首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A collection of window‐panes, vessels and alleged waste from Thamusida has been investigated by OM, SEM–EDS, ICP–MS, ICP–OES and XAS at the Fe–K and Mn–K edges. Glass samples have been characterized as natron‐based soda–lime–silica glasses, with low magnesium and low potassium. The results have been compared with 43 reference groups available for ‘naturally coloured’ and colourless glasses of both Roman and later ages. Two main types were distinguished: RBGY 1 (R oman B lue–G reen and Y ellow 1) and RBGY 2 (R oman B lue–G reen and Y ellow 2). Given their compositional similarity to the Levantine I or, to a lesser extent, HIMT glasses, the Syrian–Palestinian coast for RBGY 2 and Egypt for the RBGY 1 have been suggested for their provenance. Most Thamusida samples have been assigned to the RBGY 2 type. A small group of Thamusida colourless vessels was included into the RC (R oman‐C olourless) compositional field; the latter still being defined. The alleged waste pieces may define a local production that should have been of secondary type. The investigations performed on local raw materials seem to discount the possibility of a primary glass‐making site. XAS measurements determined that Fe2+ contents ranging between 30 and 52% are able to assure an aqua blue colour; below 30%, the glasses turn light green or light yellow.  相似文献   

2.
Abstract

Excavations were conducted in 1997 and 2004 along a 1200 m-long waterline corridor through the middle of the central plaza at Cahokia, the largest and possibly earliest Mississippian period (A.D. 1050–1350) population center in North America. These excavations provide a unique window into previously unknown aspects of the construction and use history of this singular monumental space. Built as the centerpiece of Cahokia’s city plan in the middle of the 11th century A.D., the plaza appears to have been more spacious than the most generous previous estimate. The labor needed to build one-quarter to one-third of this plaza may have exceeded 10,000 person-days. Once built, evidence points to the possible existence of a gallery of upright posts and small buildings in front of Monks Mound, the largest earthen pyramid in the center of the site complex. By the 13th century, domestic buildings appear to have lined the plaza edges.  相似文献   

3.
Marine resources were an integral and consistent component of subsistence strategies employed in south‐eastern Arabia throughout late prehistory. Of particular interest is the movement of these resources from the coast to interior sites and the implications of this movement for transhumance and trade in the region during this period. Marine species were frequently identified in the faunal assemblage from the inland site of Saruq al‐Hadid, dating from the Bronze Age to Early Iron Age (c.2000–c.800 BCE). This included marine fish species, along with two cormorant species (Phalacrocorax sp.) and several fragments of dugong (Dugong dugon). Twenty‐seven families of marine shell were also identified in the remains recovered from the site. The presence of these remains at this inland site demonstrates that resources were frequently moved from the coast to the interior throughout Saruq al‐Hadid’s occupation, indicative of their enduring significance in subsistence strategies employed at the site. This paper presents the results of zooarchaeological analysis of these remains and discusses the significance of their presence at Saruq al‐Hadid, with reference to subsistence, craft production and intra‐regional exchange during the Bronze and Iron Ages.  相似文献   

4.
This paper focuses in the morphometric analyses of Lama guanicoe remains recovered from the hunter–gatherer archaeological site Alero Deodoro Roca, located at Sierras Pampeanas Australes region (Córdoba Argentina), an area that has little information on the body‐size variability of these artiodactyls. Because of the sparse osteometric data in the region, we focused on determining inter‐intraspecific differentiation of wild camelids through corroborated osteometric techniques and multivariate statistical analyses of proximal phalanges. Our results showed a clear interspecific differentiation between modern vicuñas and archaeological specimens. We could also distinguish at least three guanaco size groups (small, medium and large) with the archaeological remains from the late Holocene (3000–3600 bp ) of the site, presenting medium‐size characteristics. Finally this paper aims at establishing a first approach in the characterisation of guanaco body size in the mountainous region of Córdoba. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

