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裂谷作用对层序地层充填样式的控制——以西非裂谷系Termit盆地下白垩统为例 总被引：1，自引：0，他引：1
Termit盆地位于尼日尔东南部,属于西非裂谷系的北延部分,是发育于前寒武系—侏罗系基底之上的中、新生代裂谷盆地。该盆地早白垩世—古近纪经历了"裂谷—坳陷—裂谷"的构造演化过程及"陆相—海相—陆相"的沉积演化过程,表现为晚白垩世大规模海侵、早白垩世和古近纪两期裂谷叠置的特点。基于构造作用影响裂谷盆地层序发育的观点,分析了Termit盆地下白垩统裂谷阶段内的层序地层充填样式。根据裂谷作用的强弱,将早白垩世裂谷阶段划分为裂谷初始期、裂谷深陷期及裂谷萎缩期3个阶段。裂谷初始期层序断裂活动弱,构造沉降小,长轴物源体系较为发育,陡坡带为加积至退积型河流或三角洲沉积,缓坡带发育加积型河流或三角洲体系。裂谷深陷期层序断裂活动强烈,构造沉降大,陡坡带形成退积型水下扇或滑塌扇沉积,缓坡带发育退积型三角洲体系,盆地中心为泥岩充填。裂谷萎缩期层序断裂活动减弱并趋于停止,陡坡带为进积型扇三角洲沉积,缓坡带发育进积型三角洲体系。研究表明:裂谷作用对层序地层充填样式具有明显的控制作用,以构造作用为主线的裂谷盆地层序地层分析方法,能有效预测沉积体系和储层分布。 相似文献
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以板块构造演化为基础,利用地震、地质等资料,再现南大西洋两岸共轭型被动陆缘盆地原型盆地形成演化过程。首次依据盆地结构差异及沉积充填特征,将研究区被动陆缘盆地进一步划分为“三段”“四类”;结合对已发现大油气田的解剖,搞清了每类盆地大油气田成藏规律,并分别建立了其大油气田成藏模式。认为两岸“三段”“四类”盆地都经过了早期陆内裂谷、过渡期陆间裂谷及漂移期被动陆缘三个原型阶段。南段为下伏裂谷层系比较发育的“断陷型”盆地,上覆坳陷沉积厚度较薄,仅作为区域盖层,形成“裂谷层系构造地层型”大油气田。中段为裂谷、坳陷层系都比较发育且过渡阶段有盐的“含盐断坳型”盆地,以过渡期陆间裂谷盐岩充填为特征,其上、下的漂移期海相及裂谷期湖相页岩均可形成有效烃源岩,海相页岩及盐岩分别作为优质盖层,形成了“盐下碳酸盐岩盐上重力流扇体型”大油气田。北段为裂谷层系分布范围小、坳陷沉积范围广且厚度大的“坳陷型”盆地,受 “窄”陆棚、“陡”陆坡控制,坳陷层系重力流扇体自始至终比较发育,源于坳陷层系下部海相页岩中的油气直接充注于本身内部裙边状分布的重力流复合扇体之中,形成“漂移期重力流扇体群型”大油气田。另外,研究区还发育尼日尔、福斯杜亚马逊、佩罗塔斯三个具有独特构造沉积特征的 “三角洲型”被动陆缘盆地,其特殊性体现在三角洲层系由于沉积速率极高,从陆向海形成生长断裂带-泥岩底辟带-逆冲断裂褶皱带-平缓斜坡带四大环状构造带。除了前三角洲层系可以作为有效烃源岩之外,本身也可以形成自生自储自盖型组合,形成独特的“四大环状构造带型”大油气田,即在由陆向海生长断裂带-泥岩底辟带-逆冲断裂褶皱带-平缓斜坡带四大环状构造带上都可以形成大油气田。 相似文献
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措勤盆地的主要形成、发育期为中生代。由于受南、北两条特提斯构造带的影响 ,盆地内东西向构造岩相分带比较明显 ,并与一定的沉积环境相对应 ,即由海相 -三角洲相 -滨滩相 -台地相 -陆相沉积。晚中生代措勤盆地的地层说明了盆地的演化经历了从沉陷—稳定—隆起的构造旋回过程 ,从而反映了从裂谷—洋盆—残余海封闭及断陷盆地发育的沉积历史。在盆地内 ,川巴—色林错地区发育了一套具有一定生油条件、富含有机质的残留海盆沉积 ,同时 ,该地区在白垩纪又经历了海进—海退旋回 ,这为该区储油盖层的形成和配置提供了优越的沉积条件。因此该区具有良好的油气远景。 相似文献
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中国近海新生代具有不同类型的沉积盆地,它们是不同板块之间的相互作用而形成的,包括板内裂谷型、板缘聚敛型和板缘离散型沉积盆地,其中板缘聚敛型可细分为裂谷型和坳陷型,板缘离散型可细分为裂谷型、坳陷型和扭张型。②不同类型的沉积盆地能够反映不同沉积环境的演变特征。在盆地的断陷—坳陷发育期,板内裂谷型沉积盆地沉积环境以陆相为主;板缘聚敛型沉积盆地的沉积环境总体上具有海相到陆相的演变特征;板缘离散型沉积盆地沉积环境总体上具有陆相到海相的演变特征。③在不同盆地结构和沉积环境下,发育不同类型的沉积体系。裂谷型沉积盆地以近源堆积的沉积体系为主,坳陷型沉积盆地以远源堆积的沉积体系为主;板缘聚敛型沉积盆地坡折及三角洲发育规模小,板缘离散型沉积盆地坡折及三角洲发育规模大。 相似文献
