东濮凹陷原油含硫化合物的分布特征及其应用     

徐田武  李素梅  张洪安  张云献  吴建勋  史权  陈湘飞  纪红  万中华 《现代地质》2019,33(3):629-642

东濮凹陷盐湖相原油中杂原子化合物研究薄弱。采用高分辨率质谱结合色谱-质谱技术,对东濮凹陷盐湖相、淡水湖相原油中的含硫化物进行了检测。结果表明,原油中含有丰富的含硫化合物,S1和O1S1占绝对优势,咸水相原油富含S1类、淡水相原油相对富集O1S1类,指示O1S1/S1具有原始沉积环境指示意义。东濮盐湖相原油中的硫化物富含碳数为C27-35、C40的化合物,与原油中丰富的甾类、藿烷类与β-胡萝卜类化合物碳数相吻合,指示菌藻类、色素类生源的重要贡献。随成熟度增加,硫化物缩合度增加、烷基侧链碳数范围降低,相关参数DBE6/DBE12-S1、DBE3+6/DBE12+15+18-S1等可用于辅助评价原油成熟度。东濮低熟油含有丰富的低热稳定性硫化物,指示富硫干酪根和/或富硫大分子低温降解是低熟油形成的重要机制之一。  相似文献   

三峡水库汛期泥沙淤积对坝前水位的滞后响应          下载免费PDF全文

唐小娅  童思陈  许光祥  黄国鲜  王涛 《水科学进展》2019,30(4):528-536

河床演变中普遍存在着滞后现象,而以往的三峡水库泥沙研究对滞后现象鲜有考虑。为深入认识三峡水库运行带来的泥沙淤积特征,建立了考虑上游来沙和坝前水位双重影响的泥沙淤积滞后响应模型。基于2003—2017年实测水沙资料,分析了三峡入库水沙特性及汛期泥沙淤积特点,利用滞后响应模型探究了汛期泥沙淤积的滞后规律。结果表明:2003—2012年入库水沙呈现“大水带大沙,少水带少沙”的特点,汛期淤积随坝前水位抬升而增加;2013—2017年入库水沙关系的一致性发生变化,受上游梯级库群拦沙影响,汛期淤积减缓。三峡水库汛期累计淤积与5年线性叠加坝前水位之间有较好的相关关系,汛期淤积不仅与当年来沙和坝前水位运行有关,也与前4年的来沙和坝前水位调度有关。  相似文献   

末次冰期毛乌素沙地湖泊消涨过程:沉积证据     

刘小槺  鲁瑞洁  高尚玉  段晨曦 《第四纪研究》2019,(4):825-836

毛乌素沙地位于东亚季风边缘区,对于气候变化响应敏感.基于沙地的侵蚀-堆积关系,在侵蚀作用为主的沙地西北部和中部很难找到沉积相对连续且分辨率较高的地层剖面,因此已有的末次冰期古气候环境研究多集中于堆积作用为主的沙地东南缘的萨拉乌苏河河谷地区.本文选取位于沙地腹地,厚度为3.5 m的风成砂-河湖相沉积序列——神水台(SSTG)剖面为研究对象,基于AMS 14C和OSL年代数据,推测得出剖面中湖相层的上界和下界分别为约24.2 ka B.P .和42.7ka B.P.,依据沉积地层和环境代用指标分析结果,针对末次冰期毛乌素沙地湖泊消涨的一般过程进行了探讨.结果表明,自约5万年以来,由神水台(SSTG)剖面指示了两次明显的湖泊主要发育期,时间分别约为42.7~34.3 ka B.P.和31.1~24.2 ka B.P.,期间粘土含量、有机质、红度均表现为低值,为含淡水螺壳化石的典型湖泊相沉积,且与毛乌素沙地已有湖泊发育的年代结果基本一致.在两期湖相层之间的砂层,平均粒径、砂含量表现为峰值,指示了一次明显的湖泊消退的过程,其时间约为34.3~31.1 ka B.P.;在湖相层上下可能均为风力作用为主导的风沙沉积.通过区域对比并初步探讨其可能的驱动机制,结果表明SSTG剖面记录的湖泊消涨过程主要受控于东亚季风强度的变化.  相似文献   

