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准噶尔盆地玛湖凹陷风城组页岩油勘探取得巨大突破,但是按照普遍认可的页岩油烃源岩评价标准,本区的烃源岩品质并不理想。为了科学评价玛湖凹陷烃源岩品质特征,本文在系统的岩心观察和有机地球化学分析的基础上,揭示烃源岩的形成环境,并按照矿物组成对烃源岩分类评价。玛湖凹陷风城组细粒岩主要沉积于正常半深湖、咸化半深湖、半咸化半深湖、含热液半深湖和滨浅湖环境中,各环境中细粒岩的有机质特征存在一定区别,其中半咸化半深湖有机质较为富集,w (TOC)均值在1%左右。进一步结合有机质类型判别图解,表明咸化半深湖和含热液半深湖有机质来源以湖泊生物为主,而其他环境中存在湖泊和陆源混合有机质来源。基于有机质生烃潜力评价和成熟度（Vre=0.74%）估算,表明目前风城组烃源岩中有机质正处于大量排烃的成熟阶段,且确定了细粒岩中的烃类为原生烃。由于不同矿物组成的烃源岩吸附能力的差异,按照陆相泥质烃源岩和碳酸盐质烃源岩开展分类评价,结果表明风城组沉积了累计厚度近250 m的的有效烃源岩,且富含以藻类体为主的有机质。 相似文献
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This paper describes the mobilization and speciation of As found in hydrothermally altered rock under oxic column conditions. The altered rock sample was obtained from a tunnel project located in the Nakakoshi area of Hokkaido, Japan, whose geology is represented by slate, shale and sandstone. This area has undergone silicification, pyritization and argillic alteration resulting in As-enrichment of the rock. Results of the column experiments show that the infiltration rate, bulk density and rock bed thickness affected the duration of water residence, which in turn influenced the pH of the rock–water system. Coexisting ions most notably Ca2+ at amounts greater than ca. 50 mg/L retarded the mobilization of As. Mobilization of As from the rock with time occurred in two stages: stage 1 (weeks 1–20) with higher As leaching and stage 2 (weeks 20–76) characterized by nearly constant As release. In addition, pore water As concentrations revealed that the columns developed into two regions: the top half where most of the leaching occurred and the bottom part dominated by adsorption. Thus, the mechanism controlling the mobilization of As from the rock is a combination of one or more of the following processes: dissolution of soluble As-bearing fractions, pyrite oxidation and adsorption reactions. Arsenite (As[III]) was the dominant species in the effluent at the start of the experiment in columns with shorter water residence time and lower pH conditions (<8). On the other hand, arsenate (As[V]) was the major inorganic species released from the rock at higher pH (8–9.5) and when the system was close to equilibrium. Speciation of As with depth also indicated that As[III] disappeared around the bottom half of the columns, probably as a result of adsorption and/or oxidation. Arsenic speciation is partially controlled by the pH dependent adsorption of As species. The important adsorbent phases in the rock included Fe–Al oxides/oxyhydroxides, clay minerals and organic matter, which permitted the columns to attenuate additional As loadings including As[III]. Implications of these results on the design of a novel disposal method for these altered rocks include the enhancement of As adsorption through the addition of natural or artificial adsorbents and the utilization of a covering soil with low permeability to minimize rainwater infiltration into the rock. 相似文献
