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1.
G. N. Baturin 《Lithology and Mineral Resources》2001,36(2):99-108
Uranium and thorium content, as well as their distribution patterns are studied in biogenic phosphates from the Atlantic and Indian oceans. The material studied is represented by differently lithified fish remains (bones, scales, teeth) and marine mammal bones (ribs, vertebras, earbones) collected from both reduced shelf sediments and oxidized pelagic ones. The U content in the material varies from 0.7 to 700 ppm, and the Th content ranges from less than 0.5 to 14 ppm. The U/Th ratio varies from 0.16 to 400. Contents of both elements increase with the lithification of biogenic phosphates. The U concentration is more intense on shelves, whereas the thorium concentration increases in pelagic areas. A partial positive correlation of U and Th with Fe but a negative correlation of U with organic carbon are noted. The latter corresponds to increasing lithification of biogenic phosphates. Calcium phosphate, which is transformed from hydroxyapatite to fluorcarbonate-apatite serves as the main carrier of U, while transformed organic matter is a minor agent. Thorium is mainly bound with Fe. 相似文献
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John P. Gerry 《Geoarchaeology》1997,12(1):41-69
This article discusses dietary patterns among the Classic Maya as they are revealed by stable carbon and nitrogen isotope ratios preserved in human bone. Skeletal samples are drawn from seven sites: Uaxactun, Holmul, Baking Pot, Barton Ramie, Siebal, Altar de Sacrificios, and Copán. The isotopic results indicate that Maya nutrition was not so much socially dictated as it was spatially determined; i.e., neither class nor gender nor chronological context are significant factors of isotopic variation when compared to geographic location. These data specifically challenge the notion that Maya elites had quantitative dietary privileges; they do, however, allow for the existence of qualitative privileges. Micro-environmental factors might account for the regional groupings defined, but ultimately, settlement density is considered a more significant variable. © 1997 John Wiley & Sons, Inc. 相似文献
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The Downton Bone Bed is a Konzentrat-Lagerstätte deposit located in the Welsh Borderlands, United Kingdom. The Downton Bone Bed is late Silurian, considered to be P?ídolí in age, and occurs within the Platyschisma Shale Member of the Downton Castle Sandstone Formation. The bone bed is exposed at Weir Quarry (Herefordshire), which this study proposes should become established as the type locality for this stratigraphic horizon, due to the destruction of other localities and lack of access to other sites. As Weir Quarry is one of the last remaining exposures of this unit, the objective of this study is to qualitatively describe the sedimentology, ichnology, and invertebrate palaeontology of the bone bed, to enhance the regional understanding of the palaeogeography, depositional environments and depositional processes of the Welsh Borderlands during the late Silurian. Parasequence thickness and frequency, and sedimentary structures such as hummocky cross stratification, observed within the Downton Castle Sandstone Formation, have traditionally been explained to have formed by sea-level oscillations. These are interpreted to have formed entirely by nearshore to shoreface, shallow marine autogenic sedimentary processes, such as storm events (tempestites) and tidal scour. It is interpreted that formation of the Downton Bone Bed occurred as a by-product of these autogenic sedimentary processes, through winnowing and erosion during storm-driven scour and reworking. The low diversity ichno- and invertebrate fauna observed within the Downton Bone Bed is consistent with a nearshore depositional environment and is indicative of a stressed ecosystem due to fluctuating salinity and oxygen levels. 相似文献
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《Journal of Asian Earth Sciences》2010,39(6):233-254