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南华纪华南发育一系列裂谷及其相关的沉积盆地,在扬子地块的西部康滇地区、中部四川盆地及东部湘桂地区皆有裂谷盆地的直接证据.扬子地块北缘大巴山地区地形复杂、研究基础薄弱,对裂谷盆地是否存在尚未有清楚的认识.该研究有助于正确了解大巴山地区南华纪裂谷的空间展布规律,并对扬子北缘的地球动力学研究提供一定的启示.针对大巴山地区利用重力异常及野外露头资料开展了综合研究,揭示了扬子北缘大巴山南华裂谷的东西向展布形态,裂谷从南秦岭中部延伸到四川盆地东北部.同时构建出裂谷内与裂谷肩的地层充填序列及空间格架.基于上述盆地格架与沉积填充特征,提出大巴山地区弧后裂谷的构造背景. 相似文献
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羌塘—拉萨碰撞造山作用是青藏高原中生代最为重要的构造事件, 羌塘盆地内晚白垩世阿布山组是羌塘—拉萨碰撞造山作用的沉积记录。托纳木地区发育了北羌塘坳陷少有的晚白垩世阿布山组沉积, 然而对其形成构造背景和动力学机制尚不清楚。本文通过对托纳木地区阿布山组沉积环境、物源区详细表明, 该地区阿布山组下部以冲积扇环境为主, 中上部为辫状河环境。砾石成分、古水流、砂岩岩石学、砂岩重矿物、碎屑锆石U-Pb定年等物源综合分析显示中央隆起带和盆地内部均为阿布山组提供物源, 结合邻区阿布山组对比, 认为研究区物源来自盆地内西南方向下伏沉积、晚三叠世那底冈日组火山岩以及盆地基底, 阿布山组沉积受盆地内构造控制。托纳木地区阿布山组物源区特征反映了北羌塘晚白垩世地体内部的逆冲事件, 与羌塘—拉萨地体碰撞有关。 相似文献
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滇中新元古代裂谷盆地充填序列及演化模式:对Rodinia超大陆裂解的响应 总被引：5，自引：0，他引：5
以滇中新元古代裂谷盆地沉积充填为研究对象,开展了系统的沉积学和盆地分析研究。结果表明,滇中新元古代裂谷盆地具有4个充填序列,分别代表盆地的4个发展阶段。其中,序列I为柳坝塘组及陆良组下段,沉积时限为820~800 Ma,属低密度浊流和深水饥饿沉积,代表裂谷盆地的快速沉降阶段;序列II为澄江组、陆良组上段及牛头山组,沉积时限为800~725 Ma,属扇三角洲-湖泊沉积,代表裂谷盆地的成熟发展阶段;序列III为南沱组,沉积时限可能为725~635 Ma,属大陆冰川沉积,代表裂谷盆地开始向被动大陆边缘盆地转换的阶段;序列IV主要为陡山沱组,沉积时限为635~551 Ma,属潮坪沉积,为裂谷盖地层。进一步研究揭示,滇中新元古代裂谷盆地由幼年期分布局限的小型同向半地堑盆地群演化为成熟期统一的大型半地堑盆地,属上叠滑脱盆地。综合研究证实,滇中新元古代裂谷盆地应为陆内裂谷盆地,是Rodinia超大陆裂解的产物。 相似文献
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新疆库鲁克塔格南华系砂岩碎屑组成对其物源及盆地演化的指示 总被引：1，自引：0，他引：1
库鲁克塔格南华系记录了塔里木北缘同期的火山-沉积事件和蚀源区物质组成及演化的信息。该区不同剖面内南华系各组砂岩碎屑组分的统计分析显示,贝义西组砂岩在不同剖面内组成差异显著:西山口剖面以岩屑砂岩为主,且岩屑为火山岩岩屑与沉积岩岩屑,物源为再旋回地层,而依格孜塔格剖面以长石砂岩和岩屑长石砂岩为主,岩屑主要为变质岩岩屑,物源为下伏古元古代高级变质岩。砂岩碎屑组成在剖面上垂向的变化表明贝义西组沉积期与照壁山组沉积期间（725 Ma±）存在一个沉积转型事件,导致贝义西组之上的照壁山组、阿勒通沟组及特瑞艾肯组砂岩组成在不同区域趋于一致,转变为代表基底隆起-过渡大陆区物源的典型“长石砂岩”。南华系砂岩碎屑组成与大陆裂谷盆地沉积砂岩相似,且物源区存在由前裂谷地层-过渡裂谷肩部-切割裂谷肩部-克拉通内部的连续演化过程,是库满凹陷早期裂解的岩相学记录。 相似文献
