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1.
同构造沉积盆地的沉积作用与构造环境及其活动性质有着内在的统一性,尽管控制沉积作用的因素很多(诸如气候、物源等),但最基本的因素乃是同沉积作用的构造活动,它控制着沉积体的分布、厚度、相型等。甚至不少沉积体是在两种或三种构造环境下发生的,因而有着纵横交替、相互更叠的复杂层序。而作为特殊沉积作用的沉积矿产,则更显著地制约于同沉积构造活动,尤其作为导矿构造的基底构造以及盆地演化中的控制性构造,则是寻找隐伏矿产的一  相似文献   

2.
The Eocene to Oligocene sediments of the Ecuadorian Oriente Basin record two kinds of second-order stratigraphic response to the tectonic evolution. Lower Eocene shows evidences of local scale syntectonic deposits. This tectonic activity can be related to right lateral convergent movements inverting pre-cretaceous extensional structures. Upper Eocene and Oligocene sediments are integrated as the expression of an isostatic rebound characterizing a basin scale syntectonic deposition. This response is evidenced by a reciprocal architecture of the depositional sequences identified in the sedimentary formations. These data have allowed us to propose a new geodynamic model for the Paleogene evolution of the Oriente Basin.  相似文献   

3.
《Gondwana Research》2003,6(1):65-77
A sedimentary succession included in the lower section of the Playa Hermosa Formation from the Playa Verde Basin, Uruguay, is described. Two facies associations, one mainly coarse- to medium-grained and other one fine-grained, have been defined (FA I-II). In the first one, breccias, conglomerates, sandstones and minor mudstones were deposited in a subaqueous depositional setting (proximal) suggesting slope instability and resedimentation processes. The second one contains diamictites, rhythmites, sandstones and mudstones and presents abundant evidence of soft-deformation, also interpreted to be deposited in a subaqueous environment (distal). Dropstones, clast layers, diamictites, rhythmites and varve-like deposits are interpreted as ice rafting processes generated during a glacial episode. This glacial-related succession constitutes the first record from the Varanger glaciation at the Río de la Plata Craton of the late Neoproterozoic age and also represents one of the oldest sedimentary records after the collision of the Río de la Plata and Kalahari Cratons. A combined interaction of extensional faulting and glaciation in a tectonically active basin with locally high subsidence rates, resulted in high rates of sedimentation and resedimentation processes. As a whole, the sedimentary succession sets a relevant datum to be used in future paleogeographic reconstructions of the Vendian glacial record in southern South America.  相似文献   

4.
The Late Proterozoic Conception Group, exposed on the Avalon Peninsula in Newfoundland, Canada, is a 4 km thick turbidite succession containing a conformable 300 m thick sequence of diamictites (the Gaskiers Formation) near the base. Massive and crudely-stratified diamictites form beds up to 25 m thick which have a tabular geometry with slightly erosive basal contacts and are interbedded with mudstones and fine-grained, thin-bedded turbidites. These diamictites are interpreted as submarine debris flow deposits. Disrupted diamictites form strongly deformed units that contain large, complexly folded rafts of mudstone and turbidite facies. These diamictite units are interpreted as submarine slumps. Diamictites contain glacially-striated and faceted clasts; clasts and matrix are predominantly of volcanic provenance. One outcrop shows interbedded volcanic agglomerate and diamictite, and volcanic bombs can also be identified. The interbedding of diamictites with turbidites and the stratigraphic context provided by the thick sequences of turbidites below (Mall Bay Formation) and above (Drook Formation) indicate a deep marine slope setting of diamictite deposition. Diamictite facies record remobilization and downslope transfer of large volumes of unstable volcanic and glacial debris initially deposited in a shallower water marginal marine zone. The regional tectonic framework suggests the Conception Group accumulated in a deep, southward-opening ensialic rift basin with active but waning volcanic centres to the north. The Gaskiers Formation may be representative of other Late Precambrian glacially-influenced diamictite sequences that were deposited around the North Atlantic region and in Europe. These deep marine diamictite sequences characterized by debris flows, turbidites, and slump deposits, can be contrasted with more extensive shallow marine shelf diamictite sequences found in association with dolomites and tidally influenced shallow water facies in other basinal settings.  相似文献   

