黄骅坳陷港西构造西端歧81断块微生物异常研究

油气微生物勘探(MPOG)技术作为一种新的地表油气勘探方法,以其直接、有效、多解性小且经济等优势日益受到全球油气勘探界的重视。将油气微生物勘探技术应用于港西地区,得出油气分布规律,其基本上为油异常区,且未连片分布,而气异常区基本为背景值区。结合区域地质资料、油气井资料以及生物灰岩分布规律等信息,分析歧81断块的主控因素,揭示该断块的油气成藏规律。通过较成熟开发区的异常区与研究区内其它异常区的微生物异常值进行对比,研究区内异常区的微生物异常值的平均值均没有前者高,合理直观地了解了歧81断块的含油气远景。最后指出其主要储层,同时进行了含油性预测,应优先在异常值较强烈的区域进行勘探,并确定了有利的布井点位,从而大大降低勘探风险。     

Holocene evolution of the Anichab Pan on the south-west coast of Namibia

Coastal sediment-filled depressions (pans) are one of the few areas that contain Quaternary records of sea-level and palaeoenvironmental change along the western margin of southern Africa. Anichab is a 128 km² salt-encrusted pan on the hyper-arid southern coast of Namibia with an emergent, well-preserved and in-place mid-Holocene mollusc assemblage. The molluscs are typical of subtidal sands on the sheltered side of offshore islands but include several warm-water species no longer found living along this coast. The Holocene evolution of the pan was largely influenced by changes in sea level and supply of sand along the coast. Calibrated radiocarbon ages of mollusc shells indicate a maximum Holocene sea level of ca 2 m above mean sea level (msl) from 7·0 to 6·3 ka and a return to near present-day sea level by 5·3 ka. The pan surface is 2 m below msl and has been emergent since 4·9 ka from the build up of sandy beaches and coastal dunes. A thin (1–4 cm) halite crust occurs over much of the pan surface but a layer of halite-cemented sand up to 40 cm thick is restricted to the central pan. Gypsum occurs near the subsurface brine interface and is limited by calcium to the edges of the pan. Nodules of calcite-cemented sand are forming in brackish, relatively high alkalinity subsurface waters in the south-east corner of the pan and nodules of aragonite-cemented sand are forming in brines 1 m below the central pan surface. Although modern dolomite has been reported from coastal lagoons of Brazil and Australia, carbonate cements are a minor feature of Anichab Pan and dolomite was restricted to a single reworked nodule most likely of Late Pleistocene age. Therefore, Anichab Pan does not appear to be a modern analogue to extensive, mixed-water dolomite cements found in Upper Pleistocene sediment-filled depressions on the Namibian shelf.     

白云鄂博碳酸盐矿物的矿物化学成分标型特征

对白云鄂博地区不同产状的碳酸盐矿物进行了系统的电子探针分析,其结果表明白云鄂博ＲＥＥ－Ｎｂ－Ｆｅ矿床的赋矿白云岩中,无论是粗粒结构的,还是细粒结构的白云岩,其主要造岩矿物白云石或者铁白云石均具高锰（ＭｎＯ〉０．５ｗｔ％）和高锶（ＳｒＯ〉１．５ｗｔ％）的特征,与矿床北东方向０￣３．５ｋｍ范围内切割五台群花岗片麻岩－混合岩及白云鄂博群碎屑岩的火成碳酸岩岩墙中的碳酸盐矿物非常相似。它们完全不同于宽沟段裂以北典型沉积石灰岩厦白云质石灰岩中的方解石和白云(MnO<0.1wt％ ,SrO<0.1wt％ )。赋矿白云岩中自云石的锶和锰含量系统变他反映碳酸岩浆发生了分离结晶作用,其结果可以导致其余岩浆中REE高度富集．本文认为碳酸盐矿物的锶和锰含量可以作为识别其成囡的重要标型特征,其氧化物MnO>0.15wt％ 和Sr>0.15wt％为火成碳酸岩的标志。     

Dolomite Mountains and the origin of the dolomite rock of which they mainly consist: historical developments and new perspectives

Beginning in the late 18th Century, the Dolomite Mountains in Northern Italy have been the location for major sedimentological developments, from the discovery of the mineral dolomite to the formulation of the coral-reef hypothesis to explain the origin of the massive dolomite structures that define the splendid scenery of the region. Further, the Dolomite Mountains have inspired voluminous research into the origin of dolomite, questioning whether dolomite is a primary precipitate or a secondary replacement product. Recently, with the recognition that microbes can mediate dolomite precipitation, a new geomicrobiological approach, combining the study of modern natural environments with bacterial culture experiments, is now being used to calibrate or interpret microbial evidence derived from the dolomite rock record. This three-pronged methodology applied to the study of dolomite formation holds great promise for future research into the 'Dolomite Problem' and provides a new impetus to revisit the Dolomite Mountains in the 21st Century.     

表生和埋藏成岩作用的温压条件下不同组成碳酸盐岩溶蚀成岩过程的实验模拟

表生到埋藏成岩作用的温度与压力（４０～１００℃，常压～２５ＭＰａ），方解石、白云石相对含量不同的碳酸盐岩的溶蚀证明，在表生与相对浅埋藏的温压条件（低于７５℃、２０ＭＰａ）下，方解石的溶解速率大大超过白云石，随着温度和压力的升高，两者溶解速率的差值变小。在相对深埋藏的温压条件（高于７５℃、２０ＭＰａ）下，白云石的溶解速率已超过方解石，在１００、２５ＭＰａ的温压条件下，微晶白云石（白云石／方解石＝９８／２）的溶解速率已是含云灰岩（白云石／方解石＝１６／８４）的２倍，造成这种现象的原因是白云石的温度、压力效应大大超过方解石之故。根据实验的结果可以预测：表生与相对浅埋藏的温压条件下，石灰岩的岩溶作用较白云岩发育；但在深埋藏阶段，由溶解作用造成的白云岩次生孔隙应比方解石更为发育，这是埋藏深度大于２０００ｍ的地层中，白云岩储层多于石灰岩的重要原因。     

