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1.
内波、内潮汐沉积和复合流沉积是二十余年来在古代深水环境中新发现的一种具牵引流性质的沉积相类型,由于地层沉积记录十分有限,制约了深水底流沉积的沉积学研究。大比例尺实测地质剖面和精细露头测量表明,底流沉积发育于凭祥盆地深水沉积之中,通过对其沉积构造精细剖析和古水流测量,识别出内波、内潮汐沉积和复合流沉积,其中内波、内潮汐沉积以双向交错层理、单向交错层理、透镜状层理为特征,复合流沉积以复合流层理、丘状交错层理和较陡的爬升波纹层理为特征,进一步表明存在浊流和底流的交互作用,为古代地层中的深水底流沉积提供了又一研究实例。  相似文献   

2.
包卷层理是软沉积物变形构造的一种重要类型,其成因较为复杂。在深水沉积环境中,探讨内波、内潮汐作用与包卷层理成因之间的关系,对于丰富包卷层理形成机制和完善内波、内潮汐沉积鉴别标志均具有重要意义。鄂尔多斯盆地西缘北部内蒙古桌子山地区上奥陶统拉什仲组阻塞浊流沉积中发育的包卷层理,依据形态可分为倾向型规则包卷层理和回旋状包卷层理2类: 前者具有紧闭背形、开阔向形及背形之下发育砂核等特征,常和双向交错层理伴生; 后者属于层内扭曲变形,多限定在具有削截现象的层系内,常和复合流沉积构造及浪成波纹层理伴生。综合沉积特征、包卷层理特征、伴生沉积构造及相关研究成果可推测: 倾向型规则包卷层理主要由内潮汐形成,在液化过程中出现明显的密度倒置,因瑞利—泰勒不稳定引起变形,在流体持续剪切作用下进一步改造形成; 回旋状包卷层理主要由短周期内波形成,包括浊流反射形成的随机内波和内潮汐裂解形成的内孤立波,表现为同沉积分层液化,但一般不出现密度倒置现象,因开尔文—亥姆霍兹不稳定引起变形,流体剪切也有一定的改造作用。  相似文献   

3.
波—流相互作用是复杂水动力条件下流体相互作用的主要方式之一,由波—流相互作用形成的复合流沉积是目前沉积学在流体相互作用这一领域研究较多的一种沉积类型。以已有的文献为基础,对波—流相互作用下细砂级颗粒的运动机制进行了综述,预测了波—流相互作用的沉积特征,总结了复合流的沉积构造鉴别标志。取得的主要认识有: (1)波—流相互作用总体上属于衰弱流(waning flow)悬浮沉积,其微观的沉积机制可分为5种: 越过崩落点的喷射沉积(S1)、残余涡动沉积(S2)、未到崩落点的喷射沉积(S3)、背流面的崩落沉积(S4)、垂直降落沉积(S5);(2)波—流相互作用的沉积过程总体上受悬砂量和沉积时间的控制,5种微观沉积机制在不同的悬砂量和沉积时间条件下可形成不同的沉积机制组合,从而导致不同的底床形态;(3)复合流沉积构造鉴别标志主要有: 复合流波痕、复合流层理、爬升型复合流层理、不对称丘状交错层理、准平行层理和频繁交替的不能充分发育的浪成波纹层理与流水层理等6类。上述认识对于复杂水动力条件下的沉积学研究及对深水、浅水沉积环境的识别均具有重要的意义。  相似文献   

4.
宁夏中奥陶统香山群徐家圈组内波、内潮汐沉积类型   总被引:1,自引:1,他引:0  
内波、内潮汐沉积是深水沉积研究中一个非常年轻的研究领域,自发现到现在仅仅20年时间,对其沉积类型的研究目前尚未涉及。以宁夏香山群徐家圈组中的内波、内潮汐沉积为对象,详细描述了深水环境中形成的双向交错层理、单向交错层理、复合流层理及具有波状纹层、束状纹层和交错纹层透镜体的交错层理,并探讨了其成因机制,识别出了短周期内波沉...  相似文献   

