海南岛红树林泥炭中硫及其成因研究   总被引：4，自引：2，他引：4  

桑树勋  刘焕杰 《煤田地质与勘探》1993,21(1):12-17

海南岛红树林泥炭普遍富硫。黄铁矿、硫酸盐和有机硫是泥炭中硫的三种主要赋存形态,其中,以黄铁矿硫高为特征。利用形态硫分析、硫同位素分析等手段结合硫的时空变化特征,研究了泥炭中硫的形成机理。泥炭中硫的富集与泥炭坪环境具紧密的成因联系,全硫和形态硫的时空变化受微环境的控制;潮坪水介质中的硫酸盐是泥炭中硫的最初来源;泥炭中硫的加入,主要发生于准同生价段,在加入过程中还原硫细菌起了决定性作用。定量沉积环境分析是查明古代富硫煤田硫分布的主要途径。  相似文献   

东南沿海地震区东部中强震活动特征     

鄢挺骅 《华南地震》1993,13(4):58-62

研究了1500年以来东南沿海地震区东部中强地震的活动特征。通过对其时序演变进程的分析,长乐-诏安地震带和邵武-河源地震带地震活动参数的对比,以及对第二活跃期中强地震迁移特点的研究,对该区今后的地震活动趋势作出了估计。  相似文献   

Content of mercury in leaves of Spartina alterniflora Loisel. in Georgia,U.S.A.: an update     

S.Y. Newell  R.E. Hicks  M. Nicora 《Estuarine, Coastal and Shelf Science》1982,14(4):465-469

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The tidal intrusion front: An estuarine convergence zone     

J.H. Simpson  R.A. Nunes 《Estuarine, Coastal and Shelf Science》1981,13(3):257-IN1

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Differences in animal ¹³C, ¹⁵N and D abundance between a polluted and an unpolluted coastal site: Likely indicators of sewage uptake by a marine food web     

G.H. Rau  R.E. Sweeney  I.R. Kaplan  A.J. Mearns  D.R. Young 《Estuarine, Coastal and Shelf Science》1981,13(6):701-707

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压实粉土非线性应力-应变关系的试验研究     

彭丽云  刘建坤  肖军华  陈立宏  朱瑞龙 《工程地质学报》2007,15(1):50-55

对京九线路基粉土用GDS三轴仪进行固结不排水剪试验,研究不同围压、含水量、压实度下压实粉土样的应力-应变关系。结果表明:压实粉土在低围压下为应变软化,高围压下为应变硬化,存在一个屈服应力;含水量和压实度对粉土强度和应力-应变关系影响显著,随着含水量的减小、压实度的增大,压实粉土样强度增大,应力-应变曲线上升。对围压小于屈服应力的应变软化曲线,用常规的土的软化关系式进行拟和;对围压大于屈服应力的应变硬化曲线,用邓肯-张模型进行拟和;这二者的结合能描述压实粉土的应力-应变关系曲线,效果良好。  相似文献   

矿山滑坡天线阵列变形监测系统的方案与测试     

常松卫  邹进贵  袁细保  张洪波  邹双朝 《地理空间信息》2007,5(6):100-103

首先阐明地质灾害监测的重要性和必要性,然后分析了目前应用于滑坡安全监测自动化远程监测设备和技术,并重点介绍了GPS天线阵列变形监测系统,接着根据某矿山的一个滑坡现场,进行GPS天线阵列监测方案设计,并在实地进行数据采集测试,最后对采集数据进行处理,对几期结果的较差和精度进行分析,得出在矿山自动化监测技术中,GPS天线阵列变形监测系统是一种性价比很高的监测技术,很适合滑坡安全监测。  相似文献   

加强管理保护沿海地质环境     

戴长寿 《水文地质工程地质》1998,25(4):8-9,49

江苏沿海大陆岸线长９５３．９ｋｍ,海岸带面积约３．５万ｋｍ＾３,滩涂面积５０００ｋｍ＾２,而且每年向外海新增土地两万多亩,还拥有举世瞩目的辐射状海底沙脊群,海平面以上部分就有４００ｋｍ＾２,是江苏省宝贵的后备国土资源。沿海地区是江苏新的经济增长点。改革开放以来,沿海地区经济的发展,加之地表水体的污染逐年严重,对优质地下淡水的开采逐年增加,原有的地质环境受到破坏,出现了地下水位下降,地下淡水资源减少  相似文献   

Age of Saurashtra miliolites by U-Th decay series methods: possible implications to their origin     

N. Hussain  N. Bhandari  K. R. Ramanathan  B. L. K. Somayajulu 《Journal of Earth System Science》1980,89(1):23-29

The miliolite deposits of Saurashtra have been dated by²³⁴U,²³⁰Th,²³¹Pa and¹⁴C methods. Concordant ages of 10⁵ years using the U decay series isotopes are obtained which agree with the ages of the coral reefs of Okha-Dwaraka coast suggesting a contemporaneous origin for both. The lower¹⁴C ages (≤40,000 years) may be due to a recent influx of seawater or ground water. Quartz and clay minerals together constitute only ≤10% by weight, as such the aeolian characteristics of quartz grains may not be relevant to the origin of the miliolites.  相似文献   

Application of Two Turbulence Closure Schemes in the Modelling of Tidal Currents and Salinity in the Hooghly Estuary     

P. C. Sinha  Y. R. Rao  S. K. Dube  C. R. Murthy  A. K. Chatterjee 《Estuarine, Coastal and Shelf Science》1999,48(6):649

This paper has two purposes. The first is to study the circulation and salinity in Hooghly Estuary, along the east coast of India and the second is to compare the performance of two turbulence closure schemes by modelling it. A breadth averaged numerical model using a sigma co-ordinate system in the vertical is briefly described. Vertical diffusion of momentum and salt are parameterized by a simple first-order turbulent closure or by a one equation model for turbulent kinetic energy (TKE) which uses a specified mixing length. The results are compared with the available neap and spring tide observations along the estuary for both low and high discharge periods.The computed elevations and currents are in reasonable agreement with the observations showing no major differences in vertical current profiles by both the turbulent schemes. However, there is a slight under-prediction of bottom currents. The salinity profiles predicted by TKE model show better matching with observations. Statistical tests are also conducted to study the comparative performance of the turbulent closure schemes. The maintenance of two layer structure in residual currents and salt variability are also studied by using the model.  相似文献