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本文从人生信念、道德境界以及我国传统美德等方面阐述了敬业精神对当今激烈的市场竞争中的重要作用,并推出大力倡导敬业精神,纠正行业不正之风的基本途径和方法。 相似文献
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鉴于大陆岩浆弧上盘广泛分布有碳酸盐岩,岩体上升侵位过程使其碳通量明显的高于洋内岛弧,从而有可能影响着地质历史长时间尺度(百万年)的气候变化。陆弧碳的排放可分为两部分,一部分是与喷出岩相关的火山作用,另一部分是与侵入岩相关的脱碳过程。侵入岩的体量一般是喷出岩体量的10倍以上,由此与侵入岩有关的脱碳作用释放的碳通量不可忽视,可能类似与喷出岩有关的火山作用释放的碳通量甚至更大。火山作用能够将气体直接排入大气中,因此在以往的工作中研究较为充分。但与侵入岩相关的脱碳过程如:矽卡岩化,发生在地下,关于地下脱碳过程如何将碳释放到大气中还缺少详细的工作。本文,通过对比研究火山地区和非火山地区与侵入岩相关的深部脱碳过程,发现深部碳可以通过区域断层系统、地下水系统和热泉、火山通道、隐爆角砾岩筒、高频率的岩浆热液事件等途径瞬时地释放进入大气。通过初步估算,发现单个矽卡岩矿化事件所产生的二氧化碳通量(0.02~0.2Mt/yr)能够与目前地球绝大部分的普通单个火山的碳通量(<0.5Mt/yr)类比。因此岩浆深部脱碳过程对大气的影响至少与火山相当,其对气候的影响不可忽视。 相似文献
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Mathematical Geosciences - 相似文献
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An extension to the DRASTIC model is proposed in order to assess aquifer vulnerability to pollution. In contrast to the DRASTIC
model, which considers the unsaturated and saturated zones together and computes a global intrinsic vulnerability index, the
suggested approach discriminates between the aquifer vertical vulnerability (a concept related to the pollutant percolation)
and the groundwater susceptibility (a concept that depends on the behaviour and uses of the groundwater). This approach is
applied to the Haouz aquifer (Morocco) that supplies water to the Marrakech area. This aquifer is widely overexploited and
there is evidence that the groundwater quality is threatened by various sources of pollution. Evaluation of the vertical vulnerability
indicates that the aquifer mainly presents a moderate-to-weak vertical vulnerability. The zones potentially most favourable
to pollutant percolation are mainly located in Central Haouz, along or near the surface wadis. The aquifer susceptibility
is high in places located near the N’Fis, Baaja and Issil wadis. Everywhere else, low-to-moderate susceptibility is observed.