5.
Hummocky cross-stratification is a sedimentary structure which is widely interpreted as the sedimentary record of an oscillatory current generated by energetic storm waves remobilizing surface sediment on the continental shelf. Sedimentary structures named hummocky cross-stratification-like structures, similar to true hummocky cross-stratification, have been observed in the Turonian–Senonian Basque Flysch Basin (south-west France). The bathymetry (1000 to 1500 m) suggests that the observed sedimentary structures do not result from a hydrodynamic process similar to those acting on a continental shelf. The morphology of these three-dimensional structures shares similarities with the morphology of hummocky cross-stratification despite a smaller size. The lateral extent of these structures ranges from a few decimetres to many decimetres; they consist of convex-up domes (hummock) and concave-up swales with a non-erosive base. Four types of hummocky cross-stratification-like geometries are described; they occur in association with structures such as climbing current ripple lamination and synsedimentary deformations. In the Basque Flysch, hummocky cross-stratification-like structures are only found in the Tc interval of the Bouma sequence. Hummocky cross-stratification-like structures are sporadic in the stratigraphic series and observed only in few turbidite beds or bed packages. This observation suggests that hummocky cross-stratification-like structures are linked genetically to the turbidity current but form under a very restricted range of parameters. These structures sometimes show an up-current (upslope) migration trend (antidunes). In the described examples, they could result from standing waves forming at the upper flow interface because of Kelvin–Helmholtz instability.  相似文献   

6.
鄂东黄石地区下三叠统大冶组风暴沉积   总被引:1,自引:3,他引:1  
鄂东黄石地区下三叠统大冶组灰岩中发育了典型的风暴沉积,风暴岩由砾屑灰岩、颗粒灰岩和泥灰岩组成,其中风暴沉积构造包括丘状交错层理、递变层理、砾屑的撕裂构造及水平层理等,不同层位具有不同的风暴沉积构造类型和组合特征。根据风暴沉积的岩石特征、构造类型、规模、组合特点,并结合沉积背景分析,风暴沉积序列可进一步分为深水远源型、过渡型和浅水近源型。大冶组一段风暴沉积具有深水远源特点,沉积环境为水体较深的外陆棚; 大冶组二段风暴沉积具有过渡型特点,沉积环境为向上变浅的内陆棚; 大冶组三、四段风暴沉积具有浅水近源特点,沉积环境为浅水陆棚至滨岸。大冶组沉积序列具有向上变浅的特点,沉积环境由深水陆棚逐渐向滨岸转变。风暴沉积的识别对重建鄂东黄石地区早三叠世古地理具有重要意义。  相似文献   

7.
The Gongila Formation in the Hawal Basin displays lithological characteristics, textural variations and sedimentary structures that facilitate palaeoenvironmental reconstruction. The 41 m thick Gongila succession is divisible into: (i) a mudstone facies association (at the bottom) composed of fossiliferous limestone, clay shale, and sharp-based, graded and swaly-bedded shell debris; and (ii) a cross-stratified sandstone facies association that constitutes the uppermost 60% of the entire succession. The cross-stratified sandstone facies association is further subdivided, on the basis of sedimentary structures, into: (i) a lower interval represented by a coarsening upward fine- to medium-grained sandstone, siltstone and shale in which units characterised by parallel lamination and hummocky cross-stratification pass upward through a zone of small-scale low angle cross-stratification into units characterised by planar cross-stratification and sparse Teichichnus and Skolithos burrow traces; and (ii) an upper interval dominated by fine- to medium-grained sandstone and bioturbated siltstone characterised by erosive based, high angle tangential foresets, subhorizontal laminations and burrow structures belonging to the Thalassinoides, Ophiomorpha and Skolithos ichnogenera.The overall sequence of the Gongila Formation represents progradation on a wave influenced coast, passing from shelf mudstone at the base to lower and upper shoreface sandstones at the top. Each facies association displays an alternation between relatively high energy conditions when sediment was mainly deposited by decelerating suspension laden currents, and relatively low energy conditions when wave reworked fine-grained sediment as it was deposited from suspension. The influence of storms in these conditions is inferred from the associated lithofacies, textural characteristics and sedimentary structures.  相似文献   

