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51.
对朝鲜半岛及日本出土细形青铜武器的原料产地问题作了尝试性探讨,以了解朝、日及中国大陆古代青铜原料的流通状况。利用青铜器及铅矿物中所含铅的四种稳定同位素的比值,在三维坐标系中观察其分布规律,并结合统计学方法探讨青铜器所含铅与铅矿地域特征的关联。通过比较分析中国大陆、朝鲜半岛及日本列岛出土的部分青铜器及铅矿物标本的铅同位素比值,指出上述三地某些青铜器原料中的铅可能有共同的产地,而朝、日当地铅矿的开采似不早于公元7世纪,故朝、日细形青铜武器的铅原料可能来自中国大陆。  相似文献   
52.
At Ocean Drilling Program Site 997 in Blake Ridge gas‐hydrate field in West Atlantic, pore‐water studies revealed a pronounced downward depletion of the heavy chlorine isotope to nearly ?4‰δ37Cl at approximately 750 m below sea floor (mbsf) associated with a 10% downward chlorinity decrease. This is one of the stronger 37Cl depletions hitherto reported for marine pore waters. Chlorinity reductions in hydrate‐bearing sediments commonly result from fresh‐water release by hydrate melting. However, in situ measurements at Site 997 suggest that >50% of the chlorinity reduction occurred prior to hydrate dissociation. Modeling the chlorinity profile shows that advection of a strongly 37Cl‐depleted, low‐chlorinity water (506 mm ) from below the drilled sequence can explain the reduction prior to sampling. Fitting the model to the δ37Cl curve yielded an advection rate of 0.18 mm year?1. Diffusive mixing with near‐0‰‐δ37Cl paleo‐seawater with maximum chlorinity at shallow subsurface depths (561 mm at approximately 20 mbsf) produced the smooth, steady trend. Separating that part of the freshening caused by advection and diffusion from that due to hydrate dissociation allowed estimation of average hydrate concentrations of 3.8% of the pore space (up to 24.5% in hydrate‐rich layers; near‐100% in rare massive hydrate layers). The deep‐seated source of the 37Cl‐depleted, low‐chlorinity water remains unknown and might be located below the sedimentary section in the oceanic basement.  相似文献   
53.
广州地区出土汉代青铜器数量众多,在考古学方面研究成果不少,但通过科技考古研究其产地的却不多。为研究广州地区出土西汉青铜器矿料来源,通过对广州出土西汉青铜器进行成分分析和铅同位素比值测试,与广西、江西、云南、贵州、安徽、湖北、河南、河北、北京等地出土同时期青铜器成分进行比较,发现西汉中晚期各地青铜器合金配比情况基本趋同。且根据含砷等微量元素这一显著特征,认为与广西合浦出土同时期青铜器矿料可能来自同一个地方。测试的铅同位素比值高度集中,其矿料应该来自同一个地方。分别与广东、贵州、云南、陕西、河南等地战国至西汉青铜器铅同位素比值进行比对,发现与广东、贵州、云南出土青铜器矿料来源同属一个大的成矿区,与河南、陕西等地明显区别。验证了学者们在考古学研究认为岭南地区出土西汉青铜器产自本地的观点。  相似文献   
54.
Bone chemistry paleodietary studies are emerging as important research areas in archaeology, biological anthropology, and paleontology. With appropriate controls, the inorganic and organic chemical composition of bones and teeth can provide information about past diet and habitat use. Chemical signatures are used to address individual dietary variability in early hominid fossils, paleontological remains, and more recent human and faunal populations.  相似文献   
55.
The provenance of the highly radiogenic lead (HRL) contained in Chinese Shang bronzes has attracted great scholarly attention in recent years. A new study of the Hanzhong Shang bronzes has put forward a hypothesis that the HRL metal may come from the adjacent Qinling Mountains. This article reanalyses the lead isotope ratios and alloy compositions of the Hanzhong bronzes. Combining the analytical results, the modern ore data and the slags from Guanzhong area, we propose that there is no direct evidence to identify Qinling as the provenance of HRL metal (especially lead). Whilst over 80% of the Hanzhong bronzes contain HRL, the indigenous artefacts containing both HRL and special alloying elements (As, Sb, Ni) account only for minor portions. This fact cannot verify that HRL originates from Qinling, and even makes it difficult to prove that most of the Hanzhong bronzes use local metal resources. An alternative argument might be that the HRL used in Hanzhong derived from the Shang dynasty. The use of HRL reflects a unified system for allocating metal resources centred on the Shang kingdom, which has great significance for further understanding of the resource circulation patterns among different bronze cultures and locations during the Shang period.  相似文献   
56.
The location of Ghazali monastery away from the Nile valley within the relatively isolated environs of the Bayuda desert presents a landscape suggestive of mobility toward the monastery by those who chose to reside there as monks. To assess this potentiality, a sample of 37 individuals from the monastic cemetery (Cemetery 2) were analysed for 87Sr/86Sr and δ18O to assess residency during dental enamel formation. The data generated bring into question the nature of mobility to Ghazali monastery, particularly in regard to the potential movement of people from the Nile valley, adjacent desertic landscapes, and further afield.  相似文献   
57.
Wells located in the Colombian Andean foreland often produce biodegraded hydrocarbons and relatively fresh water (total dissolved solids concentrations of 2000 mg l?1 dominate across most of the basin). The ratio of water to hydrocarbon in the produced fluids is high and has often been interpreted by explorationists and simulation engineers as being due to massive meteoric water invasion. To challenge this hypothesis, previously published and existing data are compiled here, along with 68 new water samples collected from both the surface (rivers) and subsurface (production wells), which are analyzed for major elements, salinity, and stable isotope compositions. The data indicate a mixed origin for the water, which involves formation water, meteoric water, and a third source that we interpret as being related to diagenetic processes (such as clay dehydration). Analyses of the variation of the parameters from north to south and west to east allow us to define the mixtures as coming from waters of different origins and make it possible to determine the relative contribution of each source.  相似文献   
58.
