Early generation of 20S-5α(H),14α(H),17α(H)- and 5α(H),14β(H),17β(H)-steranes in low salinity lacustrine shales     

Maowen Li  Steve R. Larter  Bowen Mei 《Organic Geochemistry》1994,22(6)

A quantitative sterane biomarker study was conducted on a series of paralic freshwater lacustrine shale samples ranging in maturity from immature to near oil window maturity taken from Section 3 of the Shahejie Formation (Es3) in the Liaohe Basin, N.E. China. Concentrations of 5α(H),14α(H),17α(H)-20S and 5α(H),14β(H),17β(H)-steranes remain nearly constant throughout the sample suite. However, the decrease in the absolute concentrations of the 20R-5α(H),14α(H),17α(H)-C₂₉ steranes with increasing maturity results in an increase in the conventionally defined maturity parameters, 20S/(20S + 20R)-ααα and αββ/(ααα + αββ) sterane ratios. In addition, the data suggest that relatively early generation of 5α(H),14α(H),17α(H)-20S and 5α(H),14β(H),17β(H)-steranes has occurred in lacustrine sediments with a vitrinate reflectance 0.3% (R_o). The data provide strong support for the major importance of relative thermal stability of epimers, but do not exclude the possibility of isomerization as a viable mechanism for production.  相似文献   

THE DEGRADABILITY OF PARTICULATE ORGANIC MATTER IN THE GIRONDE ESTUARY, FRANCE   总被引：4，自引：0，他引：4  

林荣根 《中国海洋湖沼学报》1994,12(2):106-113

The degradability of particulate organic matter(POM)in the Gironde Estuary(France)was measuredusing the incubation technique.The influence of sample treatment and incubation conditions on the re-sults was evaluated.A mathematical model was successfully used to describe the various degradationcurves.Results showed that the upstream POM had very high degradability;the central estuaryPOM had low degradability;and that the mouth POM degradability was between that of central POM(low degradability)and marine POM(high degradability).  相似文献   

辽河油田东部凹陷中段走滑断层与油气的关系     

张延玲  杨长春  贾曙光  李明生  林会喜  刘华 《地质通报》2006,(Z2)

走滑构造不仅加速含油气盆地油气的运移和富集,而且在促使油气圈闭的形成过程中也促使形成圈闭中的优良储集层。在具备生、储、盖地质条件时,花状构造样式的含油气性优于其他构造样式,不仅控制着油气藏的分布,而且走滑断层的应力释放区往往是油气富集区。扭应力作用使生油层中的分散油气被“强拧”驱赶、运移至花状构造背斜核部,在负花状构造的上升盘中形成高产油气流。辽河坳陷内的黄沙坨和欧利坨子地区便是郯庐断裂在辽河坳陷东部凹陷中段的应力释放区,对该区走滑断层的识别和解释,不仅对东部凹陷中段油气藏的形成、分布及富集有了新的认识,而且可为寻找同类油气藏提供依据。  相似文献   

Holocene tidal palaeochannels, Severn Estuary Levels, UK: a search for granulometric and foraminiferal criteria     

J.R.L. Allen  B.E. Rinkel 《Proceedings of the Geologists' Association. Geologists' Association》2006,117(4):329-344

  相似文献   

辽河盆地新生代火山岩地球化学特征及其与油气成藏的关系   总被引：2，自引：1，他引：2  

谷团  陈淑凤  苑丽  李朝阳  刘玉平 《矿物学报》2006,26(3):325-334

辽河盆地形成于新生代时期,在其形成演化过程中,发生了多期次的火山活动,主要形成了明显富钠质的粗面质和玄武质碱性系列火山岩。稀土元素反映其形成于大陆裂谷环境,是大陆伸展构造背景下的产物。东营组和沙河街组火山岩的Sr、Nd同位素表明其可能源于软流圈,且地壳物质混染微弱,而房身泡组火山岩可能来自上地幔较浅源区,且受到了下地壳物质较强的混染。盆地内新生代火山岩与油气成藏的关系十分密切,它对油气的生成、运移、储集、封盖、遮挡、聚集和成藏有着重要的有益的影响。火山岩的异常热效应对烃源岩的生排烃起到了很好的促进作用,火山活动和火山岩就位过程及其后来被改造的过程为油气运移和聚集提供了运移通道、储集空间、封盖遮挡条件和圈闭构造。辽河油田近年的勘探实践表明,东部凹陷中段粗面岩油气藏的成藏要素配置良好,已发现了整装的千万吨级的黄沙坨油田,且开发效果良好,展示了新生代火山岩油气藏的勘探潜力,为老油田的产量接替和可持续发展提供了新的勘探目标。  相似文献   

