从砂岩成分探讨吐哈盆地构造演化   总被引：9，自引：1，他引：9       下载免费PDF全文

邵磊  Stattegger. 《地质论评》2001,47(1):19-26

陆源碎屑岩是陆相沉积盆地的主要充填物，其成分主要受物源区母岩成分控制。通过系统分析碎屑岩成分特点可以再造沉积盆地的构造演化历史。对吐哈盆地分别采用岩矿和地球化学分析手段进行系统分析，结果显示两种分析所得结构吻合性极好，反映盆地的构造演化分为二叠纪、三叠纪－侏罗纪以及白垩纪－第三纪3个演化阶段，在各阶段地层成分出现较大差异，是盆地及相邻地区遭受构造运动改造的结果。  相似文献   

Tl—In—S三元系的实验研究     

徐珏 Moh  GH 《地质论评》1993,39(3):231-235

作者通过T1—In-S三元系实验研究,在300℃等温面上发现4个三元固溶体相和2个三元相。4个三元固溶体相的成分变化范围分别是:(Ⅰ)T1_(2C)InS_(16)-T1_(40)In_3S_(33);(Ⅱ)T1_4InS_5—T1_4InS_4;(Ⅲ)T1_8In_2S_7—T1_(15)In_3S_(11)和(Ⅳ)T1_2In_2S_5。2个三元相的成分分别是T1_3InS_3和T1_2In_2S_3。这些相之间的关系清楚地示于T1-In-S相图中。此外,在600℃时合成了三元相T1In_2S_3,并对前人的实验研究进行了补充和修正。  相似文献   

MASS MOVEMENTS AND SEDIMENT TRANSPORT AS A NATURAL HAZARD     

Wolfgang KRON Senior Hydraulic Engineer  Geosciences Research Group  Munich Reinsurance Company  Munich  Germany 《国际泥沙研究》1997,(3)

I.INTRODUCTIONFormillionsofyearswindandwaterhaveshapedtheearth,mountainshavebeenliftedanderodedaway,waterhasevaporatedfromtheoceansandfallenbackonland,rivershaveformedandcarriedwaterandsedanmentfromthemoufltainstotheseas.Someoftherivers--suchastheColoradoRiverintheGrandCanyonregionofNorthAJnerica-foundstablecoursesastheycarvedthemselvesintotheground,others--suchastheYellowhiverinChina-havechangedtheircoursesfrequentlyallthewayintorecenthistory.Itwasonlyafewthousandyearsagothatmanstarte…  相似文献   

ALTERATIONS OF RIVER MORPHOLOGY DUE TO VEGETATION ON SLOPES AND FLOOD PLAINS     

Wolfgang MERTENS Prof. Dr.-Ing.  Leichtweiss-Institut fuer Wasserbau  Technical University of Braunschweig  P.O. Box  Braunschweig  Germany 《国际泥沙研究》1997,(3)

LRESEarCHACTIVITIESCharaCtCriedcofunlinedalluvialriVersisthe~linteractionbettVeenwaterflowandmovableriVerbed.Sedimenttransport,bedresistanceandriVermorphologydecisivelydependontheflowconditionsandviceversathesefactorsgovernthehydraulicprocesses.EVenundersimplifiedconditions,e.g.inlaboratorytests,theseillteractionsareeXtremelycomplexandrelldsraliZationmakesengineeringproblemsevenmored~.TomaketheseprocessesmoreunderstandablecomprehensiVeresearchprojectswereconductedatseveralGermanuniv…  相似文献   

Subsolidus Phase Relations in the System MgO-SiO_2-Cr-O and Thermodynamic Properties of Related Cr~(2+)-Containing End-members     

H.St.CO'' Neill  F.Seifert 《《地质学报》英文版》1996,70(4):420-434

Subsolidus phase relations have been determined in the systems SiO2-Cr-O and MgO-SiO2-Cr-O in equilibrium with metallic Cr, at 1100 to 1500℃ and 0 to 2.88 GPa. The results show that there are no ternary phases in the SiO2-Cr-O system at these conditions, i.e., only the assemblage eskolaite-Cr-metal-quartz (or tridymite) is found. In the MgO-containing system, however, extensive substitution of Cr2+ for Mg is observed in (Mg, Cr2+)2SiO4 olivine, (Mg, Cr2+)2Si2O6 pyroxene, and (Mg, Cr2+)Cr2O4 spinel. Cr3+ levels in olivine and pyroxene are below detection limits. The pyroxene is orthohombic at XCrPx2+ < 0.2, monoclinic at higher XCrPx2+ . Thestructure of the spinels becomes tetragonally distorted at XCr2+Sp >0.2. The experimental datahave been fitted to a thermodynamic model, and the authors obtained the mixing parameter (W) of Mg-Cr2+ in olivine, pyroxene and spinel, and the relation between temperatures and free energies of formation for the end-members: Cr2+-olivine (Cr2SiO4), Cr2+-pyroxene (Cr2Si2O6)  相似文献   

Evidence of seismites in coastal Quaternary deposits of western Oranie (northwestern Algeria)     

Mohamed Amine Boukhedimi  Amina Louni-Hacini  Youcef Bouhadad  Jean-François Ritz  Djamel Machane  Azzeddine Benhamouche  Hamid Bourenane 《Journal of Seismology》2017,21(3):539-549

