中国海相油气田勘探实例之十一 四川盆地五百梯石炭系气田的勘探与发现   总被引：1，自引：0，他引：1  

沈平  徐人芬  党录瑞  左云安 《海相油气地质》2009,14(2):71-78

五百梯石炭系气田位于重庆市开县和四川省开江县境内,是一个具有统一气水界面的大型整装气田。气田发现于1989年,探明地质储量为539.88×108m3(1993年)。石炭系气藏的气体来源于下伏志留系,为低含硫低含二氧化碳的优质干气。储层沉积相主要为海湾浅滩微相,有形成粒屑白云岩的有利条件,沉积物间歇性暴露水面,后生成岩变化作用彻底,溶孔发育。气田构造处于四川盆地开江古隆起东侧斜坡带,遭受剥蚀程度的不均匀性使局部区域石炭系缺失,由此形成大型构造-地层复合圈闭。论述了气田勘探和发现的历程及石炭系气藏的主要地质特征,总结了取得勘探突破的实践与认识。  相似文献   

松辽盆地上、下白垩统界线划分   总被引：4，自引：0，他引：4       下载免费PDF全文

黄清华  张文婧  贾琼  党毅敏  王平  高宝明  谢磊 《地学前缘》2009,16(6):77

松辽盆地白垩纪发育有热河生物群、松花江生物群和明水生物群,表现为三大生物群有序演化与更替。白垩纪中期是松花江生物群发育期,松花江生物群具有明显的地域性色彩,泉头组被子植物化石Trapaangulata、Platanus septentrionalis和孢粉化石Crenwellia、Xinjiangpollis、Quantonenpollenites、Lythraites和Gothanipollis显示其时代已进入晚白垩世。火山岩锆石SHRI MP法U-Pb年龄测试结果表明,营城组的年龄为(115.1±1.2)~(111.1±0.9)Ma,说明营城组已属晚Aptian期至早Albian期。磁性地层学研究表明,登娄库组-姚家组以稳定的正极性为主,仅在登娄库组上部和姚家组下部分别出现一次短暂的反极性事件。青山口阶下部具一套广泛分布富含有机碳的黑色页岩、油页岩沉积,其干酪根碳同位素表现为明显的正向偏移特征,为古湖泊缺氧事件的产物。结合生物、同位素年代、磁性地层研究的结果,认为青山口阶底部缺氧事件层对应于白垩纪古海洋Cenomanian-Turonian期界线缺氧事件,由此,给出的松辽盆地上、下白垩统的界线划分在泉头组和登娄库组之间。  相似文献   

Modern Sedimentation of Phosphorus and Its Microbial Decomposition and Concentration: An Example from Dianchi Lake, Yunnan, China     

XIA Xuehui  DONGYE Moxing  ZHANG Zhuo Geological Institute  Bureau of Geology  Mining of China Chemical Industry  Zhuozhou  Hebei  China Department of Biology  Yunnan University  Kunming  Yunnan  China 《《地质学报》英文版》2004,78(3):763-767

Dianchi Lake is one of the lakes with the richest phosphorus source in the world, in which the P2O5 content in the bottom sediments reaches averagely 0.51 wt % and maximally 1.92%. Studies indicate that this: extremely P-rich state is attributed mainly to the large volume (as high as hundred thousands of tons) of phosphatic matter coming into the lake as many rivers feeding the lake pass through a vast area of phosphate-mining districts, which then undergo weathering and particularly some human activities, including waste water discharge. When phosphatic matter enters the lake, its grained parts are firstly decomposed by phosphorus-decomposing bacteria, and finally accumulated in some geographically special parts of the lake, such as a bay area where water flow is much more slower than elsewhere in the lake. With the involvement of phosphorus-concentrating bacteria, the accumulated phosphates in the bottom sludge ultimately form phosphate minerals through deep-burial diagenesis.  相似文献   

滇西马厂箐斑岩型铜钼(金)矿床成岩成矿时代研究   总被引：6，自引：0，他引：6       下载免费PDF全文

和文言  莫宣学  喻学惠  李勇  黄行凯  和中华 《地学前缘》2011,18(1):207-215

滇西马厂箐铜钼(金)矿床是金沙江-哀牢山构造带与喜马拉雅期富碱斑岩有关的典型斑岩型矿床之一。富碱斑岩侵入体为多期、多阶段岩浆活动形成的复式岩体,已有的研究资料表明岩浆活动时限在64～29 Ma。文中提供的锆石LA ICP MS U Pb和辉钼矿Re Os同位素年代学研究资料显示,马厂箐含矿岩体锆石U Pb年龄(封闭温度约800 ℃时)为(3793±082) Ma,代表了富碱斑岩的成岩年龄;辉钼矿的Re Os年龄(封闭温度约500 ℃)为(3472±05) Ma,代表成矿时代。该研究结果与前人确定的晚期富碱斑岩岩浆活动的时间(32 Ma)相近,也与前人获得的蚀变黑云母K Ar定年(封闭温度300 ℃)结果(351±08) Ma相近,因此可以认为成矿作用与岩体快速冷却过程中发生成矿流体大量分离和出溶有关。成岩作用与成矿作用的时间跨度大约为2 Ma。因此,金沙江-哀牢山多金属成矿带的斑岩型铜钼矿床是与富碱斑岩成岩作用近同期成矿作用的产物,成矿作用时限集中在40~35 Ma左右。  相似文献   