5.
Scavenging is one of the primary taphonomic processes shaping the final composition of fossil faunal assemblages. The taphonomic effect of scavengers is variable and must be understood in the context of the causes of that variation. In this study, we investigated relationships between the El Niño Southern Oscillation (ENSO), variable rainfall and scavenging on 20–40 kg mammal carcasses in semi‐arid New South Wales over four years. Following periods of above‐average rainfall (coincident with the La Niña phase of the ENSO), there was an increased availability of non‐carrion food and scavenging activity was moderate. Following below‐average rainfall (coincident with the El Niño phase of the ENSO), foraging options diminished, leading to a greater importance of carrion in the diet of scavengers and a resultant increase in carcass disturbance, transport and destruction by scavengers. Feral pigs (Sus scrofa) and red foxes (Vulpes vulpes) were the most taphonomically significant scavengers in the study. Australian ravens (Corvus coronoides) and wedge‐tailed eagles (Aquila audax) were active scavengers throughout the period of the study, but had little impact on bone survival. Lace monitors (Varanus varius) also fed mostly on soft tissue and were only present seasonally. We found that climate variability in the form of short‐term oscillation can result in significant variation in the impact of scavengers on carcasses and may be an important consideration when evaluating site formation scenarios and biases in fossil faunal assemblages. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

6.
Many parts of the Arabian Peninsula contain rock art that has received minimal archaeological attention or has not yet been thoroughly surveyed. In 2001 an extensive rock‐art complex called Shuwaymis, Ha'il Province, Saudi Arabia was brought to the attention of the Saudi General Commission for Tourism and Antiquities. This paper sets out the results of the first high‐resolution geospatial mapping and recording of rock art at this remote site. The research saw the innovative use of a differential GPS to record rock‐art panels to within 5 mm of accuracy at the site of Shuwaymis‐2, the first time that such technology has been used to record rock art in the Arabian Peninsula. With such technology it was possible to show which of eighty‐three late prehistoric rock‐art panels surveyed were in their original position and which had fallen, and to demonstrate that there was spatial homogeneity of rock‐art styles and composition across the site. The mapping recorded multiple panels of cattle, ibex, equid, large cat and other animals. The depictions of lions and cattle in particular indicate that the rock art must have been engraved no later than the early Holocene humid phase (c.10–6 ka BP).  相似文献   

7.
EDS, X‐ray fluorescence, Raman spectroscopy, thermal expansion–shrinkage measurement and scanning electron microscopy were applied to determine the elemental components, structural phases and glazing temperatures of the transparent glazes, blue underglaze and overglaze tam thai (including gold‐like lustre) decorations from the 15th‐century Vietnamese porcelains/stonewares found at the Chu Ðâu–My Xa kiln site and in the Cù Lao Chàm (Hôi An) cargo. The ancient technology for colouring the glazes is discussed. The various blue tones in the underglazed décor result from cobalt‐containing manganese ore, with the intentional addition of iron oxide. The overglaze copper‐green and the gold‐like lustre were obtained by dispersing copper in lead‐based glass. The red colour was made using hematite dispersed in lead‐rich flux.  相似文献   

8.
The Early Bronze Age site of RJ‐2, located close to the coastal village of Ra's al‐Jinz on the eastern Omani coast (Niyabat Ra's al‐Hadd), was the focus of archaeological investigations for over two decades. The latest campaigns of excavation unearthed an architectural complex (Building XII) dated to the very end of the Umm an‐Nar period (Final UaN, c.2100–2000 BCE), previously attested on site by poorly preserved remains. This paper presents the remains explored during the most recent fieldwork, focusing on the stratigraphic‐structural sequence and the spatial layout. It also considers the transformations affecting structural evidence and material culture during this period, at both local and regional level, highlighting their significance for a comprehensive assessment of the last occupations related to the Early Bronze Age in south‐eastern Arabia. The paper concludes by showing how the Final Umm an‐Nar phase represents an age of substantial socio‐cultural innovations, which most likely shaped the transition towards the following Wadi Suq period.  相似文献   

9.
The production of hydrogen by serpentinization in ultramafic‐hosted hydrothermal systems is simulated by coupling thermodynamic and dynamic modeling in the framework of a thermo‐hydraulic single‐pass model where a high‐temperature hydrothermal fluid moves preferentially through a main canal of high permeability. The alteration of ultramafic rocks is modeled with a first‐order kinetic formulation, wherein the serpentinization rate coefficient, Kr, takes the form: Kr = A exp(?α(T ? T0)2). In this formulation, α determines the temperature range of the reaction and T0 is the temperature at which the serpentinization rate reaches its maximum. This model is applied to the Rainbow hydrothermal system, which is situated on the Mid‐Atlantic Ridge, and characterized by a high temperature, a high mass flux, and a very high hydrogen concentration. The results show that a first‐order kinetic law gives a useful representation of the kinetics of serpentinization. The estimated value for the parameter A in the temperature‐dependent formulation of the serpentinization rate coefficient lies in the range (1–5) × 10?11 s?1. This effective parameter is several orders of magnitude lower than the values obtained from small grain‐size experiments, but in agreement with other published modeling studies of natural systems. Numerical simulations show that the venting site is able to produce the observed high concentration of hydrogen during the whole continuous lifetime of the Rainbow site.  相似文献   

