浙江杭嘉湖平原区土壤中营养元素丰缺状况的评价   总被引：5，自引：2，他引：5  

朱立新  周国华  任天祥  张连生  王徽  顾金秋  杜雄进  王成  蒋永平  周子泉 《物探与化探》1994,18(4):251-262

根据杭嘉湖平原区区域地球化学调查的结果,对本区土壤中农作物营养元素含量及有效量特征进行了评价研究。研究结果表明,本区土壤中营养元素除Mo、S含量表现缺乏外,其它元素为足量和丰富水平。不同土壤中营养元素有效量水平存在明显差异。在区域分布规律上,营养元素的含量及有效量随成土母质、成土过程和人类耕作等因素的不同而显示其差异特征。评价研究结果为本区农业生产中的合理区划、科学施肥、合理种植、土壤改良等提供了重要的地球化学依据。  相似文献   

Infrared estimates of aliphatic kerogen carbon in sedimentary rocks     

H.J. Schenk  E.G. Witte  P.J. Müller  K. Schwochau 《Organic Geochemistry》1986,10(4-6)

An infrared routine has been developed to estimate the aliphatic portion of kerogen carbon in sedimentary rocks. The procedure does not require isolation of the organic matter and is based on a computer-assisted determination of global band areas in the region of the aliphatic carbon-hydrogen stretching vibrations around 2900cm⁻¹. From these integrated absorptions the amount of aliphatic carbon C_al (mg of aliphatic carbon per gram of solvent-extracted rock) is calculated by means of a calibration with model rocks. Carbonate overtones which interfere in the case of limestones are eliminated by comparison to a CaCO₃ standard.The method has been applied to rocks containing kerogens of different types and maturities at TOC levels of 0.5 to 12%. The aliphatic carbon concentrations range from 0.5 to 60mg·g⁻¹ and correlate reasonably well with the residual genetic potentials of the rocks as measured by S₂ values from Rock-Eval pyrolysis. The ratio S₂/C_al is found to decrease with burial depth reflecting a maturity enhanced conversion of aliphatic carbon to fixed aromatic carbon under Rock-Eval conditions.  相似文献   

盆地烃类运移二维二相流动数学模型分析与应用实例   总被引：5，自引：1，他引：5       下载免费PDF全文

陶一川  姜鹏 《地球科学》1995,20(3):314-321

从地质固体系统与流体系统相互作用所形成的能量流、物质流的观点，系统地论述了建立烃类运移主要控制方程，即烃水两相拉格朗日型异常地层压力方程和饱和度方程，研制了开发了烃类运移数值模拟系统，阐明了该耦合系统的要素功能和求解方法，提供了改善系统模拟精度的措施，最后介绍了该模拟系统在松辽盆地东南隆起某测线的应用实例。  相似文献   

塔里木盆地北部油气田水文地质及水文地球化学特征   总被引：1，自引：0，他引：1       下载免费PDF全文

张建林  陶一川  陈荣书  张忠先 《地球科学》1995,4(3)

以实测的流体资料为基础，初步揭示了塔北地区油田水文地质和水文地球化学特征。塔北地区存在两股地下水流，南部生油区为压实水流，由南向北流动，北部为重力水流，由北向南流动，这两股水流交汇于雅克拉和轮南地区，向上封闭式内泄。无论重力水流或压实水流，皆为非海相成因、非浓缩成因溶滤水。表明：油气藏的形成绝大部分是寒武－奥陶纪生油层二次成油的结果。  相似文献   