5.
南沙海域主要的新生代盆地及其类型为:(1)曾母盆地,走滑一周缘前陆型;(2)万安盆地,拉张剪切型;(3)沙巴一文莱盆地,弧前盆地;(4)湄公河盆地,陆内断陷型;(5)西纳土纳盆地,剪切拉张型。这些盆地沉积厚度大多在3000m 以上,最厚大干12000m,含海、陆相沉积,具较好的油气勘探前景。其演化历史最早的始于始新世,最晚的始于渐新世晚期,文中对各盆地演化历史作了对比。  相似文献   

6.
Tectonic activity, sea-level changes, and the climate controlled sedimentation in Late Paleozoic basins of western Argentina. The role of each factor is investigated from the geologic record of the Río Blanco and Paganzo basins using three hierarchical orders of stratigraphic bounding surfaces. First-order surfaces correspond to regional unconformities, second-order ones to local unconformities with a lesser regional extent, and third-order surfaces represent locally extended sedimentary truncation. Using this methodology, the Carboniferous–Permian record of the Paganzo and Río Blanco basins may be divided into two megasequences, four sequences, and 12 stratigraphic sections. Megasequences are bounded by regional unconformities that result from tectonic events important enough to cause regional paleogeographic changes. Sequences are limited by minor regional extension surfaces related to local tectonic movements or significant sea-level falls. Finally, stratigraphic sections correspond to extended sedimentary truncations produced by transgressive events or major climatic changes. Sequence I is mainly composed of marine deposits divided into basal infill of the basin (Section 1) and Tournaisian–Visean transgressive deposits (Section 2). Sequence II is bounded by a sharp erosional surface and begins with coarse conglomerates (Section 3), followed by fluvial and shallow marine sedimentary rocks (Section 4) that pass upward into shales and diamictites (Section 5). The base of Sequence III is marked by an extended unconformity covered by Early Pennsylvanian glacial sedimentary rocks (Section 6) that represent the most important glacial event along the western margin of Gondwana. Postglacial deposits (Section 7) occur in the two basins and comprise both glaciolacustrine (eastern region) and transgressive marine (central and western regions) deposits. By the Moscovian–Kasimovian, fluvial sandstones and conglomerates were deposited in most of the Paganzo Basin (Section 8), while localized volcanic activity took place in the Río Blanco Basin. Near the end of the Carboniferous, an important transgression is recorded in the major part of the Río Blanco Basin (Section 9), reaching the westernmost portion area of the Paganzo Basin. Finally, Sequence IV shows important differences between the Paganzo and Río Blanco basins; fluvial red beds (Section 10), eolian sandstones (Section 11), and low-energy fluvial deposits (Section 12) prevailed in the Paganzo Basin whereas volcaniclastic sedimentation and volcanism dominated in the Río Blanco Basin. Thus, tectonic events, sea-level changes and climate exerted a strong and complex control on the evolution of the Río Blanco and Paganzo basins. The interaction of these allocyclic controls produced not only characteristic facies association patterns but also different kinds of stratigraphic bounding surfaces.  相似文献   

7.
Tectonic activity, sea-level changes, and the climate controlled sedimentation in Late Paleozoic basins of western Argentina. The role of each factor is investigated from the geologic record of the Río Blanco and Paganzo basins using three hierarchical orders of stratigraphic bounding surfaces. First-order surfaces correspond to regional unconformities, second-order ones to local unconformities with a lesser regional extent, and third-order surfaces represent locally extended sedimentary truncation. Using this methodology, the Carboniferous–Permian record of the Paganzo and Río Blanco basins may be divided into two megasequences, four sequences, and 12 stratigraphic sections. Megasequences are bounded by regional unconformities that result from tectonic events important enough to cause regional paleogeographic changes. Sequences are limited by minor regional extension surfaces related to local tectonic movements or significant sea-level falls. Finally, stratigraphic sections correspond to extended sedimentary truncations produced by transgressive events or major climatic changes. Sequence I is mainly composed of marine deposits divided into basal infill of the basin (Section 1) and Tournaisian–Visean transgressive deposits (Section 2). Sequence II is bounded by a sharp erosional surface and begins with coarse conglomerates (Section 3), followed by fluvial and shallow marine sedimentary rocks (Section 4) that pass upward into shales and diamictites (Section 5). The base of Sequence III is marked by an extended unconformity covered by Early Pennsylvanian glacial sedimentary rocks (Section 6) that represent the most important glacial event along the western margin of Gondwana. Postglacial deposits (Section 7) occur in the two basins and comprise both glaciolacustrine (eastern region) and transgressive marine (central and western regions) deposits. By the Moscovian–Kasimovian, fluvial sandstones and conglomerates were deposited in most of the Paganzo Basin (Section 8), while localized volcanic activity took place in the Río Blanco Basin. Near the end of the Carboniferous, an important transgression is recorded in the major part of the Río Blanco Basin (Section 9), reaching the westernmost portion area of the Paganzo Basin. Finally, Sequence IV shows important differences between the Paganzo and Río Blanco basins; fluvial red beds (Section 10), eolian sandstones (Section 11), and low-energy fluvial deposits (Section 12) prevailed in the Paganzo Basin whereas volcaniclastic sedimentation and volcanism dominated in the Río Blanco Basin. Thus, tectonic events, sea-level changes and climate exerted a strong and complex control on the evolution of the Río Blanco and Paganzo basins. The interaction of these allocyclic controls produced not only characteristic facies association patterns but also different kinds of stratigraphic bounding surfaces.  相似文献   