The Bone Mountains, located in Southwest Sulawesi along the SE margin of Sundaland, are composed of Oligocene to possibly lower Miocene marginal basin successions (Bone Group) that are juxtaposed against continental margin assemblages of Eocene–Miocene age (Salokalupang Group). Three distinct units make up the latter: (i) Middle–Upper Eocene volcaniclastic sediments with volcanic and limestone intercalations in the upper part (Matajang Formation), reflecting a period of arc volcanism and carbonate development along the Sundaland margin; (ii) a well-bedded series of Oligocene calc-arenites (Karopa Formation), deposited in a passive margin environment following cessation of volcanic activity, and (iii) a series of Lower–Middle Miocene sedimentary rocks, in part turbiditic, which interfinger in the upper part with volcaniclastic and volcanic rocks of potassic affinity (Baco Formation), formed in an extensional regime without subduction.The Bone Group consists of MORB-like volcanics, showing weak to moderate subduction signatures (Kalamiseng Formation), and a series of interbedded hemipelagic mudstones and volcanics (Deko Formation). The Deko volcanics are in part subduction-related and in part formed from melting of a basaltic precursor in the overriding crust. We postulate that the Bone Group rocks formed in a transtensional marginal basin bordered by a transform passive margin to the west (Sundaland) and by a newly initiated westerly-dipping subduction zone on its eastern side.Around 14–13 Ma an extensional tectonic event began in SW Sulawesi, characterized by widespread block-faulting and the onset of potassic volcanism. It reached its peak about 1 Ma year later with the juxtaposition of the Bone Group against the Salokalupang Group along a major strike-slip fault (Walanae Fault Zone). The latter group was sliced up in variously-sized fragments, tilted and locally folded. Potassic volcanism continued up to the end of the Pliocene, and locally into the Quaternary. 相似文献
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珊瑚羟基磷灰石人工骨物理化学性质研究 总被引：4，自引：0，他引：4
将天然矿物材料珊瑚经自行设计的创新工艺流程“热液交换反应”合成出珊瑚羟基磷灰石(CHA)。利用扫描电镜、电镜图像处理、扫描电镜能谱、化学分析、ICP-AES和X射线衍射等方法测定其物理化学性质,并应用于临床。自行研制的CHA人工骨色白,孔隙率为25.87%~53.58%,与人骨及原珊瑚的孔隙率近似,莫氏硬度为3~4,抗压强度4.87~12.31MPa。化学成分:CaO=53.13%~64.09%,P2O5=35.52%~46.48%),CaO/P2O5=1.143~1.804。ICP-AES分析共测定24种微量元素,除Ca、P、K、Na、Al及Sr含量较高外,Pb、Co、Ni、Ba、Mn、Cr、Th、V、Cu、Ti、Mo、Zn、Mg、Nb、Be、Sc、Na和Li等,其质量分数均在(n~10n)×10-6范围,为人体所能承受含量。测试结果表明,人工骨色泽、孔隙结构和化学成分与人骨相近,具良好的生物相容性和骨传导性。临床应用60余例,无毒,无副作用,成骨能力强,是一种良好的骨移植替代品。 相似文献
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骨化学分析在古人类食物结构演化研究中的应用 总被引：1，自引：0，他引：1
古人类食物结构演化的研究,是探索人类起源和进化的重要组成部分。骨化学分析是探索古人类食物结构的主要方法,也是最为有效的方法。在概述骨化学分析原理的基础上,详细介绍了如何运用该方法了解古人类（南方古猿、人属、尼安德特人、欧洲现代人）的食物结构,并通过与现代黑猩猩的食物结构比较,揭示了从猿至人食物结构的演化过程,探讨了古人类食物结构的演变对人类进化的深刻影响。此外,提出了目前研究中尚存的2个重要问题及已有的解决方法。之后,评述了我国古人类食物结构的研究现状,并展望了古人类食物结构研究的前景。 相似文献
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山东诸城晚白垩世王氏群恐龙化石层碎屑锆石定年和物源示踪 总被引：2，自引：0，他引：2
山东东部诸城晚白垩世王氏群大面积、高密度集群埋藏的恐龙化石是近年研究的热点,但其沉积物源与精确沉积时限目前尚不明确。本文通过对山东诸城王氏群恐龙化石层中6个砂岩样品的碎屑锆石U-Pb定年表明,样品090414-24-D中最年轻的单颗粒锆石年龄(YSG)为77.3 Ma,应代表王氏群恐龙化石层的最大沉积时限(下限),结合前人对王氏群红土崖组的年代学研究表明,其沉积时限应老于73.5 Ma(上限),也说明赋存恐龙化石层的王氏群上部红土崖组为Campanian期沉积;碎屑锆石定年揭示物源的锆石年龄组成分布在100～130 Ma之间,6个样品的年龄主峰值多在110 Ma或120 Ma左右,与下伏的早白垩世青山群火山岩年龄主峰较为吻合。王氏群恐龙化石层砾岩的砾石成分和古水流研究显示,其中3组砾石统计表明砾岩层砾石成分主要由火山岩或火山碎屑岩组成,3组古水流数据表明,诸城地区王氏群红土崖组砾岩层的古流向以南和南东方向为主,尚有1组显示古流向为向北,表明王氏群物源主要来自盆地北侧莱阳和北西侧沂沭断裂带的青山群火山岩,其次为盆地南缘。本研究为诸城王氏群化石层沉积时限的限定和沉积物源的判断,以及胶莱盆地王氏群时期古地理格局的恢复等提供了重要的依据。 相似文献
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J. G. Nemliher G. N. Baturin T. E. Kallaste I. O. Murdmaa 《Lithology and Mineral Resources》2004,39(5):468-479
Samples of Recent–Miocene fish and marine mammal bones from the bottom of the Atlantic and Pacific oceans and Miocene Maikop deposits (Transcaspian region) are studied by the X-ray diffraction (XRD) technique combined with the chemical and energy-dispersive (EDX) analyses. Changes of lattice parameters and chemical composition of bioapatite during the fossilization and diagenesis suggest that the development of skeletal apatite proceeds from the dahllite- type hydroxyapatite to the francolite-type carbonate-fluorapatite. It is assumed that a jump-type transition from dahllite to francolite during the initial fossilization reflects the replacement of biogeochemical reactions in living organisms, which are subject to nonlinear laws of nonequilibrium thermodynamics, by physicochemical processes according to the linear equilibrium thermodynamics. 相似文献