A unique red calcite generation, which fills fractures/cavities, is hosted by Mesozoic carbonates in the Transdanubian Range, Hungary. Solid inclusions are located along growth zones of calcite. Hematite, the most abundant solid inclusion, gives the red colour of it. Outcrop‐scale geometry, mineralogical features and detrital mineral assemblage (hematite, gibbsite, goethite, kaolinite, smectite, illite, Cr‐spinel, monazite, xenotime, zircon, apatite and Ti‐oxide) of calcite precipitates suggest strong correlation between the calcite and nearby karst bauxite deposits. Fluid inclusion petrography and microthermometry (< 50°C; salinity from 0 to 0.17 NaCl eq. w%) of primary fluid inclusions, and the stable isotope trend of the calcite, following the meteoric water line, clearly indicate vadose and phreatic meteoric origin in a near‐surface karst system. The late Cretaceous to mid‐Eocene unconformity‐related cavity‐filling deposits occur close to the surface; indicating that the most recent Quaternary exhumation re‐exposed those surfaces that existed at the time of calcite mineralization. Thus, red calcite precipitates are interpreted as being speleothems, vestiges of the subterranean part of the pre‐Middle Eocene karst. The infiltrated, fine bauxite particles enclosed by the calcite are the witnesses of the once areally extensive pre‐Middle Eocene bauxitic blanket that became partially eroded by the time of the deposition of the cover beds. Red calcite when found in core samples may provide good evidence on bauxite formation associated with the overlying unconformity, even if it was later removed by erosion. Therefore, presence or absence of red calcite may be used as distinguishing criteria between karst episodes with or without bauxite formation.  相似文献   
59.
This study reconstructs the palaeohydrogeologic evolution of the shallow‐to‐moderate Mesozoic subsidence history for the Mecsekalja Zone (MZ), a narrow metamorphic belt in the eastern Mecsek Mountains, Hungary. Brittle deformation of the MZ produced a vein system with a cement history consisting of five sequential carbonate generations and one quartz phase. Vein textures suggest different fluid‐flow mechanisms for the parent fluids of subsequent cement generations. Combined microthermometric and stable‐isotope measurements permit reconstruction of the character of subsequent fluid generations with different flow types, as defined by vein textures, yielding new information regarding the hydraulic behaviour of a metamorphic crystalline complex. Textural observations and geochemical data suggest that fracture‐controlled flow pathways and externally derived fluids were typical of some flow events, while percolation through the rock matrix and the relationship to the Cretaceous volcanism and dyke emplacement were typical of others. The difference in the mode of calcite deposition from pervasive fluids (i.e. pervasive carbonatisation along grain boundaries versus deposition in antitaxial veins) between two calcite generations related to the volcanism inspired a stress‐dependent model of antitaxial vein growth. Textural and isotope variations in a vein generation produced by the same parent fluid indicate rock‐dependent hydraulic behaviour for different rock types, distinct action of the contemporaneous fracture systems and different extents of fluid–rock interaction. Cathodoluminescence microscopy and fluid‐inclusion microthermometry shed light on the possible role of hydraulic fracturing in the formation of massive calcite. The time of formation was estimated from the isotope composition of the oldest calcite generation and its presumptive relationship with the sedimentary sequences to the north, whereas microthermometry permitted conciliation of the reconstructed flow sequence with the Mesozoic subsidence history of the Mórágy Block (including the MZ).  相似文献   
60.
The subsistence of hunter-gatherers in the Mediterranean Basin has been the object of few studies, which have not fully clarified the role of aquatic resources in their diets. Here we present the results of AMS radiocarbon dating and of isotope analyses on the earliest directly-dated human remains from Sicily, the largest island in the Mediterranean Sea. The radiocarbon determinations show that the Upper Palaeolithic (Epigravettian) humans from Grotta di San Teodoro (15 232–14 126 cal. BP) and Grotta Addaura Caprara (16 060–15 007 cal. BP) date to the Late-glacial and were possibly contemporary. The diets of these individuals were dominated by the protein of large terrestrial mammalian herbivores, such as red deer (Cervus elaphus). There is no evidence for the consumption of marine resources, which is probably the result not only of the oligotrophic nature of the Mediterranean, but also perhaps of the lack of adequate technology for exploiting intensively the resources from this sea. In spite of being contemporaneous and of the cultural and technological affinities present between the San Teodoro and Addaura humans, the carbon (δ13C) and nitrogen (δ15N) isotope composition of their bone collagen suggests that significant differences were present in their diets. In particular, the hunter-gatherers from Grotta di San Teodoro, in NE Sicily where coastal plains are backed by high mountain chains (Monti Nebrodi), probably had easy access to resources such as anadromous brown trout (Salmo trutta), which might not have been similarly available in the NW of the island, where reliefs are noticeably lower and watercourses fewer and farther between. This study shows that the high biodiversity of this region, which results from the complex topography of Mediterranean landscapes, was probably exploited opportunistically by Late-glacial foragers. Our data also suggest that intensification and diversification of food acquisition in Sicily did not start in the closing stages of the late Pleistocene, as in other Mediterranean regions, probably because the island had only been (re-)colonized by humans around the Last Glacial Maximum.  相似文献   
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