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微生物对碳酸盐岩的风化作用 总被引：7，自引：0，他引：7
微生物-矿物相互作用可以促进许多表生生物地球化学反应过程,是表生地球化学研究的重要内容。通过综合岩石表面的微生物类群及其地质作用,分析碳酸盐岩微生物风化的各种现象,特别是微观尺度上的各种形态,阐述碳酸盐岩的微生物风化机制与风化产物,笔者提出微生物对碳酸盐岩风化的4种途径:(1)通过微生物在岩石表面和缝隙中生长,导致岩石表层发生生物溶蚀、生物磨蚀和生物钻孔作用,加速岩石风化进程;(2)微生物群体形成的钻孔网络可以增强岩石化学溶蚀的有效表面积并导致其表面强度减弱而促进机械侵蚀作用,微生物对周围岩石颗粒胶结结构的破坏、疏松作用也会导致岩石矿物颗粒的分解;(3)微生物的持水作用,微生物分泌的有机酸以及微生物呼吸所释放的CO2对岩表水分的酸化过程亦加速岩石矿物的分解;(4)微生物生长过程中从岩石内摄取营养元素和产生复杂的有机配体,能促进矿物元素的释放。文中提出在开展微生物对碳酸盐岩风化过程和机理研究的基础上,有必要引入微生物生物技术来综合开发本地低品位含钾磷矿产资源,加速岩溶地区山地土壤的形成与演化。 相似文献
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《International Geology Review》2012,54(1):52-59
Experimental data on copper sorption by organic and mineral sorbing agents have shown that sorption can take place from very dilute solutions. The degree of sorption depends on the total amount of dissolved copper in solution, the velocity of the circulating solution, on the duration of contact between the sorbent and fresh solutions, and on the degree of diffusion of the solution within the sorbent. Organic matter, namely pine loam, peat, lignite, and humic acid, absorbs copper from very dilute solutions (from 2x10-4 to 2x10-5 grams per liter copper concentrations, 2.5 to 4.5 percent); other sorbents, namely; sand, kaolin, feldspar, and quartz, absorb one-tenth as much as the organic sorbents. Desorption is very slight in organic material; it is almost complete in mineral sorbents. It is believed that sorption plays a very significant part in the formation of sedimentary copper deposits, particularly in the copper sandstones of the Urals. 相似文献
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淄博市淄川区饮用天然矿泉水按照含水层性质可划分为松散岩类孔隙水、碳酸盐岩类裂隙岩溶水和岩浆岩类构造裂隙水3大类。区内29眼井泉监测点饮用天然矿泉水检测结果显示,研究区存在锶型、锂型和锶锂复合型3种类型矿泉水。从水岩作用角度分析了矿泉水中锶和锂的来源,认为研究区广泛分布寒武纪碳酸盐岩,石灰岩尤其是鲕状灰岩中丰富的锶元素,是锶矿泉水形成主要的物源条件之一;地下水沿灰岩裂隙岩溶运动为矿泉水的形成创造了重要的水动力条件;研究区腐殖质经低矿化近中性的大气降水淋滤后,形成富含腐殖酸的偏酸性溶液入渗地下,对地下岩层产生溶解、溶滤作用,随着溶解过程的进行,岩石中的锶元素大量进入地下水中。 相似文献
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以沾化凹陷渤南洼陷罗63井和义21井沙一段取心段为例,依据研究样品的热解、全岩与黏土矿物X射线衍射、有机岩石学、孔隙度、氩离子抛光+扫描电镜以及微孔隙结构等分析结果,开展了沙一段湖相富有机质烃源岩岩石学与孔隙结构特征研究,结果表明：罗63井和义21井沙一段取心段富有机质烃源岩主要由碳酸盐矿物、黏土矿物和石英组成,另含少量长石、黄铁矿和石膏,其中黏土矿物主要由伊/蒙混层、伊利石组成,由取心段顶部至底部,碳酸盐矿物质量分数明显增高,而黏土矿物和石英则显著降低,呈现由钙质或灰质泥岩至演变为泥质灰岩的特征,岩石构造类型包括层状、纹层状和块状3类;罗63井和义21井沙一段取心段富有机质烃源岩平均孔隙度分别为2.09%和4.43%,具纹层状构造的烃源岩具有相对高的孔隙度;主要发育矿物基质孔隙（即粒间孔隙和粒内孔隙）和裂缝型孔隙两大类,而有机质孔隙不发育,孔隙半径从十几微米至几纳米的孔隙均有分布,以发育孔径50 nm以上的宏孔为主。 相似文献
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Impact of Montmorillonite and Calcite on Release and Adsorption of Cyanobacterial Fatty Acids at Ambient Temperature 总被引：1，自引：0，他引：1
