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1.
库车盆地古近纪—新近纪发育巨厚的蒸发岩沉积,根据蒸发岩沉积旋回的变化,即由于盐湖水体由淡—咸—盐—咸—淡的旋回变化,相应地沉积物发生由碎屑岩—膏岩—盐岩—膏岩—碎屑岩的变化。考虑钻井的分布位置及其剖面在时代上的完整性,选取盆地中13口井的钻井剖面进行沉积旋回识别和对比,共识别出5个蒸发岩沉积旋回,其中库姆格列木群两个,苏维依组一个,吉迪克组两个。通过对比,确立了以东秋8井剖面为库车盆地蒸发岩沉积旋回对比的标准剖面。初步分析认为,盆地蒸发岩沉积旋回的沉积区迁移特征,应受盆地基底控制和南北向构造挤压应力变化的影响。古近系蒸发岩主要分布在盆地西部,新近系吉迪克组沉积时期,盆地西北部转为陆源碎屑岩沉积(西南部发育少量蒸发岩),而东部发育巨厚的蒸发岩,显示出东西分带的特点。在始新世末印度板块和欧亚板块碰撞的远距离效应影响下,库车盆地自苏维依组沉积时期蒸发岩沉积中心就已经开始迁移,迁移中心一分为二,自盆地北西分别向南、向东移动,形成两个沉积区,吉迪克组沉积时期在上述两个沉积区继续发育盐岩、膏岩沉积。  相似文献   

2.
库车盆地在古—新近纪时期发育巨厚的蒸发岩沉积,自下而上蒸发岩沉积地层主要有:古近系的库姆格列木组、苏维依组;新近系下部的吉迪克组,依据部分钻井剖面资料,可识别出5个蒸发岩沉积旋回。库姆格列木时期巨厚的蒸发岩沉积(Ⅰ1、Ⅰ2沉积旋回期)是燕山后期相对宁静的大地构造环境反映;苏维依时期蒸发岩沉积(Ⅰ3沉积旋回期)在岩性、沉积范围上发生明显改变,反映了早喜马拉雅构造环境下的不稳定沉积,吉迪克早期巨厚的盐、膏沉积(Ⅰ4沉积旋回期)及沉积区域的继续迁移则反映了早喜马拉雅构造影响仍然存在但已经减弱;吉迪克中期(Ⅰ5沉积旋回期)蒸发岩沉积结束,盐湖沉积转变为陆源碎屑岩夹薄层石膏沉积,以砂、砾为主的山麓相沉积指示了当时山体抬升、遭受剥蚀、快速堆积的沉积环境,反映了相对活动的大地构造环境,是中喜马拉雅构造运动时期的开始。可见,库车盆地的蒸发岩沉积与喜马拉雅构造运动有较好的对应关系,是大区域的构造运动在小区域范围内的地质事件反映。  相似文献   

3.
中新生代盆地蒸发岩沉积旋回对比及库车盆地成钾探讨   总被引:3,自引:2,他引:1  
新疆库车盆地古近纪—新近纪发育巨厚的蒸发岩沉积,古近纪蒸发岩沉积主要发生在盆地西部的拜城凹陷,新近纪吉迪克时期,蒸发岩沉积迁移至盆地东部的康村凹陷。根据剖面及钻井资料,利用蒸发岩沉积旋回,对欧洲莱茵地堑盆地、库车盆地、云南兰坪_思茅盆地、江汉盆地、大汶口等盆地蒸发岩沉积特征进行分析和对比。结合蒸发岩沉积背景及库车盆地钻井资料,对库车盆地成钾影响因素、成钾可能性、成钾层位进行了探讨。研究认为,库车盆地的次级构造单元拜城凹陷、康村凹陷具有成钾的能力,钾盐层应位于Ⅰ2、Ⅰ4蒸发岩沉积旋回的上部。对比研究显示,库车盆地具有成钾的远景和潜力。  相似文献   

