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1.
农业生态地质环境研究中生物-水文地球化学方法   总被引:3,自引:0,他引:3       下载免费PDF全文
李瑞敏  侯春堂 《地球科学》1995,20(4):455-458
土壤溶液既是养分,又是养分载体,在养分由岩土→水(土壤溶液)→植物体系统中起着中介的作用。本文以金丝小枣所需养分供、输、耗系统为主线,采用生物-水文地球化学方法,通过分析计算输入系数、配比系数、吸收系数第一系列生物-水文地球化学参数,探讨讨地质环境影响枣林品质的作用机制,即地质环境的农业生态效应机制。  相似文献   

2.
土壤溶液既是养分,又是养分载体,在养分由岩土→水(土壤溶液)→植物体系统中起着中介的作用,本文以金丝小枣所需养分供、输、耗系统为主线,采用生物─水文地球化学方法,通过分析计算输入系数、配比系数、吸收系数等一系列生物─水文地球化学参数,探讨地质环境影响枣林品质的作用机制,即地质环境的农业生态效应机制。  相似文献   

3.
农业地质调查研究的几个基本问题   总被引:2,自引:1,他引:1  
阐述了现今农业地质调查研究中的农业地质环境、土壤元素有效态概念和样品采集控制方法:农业地质环境是忆地区域地质地貌背景的总合;土壤元素有效态含量包括土壤中元素活性态、部分Fe-Al共沉淀态和有机结构态含量,它们是植物天然营养元素的来源,根据农业地质环境类型的差异,划分采样单元、进行系统采集农业地质分析样品。  相似文献   

4.
俯冲带的流体地质作用   总被引:1,自引:0,他引:1  
于在平 《地学前缘》1995,2(2):175-182
俯冲带是地球上流体活动最活跃的地区之一,也是流体由表层进入深部岩石圈的主要通道。流体活动对岩石成分、成岩作用、构造变形、变质作用、部分熔融和岩浆-火山作用,以及海洋生物-化学环境都有重要的控制和影响。本文回顾和总结了俯冲带流体地质作用研究的现状和进展,对古俯冲带流体地质作用的若干问题进行了探讨。  相似文献   

5.
金和海 《铀矿地质》2003,19(2):88-93,118
本文结合盆地的区域地质背景,分析了三塘湖盆地的盖层沉积构造特征、找矿目的层的空间展布、地下水“补-径-排”系统和层间氧化带发育特征,认为该盆地相对稳定,埋藏浅的斜坡带地段具备了层间氧化带砂岩型铀矿成矿环境,应进一步开展工作。  相似文献   

6.
本文在系统研究桂北隆起区锑矿成矿地质环境,矿床特征,地球化学特征及成因机制的基础上,提出该区锑矿属浅变质碎屑岩系中的碎裂岩-石英脉型锑矿,其成因主要与地下热卤水渗滤作用有关,并着得阐明了“四阶段”区域成矿过程,此外初步总结了地层、构造等控矿规律及若干找矿标志,建立了“划带-圈区-定位”的综合找矿模型,并进行了成矿预测。  相似文献   

7.
本文结合盆地的区域地质背景,分析了盆地的沉积盖层构造特征,目的层的空间展布,“补-迳-排”系统和层间氧化带发育,认为该盆地的相对稳定,埋藏浅的斜坡带地段,具备了层间氧化带砂岩型铀成矿的环境,值得进一步开展工作。  相似文献   

8.
龙泉关韧性剪切带的新认识   总被引:1,自引:0,他引:1  
龙泉关韧性剪切带五台山花岗岩-绿岩地体与阜平高级变质地体的接触部位,它不仅改造了“阜平群”而且也改造了“五台群”宏观构造,显微组构和矿物组合研究表明,龙泉关韧性剪切带经历了两期变形作用,早期发生于恒山古陆块-车厂弧地质体-阜平古陆块碰撞过程中,形成低角度逆冲型韧性剪切带,使地壳显著增厚,晚期发生于增厚同的纵向伸展过程中,使地壳得以均衡发展,形成低角度伸展型韧性剪切带,龙泉关韧性剪切带的变形特征反映  相似文献   

9.
大别山南北缘中-晚元古代火山岩的浅变质作用   总被引:3,自引:0,他引:3  
杨荣兴 《矿产与地质》1999,13(6):358-362
研究认为:大别山深变质基底杂岩北缘中-晚元古双峰式火山岩系,普遍遭受过缘片岩相浅变质作用,相当于中-低压相系到中-高压相系。南缘火山岩系寻段发育蓝片岩带,属蓝闪绿岩相变质作用,属高压相系。变质作用过程可分为三个阶段:拉张环境中的中-低压“细碧岩化”变质作用→挤压造山环境扣-高压区域变质作用→局部地区的高压蓝闪石绿片岩相变质作用。  相似文献   

10.
表层岩溶带的岩溶动力学特征及其环境和资源意义   总被引:61,自引:6,他引:61  
蒋忠诚  袁道先 《地球学报》1999,20(3):302-308
表层岩溶带处于四大圈层的交汇带,碳- 水- 钙循环活跃,溶蚀和沉积化学反应都比较迅速,岩溶动力作用强烈而且对环境变化具有敏感性。表层岩溶带快速的岩溶过程以及对环境变化的敏感性,赋存大量短时间尺度的环境变化信息,可提高地质过程在全球环境变化研究的地位; 表层岩溶带碳- 水- 钙循环的活跃和与环境岩溶动力条件的相关性,使得表层岩溶带对环境 C O2 的变化具有调节作用,从而对碳循环的研究具有重要意义;表层岩溶带的发育使南方岩溶区具有浅层岩溶水循环与地下管道水循环耦合的二次岩溶水循环的结构特征,加强了岩溶水的调  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

13.
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003).  相似文献   

14.
HYDROGEOLOGY     
正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level  相似文献   

15.
正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7),  相似文献   

16.
17.
正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci-  相似文献   

18.
正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli-  相似文献   

19.
正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.)  相似文献   

20.
GEOCHEMISTRY     
正20142002 Wei Hualing(Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang065000,China);Zhou Guohua Element Content and Mineral Compositions in Different Sizes of Soil in Tongling Area,Anhui Province(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(11),2013,p.1861  相似文献   

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