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Brent B. Wolfe Tammy L. Karst-Riddoch Matthew D. Falcone Thomas W.D. Edwards 《Quaternary Research》2005,64(2):147-162
Multi-proxy paleolimnological analyses on lake sediment cores from “Spruce Island Lake” (58° 50.82′ N, 111° 28.84′ W), a perched basin in the northern Peace sector of the Peace-Athabasca Delta (PAD), Canada, give insights into the relative roles of flow regulation of the Peace River and climatic variability on the basin hydro-ecology. Results indicate substantial variability in basin hydro-ecology over the past 300 years ranging from seasonal to periodic desiccation in the 1700s to markedly wetter conditions during the early 1800s to early 1900s. The reconstruction is consistent with (1) dry climatic conditions that defined the peak of the Little Ice Age and subsequent amelioration evident in conventional ring-width and isotopic analyses of tree-ring records located hydrologically and climatically upstream of the PAD, and (2) Peace River flood history inferred from sub-annual magnetic susceptibility measurements from another lake sediment record in the Peace sector of the PAD. Although regulation of the Peace River for hydroelectric power generation since 1968 has long been considered a major stressor of the PAD ecosystem leading to reduced frequency of ice-jam and open-water flooding and an extended period of drying, our results show that current hydro-ecological status is not unprecedented as both wetter and drier conditions have persisted for decades in the recent past under natural climatic variability. Furthermore, paleolimnological evidence from Spruce Island Lake indicates that recently observed dryness is part of a longer trend which began some 20-40 years prior to Peace River regulation. 相似文献
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藏北羌塘盆地与西亚特提斯盆地构造比较及其油气远景 总被引：4，自引：1，他引：4
羌塘盆地是中国西部除塔里木、柴达木、准噶尔盆地外，又一大型古生代一中新生代盆地。与其具有相似构造背景的西亚特提斯带盆地群是目前世界上油气最富集的地区。通过对西亚特提斯带含油气盆地的形成、构造演化背景的分析，探讨了盆地油气富集的地质条件，认为羌塘盆地的形成演化与特提斯西段阿富汗地块具有相似性，侏罗纪的沉积演化和构造格局与中亚的长拉库姆油气盆地类似，故具备形成油气的基本条件。然而，羌塘盆地距喜马拉雅褶皱带较近，新近纪以来构造改造十分强烈。逆冲推覆作用一方面可以产生构造圈闭，但也使烃源岩的成熟度偏高，不利于油气的保存，这与中东地区含油气盆地油气大量聚集的油气田具有显著差异。为此羌塘盆地的油气勘探应寻找保存条件与生油条件相匹配的地区。 相似文献
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川西须家河组储层成岩演化 总被引：10，自引：4，他引：6
通过对川西须家河组储层砂岩中成岩矿物内流体包裹体均一温度、盐度和组分的分析,结合碳氧同位素、镜质体反射率、粘土矿X-射线衍射等特征,论证了须家河组储层砂岩成岩作用过程。本文认为须家河组随着成岩流体温度的变化以及盐度和有机组分增加,相继发生了早期碳酸盐沉淀（局限于个别夹层）,石英一期加大边生成、绿泥石薄膜生成、长石岩屑溶解、石英二期加大边生成、以及含铁碳酸盐的沉淀。由于喜山期区域性构造运动,川西须家河组发生断裂活动,深部流体进入,部分裂缝中沉积了石英和方解石等。喜山期产生的裂缝对须家河组砂岩储层油气的运移起决定性作用,形成了现今次生孔-裂缝型油气藏。 相似文献
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广东河源盆地蛋化石 总被引：3，自引：0，他引：3
河源盆地沉积了白垩系-古近系，笔者将这套地层划分为3个岩石地层单位，新建仙塘组和东源组，沿用格岭组。在河源除发现恐龙骨骼、恐龙脚印、龟鳖化石外，于白垩系东源组中还产有大量蛋化石。该组蛋化石的分布，下部以圆形蛋为主，中-上部多见长形蛋。报道了三王坝村副圆形蛋(新种)Paraspheroolithus sanwangbacunensis Fang sp．nov．、风光村树枝蛋(新种)Dendroolithus fengguangcunensis Fang sp．nov．和瑶屯巨形蛋Macroolithus yaotunensis、长形长形蛋Elongatoolithus elongates。 相似文献