4.
新疆库车坳陷发育巨厚的新近系-第四系沉积物。本文通过考察野外露头、观察岩心和岩屑、分析测井曲线和地震资料,研究了该沉积层序及其演化规律。库车坳陷新近系吉迪克组及康村组沉积时期为浅水氧化湖泊环境,自北向南发育扇三角洲-湖泊沉积体系,为均衡沉积;新近系库车组一第四系广泛发育冲积扇沉积,自下而上冲积扇的规模不断增大,代表了盆地填平补齐的过程。库车坳陷新近纪剧烈构造活动期应从库车组末期开始,第四纪早期构造活动达到最剧烈时期。  相似文献   

5.
塔里木盆地古近系层序地层研究   总被引:11,自引:0,他引:11  
运用露头、钻井岩心及测井层序地层学的有关理论方法,对塔里木盆地周边露头及盆地内钻井剖面的古近系进行了详细的沉积学和层序地层学研究,共识别出6个三级层序界面,把塔里木盆地古近系划分为5个三级层序。其中,古新世-始新世早期(库姆格列木群沉积期)发育3个层序,从下到上为S1,S2和S3。S1大致相当于库姆格列木群底部的砾岩段、膏泥岩段到白云岩段,在塔西南地区相当于土依洛克组。S2和S3大致相当于库车坳陷库姆格列木群上部两套膏盐岩段以及塔西南坳陷阿尔塔什组-齐姆根组及卡拉塔尔组-乌拉根组的两套膏盐岩段。始新世晚期-渐新世(苏维依组沉积期)发育1~2个三级层序,即S4和S5。S4相当于库车坳陷的苏维依组和塔西南坳陷巴什布拉克组的主体,S5仅在部分钻井中见到,以苏维依组顶部局部发育的扇三角洲相砂砾岩为代表。在这些层序中,低位体系域往往以发育扇三角洲分流河道及辫状河道相砂砾岩以及咸化潟湖或蒸发台地相厚层膏盐岩为特征,而水进体系域多以滨浅湖相泥岩和粉砂岩为主,高位体系域则主要为碳酸盐岩及富泥质的沉积序列。  相似文献   

6.
新疆库车坳陷古近纪发育巨厚的蒸发岩沉积,厚度从几十米至上千米不等。主要蒸发岩沉积(特别是石盐岩沉积)发生在古新世-始新世的库姆格列木群沉积期。依据3Dmine矿业工程软件、库车坳陷地形点三维坐标统计数据、部分钻井数据(包括孔位、孔深、孔斜)、石盐岩层在钻井中的沉积厚度及蒸发岩沉积旋回,对坳陷库姆格列木群蒸发岩沉积期石盐岩空间展布进行研究,绘制库车坳陷古新统-始新统石盐岩空间分布模型,探讨盆地找钾意义。通过石盐岩空间模型展布特征分析,石盐岩体与库车坳陷的地形特征和构造特征紧密相关,石盐岩受构造挤压并于与地形的总体起伏基本一致。从石盐岩体空间模型南北向剖面变化规律分析,古新世-始新世,库车坳陷西部出现2个蒸发岩沉积中心,分别位于西盐山口盐场一带和拜城凹陷。为库车次级古盐湖发育区,而钾盐的富集一般产于大的坳陷当中的次级构造单元,为有利的找钾区域。  相似文献   