    

Xu Hui  Zhang Weiping  Lang Xuxing  Guo Xia  Ge Wenzhong  Dang Renqing  Takao Takeda 《大气科学进展》2000,17(3):403-412

During the Meiyu period in June and July of 1998, intensified field observations have been carried out for the project “Huaihe River Basin Energy and Water Cycle Experiment (HUBEX)”. For studying Meiyu front and its precipitation in Huaihe River basin, the present paper has performed analysis on the middle and lower level wind fields in the troposphere by using the radar data obtained from the two Doppler radars located at Fengtai district and Shouxian County. From June 29 to July 3 in 1998, the continuous heavy precipitation occurred in Huaihe River basin around Meiyu front. The precipitation process on July 2 occurred within the observation range of the two Doppler radar in Fengtai district and Shouxian County. The maximum rainfall of the Meiyu front was over 100 mm in 24 h, so it can be regarded as a typical mesoscale heavy precipitation process related to Meiyu front. Based on the wind field retrieved from the dual Doppler radar, we find that there are meso-γ scale vertical circulations in the vertical cross-section perpendicular to Meiyu front, the strong upward motion of which corresponds to the position of the heavy rainfall area. Furthermore, other results obtained by this study are identical with the results by analyzing the conventional synoptic data years ago. For example: in the vicinity of 3 km level height ahead of Meiyu front there exists a southwest low-level jet; the rainstorm caused by Meiyu front mainly occurs at the left side of the southwest low-level jet; and the Meiyu front causes the intensification of the low-level convergence in front of it. This research was supported by Project HUBEX (Project Number: 49794030) which is funded by the National Natural Science Foundation of China (NSFC).  相似文献   

Open-coast intertidal deposits and the preservation potential of individual laminae: a case study from east-central China   总被引：3，自引：0，他引：3  

Congxian Li  Ping Wang  Fan Daidu  Dang Bing  & Li Tiesong 《Sedimentology》2000,47(5):1039-1051

Monitoring of sedimentation and erosion was conducted on an open coastal tidal flat on the southern flank of the Yangtze delta. Various elevation references were established in the intertidal zone and monitored intensively for 4 months in order to examine fortnightly and seasonal (calm weather and storm season) sedimentation and erosion. Longer term (100 years) sedimentation and preservation were investigated through examination of cores and trenches. Two different vertical grouping patterns of tidal bedding were distinguished with thinner and thicker sandy laminae. The number of sand-dominated layers and individual muddy and sandy lamina in the cores were compared with theoretically derived sedimentation rates in order to assess long-term preservation potential. Waves, especially high storm waves, have a significant influence on sedimentation and the preservation of intertidal deposits along the open-coast tidal flat. Monitoring during one season indicated that the sand-dominated layer was directly related to storm deposits, while the mud-dominated layer was deposited during calm weather conditions. The variation in sandy lamina thickness was not related to spring–neap tidal cycles during the monitoring period. The assumption of 100% preservation of sandy laminae deposited during every tidal cycle, which has been assumed in previous time-series analyses for the identification of palaeotidal periodicity, was found to be unrealistic along this open-coast tidal flat. Preservation potential decreases as temporal scale increases. During one neap–spring tidal cycle, the preservation potential of individual sandy and muddy laminae was of the order of 10%. Over a period of 100 years, the estimated preservation potential of individual laminae, including both calm weather and storm deposits, decreased to 0·2%. The 100-year preservation potential of storm-induced, sand-dominated layers was estimated to be of the order of 10%.  相似文献   

国内气象观测研究现状的文献计量学分析     

姜明  史静  杨妍辰  党岳 《气象研究与应用》2022,43(1):118-123

利用2010-2020年中国知网关于"气象观测"主题文献数据,基于文献计量学对气象观测科技论文的特征进行定量和定性分析.结果表明,10a间关于气象观测主题的科技论文数量呈先上升后下降趋势.该领域核心作者有201人,其中83％的作者来自气象行业内部;发文地域分布呈现出东部高西部低的特点,且发文机构主要为气象部门、高校及科...  相似文献   

A cross-system analysis of sedimentary organic carbon in the mangrove ecosystems of Xuan Thuy National Park, Vietnam   总被引：1，自引：0，他引：1  

Nguyen Tai Tue  Nguyen Thi NgocTran Dang Quy  Hideki HamaokaMai Trong Nhuan  Koji Omori 《Journal of Sea Research》2012,67(1):69-76

