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The German Continental Deep Drilling Program comprising a pilot borehole down to 4000 m and a main borehole down to 9101 m in southeast Germany (KTB) is continuing to provide a unique opportunity for the identification of important factors and processes in deep‐seated fluid and energy transfer. In situ stress conditions significantly impact flow, transport and exchange characteristics of fracture networks that dominate the permeability of crystalline reservoir rocks. In this paper, several scales of information are combined to present a fully three‐dimensional hydraulic finite element model of the principal KTB fault zones, and linked to a geomechanical model describing the alteration of the hydraulic parameters with stress changes caused by fluid extraction. The concept of geomechanical facies is introduced to define and characterize architectural elements in the subsurface system. Evaluation of a long‐term pump test in the KTB pilot hole, June 2002–July 2003, coupled with a geomechanical model gives an insight into some of the elastic and nonelastic processes controlling hydraulic transport in the basement rocks. Trends in the decline of the permeability and the degree of storage in the system could only partially be explained by elastic processes, clearly indicating the importance of nonelastic processes. A number of inelastic processes are suggested as areas for further research.  相似文献   

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The above article from Journal of Religious History, published online on 14 August 2019 in Wiley Online Library ( wileyonlinelibrary.com ), has been retracted by agreement between the authors, the journal Editors in Chief, Joanna Cruickshank and Kriston Rennie, and John Wiley & Sons Ltd. The retraction has been agreed following discovery of an administrative error resulting in extensive overlap between this article and previously published research.  相似文献   

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The recognition of the dynamic role of site formation processes led archaeologists to recognize a behavioral dichotomy between ‘living floors’ and palimpsests’, Yet the archaeological proxies of ‘living floor’ and ‘palimpsest’ were never defined formally, and therefore have been used variably. We use archaeological criteria mentioned in the archaeological literature to model types of formation processes. The case study of the Lower Paleolithic open-air site of Revadim Quarry, Israel is used to test the model. Two types of palimpsests, differing in the rate of accumulation and thus in their effects on the anthropogenic remains, were discerned. Based on these results we review some other Lower Paleolithic instances. A sliding scale of formation processes provides a much needed middle ground between the scales of coarse, time-averaged formation processes and short, “near real-life” behavioral episodes and is an appropriate archaeological frame of reference.  相似文献   

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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   

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Pottery assemblages from the site of Al-Khidr on Failaka Island, Kuwait, were analysed in order to reconstruct the chemical composition of Bronze Age wares and to build a mineralogical database of Bronze Age pottery dated from Failaka Periods 1–3B (2000–1650 BCE). A total of 145 ceramic sherds from Al-Khidr, as well as reference groups, were analysed by non-destructive portable X-ray fluorescence (pXRF) spectrometry. Preliminarily petrographic thin-section analysis was applied to four samples to reconstruct possible clay paste recipes and to identify raw materials. The results indicate that geochemical analyses can successfully distinguish subgroups within a typological category of ceramic assemblages. The results identified two subgroups within the Al-Khidr typological category: the Dilmun Barbar tradition and the Mesopotamian tradition. Future comparative compositional studies can be conducted to explore other aspects of craft specialisation, such as ceramic technological choices and possibly the influence of sociopolitical units.  相似文献   

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Wear analysis indicates that Sangoan core-axes from site 8-B-11 at Sai Island, Sudan, were used while hafted. The middle Sangoan occupation level at 8-B-11 served as a locale where specialized activities were performed, including core-axe manufacture and hafting. Newly manufactured quartz core-axes served as replacements for exhausted items that were mostly fabricated out of raw materials other than quartz, which were carried back to the site in their hafts for re-tooling. The hafted core-axes appear as highly mobile, curated tools, being transported across a large territory. The evidence indicates that the Sangoan is the archaeological reflection of a complex behavioural system involving economic specialization, which appeared in this part of Africa for the first time around 200 ka ago.  相似文献   

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The aim of this article is to investigate the use of the Painted Chamber in the Palace of Westminster as a parliamentary space in the 15th century, focusing on 41 openings of parliament held there between 1399 and 1484. It will examine the history and images of the Painted Chamber and the procedures of the opening of parliament through a combination of historical, art historical, and archaeological sources, scholarship and methodologies. It will argue that the Painted Chamber and the openings of parliament therein were tools used by the crown to establish a dynamic between itself and the Commons in which the crown claimed its right to authority but also encouraged a political dialogue. Furthermore, it will argue that this need for dialogue was a response to the growing political influence of the Commons.  相似文献   

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Ficus has been described as a keystone genus in the tropics. This paper reviews the Quaternary palynology literature, and vegetation research literature in Island Southeast Asia, Australasia and the Western Pacific with the aim of increasing the knowledge of the distribution history for Ficus and related species within this area. Specifically, this paper describes a GIS atlas designed to aid further analysis of the history and spread of Moraceae species. This research project synthesises the knowledge of the distribution and history of Ficus and related species in the greater Australasian area through the production of a GIS atlas, and describes the project, specifically focusing on the data collation and production of the GIS.  相似文献   