7.
全球性的构造运动末期一般伴着海退和干旱的气候环境,而蒸发岩沉积与大地构造条件紧密相关。中亚卡拉库姆盆地、阿富汗_塔吉克盆地、塔里木盆地自晚侏罗世至中新世以来至少发生了3次大规模海侵_海退旋回,每次海侵_海退均受特提斯构造事件控制。卡拉库姆盆地、阿富汗_塔吉克盆地为晚侏罗世—早白垩世蒸发岩沉积、塔里木盆地的莎车次级盆地为晚白垩世—古新世蒸发岩沉积,库车次级盆地为古新世—中新世蒸发岩沉积,形成特提斯构造域自西向东蒸发岩沉积时代逐渐变新的盐湖链。中亚及塔里木盐湖链在海侵_海退旋回的控制下,至少发生5次大规模的蒸发岩沉积,发育2种不同的蒸发岩沉积序列,分别对应3次海退期蒸发岩沉积序列及2次断续海侵期蒸发岩沉积序列,具体为晚侏罗世晚期(海退期)卡拉库姆盆地、阿富汗_塔吉克盆地蒸发岩沉积;早白垩世—晚白垩世早期(断续海侵期)阿富汗_塔吉克盆地蒸发岩沉积;晚白垩世晚期(海退期)莎车次级盆地蒸发岩沉积;古新世—中新世(断续海侵期)莎车次级盆地、库车次级盆地蒸发岩沉积;中新世晚期—上新世早期(海退期)库车次级盆地蒸发岩沉积。塔里木与中亚古盐湖发育受控于特提斯构造事件及海侵_海退旋回,而海侵_海退旋回又控制2种不同的蒸发岩沉积序列。蒸发岩沉积序列、古盐湖演化阶段、蒸发岩物质来源、沉积环境决定了盐类矿物沉积类型(单一化学岩型、陆缘碎屑岩_化学岩型),卡拉库姆盆地、阿富汗_塔吉克盆地盐类矿物与塔里木盆地相比,种类简单,反映了盆地化学岩与陆源碎屑_化学岩沉积的区别及后期构造运动对盐类矿物种类的主控作用。  相似文献   

8.
库车盆地内古近系—新近系发育巨厚的蒸发岩沉积, 尤其是盆地的中部和西部盐层发育好, 厚度大, 局部盐层己暴露地表, 是找寻各种盐类矿床及钾盐的有利地区。DZK01孔是近年来在库车盆地实施的一口以找钾为目的的科研探井。本文主要通过对钻孔古近系蒸发岩岩芯样品进行岩石学及矿物学特征研究, 进而对盆地成钾环境进行分析。DZK01孔古近系蒸发岩以含泥砾石盐岩为主, 含泥砾石盐岩为构造成因, 是古盐湖高度浓缩的产物。盆地古近系蒸发岩以沉积石盐为主, 钻孔中含钾矿物为钾石膏, 钾石盐和光卤石, 同时含钾矿物的发现证明了库车盆地古盐湖可能达到钾盐析出阶段。通过样品分析可知, 库车盆地古近纪时期古盐湖沉积环境为封闭的浅湖沉积环境, 盐湖发育过程中有五次较大规模的淡化事件, 盐类物质得到很好的聚集, 具有良好的成钾环境。  相似文献   

9.
柴西南英西地区下干柴沟组上段为一套湖盆含蒸发岩系。文章综合运用薄片、岩心、钻井、测井、化验分析等资 料,对研究区下干柴沟组上段蒸发岩系沉积旋回特征进行了研究。研究表明,平面上由盆地中心向边缘呈现蒸发岩-混积 型碳酸盐岩-碎屑岩的环带状分布,纵向上发育2 个三级旋回及6 个四级旋回期次。各级蒸发岩沉积旋回具有不对称的特 征,即快速湖侵、缓慢湖退。总结出研究区的五种蒸发岩岩相组合类型。研究区蒸发岩为气候干旱、盆地基底快速沉降背 景下,湖退时残留盐湖中以蒸发结晶为主具有一定水深的成因,并建立了沉积旋回发育模式。  相似文献   

10.
新疆拜城新近系含铜岩系沉积体系及沉积环境   总被引:1,自引:1,他引:0  
新疆拜城地区发育一套新近纪巨厚的陆相碎屑沉积岩系,其中康村组中上部含规模较大的沉积型铜矿,康村组的沉积环境及演化过程对铜矿的形成具有重要意义。基于野外和室内详细的沉积学研究,查明研究区新近系吉迪克组、康村组和库车组总体上为陆相沉积体系,主要包括冲积扇-扇三角洲沉积体系和湖泊沉积体系两大类型,划分为扇三角洲平原、扇三角洲前缘、前扇三角洲、滨浅湖和膏盐湖亚相及若干沉积微相。研究表明研究区康村期主要发育扇三角洲沉积,矿区主要含矿层位于康村组上部红色岩系向灰色岩系转变,沉积环境从扇三角洲前缘亚相到滨浅湖亚相过渡的层位上。  相似文献   

