore‐stage pyrite) and is commonly juxtaposed with some late diagenetic sparry calcite (ore‐stage calcite) in primary pores, suggesting simultaneous precipitation. Measured homogenization temperatures of greater than 100°C from fluid inclusions indicate circulation of low‐temperature hydrothermal fluids in the ore zone. The carbon isotopic compositions of late calcite cement (δ13CVPDB = ?31.0 to ?1.4‰) suggest that they were partly derived from sedimentary organic carbon, possibly from deep‐seated petroleum fluids emanating from nearby faults. Hydrogen and oxygen isotope data from kaolinite cement (δD = ?133 to ?116‰ and δ18OSMOW = 12.6–13.8‰) indicate that the mineralizing fluids differed from magmatic and metamorphic fluids and were more depleted in D (2H) than modern regional meteoric waters. Such a strongly negative hydrogen isotopic signature suggests that there has been selective modification of δD by CH4±H2S±H2 fluids. Ore‐stage pyrite lies within a very wide range of δ34S (?39.2 to 26.9‰), suggesting that the pyrite has a complex origin and that bacterially mediated sulfate reduction cannot be precluded. Hydrocarbon migration and its role in uranium reduction and precipitation have here been unequivocally defined. Thus, a unifying model for uranium mineralization can be established: Early coupled bacterial uranium mineralization and hydrocarbon oxidation were followed by later recrystallization of ore phases in association with low‐temperature hydrothermal solutions under hydrocarbon‐induced reducing conditions.  相似文献   

13.
This paper evaluates the potential contribution(s) of faunal analysis to hominin palaeoecology at regional and continental scales, through an explicit investigation of the values, methods and conceptual frameworks of palaeoanthropology and their compatibility with real data structures. It employs a problem‐framing method developed in policy‐relevant science to establish a suitable research design for ‘large scale’ faunal analysis, before testing the method in a pilot study of 48 faunal assemblages from the African Plio‐Pleistocene. Hitherto, taphonomic bias has discouraged attempts to study faunal assemblages on large spatiotemporal scales, and most scientists have restricted their work to the smaller (site or local) scale and/or a subset of the total fauna. Furthermore, palaeoanthropological studies of fauna tend to address pre‐determined questions through analysis of statistical outputs (patterns), rather than investigating the limitations and potential of the data through exploratory work. This paper, despite identifying a number of inherent constraints on palaeocommunity analysis at the large scale—including a clear tendency towards the segregation of faunal assemblages along taphonomic and geographic lines—successfully defines palaeocommunities and identifies systematic variation in their distribution in several regional datasets and at the continental scale. It suggests that the potential viability of faunal analyses for a given project could be made empirically testable, and further work on the lines defined here might provide insight into the impacts of taphonomy and ecology at the large scale. Although there are conceptual and methodological problems associated with large‐scale faunal analyses, this paper suggests that they could provide some insight into hominin environments, evolutionary ecology and biogeography as part of a holistic, multi‐scale approach to our lineages' history. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

14.
It has been 10 years since the Indian Ocean Tsunami caused serious damage to the coastal areas in South and Southeast Asia. The effects on vegetation and human settlements in the affected areas were enormous. This study presents the results of an analysis estimating the long‐term recovery using two longitudinal remotely sensed dataset: 1. Moderate Resolution Imaging Spectroradiometer enhanced vegetation index (MODIS EVI), a dataset accounting for change in the landscape and vegetation; and 2. Defense Meteorological Satellite Program‐Optical Line Scanner (DMSP‐OLS) night‐time light data in order to estimate the effects on human and economic activities. It is evident from the results of this study that the night‐time light and vegetation index datasets can both be beneficial in identifying changes caused by natural disasters and can be used to track recovery. The results using night‐time light indicates a large loss of lighted area but also a rapid recovery of night‐time light after the tsunami. Already in year 2005–2006, the levels of lighted area and sum of the lighting (SOL) intensity reached the same levels as pre‐tsunami. For MODIS vegetation index, a drop can be observed in 2005/2006 on locations close to the coastline using 1 year temporal resolution; however, when utilizing the 16 day temporal resolution, the impact of the tsunami is illustrated as a dramatic drop, mostly in pixels located within 3km from the coast. Following the drop in vegetation index due to the tsunami, it was observed that most pixels exhibited at least some level of recovery in 2 years after the event.  相似文献   