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This paper outlines the archaeological evidence found at the demolished Royal Naval Dockyard at Woolwich for the development and construction of dockyard structures of the 18th to early‐19th centuries. This is set within the framework provided by historic, documentary, map and historic‐model evidence. The results of earlier excavations at the same facility are also reviewed. The themes covered include; the interplay of ‘carpentry’ versus ‘shipwrightry’ in dockyard construction, aspects of naval timber‐supply and landscape, the recycling of ships' timbers, dockyard craft specialisation and changing relative sea‐levels. © 2011 Pre‐Construct Archaeology Limited  相似文献   

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We report overprinting stable isotope evidence of fluid–rock interaction below two detachment faults along which mantle rocks were exhumed to the seafloor, between the respective landward and seaward limits of oceanic and continental crust, at a Tethyan ocean–continent transition (OCT). This OCT, which is presently exposed in the Tasna nappe (south‐eastern Switzerland) is considered an on‐land analogue of the well‐studied Iberian OCT. We compare our results with the fault architecture (fault core–damage zone–protolith) described by Caine et al. [Geology (1996) Vol. 24, pp. 1025–1028]. We confirm the existence of a sharp boundary between the fault core and damage zone based on isotopic data, but the boundary between the damage zone and protolith is gradational. We identify evidence for: (1) pervasive isotopic modification to 8.4 ± 0.1‰ which accompanied or post‐dated serpentinization of these mantle rocks at an estimated temperature of 67–109°C, (2) either (i) partial isolation of some highly strained regions [fault core(s) and mylonite] from this pervasive isotopic modification, because of permeability reduction (Caine et al.) or (ii) subsequent isotopic modification caused by structurally channelled flow of warm fluids within these highly strained regions, because of permeability enhancement, and (3) isotopic modification, which is associated with extensive calcification at T = 54–100°C, primarily beneath the younger of the two detachment faults and post‐dating initial serpentinization. By comparing the volumetric extent of calcification with an experimentally verified model for calcite precipitation in veins, we conclude that calcification could have occurred in response to seawater infiltration, with a calculated flux rate of 0.1–0.2 m year?1 and a minimum duration of 0.2–4.0 × 104 years. The associated time‐averaged uptake flux of carbon during this period was 8–120 mol m?2 year?1. By comparison with the estimated area of exhumed mantle rocks at the Iberian OCT, we calculate a maximum annual uptake flux for carbon of 2–30 Tg year?1. This is an order of magnitude greater than that for carbon exchange at the mid‐ocean ridges and 0.1–1.4% of the global oceanic uptake flux for carbon.  相似文献   

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This paper uses strontium isotope (87Sr/86Sr), oxygen isotope (δ18O) and Ba/Sr trace element data in archaeological tooth enamel samples to investigate migration and mobility at the Late Lapita site of SAC, Watom Island in the Bismarck Archipelago. Previous archaeological models have identified Lapita mobility at a community level using obsidian distribution patterns and changes in ceramic design, whereas isotope and trace element data can potentially reconstruct prehistoric mobility on an individual level. Human and pig teeth were sampled from SAC and a selection of human teeth were included from the Late–Post Lapita site of Lifafaesing, Tanga Islands as a geographic/geological comparison.The results indicate that there is a large amount of isotopic variation in the Bismarck Archipelago which is useful for identifying non-local individuals and possibly determining their origins. One human individual and several pigs were suggested as coming from elsewhere in the region. Three potentially separate locations were identified for the non-local pigs. It is argued, using the data from SAC, that Late Lapita communities in the Bismarck Archipelago were more mobile than previously assumed. The potential for identifying individual migrants in a Lapita context are discussed in terms of assessing the more subtle aspects of Lapita society in the Southwest Pacific Islands.  相似文献   

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Unjustifiably, but often, dismissed as the driest of sources, medieval accounts can be a mine of historical and social information, and those of Isabeau of Bavaria, queen of Charles VI of France, are particularly fascinating. One of the many consequences of the king's lifelong mental instability was the development of an entirely separate financial administration for his wife and children, and this combination of radical innovation and unprecedented levels of expenditure has meant that scrutiny of Isabeau's accounts — the best preserved and most extensive of any medieval queen of France — has been considered fundamental in almost all biographical works. Although this paper looks at what could be regarded as a frivolous topic in Isabeau's wardrobe, the social concept of the royal lady as decorative fashion-plate has been particularly pertinent in recent years, but also has a long-standing pedigree. The necessity and public display of wealth were always an intrinsic element of medieval queenship, and a number of these wider themes will be explored alongside detailed analysis of two example accounts.  相似文献   

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