10.
11.
Archaeological excavation at the San Giusto site (Lucera, Italy) has unearthed a Late Antique kiln that was most certainly dedicated to the production of cooking ware. An archaeometric study of numerous specimens of cooking and painted ware found at this site was carried out using optical microscopy, scanning electron microscopy, micro‐Raman spectroscopy, X‐ray diffraction, X‐ray fluorescence, inductively coupled plasma mass and optical emission spectrometry and instrumental neutron activation analysis. The integration of historical–archaeological data with archaeometric data has revealed that these specimens can be attributed to the San Giusto site. Furthermore, the production cycle of this ware can thus be reconstructed: from the diversified supply of raw materials (fluvial and marine sediments), to the relatively complex preparation of the paste, to firing at variable temperatures (600–750°C for cooking ware; 850–1050°C for painted ware).  相似文献   

12.
This work presents the results of the first mineralogical, petrographical and geochemical characterization of the marble quarried from the Cap de Garde headland, not far from Annaba (Algeria). This site is traditionally held by archaeologists to be the main source of supply of the so‐called ‘greco scritto’ marble, which was much used by the Romans for architectural and decorative–ornamental purposes, locally from the first century bc , and in Rome and central and southern Italy from the late Flavian period until the fourth century ad . The databank relating to the quarried material, created here for the first time, is used to establish the origin of ‘greco scritto’ found in six important Roman cities of North Africa: Hippo Regius and Cuicul (Djemila), in Algeria; Volubilis, in Morocco; Cyrene, in Libya; and Carthage and Utica in Tunisia. The results of this archaeometric study support the hypothesis (already put forward by authors) that the ‘greco scritto’used in the Roman Mediterranean originated from different sites, and suggest the existence of a number of North African quarries, also in the vicinity of Annaba.  相似文献   

13.
The present study examines a sample of 105 hunter–gatherer California Amerinds to determine whether fibrocartilaginous musculoskeletal stress markers (MSMs) are better for activity reconstructions than fibrous MSMs. Femoral and humeral head diameters were measured as proxies to body size. All data were analysed for statistical significance using non‐parametric tests. Fibrous MSMs of the left deltoideus, left and right hip adductors, and left and right tibial soleus correlate positively with body size proxies. For fibrocartilaginous MSMs, the right humeral teres minor insertion negatively correlates with humeral head diameter. Both types of MSMs correlate positively with age. More upper limb fibrocartilaginous MSMs display asymmetry than do upper limb fibrous MSMs. Lower limb sex differences were found at the same MSM sites that correlated with body size. Upper limb sex differences at the right teres major, a fibrous site, and the right triceps brachii, a fibrocartilaginous site, seem to reflect activity patterns. Results suggest that fibrocartilaginous MSMs are more useful in reconstructing activity patterns because they display more asymmetry in upper limbs and are less affected by body size than are fibrous MSMs. Yet, correlations with age and a lack of variability at fibrocartilaginous MSM sites may hinder their utility in activity reconstructions. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

14.
The Cu–Fe mining district of Servette is located in the valley of Saint‐Marcel (Val d’Aosta) at about 1800 m a.s.l. in the western Italian Alps. A large furnace slag deposit occurs near the Servette mine. Slags are mainly constituted by silicate and oxide in a glassy matrix, with disseminated sulphides and iron–copper alloys, and they record temperatures of 1380–1100°C. Radiocarbon dating of slag charcoals has shown that metallurgy in this site took place around ad 890–980. The charcoal analysis has shown that coniferous wood was mainly utilized, and intensive exploitation over the centuries led to a change in the composition of the local woods.  相似文献   

