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THE ORIGIN OF DOLOMITE IN THE ASMARI FORMATION (OLIGOCENE-LOWER MIOCENE), DEZFUL EMBAYMENT, SW IRAN 总被引:3,自引:0,他引:3
A.A.M. Aqrawi M. Keramati S. N. Ehrenberg N. Pickard A. Moallemi T. Svånå G. Darke J.A.D. Dickson N.H. Oxtoby 《Journal of Petroleum Geology》2006,29(4):381-402
Dolomitisation is an important factor controlling reservoir quality in the Asmari Formation in many producing fields in SW Iran. Dolostones have higher average porosities than limestones. Petrographic and geochemical studies have been used to determine the causes of Asmari dolomitisation at the Bibi Hakimeh and Marun fields and at the Khaviz anticline. The formation is generally characterized by a large‐scale trend of upward‐decreasing accommodation. Basal strata were deposited under relatively open‐marine, high‐energy conditions, whereas the Middle to Upper Asmari succession was deposited in relatively protected settings with more frequent evidence of exposure and evaporitic conditions. There is a general upward increase in the abundance of both anhydrite (occurring as nodules and cement) and dolomite. Two main types of dolomite fabric are recognised, reflecting the textures of the precursor limestones: (1) finely crystalline pervasive dolomite (commonly <20μ) replacing mud‐rich facies; and (2) combinations of finely crystalline replacive dolomite and surrounding areas of coarser dolomite cement (crystals up to 100μ) in grain‐supported facies. Fluid inclusion data indicate that finely crystalline dolomites formed at low temperatures (ca. <50°C), while the coarser dolomite formed at higher temperatures (50–;140°C). Whole rock‐carbonate oxygen and carbon isotope analyses of pure dolostone samples show no apparent correlation with either depositional or diagenetic textures: δ18O is generally 0 to 2.7‰ PDB, and δ13C is ?1 to 4‰ PDB. The importance of evaporated seawater to Asmari dolomitisation is indicated by the ubiquitous occurrence of felty‐textured anhydrite nodules in dolostone beds and the presence of high‐salinity fluid inclusions in dolomite. The derivation of dolomitising fluids from contemporaneous seawater is supported by the general correspondence between age estimates derived from the strontium isotope composition of anhydrites and dolomites and those derived from stratigraphic considerations. This suggested synsedimentary dolomitisation. Dolomitisation of the upper half of the Asmari Formation may have occurred as a result of two syn‐sedimentary mechanisms: (1) by the reflux of evaporative brines concentrated in shallow lagoons or sabkhas, through immediately underlying strata (mainly during highstands); and (2) by the flushing of platform‐top carbonates by basinal evaporated waters during lowstand/early transgression. Continued dolomitisation during deeper burial is supported by the presence of high‐temperature fluid inclusions and iron‐rich crystal rims. Dolomite within the lower part of the Asmari Formation probably mostly formed during burial as a result of compaction of, and fluid exclusion from, the underlying Pabdeh marls and shales. 相似文献
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A. Cau R. Hale J. Dimitrov H. Zedan B. Moszkowski M. Manjunathaiah M. Spivey 《Design Automation for Embedded Systems》2002,6(4):367-399
We describe a compositional framework, together with its supporting toolset, for hardware/software co-design. Our framework is an integration of a formal approach within a traditional design flow. The formal approach is based on Interval Temporal Logic and its executable subset, Tempura. Refinement is the key element in our framework because it will derivefrom a single formal specification of the system the software and hardware parts of the implementation, while preserving all properties of the system specification. During refinement simulation is used to choose the appropriate refinement rules, which are applied automatically in the HOL system. The framework is illustrated with two case studies. The work presented is part of a UK collaborative research project between the Software Technology Research Laboratory at the De Montfort University and the Oxford University Computing Laboratory. 相似文献