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本文针对恐龙骨骼化石保护中化石风化状态难以监测的问题,采用地面三维激光扫描(TLS)方法获取化石表面的精细三维点云数据,通过间隔7个月前后两期三维数据对比,分析化石表面因风化作用产生的变化。选取山东诸城恐龙化石产地2处恐龙骨骼化石进行了两期数据采集并对化石表面整体及其裂缝进行分析,发现在监测周期内,监测对象整体无明显变化,局部存在斑状变化(偏差达0.7 mm),主要裂缝区域变化小于0.2 mm。实验结果表明本文采取的监测方法可以监测化石亚毫米级变化,对同类化石风化监测提供了参考。 相似文献
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Richard G. Klein 《Quaternary Research》1975,5(2):275-288
The relative frequencies of different skeletal elements within the bone assemblage recovered from a late Pleistocene fissure fill at Swartklip (South-Western Cape Province, South Africa) are shown to resemble those in the assemblage from the Transvaal australopithecine site of Makapansgat. Since there is evidence that carnivores, probably hyenas, accumulated the bones at Swartklip, it follows that carnivores, rather than hominids, may have accumulated the bones at Makapansgat. 相似文献
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Doklady Earth Sciences - Tooth marks preserved on a dentary fragment of eutriconodontan Gobiconodon borissiaki Trofimov, 1978 from the Early Cretaceous Zuun-Höövör locality in... 相似文献
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Ludmila A. Pavlova Ludmila Ph. Paradina Olga Yu. Belozerova 《Geostandards and Geoanalytical Research》2001,25(2-3):333-344
In this paper we report the results of electron probe X-ray microanalysis (EPMA) that was used to study environmental materials. The mode of preparation and certification of reference samples based on a basaltic glass matrix for environmental applications of EPMA is described. These samples were prepared containing scandium, strontium and barium (from 0.03 up to 7% m/m) and an evaluation was made of homogeneity, their stability to local heating, followed by analysis by independent methods for certification of composition. Matrix correction procedures for the EPMA technique have been developed for particles having a size commensurable with the volume of X-ray generation. An analytical equation for the size factor is proposed and two techniques for selecting optimum conditions for the analysis of environmental samples by EPMA are reported. These procedures provided satisfactory results when utilized in analysing sediments recovered from snow, coal fly ash and the bones of animals and fish, results from which can be used as indicators for evaluating the pollution level of the lower atmosphere, surface and ground water, as well as revealing pollution mechanisms. 相似文献
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The structure of bone detritus and iron sulfide deposits is scrutinized based on the abundant analytical data on their component composition and metal potential. It is shown that maximal concentrations of bone detritus and iron sulfides are usually spatially separated. The metal potential of bone detritus does not depend on sulfides. Moreover, its massive accumulations are usually characterized by low uranium and REE contents in the phosphate matter of fish remains. Phosphate matter in the relatively deepwater deposits usually characterized by a lower content of bone detritus has the highest metal content. Deposits formed in the relatively shallow-water settings are characterized by a higher concentration of bone detritus and lower metal content. It is emphasized that sources of rare elements and iron remain unclear. 相似文献
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Depositional Age of a Fossil Whale Bone from São Paulo Ridge,South Atlantic Ocean,Based on Os Isotope Stratigraphy of a Ferromanganese Crust 
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下载免费PDF全文 Tatsuo Nozaki Yutaro Takaya Takashi Toyofuku Ayaka Tokumaru Kosuke T. Goto Qing Chang Jun‐ichi Kimura Yasuhiro Kato Katsuhiko Suzuki Adolpho Herbert Augustin Hiroshi Kitazato 《Resource Geology》2017,67(4):442-450
Whale carcasses (whale falls) deposited on the deep seafloor are associated with a distinctive biotic community. A fossil whale bone recovered from São Paulo Ridge, South Atlantic Ocean, during cruise YK13–04 Leg 1 of R/V Yokosuka was covered by a ferromanganese (Fe–Mn) crust approximately 9 mm thick. Here, we report an age constraint for this fossil bone on the basis of Os isotopic stratigraphy (187Os/188Os ratio) of the Fe–Mn crust. Major‐ and trace‐element compositions of the crust are similar to those of Fe–Mn crusts of predominantly hydrogenous origin. Rare earth element concentrations in samples of the crust, normalized with respect to Post‐Archean average Australian Shale, exhibit flat patterns with positive Ce and negative Y anomalies. These results indicate that the Fe–Mn crust consists predominantly of hydrogenous components and that it preserves the Os isotope composition of seawater at the time of its deposition. 