Evolution of the Mesozoic Granites in the Xiong''''ershan-Waifangshan Region,Western Henan Province,China,and Its Tectonic Implications

Based on the new data of isotopic ages and geochemical analyses, three types of Mesozoic granites have been identified for the Xiong'ershan-Waifangshan region in western Henan Province: high-Ba-SrⅠ-type granite emplaced in the early stage (～160 Ma),Ⅰ-type granite in the middle stage (～130 Ma) and anorogenic A-type granite in the late stage (～115 Ma). Geochemical characteristics of the high-Ba-SrⅠ-type granite suggest that it may have been generated from the thickened lower crust by partial melting with primary residues of amphibole and garnet. Gradual increase of negative Eu anomaly and Sr content variations reflect progressive shallowing of the source regions of these granites from the early to late stage. New 40Ar/39Ar plateau ages of the early-stage Wuzhangshan granite (156.0±1.1 Ma, amphibole) and middle-stage Heyu granite (131.8±0.7 Ma, biotite) are indistinguishable from their SHRIMP U-Pb ages previous published, indicating a rapid uplift and erosion in this region. The representative anorogenic A-type granite, Taishanmiao pluton, was emplaced at～115 Ma. The evolution of the granites in this region reveals a tectonic regime change from post-collisional to anorogenic between～160 Ma and～115 Ma. The genesis of the early- and middle-stageⅠ-type granites could be linked to delamination of subducted lithosphere of the Qiniing orogenic belt, while the late-stage A-type granites represent the onset of extension and the end of orogenic process. In fact, along the Qiniing -Dabie-Sulu belt, the Mesozoic granitoids in western Henan, Dabieshan and Jiaodong regions are comparable on the basis of these temporal evolutionary stages and their initial 87Sr/86Sr ratios, which may suggest a similar geodynamic process related to the collision between the North China and Yangtze cratons.     

Evaluation of a spatial rainfall generator for generating high resolution precipitation projections over orographically complex terrain

Space–time variability of precipitation plays a key role as driver of many environmental processes. The objective of this study is to evaluate a spatiotemporal (STG) Neyman–Scott Rectangular Pulses (NSRP) generator over orographically complex terrain for statistical downscaling of climate models. Data from 145 rain gauges over a 5760-km² area of Cyprus for 1980–2010 were used for this study. The STG was evaluated for its capacity to reproduce basic rainfall statistical properties, spatial intermittency, and extremes. The results were compared with a multi-single site NRSP generator (MSG). The STG performed well in terms of average annual rainfall (+1.5 % in comparison with the 1980–2010 observations), but does not capture spatial intermittency over the study area and extremes well. Daily events above 50 mm were underestimated by 61 %. The MSG produced a similar error (+1.1 %) in terms of average annual rainfall, while the daily extremes (>50-mm) were underestimated by 11 %. A gridding scheme based on scaling coefficients was used to interpolate the MSG data. Projections of three Regional Climate Models, downscaled by MSG, indicate a 1.5–12 % decrease in the mean annual rainfall over Cyprus for 2020–2050. Furthermore, the number of extremes (>50-mm) for the 145 stations is projected to change between ?24 and +2 % for the three models. The MSG modelling approach maintained the daily rainfall statistics at all grid cells, but cannot create spatially consistent daily precipitation maps, limiting its application to spatially disconnected applications. Further research is needed for the development of spatial non-stationary NRSP models.     

An Assembly Coastal Building Technique in Port Engineering

The assembly coastal hfilding technique initiated at home and abroad,is for a novel vertical standing harbor structure.Its main concept is the assembling components which can be combined and locked together to form a large caisson.Its application and future are discussed for a building.After many years of application and tests,the technique has a high stability,a wide range of application,low workload and fast construction speed.It can be widely applied in future for harbor engineering projects.     