A cross-system analysis of bulk sediment composition, total organic carbon (TOC), atomic C/N ratio, and carbon isotope composition (δ¹³C) in 82 surface sediment samples from natural and planted mangrove forests, bank and bottom of tidal creeks, tidal flat, and the subtidal habitat was conducted to examine the roles of mangroves in sedimentation and organic carbon (OC) accumulation processes, and to characterize sources of sedimentary OC of the mangrove ecosystem of Xuan Thuy National Park, Vietnam. Sediment grain sizes varied widely from 5.4 to 170.2 μm (mean 71.5 μm), with the fine sediment grain size fraction (< 63 μm) ranging from 11 to 99.3% (mean 72.5%). Bulk sediment composition suggested that mangroves play an important role in trapping fine sediments from river outflows and tidal water by the mechanisms of tidal current attenuation by vegetation and the ability of fine roots to bind sediments. The TOC content ranged from 0.08 to 2.18% (mean 0.78%), and was higher within mangrove forests compared to those of banks and bottoms of tidal creeks, tidal flat, and subtidal sediments. The sedimentary δ¹³C ranged from − 27.7 to − 20.4‰ (mean − 24.1‰), and mirrored the trend observed in TOC variation. The TOC and δ¹³C relationship showed that the factors of microbial remineralization and OC sources controlled the TOC pool of mangrove sediments. The comparison of δ¹³C and C/N ratio of sedimentary OC with those of mangrove and marine phytoplankton sources indicated that the sedimentary OC within mangrove forests and the subtidal habitat was mainly composed of mangrove and marine phytoplankton sources, respectively. The application of a simple mixing model showed that the mangrove contribution to sedimentary OC decreased as follows: natural mangrove forest > planted mangrove forest > tidal flat > creek bank > creek bottom > subtidal habitat.  相似文献   

张量CSAMT数据处理技术初步研究与示范应用   总被引：1，自引：0，他引：1  

孟庆奎  林品荣  李勇  李建华  朱宏伟  李荡 《吉林大学学报(地球科学版)》2015,45(6):1846-1854

面对大深度和三维探测,标量CSAMT(controlled source audio-frequency magnetotellurics)已显力不从心,而张量CSAMT正逐渐成为研究热点。在前人研究基础上,笔者就张量CSAMT数据处理方面提出Mohr圆分析和传统坐标旋转两种处理技术,并首次创新性地使用我国自主研发的综合电法仪开展了张量CSAMT示范应用。结果表明:Mohr圆分析和传统坐标旋转法相结合应用效果良好,可定性挖掘地下地质体的纵向和横向构造特征,主轴方位的视电阻率和阻抗相位与目标体对应良好,并且电阻率反演结果与钻孔等地质资料综合分析对建立试验区的地质地球物理模型是有益的。  相似文献   

Internal structures and high-velocity frictional properties of Longmenshan fault zone at Shenxigou activated during the 2008 Wenchuan earthquake          下载免费PDF全文

Yu Wang  Shengli Ma  Toshihiko Shimamoto  Lu Yao  Jianye Chen  Xiaosong Yang  Honglin He  Jiaxiang Dang  Linfeng Hou  Tetsuhiro Togo 《地震科学（英文版）》2014,27(5):499-528

This paper reports internal structures of a wide fault zone at Shenxigou, Dujiangyan, Sichuan province, China, and high-velocity frictional properties of the fault gouge collected near the coseismic slip zone during the 2008 Wenchuan earthquake. Vertical offset and horizontal displacement at the trench site were 2.8 m (NW side up) and 4.8 m (right-lateral), respectively. The fault zone formed in Triassic sandstone, siltstone, and shale about 500 m away from the Yingxiu-Beichuan fault, a major fault in the Longmenshan fault system. A trench survey across the coseismic fault, and observations of outcrops and drill cores down to a depth of 57 m revealed that the fault zone consists of fault gouge and fault breccia of about 0.5 and 250–300 m in widths, respectively, and that the fault strikes N62°E and dips 68° to NW. Quaternary conglomerates were recovered beneath the fault in the drilling, so that the fault moved at least 55 m along the coseismic slip zone, experiencing about 18 events of similar sizes. The fault core is composed of grayish gouge (GG) and blackish gouge (BG) with very complex slip-zone structures. BG contains low-crystalline graphite of about 30 %. High-velocity friction experiments were conducted at normal stresses of 0.6–2.1 MPa and slip rates of 0.1–2.1 m/s. Both GG and BG exhibit dramatic slip weakening at constant high slip rates that can be described as an exponential decay from peak friction coefficient μ _p to steady-state friction coefficient μ _ss over a slip-weakening distance D _c. Deformation of GG and BG is characterized by overlapped slip-zone structures and development of sharp slickenside surfaces, respectively. Comparison of our data with those reported for other outcrops indicates that the high-velocity frictional properties of the Longmenshan fault zones are quite uniform and the high-velocity weakening must have promoted dynamic rupture propagation during the Wenchuan earthquake.  相似文献