15.
16.
B. Jung  G. Garven  J. R. Boles 《Geofluids》2014,14(2):234-250
Fault permeability may vary through time due to tectonic deformations, transients in pore pressure and effective stress, and mineralization associated with water‐rock reactions. Time‐varying permeability will affect subsurface fluid migration rates and patterns of petroleum accumulation in densely faulted sedimentary basins such as those associated with the borderland basins of Southern California. This study explores the petroleum fluid dynamics of this migration. As a multiphase flow and petroleum migration case study on the role of faults, computational models for both episodic and continuous hydrocarbon migration are constructed to investigate large‐scale fluid flow and petroleum accumulation along a northern section of the Newport‐Inglewood fault zone in the Los Angeles basin, Southern California. The numerical code solves the governing equations for oil, water, and heat transport in heterogeneous and anisotropic geologic cross sections but neglects flow in the third dimension for practical applications. Our numerical results suggest that fault permeability and fluid pressure fluctuations are crucial factors for distributing hydrocarbon accumulations associated with fault zones, and they also play important roles in controlling the geologic timing for reservoir filling. Episodic flow appears to enhance hydrocarbon accumulation more strongly by enabling stepwise build‐up in oil saturation in adjacent sedimentary formations due to temporally high pore pressure and high permeability caused by periodic fault rupture. Under assumptions that fault permeability fluctuate within the range of 1–1000 millidarcys (10?15–10?12 m2) and fault pressures fluctuate within 10–80% of overpressure ratio, the estimated oil volume in the Inglewood oil field (approximately 450 million barrels oil equivalent) can be accumulated in about 24 000 years, assuming a seismically induced fluid flow event occurs every 2000 years. This episodic petroleum migration model could be more geologically important than a continuous‐flow model, when considering the observed patterns of hydrocarbons and seismically active tectonic setting of the Los Angeles basin.  相似文献   

17.
Few microwear studies have been conducted on tools made from quartzite. Most rely on visual observation of microwear features using optical light microscopes and scanning electron microscopes. Quantification of microwear on quartzite tools is extremely rare, even though numerous methods to mathematically document surface roughness have been applied to other silicate tools. In this paper, laser scanning confocal microscopy (LSCM) was used to document surface roughness on four experimental scrapers made from two different subtypes of Mistassini quartzite that were used on either fresh or dry deer hide. Surface roughness data were analysed using area‐scale fractal complexity (Asfc). The results of this test case indicate that Asfc can effectively discriminate between the unused and used regions on the quartzite tools based on surface roughness, and that it can also discriminate between surface roughness produced by working dry versus fresh hides. Differences in the subtypes of Mistassini quartzite did affect surface roughness, but not significantly enough to prevent discrimination of the dry and fresh hide‐working tools. Although the use of the Asfc parameter for lithic microwear analysis requires further testing, these first results suggest it could be a reliable technique to mathematically document and discriminate wear patterns on archaeological quartzite tools.  相似文献   

18.
The confocal laser scanning microscope (CLSM) has become an essential tool for a wide range of biological and clinical studies and imaging applications. The major imaging modes of the CLSM include single and serial optical sections from thick specimens (100 µm), multiple wavelength images and three‐dimensional reconstruction. Such images provide measurement of length, surface or volume of objects. Surprisingly, this advanced microscopic method has been very rarely used in anthropological research, although numerous clinical and basic science research projects showed its value to study, bone growth, bone micro‐architecture and 3D bone morphometry. We present the basic principles and advantages of CLSM and outline practical aspects of specimen preparation, image collection and digital image processing specifically appropriate for historical bone and hair material. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

19.
E. Haugan  B. Holst 《Archaeometry》2014,56(6):951-960
Plant fibres have been used since ancient times in numerous applications ranging from nets and basketry to textiles for clothing. A proper identification of plant fibre remains in archaeological excavations provides important information about resource exploitation and agriculture. In order to identify plant fibres, a series of fibre features—cross‐section diameter, lumen diameter, dislocations (nodes), cross markings, cross‐section shape and lumen shape—have been defined and characteristic traits of these features for different fibre types established. How suitable these traits really are for fibre identification has been a matter of debate. To resolve this issue, we have performed a systematic investigation of typical textile bast fibres: flax, nettle and hemp. We have investigated cross‐section diameter, lumen diameter, dislocations (nodes) and cross markings using standard compound, white light transmission microscopy. Our investigations show that all the traits that are considered characteristic for one type of plant fibre can also, on occasion, be found in other types. This demonstrates that an investigation of the traits listed above is not sufficient to ensure a correct identification of the plant fibre material; in particular, when only a small amount of material is available. This is often the case in archaeological excavations.  相似文献   

20.
The recording and 3D modelling of complex archaeological sites is usually associated with high capital and logistical costs, because the data acquisition must be performed by specialists using expensive surveying sensors (i.e., terrestrial laser scanners, robotic total stations and/or ground‐penetrating radar). This paper presents a novel, low‐cost, user‐friendly photogrammetric tool for generating high‐resolution and scaled 3D models of complex sites. The results obtained with unmanned aerial vehicle (UAV) photogrammetry of an archaeological site indicate that this approach is semi‐automatic, inexpensive and effective, and that it guarantees quality.  相似文献   

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