人工合成纳米材料在水环境中的聚沉行为研究进展     

赵晓丽  王珺瑜  方蕾  汤智  吴爱明  赵天慧 《矿物岩石地球化学通报》2019,(3):522-533,439

随着纳米科技的快速发展,纳米材料的种类和数量呈指数增长。人工纳米材料不可避免地进入水环境并发生复杂的环境行为,可能在水中分散悬浮,也可能发生团聚和沉降,从而影响其迁移、转化和归趋。本文综述了近年来有关人工合成纳米材料在水环境中聚沉行为的研究进展,分析了影响纳米材料团聚与沉降的两个主要因素:自身理化性质(材料形态、颗粒尺寸、化学组成、晶体结构、表面修饰等)和水环境要素(pH、离子种类和离子强度、天然有机质等)及相应的作用机理,剖析了当前研究中存在的问题,指出有关纳米材料与无机胶体等物质间的异团聚、各环境要素间的交互作用、以及纳米材料在接近自然环境的低浓度(<1mg/L)条件下的聚沉行为研究仍需进一步完善。  相似文献   

Response of Sublittoral Hard Substrate Invertebrates to Estuarine Sedimentation in the Outer Harbour of Bilbao (N. Spain)   总被引：1，自引：0，他引：1  

J. I. Saiz  Salinas I. Isasi  Urdangarin 《Marine Ecology》1994,15(2):105-131

Abstract. Four sampling stations with relatively similar hard-bottom substrates were investigated to determine if there were differences between the sublittoral invertebrates near the Nervión River mouth (N. Spain) and those closer to the open sea, and if faunal differences could be attributed to the impact of estuarine sedimentation. Four 100 m long transects were surveyed using photographic and quadrat techniques, yielding data on percentage cover of all invertebrates from 136 visual inventories. Data were analysed to determine whether any community response to sedimentation was evident. Ordination (multidimensional scaling) and classification (group-average clustering) based on B ray -C urtis dissimilarity measures separated the stations at three levels based on the different faunal assemblages. The analysis suggests the presence of a gradient along the estuary discharge, mainly affecting the east side of the outer part of Bilbao harbour, since the estuarine plume flows to the east. The influence can be expressed in terms of retrogression of the variety of species and disappearance of the algal fraction, which is progressively replaced by an animal assemblage of tolerant and opportunistic suspension feeders. Several 'indicator' species were identified on the basis of strong density differences between sites; matrix correlations presented here were found to produce complementary and consistent results. The role of estuarine sedimentation disturbance as the main factor controlling subtidal assemblages in outer Bilbao harbour is discussed.  相似文献   

SEDIMENT DISCHARGE OF THE HUANGHE RIVER AND ITS EFFECT ON SEDIMENTATION OF THE BOHAI SEA AND THE YELLOW SEA     

任美锷  史运良 《中国地理科学(英文版)》1991,1(1):1-18

The Huanghe (Yellow) River, with annual sediment discharge about 11 ×108tons, contributes about 17% of the fluvial sediment discharge of world's 21 major rivers to the ocean because its middle reaches flow across the great Loess Plateau of China. Sediment discharge of the Huanghe River has a widespread and profound effect on sedimentation of the sea. The remarkable shift of its outlet in 1128-1855 A.D. to the South Yellow Sea formed a large subaqueous delta and provided the substrate for an extensive submarine ridge field.The shift of its outlet in the modern delta every 10 years is the main reason why with an extremely heavy sediment input and a micro- tidal environment, the Huanghe River has not succeeded in building a birdfoot delta like the Mississippi. The Huanghe River has consistently brought heavy sediment input to sea at least since 0.7 myr.B.P. Paleochannels, paleosols, cheniers and fossils on the sea bottom indicate that the Yellow Sea was exposed during the late Quaternary glacial low-sea l  相似文献   

A ~4500 yr record of river floods obtained from a sediment core in Lake Atnsjøen, eastern Norway     

Atle Nesje  Svein Olaf Dahl  John A. Matthews  Mark S. Berrisford 《Journal of Paleolimnology》2001,25(3):329-342

