高原湿地纳帕海自然保护区功能区分区初探

高原湿地保护区具有自己独特的生态结构特征,其功能区分区不应照搬传统的3级规划模式。本文通过对纳帕海湿地保护区功能区分区的特点、现状以及存在问题的分析,提出了适合纳帕海保护区湿地特征的分区模式。     

石英脉型钨多金属矿床的扇状成矿实例及找矿模型

石英脉型钨矿床是中国数量最多的钨矿床类型,但保有储量消耗迅速,迫切需要创新找矿模型,指导找矿突破。文章结合二十余年的找矿实践,通过详细分析扇状成矿矿床实例,构建了石英脉型钨矿床新的找矿模型。该模型强调赋矿裂隙为岩浆动力成因,在花岗岩体顶部呈扇状分布型式,岩浆期后热液恰在裂隙张开时充填其中而形成扇状成矿系统;提出“就岩找矿”、“就矿找矿”、“就矿找岩”的地质、地球化学和地球物理标志,指导矿床尺度的勘查工程部署。截至目前,该模型已在广东禾尚田钨锡矿床、广西珊瑚钨锡矿床、广西社垌钨钼矿床、江西盘古山钨铋矿床等获得了验证,找矿成效显著。     

重庆市江津区地下管线普查及更新

地下管线是城市基础设施的重要组成部分.随着现代化进程的发展,地下管线已发展到包括电力、电信、给水、排水、燃气、热力、工业等多类别布局复杂的管线网.但由于历史及现实的各种原因,我国许多城市地下管线管理普遍滞后于城市发展需求,地下管线资料残缺不全,已有的资料精度不高或者与实际不符,在工程建设中经常发生损坏地下管线的严重事故...     

The deep thermal structure of the lithosphere in the northwestern South China Sea and its control on the shallow tectonics

The northwestern sub-basin of South China Sea(SCS) is a unique tectonic unit formed in the early spreading of the SCS. The northwestern Sub-basin has a series of complex geological structures such as seamounts and fault zones surrounded by the Xisha Trough, the Zhongsha Massif, and the Pearl River Valley. These extensional structures and magmatic activity in the northwestern sub-basin are closely related to the lithospheric structure and its deformation. However, details of the deep lithosphere structure are still poorly known. Here, we obtained detailed data of water and Moho depth using sonar buoys,Extended Spread Profiles(ESP), Ocean Bottom Seismometer(OBS), both Multi-beam and land-sea joint seismic surveys in the northwestern sub-basin and its surrounding areas. Then we adopted a thermal isostasy method to calculate the depth of the Lithosphere-Asthenosphere Boundary(LAB) in the northwestern sub-basin of the SCS and its surrounding regions. Results show that the range of LAB depth is ～25–110 km. The shallowest burial depth is 25–60 km occurring in the ocean basin. The depth increases to 60–110 km toward the continental margin. The lithospheric structure on the north and south sides of the Xisha Trough is symmetrical and shows the deep structure and thermal features of aborted rifts. The LAB depth in the Zhongsha Trough and the Zhongsha Massif increased from 60 to 70 km southwestwards, consistent with the trend of surface morphology.The LAB depth to the west side of the Pearl River Valley is 60–80 km, and the thinning of the lithosphere is related to the distribution of faults, depressions and the magmatic activity. The LAB depth in the northwestern sub-basin and the eastern subbasin is less than 60 km with the thinnest part being less than 46 km. Combining ocean drilling, seismic investigation, and seafloor topography, we show that the ocean basin of the northwestern sub-basin of the SCS locates within the 46 km isobath of the LAB. The formation of the rifted valleys and discrete blocks surrounding the ocean basins is both controlled by the regional tectonic movement and the deep thermal state, where their lithospheric structures show strong heterogeneity.     

标度律视角的城市效能测度及中国城市多维要素效能分析

"城市标度律"(urban scaling laws)揭示了城市系统中城市人口和城市要素间普遍存在的非线性规模缩放关系,但目前大多数城市评价忽视了这种关系,常使用人均指标比较不同规模的城市,这会导致评价结果偏差.为此,考虑城市人口和城市要素间的非线性规模缩放关系构建了要素效能指数,用以修正城市规模的影响,度量城市要素实...     

晋城煤层气藏成藏机制

通过晋城煤层气的规模开发、压裂煤层气井的解剖、井下煤层瓦斯抽放、构造地应力场研究、煤储层大裂隙系统“CT”式解剖与煤层气封闭保存条件研究, 发现3#煤储层内部存在大量煤层气包, 构造微破裂作用促使煤层气包之间广泛合并联通, 煤层气包内部储层的非均质性弱化, 渗透率增加, 煤层气包内部的游离气体比例增加, 流体压力系统边界逐渐清晰并形成煤层气藏. 揭示煤层气藏的成藏机制, 认识煤层气藏的内部细节特征, 促进了该区的煤层气开发技术进步, 提高了井下煤层瓦斯的抽放效率.      

Seasonal and Interdecadal Variations of Heat Transport over the Northern Hemisphere

1Introduction Theglobalclimatechangehasbeenoneoftheprob lemschallengingtheworldinrecentyears.TheweatherandclimateonEarthhasbeeninvariationontimescalesfromseasonaltomillennialorevenlonger.ResearchesonvariationsofweatherandclimateintheNorthernHemispherehave…     

太白山北坡花粉通量与表土花粉研究

太白山北坡各森林植被带乔木花粉百分比多高于45%,与植被组成类似。高山草甸带捕捉器样品乔木花粉百分比低于15%,与植被组成一致,但表土花粉组合中乔木花粉百分比高于50%,外来花粉数量较多,进行高山带古环境研究应予注意。太白红杉林花粉通量最低,高山灌丛草甸最高。落叶栎林带表土花粉浓度最低,红桦林带最高。表土中松、冷杉属花粉百分比远高于花粉捕捉器,表明其在表土中有较好的保存能力。落叶松属和杜鹃花科花粉在表土及捕捉器中百分比均较低,表明对植被指示性良好。栎属与桦属花粉通量类似,但桦属花粉浓度大于栎属,表明栎属较桦属易于保存。     

西藏东巧蛇绿岩中辉长岩锆石SHRIMP定年及其地质意义

东巧蛇绿岩位于分割羌塘地块和拉萨地块的班公湖—怒江缝合带中段,是该带最著名的产铬铁矿床的蛇绿岩残片之一。该蛇绿岩遭受构造肢解,恢复后的蛇绿岩剖面各岩石单元齐全。本文应用SHRIMPⅡ锆石UPb法,对东巧蛇绿岩中堆晶辉长岩进行了测年,获得辉长岩年龄为187.8±3.7 Ma。该年龄代表了东巧洋盆的形成时代,为确定研究区特提斯洋盆的古构造格局及其发育演化过程等提供了重要的年代学制约。     

近20年来福州市土地利用时空变化的遥感分析

以1986、1996和2006年三期Landsat TM影像为基本数据源,采用最大似然法分类,并以同期高分辨率的SPOT5影像进行分类后处理,最后分类后变化检测法监测了福州市1986~2006年的土地利用变化及其转移模式。结果表明,福州市近20年间土地利用发生了较大的变化,城乡建筑用地处于快速增长阶段,而耕地数量却在不断下降。经济发展、人口增长、政府决策等因素是福州市土地利用发生变化的主要驱动力。