异常压力与油气分布   总被引：123，自引：2，他引：123  

杜栩  郑洪印 《地学前缘》1995,2(4):137-148

随着油气勘探活动的不断加深，国内外相继发现了许多异常高压油气田。据不完全统计，全世界已发现超压盆地１８０多个，其中１６０多个为富含油气盆地。异常高压油气田约占全球油气田３０％左右，因此，对异常压力的研究，具有举足轻重的意义。本文介绍了异常地层压力的概念、特征及分类；详细论述了异常压力的成因，即烃类生成作用、欠压实作用、液态烃类的裂解作用、粘土矿物的后生成岩作用、构造作用、温度变化等；系统阐述了世界典型含油气盆地的超压形成机制、超压体系中油气初次运移机理以及超压与油气分布关系；并在此基础上，归纳总结出了五种超压油气藏成藏模式，即：（１）位于超压体系中的低渗超压油气藏；（２）位于超压层系中，以礁灰岩（或浊积砂岩）为储层的高压油气藏；（３）位于超压带上倾方向，以退覆三角洲平原和分流河道砂岩为储层的常压或过渡带超压油气藏；（４）位于超压带上、下部的超压油气藏；（５）位于远离超压体系的泄压区常压油气藏，本文对指导、加深新老油气区勘探具有实际应用价值。  相似文献   

Lacustrine basin hydrocarbon exploration – current thoughts     

Barry Jay Katz 《Journal of Paleolimnology》2001,26(2):161-179

Although much of the world's petroleum resource-base is associated with marine systems, regionally lacustrine petroleum systems are important. Individual accumulations may exceed several billion barrels. In each of these cases the oil is derived from a lacustrine source rock and may be produced from either nonmarine or marine reservoir rocks. The purpose of this paper is to describe the factors that control lacustrine source rock development and the nature of lacustrine reservoirs. Lacustrine oils display different physical and chemical characteristics than their marine counterparts. These differences can be related to the nature of their precursor material. Although the nature of the products are different, the geochemical threshold criteria for defining source rocks in both settings are the same because of common expulsion requirements. Commercially significant lacustrine systems require the presence of large, long-lived lakes. Such lake settings are tectonic in origin and restricted to climatic settings where precipitation exceeds evaporation. Within these large lake systems three primary factors determine source rock potential and quality. These factors are primary productivity level, organic preservation potential, and matrix sedimentation rate, which controls the dilution of preserved organic matter. Source rock potential is maximized where both productivity and preservation potential are maximized and sedimentation rate is minimized. To some degree these factors can compensate for each other. Hydrocarbon reservoir potential within lacustrine basins is partially impacted by overall tectonic setting. Within extensional settings, transport distances tend to be limited, with much of the sediment being transported away from the basin. The sediments delivered to the lake are poorly sorted and sedimentologically immature, commonly resulting in poor reservoirs due to both primary properties and their susceptibility to diagenesis. Within rifts better reservoirs tend to develop along platform or flexural margins. Stacking of reservoirs is important in lacustrine systems but baffles and barriers are often present between individual sand units. These barriers form as a result of lake level fluctuations. In compressional settings transport distances tend to be longer, resulting in more mature, better sorted sediments leading to higher quality reservoirs. These reservoirs typically develop in fluvial-deltaic and wave-dominated shoreline settings. Lacustrine carbonate reservoirs are locally important. These carbonates tend to develop during lake level lowstands and are dependent on diagenesis (dissolution and karstification) for porosity and permeability development. Lacustrine reservoirs are often stratigraphically and areally limited and display low individual well production rates. Within pure lacustrine systems exploration opportunities appear to be often restricted by either reservoir presence or quality (i.e., production rates). The best exploration opportunities in lacustrine basins appear to be associated with hybrid systems where a lacustrine source and marine reservoir exist.  相似文献   

扬子地块陡山沱期与梅树村期磷矿区域成矿规律   总被引：11，自引：1，他引：10  

东野脉兴 《化工矿产地质》2001,23(4):193-209

扬子地块是我国重要的产磷区 ,陡山沱与梅树村两大成磷期磷块岩储量占全国磷矿储量的85 %。在多年来丰富的资料积累与研究基础上 ,经过实践—理论—再实践的认识过程 ,归纳与提练出具有共性和普遍适用的海相磷块岩区域成矿规律 ,上升成为理性认识 ,因而具有很强的实用性 ,可作为成矿预测的准则。这些规律有 :含磷岩系规律、磷矿层规律、磷块岩自然类型规律、磷块岩结构类型规律、磷块岩矿物与化学成分规律、磷块岩序列规律、磷块岩成矿的构造古地理规律、陆缘坻含磷岩组规律、磷块岩富集规律等。并在此基础上划分出扬子地块的 2个三级成矿亚带和若干四级成矿区。  相似文献   