Coastal Quaternary deposits of western Oranie show typical soft-sediment deformations including sedimentary dykes, sand volcanoes, sismoslumps, thixotropic bowls, thixotropic wedges, diapir-like structures, and faults grading. Field observations indicate that these deformations exist at several levels of the studied deposits along the west Oranian coast. This study demonstrated that these structures are earthquakes-related, by analysis of potential trigger sources. Several arguments demonstrate the seismic origin: the depositional environment rich in water that located in an active tectonic region, the thixotropic nature of deformations and their large vertical and horizontal diffusion in the Quaternary series consistent with a seismic recurrence. This allows characterizing these Quaternary soft-sediment deformations as seismites that were triggered by earthquakes.  相似文献   

1989年10月和1991年3月大同地震的活动断裂   总被引：3，自引：1，他引：2  

王培德  克劳茨 《地震地磁观测与研究》2000,21(6):19-25

中国地震局地球物理研究所在 1 989年 1 0月 5.8级和 1 991年 3月 5.5级大同地震之后使用由数字地震仪组成的小孔径流动台网对其余震进行了流动观测。通过利用多道地震数据分析软件正确地确定震相 ,修改地壳速度模型等方法 ,高精度地确定了部分余震的震源位置。两次大同地震部分余震的震中分布表明 ,大同地震的主干断裂是北北东走向的断裂 ,同时伴随北西走向的分支断裂的活动。盆地的速度结构可以以双层速度结构模拟 ,其上层为 P波速度为3.1 km/s的沉积层 ,符合大同盆地为火山喷发堆积物的实际情况。  相似文献   

Spectral evolution of the peculiar Ic Supernova 1998bw     

R. A. Stathakis  B. J. Boyle  D. H. Jones  M. S. Bessell  T. J. Galama  Lisa M. Germany  M. Hartley  D. M. James  C. Kouveliotou  I. J. Lewis  Q. A. Parker  K. S. Russell  E. M. Sadler  C. G. Tinney  J. van Paradijs  P. M. Vreeswijk 《Monthly notices of the Royal Astronomical Society》2000,314(4):807-814

Supernova 1998bw holds the record for the most energetic Type Ic explosion, one of the brightest radio supernovae and probably the first supernova associated with a γ -ray burst. In this paper we present spectral observations of SN 1998bw observed in a cooperative monitoring campaign using the Anglo-Australian Telescope, the UK Schmidt Telescope and the Siding Springs Observatories 2.3-m telescope. We investigate the evolution of the spectrum between 7 and 94 d after V -band maximum in comparison with well-studied examples of Type Ic SNe in order to quantify the unusual properties of this supernova event. Though the early spectra differ greatly from observations of classical Ic supernovae (SNe), we find that the evolution from the photospheric to nebular phases is slow but otherwise typical. The spectra differ predominantly in the extensive line blending and blanketing which has been attributed to the high velocity of the ejecta. We find that by day 19, the absorption line minima blueshifts are 10–50 per cent higher than other SNe and on day 94 emission lines are 45 per cent broader, as expected if the progenitor had a massive envelope. However, it is difficult to explain the extent of line blanketing entirely by line broadening, and we argue that an additional contribution from other species is present, indicating unusual relative abundances or physical conditions in the envelope.  相似文献   

Rapid afterslip and short-term viscoelastic relaxation following the 2008 M_W7.9 Wenchuan earthquake     

Zhigang Shao Rongjiang Wang  Yanqiang Wu  Langping Zhang Institute of Earthquake Science  China Earthquake Administration  Beijing  China GFZ German Research Center for Geosciences  D- Potsdam  Germany 《地震学报(英文版)》2011,(2):163-175

Significant postseismic deformation of the 2008 M W 7.9 Wenchuan earthquake has been observed from GPS data of the first 14 days after the earthquake. The possible mechanisms for the rapid postseismic deformation are assumed to be afterslip on the earthquake rupture plane and viscoelastic relaxation of coseismiclly stress change in the lower crust or upper mantle. We firstly use the constrained least squares method to find an afterslip model which can fit the GPS data best. The afterslip model can explain n...  相似文献   

Hydrogeochemical characterization and groundwater quality assessment in the intensive agricultural zone of the Upper Cheliff plain,Algeria     

Abdelkader Bouderbala  Ben Youcef Gharbi 《Environmental Earth Sciences》2017,76(21):744

The alluvial aquifer of Upper Cheliff (northern Algeria) is known for its intensive agricultural activities, which is based especially on groundwater exploitation. This aquifer is now facing a dual problem of quantity and quality, with a decrease in the groundwater levels and an increase in mineralization. Twenty monitoring samples were collected and analyzed for major ion during the dry season 2014. In the present study, we try to characterize the hydrogeochemical processes and to assess the impact of natural and anthropogenic conditions on groundwater mineralization. The analytical results of the dry season 2014 show a groundwater quality slightly alkaline (pH > 7) and indicate that the majority of samples have a values exceeding the limits of potability fixed by WHO in 2008, due to the various sources of anthropogenic pollution. The Piper diagram shows the dominance of groundwater types: Ca–Cl, the mixed facies (Cl–SO₄–Ca–Mg), and Ca–HCO₃: The mineralization process in this aquifer is mainly controlled by the lithology of the aquifer (exchange water–rock and weathering of calcareous crust dissolution in the unsaturated zone), by anthropogenic factors (discharges of untreated urban sewage, intensive use of fertilizers in agriculture and the use of domestic septic tanks by rural inhabitants) and also by geoclimatic conditions (semiarid climate). Suitability of groundwater shows more than 80% of samples have very poor quality for drinking and more than 20% of samples indicate a quality unsuitable for irrigation.  相似文献