Minerals might act as important sorbents of sedimentary organic matter and reduce biodegradation, which favors the formation of hydrocarbon source rocks in the earth's history. Since most organic matter is degraded during the sinking process, at ambient temperature, it is important to investigate the adsorption capacity of different minerals during this process, to assess the organic loss from primary productivity to sedimentary organic matter. In this study, montmorillonite and calcite have been selected to study the impact of different minerals on the release, adsorption, and deposition of cyanobacterial (Synechococcus elonpata) fatty acids (FAs) at ambient temperature. Gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) have been utilized to detect the variation in fatty acids. Primary results suggest that minerals have a different impact on dissolved organic matter. Montmorillonite can specifically enhance the release of fatty acids from cyanobacterial cells by lowering the pH values of the solution. The adsorption of the dissolved organic matter by montmorillonite will also be enhanced under a lower pH value. Conjunction of fatty acids with montmorillonite to form a complex will favor the sinking and preservation of these organics. Selective adsorption is observed among fatty acids with different carbon numbers. In contrast, calcite does not show any impact on the release and adsorption of organic matter even though it is reportedly capable of acting as a catalyst during the transformation of organic matter at high temperature. The primary data bridge a link between primary productivity and sedimentary organic matter, suggesting the relative importance of claystones in the formation of hydrocarbon source rocks in the earth's history. 相似文献
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《Applied Geochemistry》2004,19(3):323-334
In the present study the distribution of TBT between solid and water phase as a function of several parameters was determined. Two types of clay minerals (Na-montmorillonite SWy and kaolinite KGa) and quartz sand were used as sorbents in conventional batch experiments. Sorption coefficients (Kd) followed the order montmorillonite (89 l/kg) > kaolinite (51 l/kg) > quartz (25 l/kg), while for sorption coefficients normalized to the surface area (Kd′) an opposite trend was observed, with the lowest value determined for montmorillonite (2.79 × 10−3 l/m2) and the highest for quartz sand (8.04 × 10−2 l/m2). The results demonstrate that numerous environmental parameters influence the adsorption process of TBT, such as solid/solution ratio, clay content and salinity. Another important factor governing TBT adsorption is pH, because it affects both the TBT species in the water phase as well as the surface properties of the mineral phase. The maximum of TBT adsorption onto clays was always around pH 6–7. According to the data, it is evident that the content of organic matter in the solid phase plays an important role on TBT adsorption, either as particulate organic matter (POM) or organic matter adsorbed to mineral particles (AOM). Experiments were carried out with well characterized organic matter and the results showed a linear increase of Kd from 51 up to 2700 l/kg upon the addition of 5% of particulate organic matter to pure phased kaolinite. TBT adsorption onto mineral surfaces, which were previously enriched with adsorbed organic matter, was investigated at different pH. The present study points to the importance of identifying and characterizing sorbents and envrionmental conditions, in order to predict and model TBT distribution in natural systems. 相似文献