This new approach therefore enables areas of vertical vulnerability and areas of susceptibility to be delineated separately.
As a result, it constitutes a valuable decision-making tool for optimising the management of aquifer water resources and land-use
planning. 相似文献
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Marc F. Benedetti 《中国地球化学学报》2006,25(B08):269-269
Nowadays, environmental problems related to soil pollution with heavy metals are numerous, therefore, it is important to understand metal behavior in aquatic sediments and soils and to appreciate their transfer. The fate of the metals in the environment is closely related to their interactions with the major reactive compartments （organic matter, iron and manganese oxides, clays）. The objective of this work is to develop an approach based on the combination of several models to study metal ion speciation in different environmental systems. Models used to describe the interactions of metals with the main reactive phases in the soil are CD-MUSIC （amorphous and crystallized iron oxides）, NICA-Donnan （organic matter and manganese oxides）, and cationic ion exchange model （clays）. Firstly, this work implies the definition of generic parameters to describe the interactions of the studied metals with iron and manganese oxides, a part of this information is missing in the literature. Then, after the validation of the approach by comparison with analytical results, this multi-surface model is applied to test sites corresponding to a soil and to two riverine environments. These new models give good predictions of the behavior of major and trace metal ions even in heterogeneous system characteristics of the natural environment. The measured free metal concentrations in the solution are in agreement with those obtained from model calculations. 相似文献
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Nutrient loading to estuaries with heavily populated watersheds can have profound ecological consequences. In evaluating policy
options for managing nitrogen (N), it is helpful to understand current and historic spatial loading patterns to the system.
We modeled N inputs to Narragansett Bay from 1850 to 2000, using data on population, human waste disposal, livestock, fertilizer,
and atmospheric deposition. We found that total N loading to the bay increased 250% from 1850 to 2000, and 80% from 1900 to
2000. Loading to the upper bay increased far more than that to the lower bay, and the most important source shifted from non-point
animal waste to human waste concentrated at sewage treatment facilities. We also modeled future N loads in 2015 under four
management scenarios. Planned improvements in sewage treatment would reduce N loads 9% below business-as-usual, to the 1990
loading rate. Greater reductions, to circa 1900 rates of loading, may be possible. 相似文献
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Nowadays, environmental problems related to soil pollution with heavy metals are numerous, therefore, it is important to understand metals behaviour in aquatic sediments and soils and to estimate their transfer. The fate of metals in the environment is closely related to their interactions with the major reactive compartments (organic matter, iron and manganese oxides, clays). The objective of this work is to develop an approach based on the combination of several models to study metal ion speciation in different environmental systems. Models used to describe the interactions of metals with the main reactive phases in the soil are CD-MUSIC (amorphous and crystallized iron oxides), NICA-Donnan (organic matter and manganese oxides) and cationic ion exchange model (clays). First, this work implies the definition of generic parameters to describe the interactions of the studied metals with iron and manganese oxides and part of this information is missing in the literature. Then, after a validation of the approach by comparison with analytical results, this multi-surface model is applied to test sites corresponding to one soil and two riverine environments.These new models give good predictions of the behaviour of major and trace metal ions even in heterogeneous systems characteristic of natural environment. The measured free metal concentrations in the solution are in agreement with those obtained from model calculations. In the case of the soil test site, the soil solution composition and speciation are predicted using the soil major constituents characteristics. 相似文献
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Der Sarkissian Rita Abdallah Chadi Zaninetti Jean-Marc Najem Sara 《Natural Hazards》2020,103(1):121-137
Natural Hazards - Estimating the resilience of a road network (one of the essential critical infrastructures in times of crisis) to natural hazards is crucial in achieving the goals of disaster... 相似文献