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MATTHEW BENNETT 《Boreas: An International Journal of Quaternary Research》2011,40(3):555-555
2010: Glaciers and Glaciation. Second edition. 802 pp. Hodder Education, London. ISBN 978‐0‐340‐905791. Paperback, Full Colour, £45.00 相似文献
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Acta Geochimica - Surface radioactive survey has been carried with portable gamma ray spectrometer (PGRS) about the 45 km2 around the Srisailam sub basin, the surface radioactive anomalies... 相似文献
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辽宁北部秀水盆地秀D1井孢粉组合及其地层意义 总被引：2，自引：1，他引：1
孢粉化石采自辽宁省北部秀水盆地的秀D1井,分析、鉴定和系统研究结果表明,来自秀D1井井深62.1~1089.7m的孢粉化石自下而上划分为3个孢粉组合,下部孢粉组合(井深703.85~1089.7m)以Osmundacidites-Klukisporites-Podocarpidites为代表,地质时代为晚侏罗世堤塘期(Tithonian),中部孢粉组合(井深381.5~699.3m)以Densoisporites-Cicatricosisporites-Piceaepollenites为代表,地质时代为早白垩世贝里阿斯期(Berriassian),上部孢粉组合(井深62.1~339m)以Cicatricosisporites-Impardecispora-Pinuspollenites为代表,地质时代为早白垩世凡兰吟期—欧特里夫期(Valanginian-Hauterivian)。秀D1井钻遇地层所含孢粉组合特征在区域上可以与冀北地区大北沟组,辽宁西部地区下白垩统义县组、九佛堂组,松辽盆地东南缘下白垩统火石岭组、沙河子组所产的孢粉组合对比。含孢粉组合地层时代的确定解决了井柱地层的划分,以及与区域地层的对比关系,同时为区域地层古生物研究提供了翔实的基础资料。 相似文献
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滦平盆地成岩作用过程及古热流体幕式运移事件分析 总被引：9，自引：0，他引：9
滦平断陷盆地形成于侏罗世－早白垩世,沉积物厚度数和千米,其中西瓜园组开阔湖的沉积体系与扇三角洲沉积体系的发育为烃源岩、碎屑岩型输导层和储层的形成奠定了充分条件。早白垩世以后,盆地持续沉降,泾源岩成熟并排烃,与烃源岩沟通的扇三角洲砂－砾岩体构成了油气输导层,可能在燕山或喜马拉雅造山期,盆地遭受剥蚀。流体在输层层中 移时形成了五种胶结物,其中硅质和钙质胶结作用对输导层影响最大,相对早期的硅质胶结之后仍 相似文献
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江西信江盆地晚白垩世风成沙丘的发现及其古风向 总被引：7，自引：3，他引：7
长期以来,江西信江盆地晚白垩世圭峰群塘边组(K2t)均定为水成沉积,本文的研究结果则认为属风成沉积.沉积结构、构造和石英沙颗粒表面特征研究结果表明,该组的主体岩性为紫红色中-细粒净砂岩,基本不含泥质和云母等悬移质,大型高角度平板状交错层理发育,层系厚度巨大,风成沙丘前积层特征明显,石英沙磨圆度好,在电子显微镜下普遍可见风成沙特有的碟形撞击坑、新月形撞击坑和毛玻璃化表面特征,属于风成沙丘沉积.古流向恢复表明,信江盆地以西风为主,东北风为次,同时见有少量东南风与西北风.根据当时的古地理格局及地表风带模式判断,研究区位于当时的北半球西风带和东北信风带之中,同时可能存在东南向和西北向的古季风. 相似文献
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《Applied Geochemistry》1988,3(6):573-582
Detailed molecular and isotopic analysis of near surface liquid hydrocarbon seepage is useful not only in determining the presence of petroleum hydrocarbons but also to indicate the type and quality of deeper seated hydrocarbons. Near surface sediment bitumens collected over known production in the offshore Santa Maria basin were shown to be similar to reservoired petroleum in the adjacent onshore. Triterpane, sterane and aromatized sterane compositional similarities between oils and near surface sediment bitumens suggest a common source in the Monterey Formation. An empirical model based on the relation between oil composition (pristane/phytane and bisnorhopane/hopane ratios) and API gravity was applied to the near surface bitumens and accurately predicted the API gravity of the nearest known production. The improvement and refinement of geochemical prospecting techniques has greatly enhanced their use and reliability as exploration tools. 相似文献
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合肥盆地南部侏罗系砂岩碎屑组分及其物源构造属性 总被引：55，自引：10，他引：45