15.
The p‐regions problem involves the aggregation or clustering of n small areas into p spatially contiguous regions while optimizing some criteria. The main objective of this article is to explore possible avenues for formulating this problem as a mixed integer‐programming (MIP) problem. The critical issue in formulating this problem is to ensure that each region is a spatially contiguous cluster of small areas. We introduce three MIP models for solving the p regions problem. Each model minimizes the sum of dissimilarities between all pairs of areas within each region while guaranteeing contiguity. Three strategies designed to ensure contiguity are presented: (1) an adaptation of the Miller, Tucker, and Zemlin tour‐breaking constraints developed for the traveling salesman problem; (2) the use of ordered‐area assignment variables based upon an extension of an approach by Cova and Church for the geographical site design problem; and (3) the use of flow constraints based upon an extension of work by Shirabe. We test the efficacy of each formulation as well as specify a strategy to reduce overall problem size.  相似文献   

16.
Br/Cl ratios of hydrothermal fluids are widely used as geochemical tracers in marine hydrothermal systems to prove fluid phase separation processes. However, previous results of the liquid–vapour fractionation of bromine are ambiguous. Here we report new experimental results of the liquid–vapour fractionation of bromine in the system H2O–NaCl–NaBr at 380–450°C and 22.9–41.7 MPa. Our data indicate that bromine is generally more enriched than chlorine in the liquid phase. Calculated exchange coefficients KD(Br‐Cl)liquid‐vapour for the reaction Brvapour + Clliquid = Brliquid + Clvapour are between 0.94 ± 0.08 and 1.66 ± 0.14 within the investigated P–T range. They correlate positively with DClliquid‐vapour and suggest increasing bromine–chlorine fractionation with increasing opening of the liquid–vapour solvus, i.e. increasing distance to the critical curve in the H2O–NaCl system. An empirical fit of the form KD(Br‐Cl)liquid‐vapour = a*ln[b*(DClliquid‐vapour?1) + e1/a] yields a = 0.349 and b = 1.697. Based on this empirical fit and the well‐constrained phase relations in the H2O–NaCl system we calculated the effect of fluid phase separation on the Br/Cl signature of a hydrothermal fluid with initial seawater composition for closed and open adiabatic ascents along the 4.5 and 4.8 J g?1 K?1 isentropes. The calculations indicate that fluid phase separation can significantly alter the Br/Cl ratio in hydrothermal fluids. The predicted Br/Cl evolutions are in accord with the Br/Cl signatures in low‐salinity vent fluids from the 9 to 10°N East Pacific Rise.  相似文献   

17.
G. ERAMO 《Archaeometry》2005,47(3):571-592
Seventy‐one oriented specimens from the pre‐industrial reverberatory melting furnace of the Derrière Sairoche glassworks (Swiss Jura) were analysed. During its period of activity (1699–1714), this glassworks produced wood‐ash glass of liquidus temperatures up to 1400°C. Textural and mineralogical features point to temperatures around 1500°C in the melting chamber. The inner structure of the furnace shows chemical contamination due to ash, molten glass and furnace gases. These results reveal the pyrotechnological know‐how of the glassmakers and prove that the thermal performance of this kind of furnace has been under‐evaluated in the past.  相似文献   