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Engracia Madejón Pilar Burgos Rafael López Francisco Cabrera 《Nutrient Cycling in Agroecosystems》2003,65(3):281-288
Disposal of urban, agricultural and industrial organic residues impliesan increasing problem because of all the economic and environmentalrepercussions involved. One of the most adequate ways of managing this problemis the agricultural use of these wastes as organic amendments. Three organicresidues (AC, olive mill waste water sludge compost; MWC, municipal solid wastecompost; and PS, paper mill sludge) were used in a 3-year field experimentinvolving orange production. The effect of their application on crop productionand on soil quality was investigated. Soil samples (0–20 cm depth)collected 11 months after the last soil amendment were analysed for: pH and EC,Kjeldahl-N, available-P, available-K, total organic carbon, humic substances,dehydrogenase, phosphatase, -glucosidase, urease andbenzoyl-argininamidehydrolysing protease (BAA-protease) activities. Generally, the application of the MWC and PSincreased orange yield when compared to control. Moreover, total organic carbonand humic substances significantly increased in soils treated with all theorganic amendments. Organic fertilisation increased the Kjeldahl-N andavailable-P contents of the soil. The application of the organic residues also causedsignificant increases in dehydrogenase, -glucosidase, urease andBAA-protease activities of the soil. Significant positive correlations (p <0.01) between these enzymatic activities and total organic carbon were foundforall treatments. Significant positive correlation between dehydrogenase, urease,-glucosidase, and BAA-protease and orange yield was also found. However,a clear inhibition of phosphatase activity was observed in soils treated withPS. The results indicate that the repeated application to the soil of moderateamounts of organic amendments has positive effects on the chemical andbiochemical properties of the soil, as well as on the orange yield. 相似文献
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In this paper,a TPP(Task-based Parallelization and Pipelining)scheme is proposed to implement AVS(Audio Video coding Standard)video decoding algorithm on REMUS(REconfigurable MUltimedia System),which is a coarse-grained reconfigurable multimedia system.An AVS decoder has been implemented with the consideration of HW/SW optimized partitioning.Several parallel techniques,such as MB(Macro-Block)-based parallel and block-based parallel techniques,and several pipeline techniques,such as MB level pipeline and block level pipeline techniques are adopted by hardware implementation,for performance improvement of the AVS decoder.Also,most computation-intensive tasks in AVS video standards,such as MC(Motion Compensation),IP(Intra Prediction),IDCT(Inverse Discrete Cosine Transform),REC(REConstruct)and DF(Deblocking Filter),are performed in the two RPUs(Reconfigurable Processing Units),which are the major computing engines of REMUS.Owing to the proposed scheme,the decoder introduced here can support AVS JP(Jizhun Profile)1920×1088@39fps streams when exploiting a 200 MHz working frequency. 相似文献
8.
BLAS (Basic Linear Algebra Subprograms)是一个基本线性代数操作的数学函数标准, 该库函数分为三个级别, 每个级别提供了向量与向量(1级)、向量与矩阵(2级)、向量与向量(三级)之间的基本运算. 本文研究了在申威1621处理器上BLAS一级函数的优化方案, 以函数AXPY为例, 充分利用平台的架构特点对其进行性能调优,设计了自动的线程分配方案. 实验结果显示优化过后的BLAS一级函数AXPY相对于GotoBLAS参考实现版本的单核和多核加速比分别高达4.36和9.50, 对于每种优化方式均得到了一定的性能提升. 相似文献
9.
周密 《数字社区&智能家居》2009,(3)
视频解码芯片的结构因硬件强大的处理能力和软件灵活的可编程功能从硬件转向软硬件分区结构。该文针对AVS标准的算法和解码实现复杂程度,根据软硬件协同设计思想提出了一种结构划分合理的AVS高清视频解码器软硬件分区结构。根据AVS算法的特点该结构将宏块层以上部分的元素解析划归到软件解码中,将宏块层解码划为硬件处理。经验证,该结构设计可实现AVS高清码流解码,并在C语言编写的硬件平台仿真程序中得以实现。 相似文献
10.
软硬件通信模式的选择对软硬件通信效率产生很大影响.根据硬件函数的特点,提出一种根据软硬件通信量自适应地选择通信模式的软硬件双通信模式,并构建了一种通信模式自适应决策算法,软硬件通信模式的选择对用户透明.实验表明,根据运行时系统状态自适应地选择通信模式,软硬件通信效率得到优化,面积开销也适当减少. 相似文献