沉积盆地地下水与油气成藏－保存关系

含油气沉积盆地地下水动力场可以划分为：①泥岩压实水离心流;②大气水下渗向心流;③(层间)越流、越流——蒸发泄水和④滞流四种局部水动力单元类型。通常盆地边缘大气水不对称下渗,发育向心流,中央凹陷区以泥岩为主的砂泥岩地层压实,发育离心流,大气水下渗向心流与地层压实离心流汇合,发育越流泄水。沉积盆地地下水动力场演化和地下水成因控制了地下水化学场的分布规律。在离心流和向心流流动过程中,地下水浓缩、盐化,在越流泄水区形成高浓缩、高盐化地下水。泥岩压实离心流是沉积盆地油气运移的主要动力之一,在地层压实排水离心流过程中,由于岩性、地层、断层等圈闭使得部分油气在运移过程中聚集;在地下水越流泄水过程中有利于油气大量聚集—富集;在向心流推进过程中,早期聚集的油气可能部分被破坏,此外也可能在特定的地质条件下形成水动力和部分岩性、地层、断层油气藏。     

Assessment of heavy metals contamination in urban topsoil from Changchun City,China

Due to the rapid urbanization and industrialization that has occurred in China over the last few decades, metals have been continuously emitted into the urban environment and now pose a serious threat to human health. Indeed, there is a growing concern over the potential for pollution of urban soils with heavy metals. Therefore, an extensive soil survey was conducted in urban areas of Changchun, China, to evaluate the current status of heavy metal contamination in soils and to evaluate its potential sources. A total of 352 samples of urban soils were collected from urban areas of Changchun using a systematic sampling strategy in which one sample per km² was taken (0 ~ 20 cm). The levels of Cu, Pb, Zn and the major elements (Mn, Al₂O₃, CaO, Fe₂O₃, MgO, SiO₂, K₂O and NaO) were then determined by X-Ray fluorescence spectrometry (XRF), while the level of Cd was determined by graphite furnace atomic absorption spectrometry (GF-AAS), and the Hg and As concentrations were determined by atomic fluorescence spectroscopy (AFS). The results indicated that, when compared with the background values of topsoil in the Changchun region, the topsoil in urban areas were enriched with metals, particularly Cu, Cd, Zn, Pb and Hg. The results of correlation coefficient analysis showed that Hg, As, Cd, Cu, Pb and Zn were significantly positive correlated with each other, while Cr and Mn formed another group. Moreover, significantly positive correlations were observed between pH and Zn, Pb, Cu, Cd, As and Hg, indicating that pH influences the distributions of these metals in urban soils in Changchun. Principal component analysis (PCA) was conducted to identify sources of heavy metals and the results revealed distinctly different associations among the trace metals and the major elements in the urban soils. The concentration of Cr appeared to be controlled by the parent material (natural sources), while Cu, Pb and Zn were mainly from vehicle emissions, with Zn primarily coming from vehicle tires. Additionally, Hg and As primarily originated from coal combustion, while Cd was mainly associated with industrial sources. According to the pollution index (PI) of each metal, the overall levels of metal pollution were not especially high, but there were clearly contaminated sites concentrated in the central and northeast portion of the studied region. The Nemerow integrated pollution index (NIPI) of the seven metals also indicated that urban soils in Changchun city were classified as having low level of pollution.     

大兴安岭西坡额仁陶勒盖银多金属矿区火山岩岩石成因及其地质意义:年代学、地球化学特征

为揭示额仁陶勒盖银矿床火山岩与成矿作用的关系,对矿区内赋矿围岩火山岩展开了系统的年代学和元素地球化学研究。成果揭示:(1)赋矿围岩粗面安山岩的单颗粒锆石U-Pb年龄为(173.4±4.6)Ma;(2)粗面安山岩具有富集大离子亲石元素、亏损高场强元素以及弱的负铕异常的特征;对比洋壳成分,成矿元素呈现强烈亏损V、Cr、Ni、Co、Mo、Cu,富集W、Bi、Pb和相对富集Au、As、Sb、Te以及相似的Zn、Ag、B含量为特征。结合前人的研究成果,认为矿区内火山岩是成矿早期的产物,岩浆起源于流体交代过的大洋性质的岩石圈地幔,岩浆演化过程中有少量斜长石等矿物分离结晶作用和微弱的地壳物质混染,形成的构造环境可能为华北板块、蒙古块体与西伯利亚板块对接碰撞后的初期地壳伸展环境,且该阶段火山作用不具有直接提供成矿流体的属性,提供成矿流体的岩浆作用可能是早白垩世早期石英二长斑岩岩浆(138 Ma)。     

强台风“菲特”(1323)极端降水研究进展

台风暴雨灾害是台风三类灾害(暴雨、大风、风暴潮)之首,而台风极端降水是暴雨灾害的直接原因,对台风极端降水的研究有利于增强对台风极端降水机理的认识和提高极端降水的预报水平.强台风“菲特”(1323)具有登陆强度历史罕见、降雨强度大、影响范围广、引发灾害重等特点,本文对“菲特”极端降水特征及其形成机理研究进行了回顾和总结....     