11.
Bristol Dry Lake, a 155 km2 continental-sabkha playa basin in the Mojave Desert of south eastern California, is filled with at least 300 m of interbedded terrigenous clastics, gypsum, anhydrite, and halite. Evaporite facies conform approximately to a bull's eye pattern with gypsum and anhydrite surrounding a basin centre accumulation of halite. Transects through Bristol Dry Lake, from the alluvial fan to the centre of the playa, reveal: (1) crudely-bedded, alluvial fan clastics interfingering with (2) playa-margin sand flat and wadi sand and silt, followed by (3) gypsum, anhydrite, chaotic mud halite, and clay of the saline mud flat, and (4) salt-pan halite beds. Terrigenous clastics were deposited in Bristol Dry Lake by sheetflow and by suspension settling from ponded floodwater. Some sediment has been reworked by aeolian processes to form barchan dunes around the playa margin. Thin nodular-like beds of anhydrite and several types of gypsum occur across most of the playa. Giant hopper-shaped halite cubes are suspended in saline mud flat facies, suggesting that they grew displacively in brine soaked sediment just below the surface. Thick beds (4 m) of halite, in the playa centre, may have formed through a complex alternating history of subaqueous and intrasedimentary precipitation under the influence of periodic floods, intense evaporation and brine-level lowering, and capillary discharge of brines. The stratigraphy in the playa centre is cyclic. An ideal cycle consists of: (1) chaotic mud halite at the base overlain by (2) green to red clay with abundant, giant hoppers, and at the top (3) red clay, gypsum, and anhydrite with flaser- to wavy-bedded sand and silt. This type of cycle probably records a gradual progradation of mud-flat facies over salt pans. Bristol Dry Lake sediments are nearly identical to some of the Permian evaporites of the Permian Basin region, U.S.A. and they can serve as modern analogues for ancient-sabkha facies analysis.  相似文献   

12.
新疆莎车盆地古新世断续海侵环境下发育阿尔塔什组巨厚的石膏岩,古新世早期盐湖沉积范围位于西昆仑及南天山山前,伴随着后期海侵范围的进一步扩大,盐湖沉积范围覆盖整个莎车盆地.论文通过对西昆仑及南天山山前5口石油钻井剖面中阿尔塔什组含盐系地层开展钻孔岩屑地球化学分析,认为古新世早期盐湖中钾、钠、钙、镁、硫酸根变化趋势基本符合盐...  相似文献   

13.
Messinian evaporites, which resulted from the salinity crisis during the final closure of the Mediterranean Sea, are exposed in SE Turkey. These evaporites formed in two isolated sub-basins, Iskenderun-Arsuz (IA) and Hatay-Samanda? (HS), which belong to different depositional configurations and tectonic structures. The Neogene fill of these sub-basins consists of a thick sedimentary succession that started with Early Miocene terrestrial clastics, followed by reefs (Middle Miocene) and shallow water siliciclastics (Tortonian - Early to Late Miocene) and finally Messinian evaporates. These sub-basins accumulated in a diverse range of depositional environments from very shallow to deeper water. Evaporite facies in the IA sub-basin consist of sabkhas, saline lagoons and ponds. They are mainly represented by chemical deposits such as scattered gypsum nodules and balls, nodular bedded gypsum, laminated gypsum (Type-A) and selenites (Type-S1). Evaporites in the HS sub-basin mainly consist of detrital gypsum composed of gypsum laminae (Type-B, C), gypsum arenite-rudites and deeper water selenites (≤ 20 m), and resedimented selenites (Type-S2), which were deposited on a sulfate platform with a slope-basin transitional zone. Secondary gypsum with alabastrine and porphyroblastic textures as well as satin spar veins is commonly associated with the sabkha-type evaporites of the IA sub-basin. Deeper-water clastic evaporites of the HS sub-basin have generally remained as primary gypsum or have only been slightly affected by diagenetic alterations. The isotope values (87/86Sr; δ18O SMOW; and δ34S CDT) from the different kinds of gypsum lithofacies of the sub-basin are similar to those of the Messinian evaporites in other peri-Mediterranean basins, indicating an origin from marine water without external or basinal contributions.The Messinian evaporites examined in this paper are overlain by Early Pliocene (Zanclean) deposits composed of shallow- and deep-water siliciclastics and carbonates with local intercalations of Lago-Mare-type strata. Throughout the Messinian evaporitic stage, the IA sub-basin was mainly comprised of shallow water evaporites, while the HS sub-basin underwent deepening related to regional tectonics induced by the Dead Sea Fault during the construction of the Hatay Graben.  相似文献   