187Os/188Os ratios of three Fe–Mn crust samples increased from 0.904 to 1.068 in ascending stratigraphic order. The value of 1.068 from the surface slice (0–3 mm depth in the crust) was identical to that of present‐day seawater within error (~1.06). The value of 0.904 from the basal slice (6–9 mm) equaled seawater values from ca. 4–5 Ma. Because it is unknown how long the bone lay on the seafloor before the Fe–Mn crust was deposited, the Os stratigraphic age of ca. 5 Ma is a minimum age of the fossil. This is the first application, to our knowledge, of marine Os isotope stratigraphy for determining the age of a fossil whale bone. Such data may offer valuable insights into the evolution of the whale‐fall biotic community. 相似文献
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There are few inter-African country urban analyses because of the continent’s enormous size and socioeconomic diversity, language barriers, and wide variations in national and regional urban research capacity. Nevertheless, comparative urban studies are critical in understanding contemporary African urbanization. In this comparative spatial and temporal analysis of Ghana and Kenya’s urbanization, we find that both countries are urbanizing rapidly and are faced with many common urban problems. Moreover, Ghana is more urbanized than Kenya and has a larger indigenous urban imprint and a more widely dispersed urban pattern. Besides their physiographic and population conditions, we trace these countries’ convergent and divergent urban trends to their shared but unique experiences of colonialism, nationalism and globalization. 相似文献
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Friedemann Freund 《Physics and Chemistry of Minerals》1987,15(1):1-18
The dissolution of H2O and CO2 in structurally dense, nominally anhydrous and non-carbonate oxide matrices such as MgO and CaO is reviewed. H2O and CO2 are treated as gaseous oxide components which enter into solid solution with the refractory oxide hosts. They form anion complexes associated with cation vacancy sites. Evidence is presented that OH? pairs which derive from the dissolution of H2O are subject to a charge transfer (CT) conversion into peroxy moieties and molecular hydrogen, O 2 2? ... H2. Because the O 2 2? moiety is small (O?-O? distance ≈ 1.5 Å) high pressure probably favors the CT conversion. Mass spectroscopic studies show that molecular H2 may be lost from the solid which retains excess oxygen in the form of O 2 2? , leading to the release of atomic O. The dissociation of O 2 2? moieties into a vacancy-bound O? state and an unbound O? state can be followed by measuring the internal redox reactions involving transition metal impurities, the transient paramagnetism of the O? and their effect on the d.c. conductivity. Evidence is presented that CO2 molecules dissolve dissociatively in the structurally dense oxide matrix, as if they were first to dissociate into CO+O and then to form separate solute moieties CO 2 2? and O 2 2? , both associated with cation vacancy sites. In the CO 2 2? moiety (C-O? distance 1.2–1.3 Å, OCO angle ≈ 130°) the C atom probably sits off center. The transition of the C atom into interstitial sites is accompanied by dissociation of the CO 2 2? moiety into CO? and O?. This transition can be followed by infrared spectroscopy, using OH? as local probes. Further support derives from magnetic susceptibility, thermal expansion, low frequency dielectric loss and low temperature deformation measurements. The recently observed emission of O and Mg atoms besides a variety of molecules such as CO, CO2, CH4, HCN and other hydrocarbons during impact fracture of MgO single crystals is presented and discussed in the light of the other experimental data. 相似文献
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利用GC-MS（气相色谱—质谱仪）,对采自湖北清江流域和尚洞洞顶的土壤样品与洞内石笋样品进行分析,发现土壤中存在的七个系列单甲基支链烷烃在所有的石笋样品中均可以找到,呈现相似的分布模式,石笋中七个系列支链烷烃有可能来自洞穴滴水携带的土壤中的支链烷烃,但是也不能排除石笋原地生长的微生物的贡献。烷基环己烷的分布在土壤与石笋中呈现了相似的分布模式,但是主峰碳数有所变化,高碳数部分与低碳数部分的相对含量也发生了变化。主要原因可能是微生物选择性降解的结果,也有可能是土壤与石笋中微生物种类分布差异所造成的。本次研究初步显示了相对封闭稳定的洞穴沉积物与上覆土壤层中生物标志化合物的异同。 相似文献