Chemical variation from biolipids to sedimentary organic matter in modern oceans and its implication to the geobiological evaluation of ancient hydrocarbon source rocks     

Wang Hongmei  Ma Xiangru  Liu Deng  Yang Xiaofen  Li Jihong 《Frontiers of Earth Science》2007,1(4):399-404

Understanding the dynamics of organic matter in modern marine water columns greatly favors the geobiological evaluation of hydrocarbon source rocks. Biolipids could make great contribution to petroleum hydrocarbons due to their comparable chemical components and the slightly refractory characteristics of biolipids during the microbial/thermal degradation. A variety of environmental factors such as temperature, CO₂ and salinity could affect the biochemical contents in microorganisms. As a result, microorganisms living in a changing environmental condition might have a different contribution to the petroleum formation. Organic carbon flux is shown to bear a positive correlation with the primary productivity only within a certain range of biomass volumes in a specific biohabitat. Furthermore, organic matter is degraded much quickly in a water column with oxic conditions. Therefore, the anoxic condition, along with the enhanced biological productivity, would be one of the significant factors in the formation of high-quality hydrocarbon source rocks. The formation of biofilms and microbial mats favors the preservation of sedimentary organic matter by decreasing the degradation rate of organic matter. Identification of biofilms and microbial mats in sedimentary rocks will thus greatly help to understand the depositional processes of organic matter finally preserved in hydrocarbon source rocks. __________ Translated from Earth Science—Journal of China University of Geosciences, 2007, 32(6): 748–754 [译自: 地球科学—中国地质大学学报  相似文献   

萃取富集-火焰原子吸收法测定碳酸钙中铅和镉     

黄俭惠  邱丽 《矿产与地质》2007,21(4):479-481

将碳酸钙试样用盐酸溶解后,在0.6mol/L的盐酸介质中,用KI-MIBK萃取试样中微量的铅和镉,有机相用原子吸收分光光度法测定。该方法测定铅的相对标准偏差为2.38%-6.31%,回收率为96.5%-97.0%;测定镉的相对标准偏差为4.50%-5.52%,回收率为96%-102.8%。结果可靠,具有灵敏、准确、快速、选择性好等优点。适用于碳酸钙中铅、镉的测定。  相似文献   

柴达木盆地北缘中侏罗统大煤沟组七段烃源岩有机地球化学特征及生烃潜力   总被引：2，自引：0，他引：2  

刘云田  杨少勇  胡凯  曹剑  边立曾  汪立群  陈琰 《高校地质学报》2007,13(4):703-713

柴达木盆地北缘地区在中侏罗世晚期,即大煤沟组七段(J2d7)时演化至最大湖侵期,发育了一套湖相泥页岩。通过对区内鱼卡煤矿井下样品的实测分析,结合先前报道的研究成果,确认了这套湖相泥页岩为优质烃源岩,藻类体、角质体和孢子体是这套源岩的主要生烃显微组分,有机质类型最好可达II1型。热演化研究表明,该套源岩在不同构造单元处于差异热演化阶段,既可生油亦可生气。虽然J2d7段烃源岩在平面上不同凹陷区具有一定的非均质性,但其生烃潜力,特别是在赛什腾—鱼卡凹陷地区,完全可与我国西北地区其它侏罗系优质烃源岩相媲美。长期以来,下侏罗统烃源岩被认为是柴北缘地区的主要油气源,J2d7段优质烃源岩的确认,对于深化柴北缘地区的油气勘探和地质研究具有重要意义。  相似文献