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碳酸盐岩烃源岩判识与实践——以四川盆地为例 总被引：1，自引：0，他引：1
碳酸盐岩可以成为烃源岩,并为油气藏提供丰富的烃源,但不是所有碳酸盐岩都可以视为烃源岩。碳酸盐岩在成藏进程中,往往作为输导层或储集层,并常有外源有机质的干扰。碳酸盐岩烃源岩应该是有机质原生赋存(与矿物结合成为沉积的一部分),具有一定丰度值,在适宜的热成熟阶段,同样可以形成液态烃和气态烃。碳酸盐岩烃源岩发育于低能环境的沉积相——开阔海台地相、局限海台地相、生物泥丘相、斜坡相,等等。泥质泥晶灰岩,生物泥—粒泥岩—泥粒岩微相,应该是碳酸盐岩烃源岩的主要岩类。碳酸盐岩烃源岩与油系泥质烃源岩比较,具有油窗凸显且高峰期前移、气态烃峰期不明显且有后延、液态烃产率高的特点。据对碳酸盐岩烃源潜量的评估,它在四川盆地烃源中占20%～25%,为油气成藏作出了重要贡献。 相似文献
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Certain factors influencing the incorporation, transport and release of fatty acids by clay minerals, calcite and marine sediments have been investigated.Salinity was found to be an important factor. The adsorption of heptadecanoic acid by bentonite clay at 4%. was nearly triple that at 0%.. However, from 4%. to 35%., only a minor adsorption increase occurred. This behavior is believed to be related to flocculation of the clay at the lower salinity range. The pH over the range of 6.0–8.5 has a small influence on fatty acid-clay association, depressing it somewhat as the basicity increases.When the temperature of the fatty acid solution was increased from 0°C to 50°C, a decrease in adsorption on to clay was found. This effect may be due to increased water solubility of the acid at higher temperatures, since solubility is very important in controlling the degree of fatty acid-mineral interaction. Furthermore, apparent solubilization of fatty acids by indigenous dissolved organic matter in sea water reduces adsorption on to clay minerals.Based upon the heat of adsorption of ?14.6 kcal/mole, fatty acids are physically bound to clay minerals by weak van der Waals forces and hydrogen bonds.Bentonite and kaolinite were found to be the most adsorptive minerals investigated, followed in order by illite, montmorillonite and calcite. Sediments from Narragansett Bay were found to lie between illite and montmorillonite in adsorptive capacity after indigenous sediment organic matter had been removed. Sediment organic matter reduced fatty acid uptake by a factor of 1.6. 相似文献
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应用岩石热解数据S2-TOC相关图进行烃源岩评价 总被引：1，自引：0，他引：1
应用岩石热解数据评价烃源岩的传统方法具有一定的局限性。由于矿物基质的吸附或“死碳”的影响,有机质类型的“范氏图解”往往夸大烃源岩有机质类型的非均质性。对松辽盆地上白垩统不同有机质丰度和有机质类型的烃源岩生烃动力学研究表明,它们具有相似的生烃动力学特征,说明尽管有机质丰度存在较强的非均质性,但其有效源岩类型（区别于应用范氏图划分的有机质类型）是一致的。这些烃源岩的岩石裂解烃（S2）与有机质丰度（TOC）的相关系数很高,与生烃动力学的分析结果一致,表明应用S2-TOC相关图划分烃源岩的有机质类型可以更真实地反映烃源岩的有效源岩类型,S2-TOC相关图是评价烃源岩有效源岩类型的有效手段。过去岩石热解数据用于反映烃源岩成熟度的主要指标是tmax,tmax对于偏Ⅱ／Ⅲ型的烃源岩比较适用,而对于Ⅰ型烃源岩,由于生油窗内变化不明显,tmax不能完全反映有机质的成熟过程;而且tmax也受运移油等其他因素影响。不同成熟度的烃源岩的S2-TOC图分析结果显示,随着成熟度的增加,S2-TOC的回归斜率和TOC逐渐减小;利用不同成熟度的烃源岩建立的S2-TOC图可用于评价烃源岩的成熟度。松辽盆地不同沉积相中烃源岩的S2-TOC相关图的特征表明。只要有有利的有机质保存条件,各沉积相下均可发育优质的烃源岩;S2-TOC相关图可以反映烃源岩形成的沉积环境和有机质保存条件。 相似文献