Notes on Extended-Range Atmospheric Prediction in the Northern Hemisphere Winter

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黔北务正道地区铝土矿稀土元素地球化学特征

选取新模向斜的一个钻孔剖面,对铝土矿的矿物组成及稀土元素地球化学特征进行了研究。铝土矿矿石矿物以一水硬铝石为主,另有少量一水软铝石。其次为高岭石、绿泥石等黏土矿物,以及少量重矿物。此外,在含矿岩系近底部还发现有富集Ce元素的矿物氟菱钙铈矿[Ce2Ca(CO3)3F2]。从剖面顶部至底部,铝土矿中稀土元素含量呈逐渐增加的趋势,且稀土元素参数LaN/YbN、LaN/SmN和GdN/YbN的数值均随深度逐渐增大。说明从剖面顶部至底部,稀土元素的淋滤迁出逐渐减弱,且稀土元素间存在一定的分异。稀土元素间的分异可能由不同的含稀土元素矿物抗风化淋滤差异所致。铝土矿稀土元素配分模式表现为LREE明显富集、MREE中等-弱富集、HREE相对平坦的特征,且具有明显的正Ce异常。δCe异常值随深度增加逐渐减小,接近含矿岩系底部,δCe异常值再次增大。含矿岩系上部的Ce异常是由氧化条件下Ce3+向Ce4+转变并形成方铈矿(CeO2)所致。随着深度的增加,含矿岩系的氧化性逐渐减弱,从而δCe异常值逐渐减小。接近含矿岩系底部,由于氟菱钙铈矿[Ce2Ca(CO3)3F2]的形成,导致δCe异常值再次增大。氟菱钙铈矿的沉淀可通过氟化物络合物(CeF2+或CeCO3F0)与Ca2+和HCO3-发生反应来完成。     

新疆西准噶尔地区塔斯特岩体锆石LA-ICPMS年龄及其意义

西准噶尔萨吾尔地区地处新疆阿勒泰地区吉木乃县及塔城地区和丰县。酸性侵入岩在区内较发育,其研究对于准噶尔地区后碰撞构造-岩浆演化时限的厘定具有重要的意义。塔斯特岩体是萨吾尔地区重要的复式花岗岩体,与区内铜、金矿化关系密切。塔斯特岩体锆石 LA—ICPMS 年龄为337±4Ma(1σ),形成于早石炭世。结合已有的地球化学特征研究,这一年龄显示西准噶尔地区在早石炭世已处于后碰撞环境。本文获得的塔斯特岩体成岩年龄是目前在准噶尔地区获得的最老的后碰撞花岗岩锆石 U—Pb 年龄之一,为准噶尔地区后碰撞构造-岩浆演化时限的厘定提供了新的证据。     

更新世冰盖与大洋碳储库相互作用的箱式模型模拟

全球大洋深海有孔虫碳同位素(δ13C)记录中广泛发现40万年周期,这一周期可能与偏心率长周期的轨道驱动有关.1.6 Ma以来,δ13C的这一长周期拉长到50万年,且重值期不再与偏心率低值对应.目前对δ13C 40万年周期的成因及其周期拉长的机制还不明确.这里使用了包含9个箱体的箱式模型,用于研究热带过程与冰盖相互作用及其对大洋碳循环的影响.模拟结果显示当北半球高纬海区海冰迅速增大时冰盖迅速融化,进入冰消期,而当海冰快速消失后,冰盖则重新缓慢增长.冰盖变化具有冰期长,间冰期短的非对称形态.在季节性太阳辐射量的驱动下冰盖变化具有10万年冰期-间冰期旋回.当冰盖融化速率受北半球高纬夏季太阳辐射量控制时,冰盖变化的岁差周期明显加强,相位与地质记录一致,说明轨道驱动可以通过非线性相位锁定机制使冰盖变化与其在相位上保持一致.海冰的阻隔效应使大气中CO₂在冰消期时增多.冰期时大洋环流减弱使大气中CO₂逐渐减少.当模型只有ETP驱动的风化作用而不考虑冰盖变化时,模拟的δ13C记录显示极强的40万年周期,体现了大洋碳储库对热带风化过程的响应.当同时考虑冰盖变化和风化作用时,模拟的δ13C结果中40万年周期减弱而10万年周期加强,并且40万年周期上碳储库与偏心率的相位与不考虑冰盖变化时的相位也存在差异,反映了冰盖变化引起的洋流改组压制了大洋碳循环对热带过程的响应.      