To extend the historical record of river floods in southern Norway, a 572-cm long sediment core was retrieved from 42 m water depth in Atnsjøen, eastern Norway. The sediment core contains 30 light gray clastic sediment layers interpreted to have been deposited during river floods in the snow/ice free season. In the upper 123 cm of the core, four prominent flood layers occur. The youngest of these overlap with the historical record. The thickest (flood layer 5) possibly reflects a general increase in river-flood activity as a result of the post-Medieval climate deterioration (lower air temperatures, thicker and more long-lasting snow cover, and more frequent rain/snow storms) associated with the Little Ice Age. The most pronounced pre-historic flood layers in the core were, according to an age model based on linear regression between eleven bulk AMS radiocarbon dates, deposited around 4135, 3770, 3635, 3470, 3345, 2690, 2595, 2455, 2415, 2255, 2230, 2150, 2120, 1870, 1815, 1665, 1640, 1480, 1400, 1380, 1290, 935, 885, 670, 655 and 435 cal. BP (BP = AD 1950). The mean return period of the river flood layers is, according to the linear regression age model, ~ 150 ± 30 cal. yr (mean ± 1 S.E.).  相似文献   

Carbon isotope characteristics,origin and distribution of the natural gases from the Tertiary salty lacustrine facies in the West Depression Region in the Qaidam Basin     

张晓宝  胡勇  马立元  孟自芳  段毅  周世新  彭德华 《中国科学D辑(英文版)》2003,46(7):694-707

Since the Meso-Cenozoic, controlled by paleoclimate, a series of fresh to brackish water basins and salt to semi-salt water basins were developed in wet climatic zones and in dry climate zones in China, respectively[1]. The geological and geochemical char…  相似文献   

Strike-slip tectonics within the SW Baltic Sea and its relationship to the inversion of the Mid-Polish Trough—evidence from high-resolution seismic data     

Piotr Krzywiec  Regina Kramarska  Piotr Zientara 《Tectonophysics》2003,373(1-4):93

The SW Baltic Sea occupies an area where crustal-scale regional tectonic zones of different age merge and overlap, creating a complex tectonic pattern. This pattern influenced the evolution of the Mesozoic sedimentary basin in this area. We present an interpretation of new high-resolution seismic data from the SW Baltic Sea which provided new information both on modes of the Late Cretaceous inversion of this part of the Danish–Polish Mesozoic basin system as well as on relationship between tectonic processes and syn-tectonic depositional systems. Within the Bornholm–Dar owo Fault Zone, located between the Koszalin Fault and Christiansø Block, both strike-slip and reverse faulting took place during the inversion-related activity. The faulting was related to reactivation of extensional pre-Permian fault system. Syn-tectonic sedimentary features include a prominent, generally S- and SE-directed, progradational depositional system with the major source area provided by uplifted basement blocks, in particular by the Bornholm Block. Sediment progradation was enhanced by downfaulting along a strike-slip fault zone and related expansion of accommodation space. Closer to the Christiansø Block, some syn-tectonic deposition also took place and resulted in subtle thickness changes within the hinge zones of inversion-related growth folds. Lack of significant sediment supply from the inverted and uplifted offshore part of the Mid-Polish Trough suggests that in this area NW–SE-located marginal trough parallel to the inversion axis of the Mid-Polish Trough did not form, and that uplifted Bornholm Block played by far more prominent role for development of syn-inversion depositional successions.  相似文献   

滇西南牡音河组的沉积特征-环境意义及与之相关的若干地质问题   总被引：1，自引：1，他引：1       下载免费PDF全文

方念乔  刘本培  冯庆来 《地球科学》1996,5(1)

地处古特提斯域的牡音河组是一套由放射虫硅质岩和凝灰岩组合而成、沉积速率极低的远洋沉积序列。它所包括的４个放射虫组合指示其形成时代为晚二叠世末至中三叠世，从而大大改变了我们以往对古特提斯演化所拟定的时间表。详细的岩相和岩石地球化学分析表明，牡音河组的中、下部与大洋岛弧的火山活动关系密切，上部则有接受更多陆源物质的趋向。这一沉积记录所反映的演化趋可能标志着古特提斯残留海的一次重大构造转折。但是，牡音河组内所有火山碎屑和陆源碎屑仅仅构成若干夹在正常远洋序列中的远源薄层，这意味着古特提斯残留海仍然具有相当规模，距离完全闭合尚远。就牡音河组与相邻一些地层单位的关系，探讨了若干造山带地层学研究中值得注意的基本问题  相似文献