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11.
掌握澳门附近海域沉积物的污染状况及特征,对于合理安排澳门海洋海岸工程疏浚泥的海洋倾倒,防止造成海洋污染有十分重要的意义。根据1997—1999年连续三年对澳门附近主要区域的海洋沉积物采样测定结果,通过分析认为澳门附近海域沉积物污染具有下列特征:1)沉积物中重金属和油类含量普遍较高,除了总Hg外均高于珠江口海区的其他港口;2)沉积物中污染物的分布受人类活动的影响明显,澳门内港受船只排污、码头作业、陆地工业和生活污水排放的影响,是澳门附近海域沉积物污染最为严重区域;3)受水质交换的影响明显,澳门外港、路环岛东北等区域受珠江径流影响水质交换较快,沉积物中污染物的含量较低,而内港由于水质交换较差,沉积物中污染物的含量相对较高;4)与沉积物的成分组成(吸附)有关,大部分污染物与沉积物中粉砂有较好的相关性,表明粉砂对污染物质有较广泛性的吸附能力,尤其是Cu、Zn、Cd、油类、有机质。 相似文献
12.
N. Mihalopoulos J. P. Putaud B. C. Nguyen S. Belviso 《Journal of Atmospheric Chemistry》1991,13(1):73-82
Measurements of the concentrations of carbonyl sulfide (COS) in the marine atmosphere were made over a period of two years in the southern Indian Ocean (Amsterdam Island, 37°50 S–77°31 E; March 1987–February 1988 and April 1989–February 1990). The mean atmospheric COS concentration for the whole period was 475±48 pptv (n=544). Atmospheric COS concentrations show no significant seasonal variation with a summer to winter ratio of 1.05. Taking into account the observed variability of the atmospheric COS concentration (10%), a value of 1.4 yr is estimated as a lower limit for the atmospheric COS lifetime. A comparison of the COS data at Amsterdam Island with those obtained in the Southern Hemisphere in the past 12 yr does not reveal any significant trend in the tropospheric background COS mixing ratio. 相似文献
13.
New mapping in the northern part of the Paleozoic Acatlán Complex (Patlanoaya area) records several ductile shear zones and brittle faults with normal kinematics (previously thought to be thrusts). These movement zones separate a variety of units that pass structurally upwards from: (i) blueschist-eclogitic metamorphic rocks (Piaxtla Suite) and mylonitic megacrystic granites (Columpio del Diablo granite ≡ Ordovician granites elsewhere in the complex); (ii) a gently E-dipping, listric, normal shear zone with top to the east kinematic indicators that formed under upper greenschist to lower amphibolite conditions; (iii) the Middle–Late Ordovician Las Minas quartzite (upper greenschist facies psammites with minor interbedded pelites intruded by mafic dikes and a leucogranite dike from the Columpio del Diablo granite) unconformably overlain by the Otate meta-arenite (lower greenschist facies psammites and pelites): roughly temporal equivalents are the Middle–Late Ordovician Mal Paso and Ojo de Agua units (interbedded metasandstone and slate, and metapelite and mafic minor intrusions, respectively) — some of these units are intruded by the massive, 461 ± 2 Ma, Palo Liso megacrystic granite: decussate, contact metamorphic muscovite yielded a 40Ar/39Ar plateau age of 440 ± 4 Ma; (iv) a steeply-moderately, E-dipping normal fault; (v) latest Devonian–Middle Permian sedimentary rocks (Patlanoaya Group: here elevated from formation status). The upward decrease in metamorphic grade is paralleled by a decrease in the number of penetrative fabrics, which varies from (i) three in the Piaxtla Suite, through (ii) two in the Las Minas unit (E-trending sheath folds deformed by NE-trending, subhorizontal folds with top to the southeast asymmetry, both associated with a solution cleavage), (iii) one in the Otate, Mal Paso, and Ojo de Agua units (steeply SE-dipping, NE–SW plunging, open-close folds), to (iv) none in the Patlanoaya Group. 40Ar/39Ar analyses of muscovite from the earliest cleavage in the Las Minas unit yielded a plateau age of 347 ± 3 Ma and show low temperature ages of 260 Ma. Post-dating all of these structures and the Patlanoaya Group are NE-plunging, subvertical folds and kink bands. An E–W, vertical normal fault juxtaposes the low-grade rocks against the Anacahuite amphibolite that is cut by megacrystic granite sheets, both of which were deformed by two penetrative fabrics. Amphibole from this unit has yielded a 40Ar/39Ar plateau age of 299 ± 6 Ma, which records cooling through 490 °C and is probably related to a Permo-Carboniferous reheating event during exhumation. The extensional deformation is inferred to have started in the latest Devonian ( 360 Ma) during deposition of the basal Patlanoaya Group, lasting through the rapid exhumation of the Piaxtla Suite at 350–340 Ma synchronous with cleavage development in the Las Minas unit, deposition of the Patlanoaya Group with active fault-related exhumation suggested by Mississippian and Early Permian conglomerates ( 340 and 300 Ma, respectively), and continuing at least into the Middle Permian (≡ 260 Ma muscovite ages). The continuity of Mid-Continent Mississippian fauna from the USA to southern Mexico suggests that this extensional deformation occurred on the western margin of Pangea after closure of the Rheic Ocean. 相似文献
14.
车镇凹陷上古生界高分辨率层序地层研究 总被引:2,自引:0,他引:2
以高分辨率层序地层学原理为指导,利用测井、岩芯和录井等资料,对车镇凹陷上古生界不同级次基准面旋回进行了高分辨率层序划分。将上古生界划分为2个超长期、7个长期、16个中期和45个短期基准面旋回,精细对比研究了短期、中期和长期基准面旋回。其中,短期基准面旋回可分为2大类3种亚类,并区别出A型、B型不对称短期基准面旋回和C型对称性短期基准面旋回,总结了它们的结构特征、形成条件、岩性岩相组成;通过研究不同沉积体系下中期、长期基准面旋回特点,得出中期、长期基准面旋回的特点和发育特征,区别出不同沉积环境下层序界面特点;分析了研究区内超长期基准面旋回特征,综合分析认为车镇凹陷超长期基准面旋回以下降半旋回为主。 相似文献
15.
