陕西蓝田地区三趾马化石新材料

刘东生等60多年前描述的在陕西蓝田灞河组下部的Hipparion sp., 材料较少, 但形态特殊, 此后一直未见相关报道。近年来在这一地区又发现了类似三趾马化石的新材料。新发现的Hipparion sp. 个体小, 原尖短、圆, 次尖明显偏向舌侧, 次尖颈收缩, DP4的次尖几乎完全孤立; 原小尖褶长大复杂, 次附尖粗大、分叉, 向外伸出; 端附尖长大, 根部收缩, 内侧收缩沟内伸, 并呈复杂的褶沟。这些组合特征与包括Hipparion chiai在内的灞河组上部3种三趾马扁长的原尖截然不同, 也区别于九老坡的Hipparion plocodus(Hipparion fossatum), 而接近于大庙沟的Hipparion sp.。新材料的发现表明灞河早期的这种形态比较特殊的三趾马可能延续到了灞河晚期, 甚至更晚的时代, 同时在白鹿塬西侧蓝田汤峪河道一带有新近系地层出露。     

Geology,geochemistry, and geochronology of the Miaowan ophiolite,Yangtze craton: Implications for South China's amalgamation history with the Rodinian supercontinent

We report the presence of a Grenvillian ophiolite on the northern margin of the Yangtze craton, drastically changing current ideas about South China's role in plate reconstructions of the Rodinia supercontinent. Strongly deformed amphibolites that locally show relict pillow lavas, isotropic and layered metagabbro, diabase dikes, serpentinized dunite and harzburgite with podiform chromite are dated at circa 1100–985 Ma (U–Pb zircon). The ophiolite is structurally dismembered and thrust over the Proterozoic shelf sequence that covers the north margin of the Yangtze craton, and overrode a flysch to conglomerate-wildflysch unit shed from the ophiolite and a magmatic arc terrane and deposited on the older Yangtze carbonate platform. The youngest clasts in the conglomerate are circa 861–813 Ma (U–Pb zircon), giving a maximum age for ophiolite emplacement. Fine-grained layered amphibolites exhibit slightly depleted-flat type REE curves with no obvious Eu anomalies, and are N-MORB type tholeiites. Metagabbro has typical cumulate textures, flat REE distributions and obvious positive Eu anomalies. The REE characteristics of serpentinized dunites show a U-shape of slight loss of middle REE, representing cumulates metasomatized by LREE slightly enriched mantle. All these features indicate that the metamafic–ultramafic rocks from the Proterozoic Miaowan Formation form a structurally dismembered ophiolite resting above an ophiolitic wildflysch, sitting on top of the Proterozoic shelf sequence on the Yangtze craton. The ophiolite is contemporaneous with an arc sequence preserved to the north on the edge of the Yangtze craton, suggesting that the entire ophiolitic forearc–arc was accreted to the Yangtze craton between 1000 and 850 Ma. Xenocrystic zircons in granite clasts in the basal wildflysch unit have ages consistent with Australian affinity, and detrital zircons in the arc sequence also show derivation from Australia, suggesting that the arc formed on the Australian segment of Rodinia before collision with the Yangtze craton. The discovery of the Proterozoic Miaowan ophiolite supplies important evidence for the existence of a Neoproterozoic oceanic basin on the north margin of the Yangtze craton, and demonstrates that the Yangtze craton first collided with Rodinia on its northern margin, with subsequent accretion of the Cathaysian block on the southern margin of the craton.     

断陷盆地单层暗色泥岩厚度与优质烃源岩的关系及其对成藏的控制——以海拉尔盆地为例

首次应用单层厚度最大暗色泥岩对海拉尔盆地油气成藏进行研究,为断陷盆地油气勘探提供新的思路和方法。研究表明:单层厚度最大暗色泥岩层段中发育优质烃源岩,具有较高的生烃潜力,应用寻找单层最大厚度暗色泥岩的方法追踪优质烃源岩是一种简单而又有实际意义的一种方法;单层暗色泥岩的厚度与油气的聚集密切相关,单层厚度越大,单井的产能越高;单层暗色泥岩在断陷盆地中受沉积相带演化呈现明显的规律性,从陡坡带到缓坡带发育两个高值区,缓坡带单层暗色泥岩厚度高值区紧邻的砂体是油气主要富集带。     

Detecting hotspots of urban residents’ behaviours based on spatio-temporal clustering techniques

Hotspots are regions where the number of spatial objects is obviously high within the time intervals. As the behaviours of urban residents are considered as a typical kind of spatio-temporal pattern, the detection of hotspots of urban residents’ behaviours appears necessary, since important information might be discovered in hotspots. In this paper, we propose an approach to detect the spatio-temporal hotspots of urban residents’ behaviours. This approach is validated based on the GPS data of floating cars of a city in southern China. The approach consists of four main steps: first, the effective spatio-temporal trajectories and the important characteristic points contained in each trajectory are extracted from the GPS data; second, the spatio-temporal clusters are generated by clustering the characteristic points based on a kernel density estimation algorithm; third, the spatio-temporal hotspots are detected by filtering the spatio-temporal clusters with high densities; last, the detected hotspots are analysed and interpreted. The results show that the proposed approach is effective and useful in detecting hotspots of urban residents’ behaviours.     

