北非库弗腊盆地油气成藏条件及地质风险初探

库弗腊盆地是在稳定结晶基底上形成的大型古生代克拉通内坳陷盆地。油气地质评价认为，该盆地发育始寒武系一自垩系的浅海相与河流相交互沉积，依据钻井、露头、孢粉组合可将其沉积序列划分为8套地层单元。推测盆地存在3套烃源岩：始寒武系泥岩、奥陶系泥岩、志留系Tanezzuft组泥岩，其中Tanezzuft组泥岩是盆地最有可能的烃源岩。库弗腊盆地可能存在奥陶系一志留系和始寒武系两套成藏组合，盆地模拟结果表明盆地的两个沉积中心（uri槽和Kalanshiyu槽）的烃源岩已达到生油窗范围，是否存在有效烃源岩是决定该盆地油气潜力的主要因素和油气勘探的最大地质风险所在。图4参18     

现代湖泊中的造迹生物暨滨湖带生物痕迹——以青海湖为例

现代湖泊中的造迹生物以底栖的寡毛类蠕虫、甲壳动物、软体动物的双壳类和腹足类、昆虫幼虫为主。通过观察,作者发现青海湖滨湖带有5类生物痕迹,它们是鸟的足迹、足辙迹、昆虫爬迹、钩虾的拖迹和甲壳虫的潜穴.生物痕迹的分布和底栖生物的分布一样受控于盐度、底层性质和岩性,共生动植物数量等环境条件。     

渤海湾盆地复式油气聚集带高勘探程度区进一步挖潜的领域

渤海湾盆地复式油气聚集区经过了40年的勘探,目前已进入了高勘探程度区.油气聚集的复杂规律表明,渤海湾盆地仍具有巨大的资源潜力,进一步挖潜的领域非常广阔.以第三系为烃源岩的含油气层系的勘探精度仍有待于进一步提高,同时必须将以古生界、中生界和中上元古界为烃源岩的含油气层系作为今后挖潜的重要领域.渤海湾盆地任何层系都可能形成和聚集油气,因此仍有多种复杂的油气藏类型尚待进一步认识和发现.     

鄱阳湖湖底沉积物放射性水平

本文报道了1985年鄱阳湖湖底沉积物放射性水平的调查结果。沉积物中 U、Th、~(226)Ra、~(40)(?)和~(137)Cs 的比活度分别为64.8、67.9,58.9、676.1和3.5Bq/kg;用~(137)Cs 测龄方法作了沉积物泥芯垂直深度的年代定位,由此得知1985—1958年对应深度沉积物中 U、Th、~(226)Ra 和~(40)K 的比活度与1957—1930年对应深度沉积物比较无显著性差异;U、Th 和~(226)Ra 的浓集因予分别为5.2×10~413.9×10~4和4.8×10~4L/kg。     

乌江流域大型复杂水电站群联合优化调控关键技术及其应用研究

根据乌江流域总体规划、长江三峡以上防洪要求、南方电网运行特点、乌江流域水文特性等,贵州乌江水电开发有限责任公司组织开展了乌江梯级水库优化调度和发电优化控制的基本理论研究,并根据该研究建立了乌江流域水电站群联合优化调控系统,经过一系列优化调度规则、方法、措施在系统中的应用,实现了节水增发电的目的,取得了良好的社会经济效益。     

How Non-native Species in Lake Erie Influence Trophic Transfer of Mercury and Lead to Top Predators

Lake Erie's food web has been dramatically modified by exotic species. Both exotic dreissenid mussels and the round goby Neogobius melanastomus have shifted the food web from a pelagicbased to a benthic-based one, potentially creating a new pathway for contaminant transfer to top predators. Before the invasion of round gobies, few predators of dreissenids occurred in Lake Erie, allowing contaminants to be confined to these benthic organisms. The invasion of the round goby has produced a new pathway through which these contaminants can enter the food web. To characterize heavy-metal transfer through this new food web and to assess risk to humans, water, surficial sediment, dreissenid, round goby, and smallmouth bass Micropterus dolomieui samples were collected at three sites during summers, 2002 and 2003, and analyzed for total lead (Pb), total mercury (Hg), and methyl mercury (MeHg). In addition, we compared smallmouth bass Pb and Hg concentrations to those measured in 1993/1994, before round gobies were prevalent. Pb biodiminished and MeHg biomagnified through the food web to smallmouth bass; patterns were similar among our three sites. Total Pb concentrations in smallmouth bass were higher before the incorporation of round gobies into their diet. We attributed this decline to changes in food web structure, changes in contaminant burdens in prey, or declines in sediment Pb concentrations in Lake Erie. By comparison, Hg concentrations in smallmouth bass changed little, before and after the round goby invasion, possibly due to a shift in diet that increased growth. Despite a decline in sediment Hg concentrations in Lake Erie, smallmouth bass continued to accumulate Hg at historical rates possibly because of their high consumption rates of benthivorous round gobies. As smallmouth bass continue to consume round gobies during their lives, their Hg concentrations may well continue to increase, potentially increasing the risk of Hg contamination to humans.     