14.
唐山曹妃甸浅层水咸化机制及反向模拟   总被引:2,自引:0,他引:2  
王聪  梁杏  李静 《地质科技情报》2012,31(3):104-108,115
采集了唐海至渤海湾剖面的13组水样,分析了研究区浅层地下水的化学特征及成因机制.运用Phreeqc软件反向模拟了地下水流路径上浅层微咸水(咸水)的补给机理及咸化过程.结果显示:浅层地下水由北向南,ρ(TDS)由0.36 g/L逐渐上升到39.2 g/L,水化学类型从HCO3·Cl-Ca·Mg·Na型过渡为Cl· HCO3-Na型再转变为Cl-Na· Mg型.微咸水形成以咸淡混合为主,期间伴随着岩盐、斜长石、CO2、高岭石、钾长石、石膏的溶解及钙蒙脱石、方解石的沉淀析出.咸水形成初期主要受海水入侵影响,后期受蒸发作用影响又进一步咸化.  相似文献   

15.
东濮凹陷北部盐湖相膏盐岩极其发育,膏盐岩对烃源岩性质及生烃特征的影响研究薄弱。采用地质与地球化学相结合途径,探讨了含膏盐岩层系烃源岩特性及其成烃演化规律。结果表明,盐区与无盐区烃源岩的特性有很大差异,北部盐湖相含盐区深灰色、褐色等暗色页岩有机质丰度一般大于15%,有机质类型以Ⅱ1型和Ⅰ型为主,是区内主要的优质烃源岩;南部淡水湖相无盐区主要发育有利生气的Ⅱ—Ⅲ型干酪根,反映东濮凹陷烃源岩的质量及生烃潜能与膏盐岩的发育密切相关。观察到膏盐岩影响烃源岩的成烃演化进程,当膏盐层厚度为50 m时,生油窗的范围显著增加;随着盐岩厚度(>50 m)的增加,湿气窗的范围也逐渐增加;当膏盐岩厚度约400 m时,生油窗范围开始减小,湿气窗的范围仍有增加趋势。膏盐岩对烃源岩“生油气窗”的影响是基于其较高的热导率属性,通过影响地温场而实现。以地质解剖为依据,建立了文留地区含膏盐岩层系烃源岩成烃演化模式。东濮凹陷含膏盐岩层系烃源岩的演化特征对该凹陷及同类含膏盐岩盆地油气勘探具有重要指示意义。  相似文献   

16.
西部干旱地区节水钻探的新思路及其配套技术   总被引:1,自引:0,他引:1  
钻探过程需要消耗大量的地表水.为解决干旱地区工程型缺水的问题,提出了基于孔内地层水局部循环的节水钻探新思路;论述了以脉动器和潜水柱塞泵为主的节水钻探关键技术及其结构设计和参数设计;研讨了开发配套技术的必要性,提出了解决管线刚度和气泡问题、提高吸水效率、对反向行程水击的补偿等6项配套技术.中国属于严重缺水国家,利用地层水实现孔内局部循环钻进是经济、环保的好方法,生产试验表明借助中俄合作开发的节水钻探新思路,达到了既节水5~20倍,又不扰动地层,还能提高钻探效率的目的.  相似文献   