8.
塔里木盆地苏盖特布拉克地区下寒武统肖尔布拉克组发育较为典型的风暴岩。风暴沉积标志主要有冲刷充填构造、风暴砾屑层和丘状交错层理等。在野外实测和室内薄片观察基础上,依据风暴沉积物、沉积位置和沉积标志组合的不同,划分出5种风暴沉积序列。序列Ⅰ为mm级或cm级的递变纹层,截切深水微生物礁,为风暴浪基面以下的深水陆棚远源风暴浊流沉积;序列Ⅱ发育异地型风暴砾屑、粒序段、平行纹层段和水平层理黑色钙质页岩,为风暴浪基面与晴天浪基面之间的缓斜坡下部沉积;序列Ⅲ为风暴成因的生屑、砾屑与平行纹层、丘状纹层的组合,多出现在风暴浪基面与晴天浪基面之间的缓斜坡上部;序列Ⅳ以渠模与复合丘状交错层理的组合为特征,为水体较浅的晴天浪基面附近的沉积;序列Ⅴ由风暴砂砾屑及沉积充填构造、平行纹层段组成,上部单元为正常天气沉积的蓝细菌礁滩垮塌体,为晴天浪基面以上的台地边缘礁滩前缘沉积。风暴层序自下而上的沉积环境演化为深水陆棚→浅水陆棚缓斜坡下部→缓斜坡上部→台地边缘前缘,形成向上变浅沉积特征。风暴岩的发现和研究,对于塔里木早寒武世古纬度与古板块演化、古地理及沉积学研究具有重要意义。  相似文献   

9.
李向东  魏泽昳  陈洪达 《地质学报》2023,97(4):1278-1294
虽然地层记录中的内波和内潮汐沉积研究已有30年的研究历史,但尚未涉及深水环境中内波和内潮汐成因研究,不利于对深水复杂水动力环境下各种流体交互作用的深入研究,同时由于已发现研究实例中缺乏生物化石和遗迹化石,从而在很大程度上限制了对内波和内潮汐沉积和油气生成及运移之间的关系研究。本文以鄂尔多斯盆地西缘北部桌子山地区上奥陶统拉什仲组深水沉积为研究对象,在详细的野外观察基础上,采用沉积地球化学和沉积学相结合的方法对该组中发育的内波和内潮汐沉积进行了综合研究。结果表明:拉什仲组中的双向交错层理和浪成波纹层理可相互伴生,多发育在完全或近于完全的鲍玛序列Tc段,其寄主岩性主要为灰绿色薄-中层细砂岩、粉砂岩、黏土质粉砂岩和粉砂质黏土岩;沉积时水体介质具有海水性质总体上不明显、氧化-还原分层、盐度倒置、不受热液影响和水动力较强等现象。结合拉什仲组存在的浊流反射现象认为:拉什仲组沉积于局限海深水斜坡至盆地环境,其内波和内潮汐的形成与低密度浊流反射形成的密度跃层密切相关,具有事件性作用特征,并伴生有大量的生物化石(笔石)及遗迹化石。这种新型内波和内潮汐沉积对于深水牵引流沉积油气勘探具有...  相似文献   

10.
Primary sedimentary structures exhibiting the diagnostic criteria for single sets of hummocky cross-stratification (Harms et al.) have been found in the surf zone of a storm-wave dominated coastline in the Canadian Great Lakes. Epoxy peels of box cores (0.45 m × 0.30 m) reveal hummocky stratification in well-sorted, fine-grained sands in water depths less than 2 m under conditions of wave breaking and strong longshore currents. The wavelengths of the hummocks (0.3–0.6 m) are somewhat smaller than the norm for their ancient analogues, but the ratios of length to height (8–12) are comparable. Depth of activity rods have been used to identify those hummocks that formed during sediment transport events when the near-bed currents were recorded directly using electromagnetic flowmeters. Results from such experiments clearly identify the hummocky stratification as being produced by an actively growing bedform with little or no lateral migration. Hummocks occur under conditions close to that expected for the upper flat bed. In one vertical sequence, the hummocky cross-stratification is underlain by subhorizontal, planar lamination and overlain by undulatory lamination which grades upward into small-scale, trough cross-lamination of wave ripple origin. This sequence was associated with a single storm and would appear to represent a combined-flow regime sequence with the hummocky structure representing a post-vortex (?) ripple bedform. At the inferred time of hummock formation, near-bed oscillatory flows were dominant and reached maxima of 1.1 m s ?1 with a superimposed longshore current of 0.27 m s?1. Rapid sedimentation associated with vertical growth of the hummocky bedform was triggered by a significant reduction in the orbital currents (by 19%) and'steady'currents (by 67%) while the total bed shear remained high.  相似文献   