A comparison of brachyuran crab community structure at four mangrove locations under different management systems along the Melaka Straits-Andaman Sea Coast of Malaysia and Thailand

Brachyuran crab community structure was compared between mangrove sites under different management systems from four locations along the Melaka Straits-Andaman Sea Coast. Klong Ngao, a mangrove estuary in Ranong Province of southern Thailand, lies within a Biosphere Reserve designated in 1997. Sites were positioned in plantations at a former charcoal concession forest, a disused tin mine, and an abandoned shrimp pond along this estuary. The Merbok estuary in Kedah, Malaysia, is partially managed: the mangroves are cut for charcoal and poles on a small scale and the forests are left to regenerate naturally. The Matang Mangrove Forest Reserve in Perak, Malaysia, is heavily exploited but well managed, forRhizophora wood to produce charcoal, and has been for 100 years. Sites were positioned in plantations of different ages. Kuala Selangor Nature Park, Selangor, Malaysia, was established as a nature reserve in 1987 and contains mature mangrove forest regenerating naturally from previous selective felling. At Klong Ngao and Matang, mature reserve forest sites were also studied for comparison with plantation sites. The sites included both upstream and downstream locations and were of similar area, minimizing effects from possible species-area relationships. Sites were chosen with similar environmental conditions and with a dominance ofRhizophora spp. At each site per location, the brachyuran crabs were sampled quantitatively in 100 m² quadrats by three independent 15-min timed crab catches. The crab community recorded was analyzed by univariate and multivariate statistical techniques. Management history plays an important role in moderating the crab community structure. The crab community also changes with the age of the mangrove forest stand. Sesarmid crabs consistently dominated in mature forests, whereas young plantations were colonized mainly by ocypodid crabs. The findings show that heavily effected sites—e.g., disused tin mining areas, former concession forests, and abandoned shrimp ponds—can be rehabilitated by planting mangroves and that the crab community is a useful ecological indicator of habitat status.     

黔北务正道地区铝土矿形成环境的古盐度识别

通过对黔北务川—正安—道真铝土矿中的B、Sr、Ba、V、Zr及其生物标志化合物的分析,对务正道地区铝土矿沉积环境的古盐度进行了研究。结果表明,铝土矿的沉积受到海洋环境的影响,主要形成于半咸水-淡水环境中。沉积环境为半封闭海湾,海侵使成矿区低盐度水体变为半咸水或咸水,随后陆地淡水输入等淡化作用将半咸水或咸水淡化,淡化的程度与范围取决于淡化时间的长短,经淡化后的水体在下一轮海侵中再次被咸化,水体的古盐度随海平面升降在淡水-咸水之间循环。     

Analysis of the Marmara flood in Turkey, 7–10 September 2009: an assessment from hydrometeorological perspective

Turkey often suffers from flood-related damages and causalities as a result of intense and prolonged storms that are usually convective or cyclonic in origin. The impact is more distinctive in Aegean and Mediterranean coasts of the country where quantity and distribution of rainfall is influenced by Mediterranean cyclones, especially in late autumn and early winter. The floods sometimes became very hazardous when combined with urbanization effects, especially in the densely populated coastal communities and major cities. Severe weather was marked in the early parts of September 2009 that produced record-setting rainfall amounts across the Marmara region of Turkey and led a series of flash floods which affected ?stanbul and Tekirda? provinces especially. The overall flooding was the result of successive and persistent intense rainfall episodes over a 3-day period which produced more than 250-mm rainfall over portions of the region. The floods resulted in death of 32 people and caused extensive environmental and infrastructural damage in the region. This study provides in-depth analysis of hydrometeorological conditions that led to the occurrence of flash floods in Marmara region during 7–10 September 2009 period and also discusses non-meteorological factors that exacerbated the flooding conditions. Main meteorological settings that led to intense storms were presence of cold air in the upper atmosphere, a slow-moving quasi-stationary trough, and continuous resupply of moisture to the surface low from the warm Aegean Sea. Radar images showed the development of clusters of convective cells that remained quasi-stationary over portions of the region. The 24-h rainfall amounts varied between 100 and 253 mm in most parts of the region during the flooding period with diverse spatial patterns. The southern locations received the highest amount of the rainfall as compared to stations located in northern slopes of the region. Typical effects of orography that enhance rainfall in the coastal areas, however, were not observed during the Marmara flood. Some features of the synoptic pattern observed prior and during the flooding period, supported the back door cold front concept. This is characterized with easterly to northeasterly surface flows forced by an anticyclone, advection of cold continental air over the warm Black Sea which provided anomalous moisture to trigger cyclogenesis over the Marmara region, and falling of core of the intense rainfall over the Marmara Sea. The study concluded that although the meteorological settings were favorable for the convective rainfalls, urbanization factors, such as land use changes and occupation of flood plains, played major role in aggravating the worst flood observed in the region in recent decades.