根据侏罗系砂岩碎屑的岩矿组成及主元素地球化学分析, 认为合肥盆地南部侏罗系物源主要来自大别造山带, 具有明显的陆壳岛弧混杂属性。主要物源类型经历了下—中侏罗统的 “再旋回造山带”类型向上侏罗统 “弧造山带”类型的复杂演变, 期间中侏罗世特别是相当于凤凰台组时期由于强烈的剥离作用, 大别造山带切割的 （ｄｉｓｓｅｃｔｅｄ） 岩浆弧物源已有所暴露。据古地理恢复, 推断侏罗纪合肥盆地南部沉积演化曾受控于挤压动力体制, 极可能与扬子板块进一步陆内俯冲作用有关 相似文献
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The regional thermal field of the NE-German basin is modeled by a three-dimensional finite-element approach and is compared to classical one-dimensional extrapolations. Two alternative boundary conditions are assumed at the approximate depth of the Moho: a constant temperature distribution and a constant heat flow. Surprisingly, both results are almost identical down to approximately 10?km depth. Based on the models presented, the results are due to a complex interaction of different strata and the related regional variability of conductivities. In addition, the available temperature maps for different depths (Hurtig et al. 1992) indicate a relative high heat flow at the basin margins especially at the southern and eastern boundary. The models are able to reproduce the generalized pattern by regarding only a conductive heat flow. However, because both models are successful at shallow depth, we conclude that the current techniques of thermal modeling require improvement, even on the theoretical aspects of depth continuation and inversion. 相似文献
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《Journal of Structural Geology》2001,23(2-3):393-406
Brittle tectonic analysis of Cretaceous–Paleogene sediments at a total of 17 sites located in the Isle of Wight (U.K.) enables four main tectonic events that occurred prior to and after the folding to be identified and successive palaeostress tensors to be determined using the inversion method. Three of the events can be shown to have occurred prior to the folding: (1) a syn-sedimentary extension of Upper Cretaceous age; (2) a strike-slip faulting regime with an ESE–WNW direction of compression; (3) a compressional regime, marked by strike-slip faulting, with an NNE–SSW to N–S direction of compression. The fourth and last compressional event took place after the folding and is characterised both by reverse and strike-slip faulting, with a dominant N–S direction of compression. Syn-folding faults also developed between the third and fourth events. All four events can be connected to the extensional tectonics and different steps of structural inversion, both of which were integral to the development and evolution of the Wessex basin. 相似文献
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西藏东北部比如盆地中生界油气苗的发现与意义 总被引：1，自引：0，他引：1
比如盆地位于西藏的东北部。野外石油地质考察期间,在比如盆地发现了大量的地表油气苗。油气苗均为干沥青,出露层位集中在中-上侏罗统拉贡塘组与下白垩统多尼组中,其他层位未发现油气苗。镜下观察结果显示,拉贡塘组与多尼组碎屑岩骨架颗粒之间发育有油气包体与不发光沥青。从地表出露形态与特点看,干沥青主要分布于断裂带、裂缝等构造强变形的部位。与青藏高原腹地同类残留盆地对比,比如盆地新生代构造变形更强烈,盆地抬升并遭受剥蚀的幅度更大。由此,提出高原找油可能面临的诸多难题,应该重点关注新生代构造与构造地貌演化对油气藏的影响。 相似文献
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Malcolm G. Anderson 《Earth》1981,17(3):313-314
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