18.
The solubility of quartz has been measured in a wide range of salt solutions at 800°C and 0.5 GPa, and in NaCl, CaCl2 and CsCl solutions and H2O–CO2 fluids at six additional PT conditions ranging from 400°C at 0.1 GPa to 800°C at 0.9 GPa. The experiments cover a wide range of compositions along each binary. At PT conditions where the density of pure water is low (0.43 g cm?3), addition of most salts produces an enhancement of quartz solubility at low to moderate salt concentrations (salt‐in effect), although quartz solubility falls with further decrease in XH2O. At higher fluid densities (0.7 g cm?3 and greater), the salt‐in effect is generally absent, although this depends on both the cation present and the actual PT conditions. The salt‐in effect is most readily produced by chloride salts of large monovalent cations, while CaCl2 only produced a salt‐in effect at the most extreme conditions of high‐T and low‐P investigated (800°C at 0.2 GPa). Under most crustal conditions, the addition of common salts to aqueous fluids results in a lowering of quartz solubility relative to that in pure water (salt‐out effect). Comparing quartz solubility in different fluids by calculating XH2O on the basis that all salts are fully associated under all conditions yields higher quartz solubility in solutions of monovalent salts than in solutions of divalent salts, absolute values are also influenced by cation radius. Quartz solubility measurements have been fitted to a Setchenow‐type equation, modified to take account of the separate effects of both the lowering of XH2O and the specific effects of different salts, which are treated as arising through distinct patterns of non‐ideal behaviour, rather than the explicit formation of additional silica complexes with salt components. Quartz solubility in H2O–CO2 fluids can be treated as ideal, if the solvation number of aqueous silica is taken as 3.5. For this system the solubility (molality) of quartz in the binary fluid, S is related to its solubility in pure water at the same PT conditions, So, by: Quartz solubility in binary salt systems (H2O–RCln) can be fitted to the relationship: where salt concentration mRCln is expressed as molality and the exponent b has a value of 1 except under conditions where salting‐in is observed at low salt concentrations, in which case it is <1. Under most crustal conditions, the solubility of quartz in NaCl solutions is given to a good approximation by: We propose that quartz solubility in multicomponent fluids can be estimated from an extended expression, calculating XH2O based on the total fluid composition (including dissolved gasses), and adding terms for each major salt present. Our experimental results on H2O–NaCl–CO2 fluids are satisfactorily predicted on this basis. An important implication of the results presented here is that there are circumstances where the migration of a fluid from one quartz‐bearing host into another, if it is accompanied by re‐equilibration through cation exchange, may lead to dissolution or precipitation of quartz even at constant P and T, with concomitant modification of the permeability structure of the deep crust.  相似文献   

19.
The aim of this study was to determine the process–structure–property relationships between the pre‐ and post‐CO2 injection pore network geometry and the intrinsic permeability tensor for samples of core from low‐permeability Lower Triassic Sherwood Sandstone, UK. Samples were characterised using SEM‐EDS, XRD, MIP, XRCT and a triaxial permeability cell both before and after a three‐month continuous‐flow experiment using acidic CO2‐rich saline fluid. The change in flow properties was compared to those predicted by pore‐scale numerical modelling using an implicit finite volume solution to the Navier–Stokes equations. Mass loss and increased secondary porosity appeared to occur primarily due to dissolution of intergranular cements and K‐feldspar grains, with some associated loss of clay, carbonate and mudstone clasts. This resulted in a bulk porosity increase from 18 to 25% and caused a reduction in mean diameter of mineral grains with an increase in apparent pore wall roughness, where the fractal dimension, Df, increased from 1.68 to 1.84. All significant dissolution mass loss occurred in pores above c. 100 μm mean diameter. Relative dilation of post‐treatment pore area appeared to increase in relation to initial pore area, suggesting that the rate of dissolution mass loss had a positive relationship with fluid flow velocity; that is, critical flow pathways are preferentially widened. Variation in packing density within sedimentary planes (occurring at cm‐scale along the ‐z plane) caused the intrinsic permeability tensor to vary by more than a factor of ten. The bulk permeability tensor is anisotropic having almost equal value in ‐z and ‐y planes but with a 68% higher value in the ‐x plane (parallel to sedimentary bedding planes) for the pretreated sample, reducing to only 30% higher for the post‐treated sample. The intrinsic permeability of the post‐treatment sample increased by one order of magnitude and showed very close agreement between the modelled and experimental results.  相似文献   

20.
Pottery from the Neolithic Mendandia site has been studied. The radiocarbon dating of the site corresponds to a range of dates from 7488–7546 cal bc to 5283–5437 cal bc : the first occurrence of pottery is dated at 5968–6040 cal bc for the lower level III, and up to 5386–5560 cal bc for level II. The antiquity of the potsherds places them within the oldest pottery production sequences in the Iberian Peninsula, which adds to the interest of this study. Ten potsherds from level II and five from level III are analysed for their petrographic and chemical characterization. The petrographic data show two different methods of raw materials manufacture—intentionally tempered pottery (ITP), using calcite and/or limestone and grog, and naturally or non‐intentionally tempered pottery (NTP). According to the matrix paste features, on the basis of the amount, shape, and average or size range of the mineral inclusions, clayed (type A) and sandy (type B) paste types were established and related to two different source areas. The chemical features also indicate two raw material sources and are in agreement with the petrographic paste types. The absence of significant chemical and mineralogical differences between the pottery from levels II and III suggests two contrasting areas for raw materials supply that lasted for at least 600 years.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号