鄂尔多斯盆地南部加里东期岩溶古地貌与天然气成藏条件分析

认识鄂尔多斯盆地南部地区岩溶古地貌和成藏条件是加快该地区勘探步伐面临的重要问题。鄂尔多斯盆地南部加里东期风化壳储集层的分布主要受岩溶古地貌、风化壳层位及沉积相控制。马五段为云坪相带，溶蚀孔洞较为发育；平凉组为深水斜坡相带，多形成断裂、裂缝及洞穴储集空间。中央古隆起西侧古地貌为岩溶斜坡，地表岩溶作用较弱，但断裂发育，洞穴系统较发育；中央古隆起南侧古地貌为岩溶台地，断裂、洞穴系统和风化裂隙相对较为发育；中央古隆起区古地貌为岩溶台地，地层较老，岩性致密，风化壳顶部垂直裂隙带发育，岩溶孔洞不发育；中央古隆起东侧古地貌多属于岩溶阶地或鞍地，风化壳多位于云坪及含膏云坪相带，溶蚀孔洞较为发育。岩溶古地貌天然气成藏主控因素主要为生烃中心、岩溶古地貌、风化壳的层位和沉积相带，有利区带主要在耀县、旬邑、淳化平凉组生烃中心和中央古隆起东侧马五段有利沉积相带。图9表1参13     

柴达木盆地北缘侏罗系沉积环境演变及其石油地质意义

柴达木盆地北缘(柴北缘)东段大煤沟剖面侏罗系沉积层序发育完整。下侏罗统岩性以细砾岩、细—粉砂岩与炭质泥岩和页岩的不等厚互层为特征,其中大煤沟组一、二段与辫状河三角洲平原相关的湖沼相炭质泥页岩较发育,多含叶肢介、双壳类和植物等静水环境生物化石,沉积环境为辫状河三角洲—滨浅湖体系;由3个中期基准面升降旋回构成1个长期旋回。中侏罗统厚层河流—冲积相砂砾岩较发育,化石面貌以介形虫和植物为主,沉积环境为扇三角洲—滨浅湖体系,中上部发育较深湖相沉积;由9个中期基准面升降旋回构成1个长期旋回。不同时期和地区的化石与岩相分布特征反映侏罗纪沉积中心由西向东迁移。构造活动和气候是沉积环境的主要影响因素,但前者起重要的控制作用。早侏罗世潮湿气候下的辫状河三角洲平原为柴北缘提供了重要的生烃母质,但中侏罗世中晚期半干旱气候更有利于形成高品质的烃源岩。图5表1参18     

核磁共振测井在致密含气砂岩中的应用

通过对核磁共振测井的T₂谱及其T₂截至值的合理选取，解释并获得了鄂尔多斯盆地西缘上古生界山西组、石盒子组致密砂岩储集层的总孔隙度、有效孔隙度、毛细管束缚水体积、可动水体积及渗透率等参数，据此预测的储集层孔隙结构特征与岩心分析测试结果很吻合。研究还发现，致密含气砂岩的T₂谱具有分布范围窄-中等，波形及差谱分析谱位置明显后移、分布中等、呈单峰的典型特征。结合常规测井资料，综合研究了致密砂岩储层特征及其含气层的测井响应。经测试验证，致密含气砂岩储层的核磁共振测井解释结果十分可靠，表明核磁共振测井可用于该区致密含气砂岩复杂储集层评价。     

Psychrotrophic violacein-producing bacteria isolated from Lake Winnipeg,Canada

Violet and purple bacterial pigmentations are uncommon when considering strict aerobes. Here we report discovery of two novel isolates, P102 and P117 from the freshwater Lake Winnipeg, each with violet to deep purple colony colouration. The relationship between pigment production and growth was investigated under different conditions, including a variety of carbon sources, pH, and temperatures. The violet compounds were purified using polar organic solvents, and then structurally characterized via mass spectrometry and nuclear magnetic resonance to be violacein and deoxyviolacein. Strain P117 produced higher concentrations of the darker pigment deoxyviolacein, which resulted in a deeper hue of violet than in cultures of P102. Strain P102, synthesized violacein maximally in liquid rich organic medium at pH 8 and 20 °C, and had 99.3% sequence similarity to the 16S rDNA from Janthinobacterium lividum. Strain P117, related to Massilia violaceinigra sharing 99.2% 16S rDNA sequence similarity, also produced violacein at similar optimal conditions, but developed higher concentrations of pigment at 15 °C. Culture-based methods found that violacein producers composed 0.001% or 0.023% CFU of environmental heterotrophic populations using BG-11 and potato-based media, respectively. Culture-independent high-throughput ribosomal 16S V4 sequencing of environmental DNA was used to detect Gram-negative species known for their production of violacein. Of all bacterial and archaeal sequences present during the fall in littoral waters and sediment of Lake Winnipeg, 5.5% and 6.3%, respectively, belonged to species that have similar pigment, demonstrating the scarcity of violacein producers in this aquatic freshwater system.