泉州湾河口湿地保护现状及发展对策   总被引：1，自引：1，他引：1  

李经建  林永源 《湿地科学与管理》2006,2(1):47-50

泉州湾河口湿地位于福建泉州市辖区内主要河流晋江和洛阳江的出海口,优越的地理位置,适宜的气候条件,丰富的野生动植物和湿地资源,使之成为水禽迁徙的重要栖息地。本文通过对泉州湾河口湿地面临的自然环境条件变化、保护管理现状、人为影响等的研究,提出了保护与发展对策。  相似文献   

辽河滩海燕南潜山带中生界火成岩储层预测及勘探潜力初探     

罗海炳  付秋萍 《海相油气地质》2006,11(1):35-39

利用地震多属性分析等技术,对辽河坳陷滩海燕南潜山带中生界火成岩储层的分布、储层物性特征以及可能的含油气特征进行了初步预测。该火成岩以安山岩为主,钻时曲线普遍偏高,表明地层坚硬致密,一经构造运动等因素改造后,可以形成良好的裂缝性储层。本区溢流相火成岩含油气前景较好,应结合地震波形分类结果精细地圈定其分布范围,以作为今后勘探的有利地区。  相似文献   

Seismic framework and the Holocene morphological evolution of the Changjiang River mouth, China   总被引：2，自引：0，他引：2  

Zhanghua Wang  Zhongyuan Chen  Jing Chen  Zixin Wei 《Geomorphology》2007,85(3-4):237

Acoustic profiling in combination with coring has been used to examine the recent evolution of river mouth of the Changjiang. Two acoustic facies are present. Petrologic, radiometric and seismic analyses show that the upper facies I of 10–20 m thick fine sand and silt represents the sandy shoals of late Holocene age in the distributary, and the 5–20 m thick lower facies II of fine-grained silty clay with abundant marine microfossils represents the mid-Holocene prodelta facies deposited as fillings in the former large estuarine valley of late Pleistocene to early Holocene origin. Rapid accumulation during the Holocene has led to some instability of unconsolidated sedimentary strata in the distributary, such as strata collapse and mud diaper formation. The existence of large cross beddings, such as tabular and trough stratification in facies I identifies the sediment transport as predominantly bed load, driven by runoff and tidal currents. Two sets of discrete flood-ebb flow troughs, oriented NW and SE reflect controls by tidal waves generated from the sea and the superimposition of runoff and ebb flows. Symmetrical sand waves that appear at the northern trough of one of the distributaries also indicate the balancing sediment dynamics between runoff-ebb and flood currents, whereas the asymmetrical ones in the southern trough indicate superimposed sedimentation by runoff and ebb flows. A large quantity of sediment has been deposited in the slack water region between the discrete flood and ebb flows to form sandy shoals — the principal mechanism of the evolution of estuarine islands in the Holocene Changjiang mouth. The morphology of the extended river mouth to the southeast possibly indicates an external driving force, such as the Coriolis Effect, NW-prevailing wind and longshore currents.  相似文献   

辽河坳陷滩海月东油田新近系馆陶组底界研究   总被引：3，自引：9，他引：3  

崔向东  王仁厚  石敦久  袁清秋  马宏斌 《地质科学》2007,42(3):455-468

辽河坳陷南部滩海地区馆陶组底界的确定长期以来缺乏划分的依据,因靠近南部中央低凸起及其两侧的馆陶组巨厚块状砂砾岩层与下伏东营组之间发育一套厚50～100m不等的砂砾岩与砂泥岩的正粒序沉积,其时代归属有不同意见。本文首次在这套有争议的地层的岩心中发现了属新近纪的孢粉化石组合以及属于古近纪沙河街组和东营组中-下部的藻类再沉积化石,为本套地层归属新近纪馆陶组提供了可靠的生物化石对比依据。渤海湾盆地的新近系与下伏古近系间普遍为角度不整合接触,因风化侵蚀面起伏不平而馆陶组与下伏东营组的岩性变化可分为突变型、渐变型和“三明治”型3种。正确认识馆陶组底界对合理划分和对比油气层组有重要的勘探意义。  相似文献   

辽东-吉南地区硼矿床地质特征及成矿远景   总被引：1，自引：0，他引：1  

夏学惠  赵玉海  闫飞 《化工矿产地质》2007,29(3):169-177

产于辽东-吉南地区裂谷盆地中的古元古界辽河群里尔峪组为一套含硼岩系。其中划分的上、中、下三个含硼岩系分别赋存硼镁石-遂安石型、含磁铁矿-硼镁石型和硼镁铁矿型三类硼矿床。硼矿的发育与地层、围岩物质成分、围岩厚度及电气变粒岩等均有一定关系。通过分析研究,划分出营口后仙峪外围、风城和宽甸3个成矿远景区。并圈定出后仙峪硼矿外围、凤城县东汤镇西山、宽甸牛皮闸—大西岔、集安太平沟—小西沟、宽甸县老阳沟等4个找矿靶区。  相似文献