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1.
江西信丰县铁石口剖面二叠—三叠系界线综合研究   总被引:3,自引:0,他引:3  
首次对江西信丰县铁石口二叠-三叠系界线剖面的生物地层学、岩石地层学、微量元素、碳及氧稳定同位素、粘土岩和沉积环境以及数学地质的有序最优分割计算进行了综合研究,通过分析,将铁石口剖面二叠-三叠系界线置于第26层底。界线粘土岩(第26层)的矿物组成以伊利石和高岭石为主,仅含少量蒙脱石-伊利石不规则混层矿物,这是首次发现的新类型界线粘土岩。  相似文献   

2.
首次对江西信丰县铁石口二叠—三叠系界线剖面的生物地层学、岩石地层学、微量元素、碳及氧稳定同位素、粘土岩和沉积环境以及数学地质的有序最优分割计算进行了综合研究,通过分析,将铁石口剖面二叠—三叠系界线置于第26层底。界线粘土岩(第26层)的矿物组成以伊利石和高岭石为主,仅含少量蒙脱石 伊利石不规则混层矿物,这是首次发现的新类型界线粘土岩。  相似文献   

3.
推荐一条GSSP的辅助剖面   总被引:1,自引:0,他引:1  
该文赞同以Hindeodus parvws的首次出现作为划分二叠-三叠系界经的生物标志,笔者强调只有以正模及其描述为准所厘订的H、parvus,且以主齿、细齿保存完美、距界线粘土层顶面位置最低以及其顶面至界线生物面之上均为单一岩相的H、parvus的首次出现点位,才有可能成为二叠-三叠系全球界线层型剖面点的位置、东岭剖面可以它典型的H.parvus距界线粘土层顶面仅高出13cm,化石保存完好以及界  相似文献   

4.
四川重庆中梁山和广元上寺P-T界线处二叠系顶部的粘土岩主要由规则混层伊利石-蒙脱石组成,而三叠系底部的粘土岩主要由伊利石和混层绿泥石-蒙脱石组成。形成二叠系顶部规则混层伊利石-蒙脱石并使之得以保存的相对酸性成岩介质可能与晚二叠世生物相对繁盛和绝灭造成的有机质埋藏有关,而三叠系底部的粘土矿物则与相对富镁、钾的成岩介质有关。此外,两地混层伊利石-蒙脱石中混层比例的差别还反映了这一等时面上所经历的最大古地温的差别,这与它们所经历的埋藏史的不同有关。  相似文献   

5.
目的对新疆准噶尔盆地南缘、吐哈盆地和三塘湖盆地的二叠系及其与三叠系界线的划分提供新的依据。方法在该区长期工作的基础上,参考前人地层划分成果及当地使用习惯,利用岩石地层、生物地层、火山岩同位素年龄、古地磁等方法进行综合分析,对三地区的二叠系进行了综合划分与对比。结果将新疆北部二叠系分别称下、中、上统,与中国南方及国际标准的3个统对应;中二叠统对应于瓜德鲁普统,地质时代为早二叠世(290~265 Ma),中、上二叠统界线在中二叠统塔尔郎组上部,上二叠统与三叠系界线在上二叠统锅底坑组内;中二叠统分布于准噶尔盆地中南部、吐哈盆地北部和三塘湖盆地南部。结论建议将大龙口、锅底坑、塔尔郎沟、照壁山剖面和跃进沟剖面分别作为北疆地区二叠系—三叠系标准剖面。  相似文献   

6.
Clarkina在赣南桃江剖面P/T界线粘土岩中的发现   总被引:1,自引:1,他引:0  
该文报道了Clarkina changxingensis,C.dicerocarinata,C.sp。l cf.tulongensis,鱼牙和海绵化石,以及六方双锥石英晶体,微球粒,玻屑和锆是体在主丰地区二叠-三叠系界线粘土岩中的发现,通过对江西桃江,浙江煤山,西藏色龙P/T界线剖面与江西东岭,沿沟P/T界线剖面相互对比后认为,以.C.tulongensis或C.meishanensis首次出现的  相似文献   

7.
新疆南天山库车河地区山着二叠-三叠系的连续剖面,剖面中地层界线清楚,化石较为丰富。在上二叠统比尤勒包谷孜群中发现了安加拉大陆晚二叠世植物群的典型代表“Callipteris”zeilleri和俄罗斯库滋涅茨克煤田上二叠统顶部的特有种Yavoskya mungatica。而下三叠统俄霍布拉克群的植物化石具明显的中生代面貌。因此,库车河地区海西期花岗岩之上覆盖着晚二叠世晚期地层,它与下三叠统俄霍布拉克  相似文献   

8.
把二叠-三叠系界线置于Hindeodus parvus带的底部,即以H.parvus的首次出现作为三叠纪的开始,是目前大多数学者采纳的划分方案。由于H.parvus的鉴定分歧较大,导致H.parvus在各剖面“首次出现”的层位,特别是点的位置,缺乏共同的标准和藉以对比的标志。文中分析了H.parvus种的标准性及首次出现的点的位置。以Kozur and Pjatakova(1976)描述的正模(f  相似文献   

9.
本文以层序地层学理论为指导,通过对皖南地区早二叠世晚期至晚二叠世早用沉积层序特征的综合分析,并辅以生物化石的年代,提出了二鳖系上、下统界线的一种新的确定方法,即将其界线确定在两层序的分界处.  相似文献   

10.
本文首次报道并描述了江西信丰县铁石口地区的二叠—三叠纪的牙形石动物群;根据牙形石和菊石、双壳类、腕足类,将“铁石口系”划分为三部分:下部(层1~10)、中部(层11~20)、上部(层21~23),它们分别相当于Griesbachian阶、Nammalian阶、Spathian阶。层2~8中发现了二叠纪型和三叠纪化石伴生的混生动物群。三叠系与二叠系之间可暂时以层1厚约3cm的黄白色粘土岩为界线,二系为整合关系。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

13.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

14.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

18.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

19.
20.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

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