潮汐沉积韵律计算新方法及其应用——以四川江油地区中三叠统雷口坡组藻白云岩为例

提出一种新的高精确度的方法来计算沉积旋回韵律,即以样品断面光学灰度参数作为韵律沉积变化的替代指标,利用数字图像分析软件,通过最小二乘法、一阶差分法等数据处理后,定量计算沉积旋回韵律。对采自四川江油西南部中三叠统雷口坡组的纹层藻白云岩样品进行研究,观察样品抛光面和薄片,确定藻白云石具有明显的潮汐沉积韵律纹层。应用此方法计算得出研究区样品共有217个潮汐层偶对,层偶对最大厚度为4.2mm,通过人工计数对比证明了该方法的可行性。这种技术方法与传统方法相比更省时、更高效,可推广性高,同时也可应用于其它类型频段韵律旋回中。     

上海饮用天然矿泉水

上海市区西部发现饮用天然矿泉水,这是上海市民的福音。文中论述了矿泉水的地质、水文地质条件,分析了矿泉水的水质特征,以及形成的地球化学环境,并展望了上海开发矿泉水的远景。     

岩石标准物质的研制

研制了霓霞正长岩，粗面岩，花岗闪长岩，辉长石，流纹岩及白云岩６种不同类型的岩石标准物质，对用Ｘ射线荧光光谱均匀性检验实际取样量进行了探讨，选择分析测试方法时，除采用了标准方法和长期应用的分析方法外，还采用了近年发展起来的新技术新方法，在定值中应用了多参数统计定值模式，给出了６９个元素的标准值和参考值，该批标准物质于１９９１年１月经国家技术监督局审核批准为国家一级标准物质，编号分别为ＧＢＷ０７１０９     

粘土质白云岩去除水中铜离子的效果及其机制

利用静态吸附实验研究了溶液pH值、反应时间、初始Cu2+浓度等因素对凹凸棒石粘土矿中粘土质白云岩去除Cu2+效 果的影响,将准一级、准二级、Elovich动力学方程与反应动力学进行拟合,再利用Langmuir、Freundlich等温方程对实验数 据进行等温式拟合,并与普通白云岩和凹凸棒石粘土进行了对比研究。结果表明,粘土质白云岩相对于其他两种材料受pH 影响较小,且在pH3~5范围内对Cu2+去除率均大于85%,最佳pH为5;对Cu2+的去除符合准二级动力学模型,粘土质白云 岩对铜的去除速率和去除率均最高;等温数据符合Freundlich模型,对Cu2+的最大去除量（pH=5,30℃）为186.2×10-3。粘 土质白云岩去除水中Cu2+的主要机制为矿物水化与溶解引起的表面沉淀及凹凸棒石与新生碱式碳酸铜[Cu2CO3(OH)2]胶体的静 电吸附。粘土质白云岩中纳米凹凸棒石与亚微米多孔白云石共生,具有较高的化学反应活性,除Cu2+效果明显优于普通白 云岩和凹凸棒石粘土,在处理含Cu2+废水方面具有潜在应用价值。     

Activity of Silica-Rich Hydrothermal Fluid and Its Impact on Deep Dolomite Reservoirs in the Sichuan Basin, Southern China

Well-developed dissolution pores occur in the dolomites of the Sinian Dengying Formation, which is an important oil and gas reservoir layer in the Sichuan Basin and adjacent areas in southern China. The pores are often filled with quartz, and some dolomites have been metasomatically altered to siliceous chert. Few studies have documented the characteristics, source or origin of silica-rich fluids and their effects on the dolomite reservoir. The peak homogenisation temperatures(T_h) of fluid inclusions in pore-filling quartz are between 150℃ and 190℃, with an average of 173.7℃. Gases in the inclusions are mainly composed of CO_2, CH_4 and N_2. Compared with host dolomite, pore-filling quartz and metasomatic chert contain higher amounts of Cr, Co, Mo, W and Fe, with average concentrations of 461.58, 3.99, 5.05, 31.43 and 6666.83 ppm in quartz and 308.98, 0.99, 1.04, 13.81 and 4703.50 ppm in chert, respectively. Strontium levels are lower than that in the host dolomite, with average concentrations in quartz and chert of 4.81 and 11.06 ppm, respectively. Rare earth element compositions in quartz and chert display positive Eu anomalies with a maximum δEu of 5.72. The δD_(SMOW) values of hydrogen isotopes in water from quartz inclusions vary from-85.1‰ to-53.1‰ with an average of-64.3‰, whereas the δ~(18)O_(SMOW) values range from 7.2‰ to 8.5‰ with an average of 8.2‰. The average ~(87)Sr/~(86)Sr ratios in quartz and chert are 0.711586 and 0.709917, respectively, which are higher than that in the host dolomite. The fluid inclusions, elemental and isotopic compositions demonstrate that the formation of quartz and chert was related to silica-rich hydrothermal fluid and that the fluid was the deep circulation of meteoric water along basement faults. Interactions with silica-rich hydrothermal fluids resulted in densification of dolomite reservoirs in the Dengying Formation through quartz precipitation and siliceous metasomatism. However, it increased the resistance of the host dolomite to compaction, improving the ability to maintain reservoir spaces during deep burial. Evidence for silica-rich hydrothermal activity is common in the Yangtze Platform and Tarim Basin and its influence on deep dolomite reservoirs should be thoroughly considered.