11.
Geological domains in northeastern India evolved though time after the rupture of the Gondwanaland. Collision of the Indian and the Burmese plates took place during the middle part of Cretaceous. Evolution of the Paleogene Barail trough, Neogene Surma and Tipam Groups took place gradually. The Barail trough originated at the active margin of the Indo-Burmese plate convergence. Previously, the Barail sedimentary wedge was interpreted to have been deposited in a deltaic to shallow-marine environment. Latter studies have proposed a new depositional model. The Barail Group, a part of the Assam-Arakan Orogen comprises the lowermost Laisong Formation, middle Jenam and upper Rinji Formation. Most of the Paleogene strata of the Barail Group carry imprints of a deep-water submarine fan near an active subduction zone. A deep-water proximal- to mid-fan depositional setting has been ascribed to the lower Laisong strata. Facies analysis of the extensive exposures of the Jenam Formation, near the Jenamghat, Assam, have enabled a detailed reconstruction of a proximal to mid-part of a submarine fan under an overall influence of turbidity currents and debris flow, ultimately evolving into turbidity currents. The Jenam sedimentary wedge bears tell-tale preservation of olistostromes (chaotic facies) with abundant volcaniclastics and basic rock fragments, massive sandstones, conglomeratic sandstone to sandstone-siltstone-shale and sandstone-siltstone-mudstones with profuse turbidites. Facies attributes amply signal the inherent instability of the Barail trough owing to its location near an active subduction zone. The Jenam suite of rocks containing a strong impress of volcanogenic materials along with quartzo-feldspathic rocks were mixed up by turbidity currents and shed into the submarine environment as the Jenam deep-water turbidites.  相似文献   

12.
鄂尔多斯盆地西缘桌子山地区中奥陶统克里摩里组下段以深灰色薄—中层石灰岩夹灰黑色极薄层泥岩为特征,石灰岩单层略显透镜状且基本未受后期成岩作用改造,其中石峡谷剖面垂向上特征变化明显,是研究该组沉积过程的理想剖面。本次研究在详细的野外观察基础上,依据岩石特征和沉积构造进一步确认克里摩里组深水斜坡沉积背景和等深流沉积,同时详细研究了薄—中层石灰岩的充填特征和形态特征,探讨其水动力特征和沉积机制。结果表明: (1)在粉晶石灰岩和灰泥石灰岩中,晶粒呈散点状分布,粉晶之间为灰泥充填,同时岩层内部具有不均一性,粗粉晶、细粉晶和灰泥呈相间分布;(2)石灰岩主要发育和单层内粒度(方解石晶粒)变化有关的沉积构造,包括具有双向递变特征的粒序层、条带状构造和水平层—均匀层—水平层序列;(3)石灰岩层中透镜体发育,包括薄层中的小型连续透镜体、中层(一般小于30cm)中的长透镜体以及由多个石灰岩层组成的透镜体,后者侧向上尖灭于页岩或地形高处,其内部单个岩层可呈对称性尖灭;(4)剖面上发育单层石灰岩厚度向上变薄的垂向序列以及由该序列组成的石灰岩叠置层。结合已有研究成果认为: 克里摩里组下段薄—中层石灰岩沉积于深水底流发育环境,其水动力具有低速、弱—强—弱周期变化和空间上受限的特征,应为等深流水道沉积,其沉积机制可分为3个阶段,即等深流作用前的清水钙质沉积、等深流作用期间对沉积物的改造和等深流作用后的浑水泥质沉积。  相似文献   

13.
塔中地区中—上奥陶统内波内潮汐沉积与油气勘探   总被引:1,自引:0,他引:1  
现代海底普遍发育由内波、内潮汐引起的深水牵引流,内波、内潮汐不仅可形成各种小规模、分散的深水牵引流沉积,而且还可建造千米级的大型沉积物波。在古代地层记录中已发现各种厘米级的内波、内潮汐沉积单元,但尚未发现内波成因的大型沉积物波。通过对塔中地区中—上奥陶统碎屑岩段岩心观察和地震剖面的系统分析,发现了该岩段内由内波和内潮汐作用形成的各种牵引流沉积构造单元。已识别出4种内波、内潮汐沉积微相类型及5种基本垂向沉积层序,同时还在研究区中一上奥陶统陆坡相中识别出了内波成因的大型沉积物波。这些内波、内潮汐沉积具有较好的油气潜能,是该区中—上奥陶统潜在的油气勘探新领域。  相似文献   