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17.
Quick-look assessments to identify optimal CO2 EOR storage sites 总被引:1,自引:0,他引:1
Vanessa Núñez-López Mark H. Holtz Derek J. Wood William A. Ambrose Susan D. Hovorka 《Environmental Geology》2008,54(8):1695-1706
A newly developed, multistage quick-look methodology allows for the efficient screening of an unmanageably large number of
reservoirs to generate a workable set of sites that closely match the requirements for optimal CO2 enhanced oil recovery (EOR) storage. The objective of the study is to quickly identify miscible CO2 EOR candidates in areas that contain thousands of reservoirs and to estimate additional oil recovery and sequestration capacities
of selected top options through dimensionless modeling and reservoir characterization. Quick-look assessments indicate that
the CO2 EOR resource potential along the US Gulf Coast is 4.7 billion barrels, and CO2 sequestration capacity is 2.6 billion metric tons. In the first stage, oil reservoirs are screened and ranked in terms of
technical and practical feasibility for miscible CO2 EOR. The second stage provides quick estimates of CO2 EOR potential and sequestration capacities. In the third stage, a dimensionless group model is applied to a selected set
of sites to improve the estimates of oil recovery and storage potential using appropriate inputs for rock and fluid properties,
disregarding reservoir architecture and sweep design. The fourth stage validates and refines the results by simulating flow
in a model that describes the internal architecture and fluid distribution in the reservoir. The stated approach both saves
time and allows more resources to be applied to the best candidate sites. 相似文献
18.
基于系统的地震剖面解释及其与塔中地区的对比,本文探讨了塔里木西部地区古生代断裂活动的方式和机制。玛东断裂带是一条宽阔的北东向盖层滑脱型褶皱冲断带,前展式向东南扩展,冲断作用发生在奥陶纪末。巴东断裂(吐土休克Ⅱ号断裂)为北西向基底卷入型冲断带,奥陶纪末和中二叠世末发生冲断。巴西断裂和塔参2井南断裂是海西期的正断层。塔里木古板块古生代的发育受邻侧的造山带演化制约,近东西向和北东向断裂奥陶纪末的冲断是继承基底构造发育的。塔中地区的近北西向断裂是晚寒武世的新生断裂,加里东运动可分为两幕:奥陶纪末的冲断(艾比湖运动)和晚志留-中泥盆世的冲断-走滑,后者向西明显减弱。塔里木西部的部分北西向断裂(如康西断裂)可归入塔中北西向断裂系。北东向的玛东断裂带是其西的向北(东)冲断的吐木休克断裂带与其东的向南偏东冲断的塔中8-1井——塔中5井断裂带之间的调节断层。 相似文献
19.
运用源控含油气系统理论与综合分析技术,按成藏“层次分析”方法,通过对生、储、盖、圈(闭)静态要素及其内生、排、运、聚、散(失)动态过程的综合研究,对松辽盆地中央坳陷的三肇凹陷葡萄花油层成藏条件进行探讨,提出了以次级凹陷为中心、不同类型的油气聚集带紧邻并围绕次级凹陷最低部位呈环带状分布的大型凹陷内成藏模式,并进一步提出永乐次级凹陷中心及其三级聚油环带及徐家围子次级凹陷以西为"网式"运聚特征;在凹陷级成藏模式的指导下,通过对大面积密井网开发区综合解剖,提出三级构造带中单个的局部构造圈闭(群)、单个的(局部构造——)岩性圈闭(群)控油和成藏规律,为认识本区基本控油单元、油水分布规律、油气勘探及扩大新探区提供重要的理论依据。 相似文献
20.
中国-俄罗斯原油管道工程(漠河-大庆段)冻土工程地质考察与研究进展 总被引:4,自引:2,他引:2
李国玉 金会军 盛煜 张建明 俞祁浩 齐吉琳 温智 吕兰芝 童长江 郭东信 王绍令 魏智 杨思忠 吉延俊 于少鹏 何瑞霞 常晓丽 郝加前 陈友昌 吴伟 翟镇远 赵意民 《冰川冻土》2008,30(1):170-175
在2005-2007年期间,先后3次对中国-俄罗斯原油管道漠河-大庆段沿线的冻土工程地质条件等进行科学考察,开展了冻土工程地质条件及其在气候变化和人类活动作用下的评价和预测研究.考察研究结果表明:管道沿线多年冻土在各类融区、季节冻土和水系等分隔作用下呈片状或岛状分布,沿线岛状、稀疏岛状及零星岛状占多年冻土区段的40%左右;管道沿线多年冻土随着气候的转暖和人类活动的影响不断退化.地形地貌单元、植被分布、地表水分条件的变化等局部因素对多年冻土的分布和地下冰的赋存产生重要的影响,管道沿线大约分布有50 km左右的沼泽湿地,其表层为腐殖质土及泥炭层,泥炭层下面分布着含土冰层或地下冰,是管道沿线最差的冻土工程地质地段;由于中俄原油管道沿线水系发育多,冻胀丘、冰椎和冰幔等不良冻土现象广泛分布.科学考察的成果为管道沿线冻土工程地质条件评价和预测、管道的稳定性影响分析以及后期的长期检测系统设置等研究奠定坚实的基础,进一步为即将开工的中俄原油管道漠河-大庆段工程的设计、施工提供科学依据. 相似文献