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压溶碳酸盐岩地层厚度恢复初步探讨 总被引：1，自引：0，他引：1
通过碳酸盐岩压溶作用基本特征的分析,笔者提出了压溶的碳酸盐岩地层厚度恢复的原理和公式,同时还探讨了缝合线有机质丰度的校正方法与公式。实际计算结果表明了碳酸盐岩地层的压溶作用是很强的,压溶的碳酸盐岩地层厚度在相应的碳酸盐岩岩心长度中所占的百分比最低为２．１０％,最高可达５８％,主要集中于３１％以下,平均为１１．６０％。 相似文献
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通过模拟实验,对碎屑岩和碳酸盐岩中分散可溶有机质裂解生气的模式及产物特征进行了探讨。实验表明,分散于碎屑岩与碳酸盐岩中的可溶有机质在高温热裂解演化过程中,其产气率存在着明显的差别。对于碎屑岩而言,当分散可溶有机质丰度小于0.3%时,裂解产气率与岩石中分散可溶有机质含量呈正相关关系,大于0.3%时几乎不变,而碳酸盐岩中分散可溶有机质产气率与分散可溶有机质含量的关系不是很明显。赋存于两类不同岩石中的分散可溶有机质的裂解气的及干燥系数也存在着较大差异。结果表明上述地球化学特征均与岩石对类烃气体的选择性吸附有关。 相似文献
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烃源岩形成研究一直集中于海相盆地的“生产力模式”和“保存模式”之争, 湖相盆地研究较少.利用二连盆地烃源岩有机碳、碳酸盐碳同位素、热解参数、还原硫等地球化学分析数据, 表征了湖盆古生产力和陆源有机质输入, 研究了有机质供给和保存在烃源岩形成中的控制作用, 发现不同的湖盆中有机质供给和保存对烃源岩形成的控制作用明显不同.有机质供给量大的湖盆原始有机质含量高, 烃源岩形成主要受有机质供给控制, 受有机质保存条件影响小, 即使在含氧的水底也会有部分有机质来不及氧化而富集形成烃源岩; 有机质供给量小的湖盆原始有机质含量低, 氧化环境中大部分有机质被降解难以形成烃源岩, 只有还原环境下有机质才能得到较好的保存, 有机质保存是控制烃源岩形成的主要因素. 相似文献
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It is important to understand how phosphate sorption dynamics of coastal carbonate aquifers are affected by seawater intrusion, because many coastal aquifers are composed of carbonate rocks and subject to an increase in saltwater intrusion during relative sea-level rise. Twelve carbonate rock and unconsolidated sediment specimens were acquired from a test corehole spanning the full thickness of the Biscayne aquifer in southeastern Florida. All 12 samples exhibit low phosphorus content but variable contents of iron. Column leaching experiments were conducted with two carbonate aquifer samples, alternating between freshwater and saltwater flow. With the first influx of saltwater, phosphate concentration in leachate increased rapidly from a freshwater value of approximately 0.2 μM to peaks of between 0.8 and 1.6 μM. The phosphate concentration began to diminish as saltwater continued to flow, but sustained desorption continued for over 2 h. Overall, seawater drove sorption behavior much more than chemical composition for the aquifer rocks and sediment from the seven rock samples for which we did isotherm sorption experiments. Our results indicate that an immediate and intense pulse of phosphate desorption from carbonate rock and sediment with low phosphorus content occurs in response to an influx of seawater and that the duration of desorption will vary by layer within a single aquifer. 相似文献
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泥质岩有机质的赋存状态及其对泥质岩封盖能力的影响 总被引：11，自引：0，他引：11
应用荧光显微镜法,首次对济阳坳陷下第三系泥质岩中有机质的赋存状态进行了研究。下第三系泥质岩有机质的赋存状态可划分为顺层富集型、分散型和局部富集型等三种类型。有机质呈顺层富集型分布的泥质岩,其有机质丰度大多较高,主要沉积于半深湖-深湖相中。有机质呈分散型分布的泥质岩,其有机质丰度变化范围较大,大多形成在河流-三角洲相、滨-浅湖相或浊流沉积中。结合部分揭示泥质岩封盖能力的定量分析数据,下第三系泥质岩可概括出以下三种不同的组合特点:①泥质岩中有机质丰度高且有机质呈顺层富集型状态赋存时,泥质岩封盖能力差;② 泥质岩有机质丰度高且有机质呈分散型状态赋存时,泥质岩具有一定的封盖能力;③ 泥质岩有机质丰度低且有机质呈分散型状态赋存时,泥质岩封盖能力较好,因此,泥质岩中有机质的赋存状态对泥质岩的封盖能力有着不可忽视的影响。在研究评价泥质岩对油气藏的封盖能力时可作为重要的依据之一。 相似文献