17.
The late Permian to Triassic sediments of the Solway Basin consist of a layer-cake succession of mature, predominantly fine-grained red clastics laid down in semi-arid alluvial plain to arid sabkha and saline marginal marine or lacustrine environments. The Cumbrian Coastal Group consists of Basal Clastics and Eden Shales. The Basal Clastics are thin regolith deposits resting unconformably on all-underlying units and are composed of mixtures of angular local gravel and far-transported fine to very fine-grained sands deposited as basal lag. The Eden Shales are predominantly gypsiferous red silty mudstones, with thin very fine-grained sandstone beds, and with thick marine gypsum beds at the base, deposited at a saline lake margin. The overlying Triassic Sherwood Sandstone Group consists of the Annan and Kirklinton Sandstones. The Annan Sandstones are predominantly thick-bedded, multi-storied, fine-grained mature red quartz sandstones in which coarse sand is practically absent despite channels with clay pebbles up to 30 cm in diameter. The overlying, predominantly aeolian, Kirklinton Sandstones consist of festoon cross-bedded and parallel-laminated fine-grained sandstones, almost identical to the Annan Sandstones except that mica and clay are absent. The Stanwix Shales, located above, consist of interbedded red, blue and green mudstones, siltstones, and thin very fine-grained sandstones, with gypsum layers. Although the entire succession can plausibly be interpreted as deposited in a large desert basin opening into a hypersaline marine or lacustrine embayment to the southwest, the uniformly fine-grained nature of the succession is unusual, as is the absence of paleosols, and body and trace fossils. There is almost no coarse sand even in the river channel units, and it seems likely that the basin was not only extremely arid but supplied predominantly by wind rather than water.  相似文献   

18.
文章利用钻井岩心、岩石薄片、测井、地震资料对塔里木盆地沙雅隆起北部三道桥气田潜山的地层格架、岩石岩相特征进行分析,并通过钻井岩心样品的锆石U-Pb年代学和野外地质露头地层对比研究,对这套潜山地层的时代进行了限定。研究结果表明三道桥潜山是一套厚度在700~800 m,浅变质的海相碎屑岩-碳酸盐岩沉积,3个碎屑锆石样品的最小谐和年龄为(1522±16)Ma,表明其沉积或成岩时代应不早于中元古代。该潜山是迄今为止塔里木盆地内获得工业油气的最古老的潜山。  相似文献   

19.
Hydrogeochemistry of the Saloum (Senegal) superficial coastal aquifer   总被引:1,自引:0,他引:1  
Seawater has entered and concentrated in the Saloum hydrologic system up to 100 km upstream, contaminating both the surface water and the superficial 'Continental terminal' (CT) groundwater resources, and large proportions of cultivated lands. In the areas affected by saltwater contamination, chloride concentrations as high as 3,195 mg/l have been measured in the groundwater samples collected from wells located in the vicinity of the Saloum River, making the water inadequate for drinking water purposes. This paper presents the results of a study designed to characterise the current extent of the saline groundwater and the mechanism of saline surface water body/fresh groundwater mixing in relation to the groundwater flow trends. It also describes the groundwater chemical and isotopic composition and geochemical processes controlling the chemical patterns. Four major water types occur in the study area, namely Na-rich saline groundwater, Ca-Na-rich saline groundwater, Na-dominant fresh groundwater and Ca-dominant fresh groundwater. A hydrogeochemical zonation of the aquifer, based on the presence of different water families and on the groundwater flow, led to the identification of the main processes controlling the groundwater chemistry. Cation exchange reactions on the kaolinite clay mineral, calcite dissolution in the eastern zone where calcite minerals have been identified, reverse cation exchange reactions in the saline-contaminated band along the Saloum River and, to a lesser extent, a gypsum dissolution are the predominant processes. Results of i18O and iD analysis in 15 groundwater samples compared with the local meteoric line indicate that the groundwater has been affected by evaporation, and the groundwater is isotopically lighter as the depth of water table increases. In this study, i18O data were used in conjunction with chloride data to identify the source of high chloride. Results show a departure of the contaminated water samples from the seawater mixing line, which indicates that other processes rather than mixing between modern seawater and native groundwater alone increase the chloride concentrations.  相似文献   

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