14.
风暴岩对于古地理和古环境具有良好的指相意义。东海盆地西湖凹陷天台区始新世平湖组发育典型的风暴岩。通过详细的岩心观察,发育的风暴沉积标志主要有冲刷-充填构造、风暴撕扯构造和丘状-洼状交错层理构造等。根据风暴岩垂向上的组合特征及沉积构造差异,识别出了近源和远源两种风暴沉积类型,分别指示了不同的沉积背景:近源风暴岩表现为不完整的风暴岩垂向沉积序列,呈风暴砾屑层段(A)+泥岩段(E)叠加,为潮坪潮下带沉积;远源风暴岩具完整和不完整的风暴岩垂向沉积序列,以粒序段(B)+平行层理段(C)+丘状(洼状)层理段(D)叠加为特征,属浅海陆棚沉积。风暴层序自下而上沉积环境为浅海陆棚→潮坪,风暴岩的分布差异表明形成环境向上变浅的沉积特征。该发现为本区古环境的演变提供了重要依据。  相似文献   

15.
川西汉旺地区雷口坡组四段风暴岩特征及地质意义   总被引:2,自引:2,他引:0  
赵聪  刘树根  宋金民  唐玄  赖冬 《沉积学报》2019,37(1):94-103
通过野外实测剖面和镜下薄片观察,川西汉旺地区雷口坡组四段发育典型的风暴岩,具有底冲刷—充填构造、风暴砾屑层、菊花构造和丘状交错层理等典型风暴沉积标志。根据该风暴岩岩性、沉积位置、沉积标志组合特征,共识别出三种风暴沉积序列类型:1)序列Ⅰ由侵蚀底面及砾屑段、粒序段组成,代表靠近风暴浪基面附近的台前缓斜坡下部环境; 2)序列Ⅱ由侵蚀底面及砾屑段、粒序段、平行纹层段、丘状纹层段组成,代表靠近正常浪基面附近的台前缓斜坡上部环境; 3)序列Ⅲ由粒序段、平行纹层段组成,代表台地边缘环境。风暴层序自下而上的沉积演化为:台前缓斜坡下部—台前缓斜坡上部—台地边缘,整体为一个向上变浅的沉积序列。  相似文献   

16.
等深流沉积是深水环境中牵引流沉积的重要类型之一。虽然研究程度相对较高,但主要以深海测量和大洋钻探为平 台对现代海洋中的等深流进行研究,特别是大洋钻探339航次的执行,将等深流沉积研究推向一个新的阶段(等深岩丘结 构剖析),而对地层记录中的等深流沉积研究却非常薄弱,从而也制约了对等深流沉积的研究,特别是等深流沉积模式的建 立。鄂尔多斯盆地西缘北部桌子山地区中奥陶统达瑞威尔阶克里摩里组广泛发育等深流沉积,此次在详细的野外观察基础 上,对内蒙古乌海市海南区石峡谷剖面进行沉积学研究,该剖面克里摩里组从下到上可分为三段:下段以薄-中层叠置石 灰岩为特征、中段以石灰岩-泥岩岩组与泥岩互层为特征,上段以条纹状泥岩为特征。三段沉积分别代表了深水环境下等 深流水道沉积、天然堤沉积和深水盆地平原区极弱等深流沉积,在垂向上组成了一个完整的等深流水下水道-天然堤沉积 体系。  相似文献   

17.
辛博  刘景彦  陈薪凯  马骁  仲昭 《现代地质》2020,34(2):321-332
深水重力流作为一种重要的、特殊类型的沉积体系,自发现以来就得到了学术界的广泛关注,并在油气勘探中日益受到重视。东营凹陷古近系沙三中段发育深水重力流体系,综合地震、岩心、测录井等资料,对郝家油田史112区块深水重力流体系的沉积类型、特征及在不同层序中的发育演化进行了精细刻画,总结了该区重力流沉积模式,为开发区储层预测提供重要参考。研究表明,本区深水重力流体系发育于三级层序的高位域,从下至上可划分出4个四级层序(SQQ1-4),主要发育滑塌沉积、碎屑流沉积和浊流沉积3种成因类型,可识别出12种岩相组合。四级层序$\mathrm{SQQ}_{3}^{2}$时期重力流规模较小,$\mathrm{SQQ}_{3}^{3}$时期随着东营三角洲向湖盆中心推进,重力流规模扩大。滑塌沉积主要发育在三角洲前缘或前三角洲斜坡根部,在滑塌沉积前方形成碎屑流沉积,碎屑流向前搬运的过程中,逐渐转化成浊流沉积。三角洲前缘及前三角洲的浊流和碎屑流是开发井区进一步寻找储层的有利部位。  相似文献   