催化褪色光度法测定痕量锰的研究及应用

本研究了在ＰＨ＝４．０醋酸－醋酸钠缓冲溶液中，锰催化ＫＩＯ４氧化５－Ｂｒ－ＰＡＤＡＰ的褪色反应及其动力学条件，建立了一个痕量锰的高灵敏度新方法，方法灵敏度为１．３２×１０＾－１０ｇ／ｍｌ，测定范围Ｍｎ＾２＋浓度为０￣１．５μｇ／ｍｌ，用于测定人发，自来水，茶叶中痕量锰，结果满意。     

南方红土磁性地层年代学研究进展

南方红土是中国分布最广的第四纪土状堆积,蕴含丰富的古气候、古地理以及古人类演化的信息。然而,南方红土地区长期高温多雨的气候造成许多定年材料的缺乏,导致其年代学研究进展比较缓慢。磁性地层学方法是一种适合于中、新生代海陆相沉积物定年的快捷、有效的方法,近年来南方红土的磁性地层年代学研究取得了很好的结果。文中比较系统地总结了近年来南方红土磁性地层年代学研究方面的进展。这些研究显示南方红土中的载磁矿物包括赤铁矿、磁赤铁矿、磁铁矿和针铁矿,其中磁铁矿和赤铁矿是特征剩磁的主要载体。磁性地层结果表明南方红土记录了Matuyama负极性时晚期至Brunhes正极性时早-中期的沉积,其沉积起始年龄不晚于Jaramillo正极性亚时,即早于11 Ma。这些磁性地层学结果为揭示南方红土记录的环境变化和中国南方亚热带地区早期人类演化提供了年代学基础。     

某滑坡区滑带土工程地质特性研究

本文论述了某滑坡滑带土的工程地质特性及其滑坡稳定性的影响，为滑坡的合理整治提供了依据。     

Paragenesis and geochemistry of ore minerals in the epizonal gold deposits of the Yangshan gold belt,West Qinling,China

Six epizonal gold deposits in the 30-km-long Yangshan gold belt, Gansu Province are estimated to contain more than 300 t of gold at an average grade of 4.76 g/t and thus define one of China's largest gold resources. Detailed paragenetic studies have recognized five stages of sulfide mineral precipitation in the deposits of the belt. Syngenetic/diagenetic pyrite (Py₀) has a framboidal or colloform texture and is disseminated in the metasedimentary host rocks. Early hydrothermal pyrite (Py₁) in quartz veins is disseminated in metasedimentary rocks and dikes and also occurs as semi-massive pyrite aggregates or bedding-parallel pyrite bands in phyllite. The main ore stage pyrite (Py₂) commonly overgrows Py₁ and is typically associated with main ore stage arsenopyrite (Apy₂). Late ore stage pyrite (Py₃), arsenopyrite (Apy₃), and stibnite occur in quartz ± calcite veins or are disseminated in country rocks. Post-ore stage pyrite (Py₄) occurs in quartz ± calcite veins that cut all earlier formed mineralization. Electron probe microanalyses and laser ablation-inductively coupled plasma mass spectrometry analyses reveal that different generations of sulfides have characteristic of major and trace element patterns, which can be used as a proxy for the distinct hydrothermal events. Syngenetic/diagenetic pyrite has high concentrations of As, Au, Bi, Co, Cu, Mn, Ni, Pb, Sb, and Zn. The Py₀ also retains a sedimentary Co/Ni ratio, which is distinct from hydrothermal ore-related pyrite. Early hydrothermal Py₁ has high contents of Ag, As, Au, Bi, Cu, Fe, Sb, and V, and it reflects elevated levels of these elements in the earliest mineralizing metamorphic fluids. The main ore stage Py₂ has a very high content of As (median value of 2.96 wt%) and Au (median value of 47.5 ppm) and slightly elevated Cu, but relatively low values for other trace elements. Arsenic in the main ore stage Py₂ occurs in solid solution. Late ore stage Py₃, formed coevally with stibnite, contains relatively high As (median value of 1.44 wt%), Au, Fe, Mn, Mo, Sb, and Zn and low Bi, Co, Ni, and Pb. The main ore stage Apy₂, compared to late ore stage arsenopyrite, is relatively enriched in As, whereas the later Apy₃ has high concentrations of S, Fe, and Sb, which is consistent with element patterns in associated main and late ore stage pyrite generations. Compared with pyrite from other stages, the post-ore stage Py₄ has relatively low concentrations of Fe and S, whereas As remains elevated (2.05～3.20 wt%), which could be interpreted by the substitution of As^? for S in the pyrite structure. These results suggest that syngenetic/diagenetic pyrite is the main metal source for the Yangshan gold deposits where such pyrite was metamorphosed at depth below presently exposed levels. The ore-forming elements were concentrated into the hydrothermal fluids during metamorphic devolatilization, and subsequently, during extensive fluid–rock interaction at shallower levels, these elements were precipitated via widespread sulfidation during the main ore stage.     

浙江雷甸淡水无光珠中球文石的首次确认

球文石（Vaterite)是CaCO3很不稳定的同质多象变体，在自然界里很少出现，通过光学显微镜在淡水无光珠中发现球文石尚属首次，本文研究了淡水无光珠内球文石的显微特征、X射线粉晶衍射特征及显微红外光谱特征，研究结果表明淡水无光珍珠内球文石粉晶衍射由强至弱五个强峰的d值为0.3266,0.2723,0.3553,0.1811,0.2057nm；其红外光谱特征波数为1489，1450,1420,1087,1050,876,830,762,743cm^-1。球文石的存在是影响淡水珍珠品质的主要内在因素之一。     

Study of Dynamic Waveform Inversion with Computer

This paper has done the spectrum analysis of deformity waveform and it’s each frequency element is rectified with measuring system frequency response curve by positive and inverse Fourier transform theoretical. If all of rectified frequency elements of waveform are superposed then real waveform would be obtained. This paper has done theoretical analysis and a practical method is introduced.