青岛市洋河下游水源地地下水调蓄开采资源评价

洋河下游水源地以松散岩类孔隙水为主,含水层主要由第四纪冲积-冲洪积的砂及砂砾石组成。厚度一般4～8m,单井出水量可达800m^3/d以上,水位埋深2～4m。主要接受大气降水渗入和上游径流补给,季节性变化明显。人工开采是其主要排泄方式,地下水动态基本处于自然状态。现状条件下区内总储存量Q储=1535.71万m^3,总补给量Q补=237.31万m^3/a,总排泄量Q排=245.69万m^3/a,处于均衡状态。通过建立地下水水流数值模型,进行洋河下游水源地地下水调蓄开采量评价和水位预测,认为在该区以枯水期开采量6000m^3/d、连续开采5个月、年开采量90万m^3的开采方案,水位降深在允许范围内。因此,枯水期6000m^3/d的开采量可作为洋河下游水源地的调蓄开采资源量。     

缺资料流域水文模型参数区域化研究进展

缺资料流域由于缺乏历史径流资料无法进行水文模型参数率定,因此模型参数识别具有很大的难度和不确定性。目前国内外学者对缺资料流域水文模型参数识别一般采用区域化方法,即通过某种途径,利用有资料流域的模型参数推求缺资料流域的模型参数,从而对缺资料流域进行预报。文章总结分析了缺资料流域水文模型参数区域化方法中的参数移植法和回归法的研究进展,对存在的方法选择问题、尺度问题等进行了讨论,并指出在参数不确定性、尺度转换以及多种信息源利用等方面还有待于进一步研究。     

油田卤水中短链有机酸的来源,分布及其地球化学意义

在几乎所有的油田卤水(地层水)中都含有高浓度的短链有机酸,通常乙酸根是其中最丰富的有机阴离子。大量的模拟实验表明干酪根是有机酸最主要的来源。短链有机酸有着重要的地球化学意义,(1)可以作为石油勘探的近似指示物,(2)它们可能是天然气中某些主要成分的母体,(3)它们是地层水中最主要的弱酸阴离子,因此控制了地层水的pH值的缓冲能力,(4)作为还原剂,它们控制了地层水的Eh值和多价元素的浓度,(5)实验表明,它们还能够与储集岩中的铝、钙、硅等无机离子形成可溶络合物,使长石类矿物的溶解作用增强,从而导致砂岩储层中次生孔隙加大。     

广西中部二叠系乐平统层序地层研究

通过对分别位于台地、斜坡和盆地的广西合山马滩剖面、来宾铁桥剖面和来宾蓬莱滩剖面的廊带式追索研究,将二叠系乐平统地层自下而上划分为Ｌｐ１、Ｌｐ２、Ｌｐ３、Ｌｐ４、Ｌｐ５和Ｌｐ６６个三级层序,并建立了相应的海平面变化曲线。结合原有和最新的生物地层资料,对这３个剖面的层序地层划分实现了精确对比,从而将原有地层对比精度提高了１倍。主张以牙形石Ｃｌａｒｋｉｎａｓｕｂｃａｒｉｎａｔａ的初现作为长兴阶和吴家坪阶的分界,这一界线与上述三级层序Ｌｐ６的首次海泛面一致。长期被当作长兴阶下部带化石的Ｇａｌｏｗａｙｉｎｅｌａｍｅｉｔｉｅｎｅｎｓｉｓ和Ｐａｌａｅｏｆｕｓｕｌｉｎａｍｉｎｉｍａ可向下延入依据牙形石定义的吴家坪阶。     

Effects of Biodegradation on the Distribution of Alkylcarbazoles in Crude Oils

We have investigated the distributions of alkylcarbazoles in a series of crude oils with different biodegradation extents, in combination with biomarker parameters, stable carbon isotopic ratios and viscosities. The analyses showed that slight biodegradation has little effect on alkylcarbazoles. The concentrations of C₀-, C₁-, and C₂-carbazoles seem to display a slight decrease with biodegradation through the moderately biodegraded stage, and an abrupt decrease to the heavily biodegraded stage. The relative concentrations of C₀-, C₁-, and C₂-carbazoles do not show any apparent change in the non-heavily biodegraded stages, but through non-heavily biodegraded to heavily biodegraded stages, the percentages of C₀- and C₁-carbazoles decrease, and those of C₂-carbazoles increase significantly, which may indicate that C₂-carbazoles are more resistant to biodegradation than lower homologous species. As to C₂-carbazole isomers, the relative concentrations of the pyrrolic N-H-shielded, pyrrolic N−H partially shielded and pyrrolic N-H-exposed isomers do not show any obvious variation in the non-heavily biodegraded oil, but there is an abrupt change through the mid-biodegraded stage to the heavily biodegraded stage. This project was financially supported by the Youth Knowledge-Innovation Foundation of CNPC (No. 00Z1304).     

赵官井田10煤层底板突水危险性评价

从地质构造、含水层、隔水层、开采条件等方面详细分析了赵官井田10煤层底板突水的影响因素,确定了断层强度指数、褶皱分维值、"底板充水含水层组"水压、"底板充水含水层组"富水性、奥灰富水性、隔水层厚度、泥岩比率、底板破坏深度8个主控因素作为10煤层底板突水危险性评价的决策指标,并建立了各主控因素专题图;运用层次分析法(AHP)确定了各主控因素的权重系数,建立了基于"脆弱性指数法"的底板突水危险性评价模型,对10煤层底板突水危险性进行了定量评价,结果表明:在井田的南部煤层露头处脆弱性指数小,突水可能性较小;在井田的北部,特别是在井田东北部,脆弱性指数大,突水危险性较大。