18.
赣西北前寒武系首次发现内波内潮汐沉积   总被引:6,自引:1,他引:5       下载免费PDF全文
本文详细论述了赣西北前寒武系首次发现的深水牵引流内波内潮汐沉积特征的沉积构造、岩石组合和沉积序列。沉积构造主要发育双向和单向交错层理、曲线型和干涉波痕及波状、脉状、透镜状层理;常产于深水重力流之上或与之共生。岩石粒度结构特征为明显的牵引流性质。共划分出双向交错层理砂岩组合,单向交错层理砂岩组合,薄层砂岩——板岩组合和波状、脉状、透镜状细砂岩——粉砂岩——板岩组合;可识别出双向递变、单向递变和对偶层递变序列。在综合研究和分析的基础上,进一步阐述了内波内潮汐沉积与浊流沉积的异同点和相互关系以及内波内潮汐沉积的保存条件、沉积环境和控制机理。深水牵引流内波内潮汐沉积学特征的系统研究,对正确阐明沉积盆地的大地构造背景及形成演化具有重要意义。  相似文献   

19.
The Mesoproterozoic Pandikunta Limestone, a shallow water carbonate platform succession in the Pranhita-Godavari Valley, south India, displays well developed climbing ripple lamination and storm deposited structures, such as HCS, wave ripple-lamination, combined-flow ripple-lamination and low angle trough cross-stratification. Different types of stratification developed in calcisiltite with minor amounts of very fine quartz sand and silt. The climbing ripple structures exhibit a complex pattern of superposition of different types (type A, B and S) within cosets pointing to a fluctuating rate of suspension depositionversus bedform migration, and an unsteady character of the flow. Close association of climbing ripple structures, HCS with anisotropic geometry, wavy lamination and combined-flow ripple-lamination suggest that the structures were formed by storm generated combined-flow in a mid-shelf area above the storm wave base. The combined-flow that deposited the climbing ripple structures had a strong unidirectional flow component of variable magnitude. The climbing ripple structure occurs as a constituent of graded stratified beds with an ordered vertical sequence of different types of lamination, reflecting flow deceleration and increased rate of suspension deposition. It is inferred that the beds were deposited from high-density waning flows in the relatively deeper part of the ancient shelf. The structures indicate that the Pandikunta platform was subjected to open marine circulation and intense storm activities. The storm deposited beds, intercalated with beds of lime-mudstone, consist primarily of fine sand and silt size carbonate particles that were hydrodynamically similar to quartz silt. Detrital carbonate particles are structureless and are of variable roundness. The particles were generated as primary carbonate clasts in coastal areas by mechanical disintegration of rapidly lithified beds, stromatolites or laminites, and the finest grade was transported to the offshore areas by storm-generated currents.  相似文献   

20.
宁夏香山群徐家圈组发现深水复合流沉积构造   总被引:8,自引:1,他引:7  
宁夏香山群徐家圈组是由灰绿、黄绿色轻微变质中—细粒砂岩、钙质砂岩及粉砂岩和页岩(板岩)组成的深水沉积。在上部灰绿色页岩所夹的中层钙质粉砂岩中发现了复合流层理、准平行层理、不对称小型丘状交错层理;在下部灰绿色厚层—块状中—细粒长石石英砂岩的顶面发现了小型波痕,波痕的形态、波长与波高的分布规律均表现出复合流(combined-flow)的沉积特征。本文根据水槽实验和现代海洋沉积观测所总结出的复合流底床相图和前人在研究地层中较浅海浊流(超重流)与波浪所形成的复合流沉积时给出的复合流沉积示意图,分别对徐家圈组所发现的①小型2D波痕至小型3D波痕的演化和②复合流层理、平行层理、准平行层理和小型丘状交错层理的叠置关系及其纹层所反映的流动方向与沉积时浊流方向的关系,进行了解释。结果表明,所发现的复合流层理、准平行层理、不对称小型丘状交错层理及小型波痕应为复合流沉积,并依据徐家圈组存在内波、内潮汐沉积的事实,推测为深水短周期内波与浊流形成的复合流沉积。这可能是地层中深水复合流沉积构造的首次发现,同时也是内波与浊流形成的复合流沉积的首次发现。  相似文献   

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