8.
International Journal of Earth Sciences - Two petroleum systems are present in the eastern (Austrian) sector of the Alpine Foreland Basin. Whereas oil and thermogenic gas in Mesozoic and Eocene...  相似文献   

9.
The Malatya Basin is situated on the southern Taurus-Anatolian Platform. The southern part of the basin contains a sedimentary sequence which can be divided into four main units, each separated by an unconformity. From base to top, these are: (1) Permo-Carboniferous; (2) Upper Cretaceous–Lower Paleocene, (3) Middle-Upper Eocene and (4) Upper Miocene. The Upper Cretaceous–Tertiary sedimentary sequence resting on basement rocks is up to 700 m thick.The Permo-Carboniferous basement consist of dolomites and recrystallized limestones. The Upper Cretaceous–Lower Paleocene transgressive–regressive sequence shows a transition from terrestrial environments, via lagoonal to shallow-marine limestones to deep marine turbiditic sediments, followed upwards by shallow marine cherty limestones. The marine sediments contain planktic and benthic foraminifers indicating an upper Campanian, Maastrichtian and Danian age. The Middle-Upper Eocene is a transgressive–regressive sequence represented by terrestrial and lagoonal clastics, shallow-marine limestones and deep marine turbidites. The planktic and benthic foraminifers in the marine sediments indicate a Middle-Upper Eocene age. The upper Miocene sequence consists of a reddish-brown conglomerate–sandstone–mudstone alternation of alluvial and fluvial facies.During Late Cretaceous–Early Paleocene times, the Gündüzbey Group was deposited in the southern part of a fore-arc basin, simultaneously with volcanics belonging to the Yüksekova Group. During Middle-Late Eocene times, the Yeşilyurt Group was deposited in the northern part of the Maden Basin and the Helete volcanic arc. The Middle-Upper Eocene Malatya Basin was formed due to block faulting at the beginning of the Middle Eocene time. During the Late Paleocene–Early Eocene, and at the end of the Eocene, the study areas became continental due to the southward advance of nappe structures.The rock sequences in the southern part of the Malatya Basin may be divided into four tectonic units, from base to top: the lower allochthon, the upper allochthon, the parautochthon and autochthonous rock units.  相似文献   

10.
The Paraná Basin (1 600 000 km2) is the largest intracratonic basin in southern South America and contains a thick (1300 m) Permo-Carboniferous glacial succession (the Itararé Group). This paper describes over 1700 m of drill core recovered during recent exploration for oil and gas. Itararé Group sediments consist of massive and stratified diamictites interbedded with massive and graded sandstones, and massive and laminated mudstones. Facies are interpreted as the product of sediment gravity flows in a glacially influenced marine basin. Three stratigraphic formations can be defined across the basin, each consisting of a lowermost sandstone-rich member overlain by a diamictite-rich member. Examination of Itararé Group rocks both in core and outcrop shows that depositional processes were influenced by active faulting and downslope resedimentation on relatively steep and unstable substrate slopes. Primary glacial deposits such as tillites and associated striated pavements occur along the present eastern outcrop belt which probably coincided with the eastern basin margin during deposition of the Itararé Group. Ice masses fringing the eastern (southern African) and western (Bolivian) basin margins supplied sediment to the basin in the form of fluvio-glacial deltas, fans and floating ice tongues. This sediment was then resedimented downslope as debris flows and turbidites. Both stratigraphic relationships and the regional distribution of facies types identify a clear pattern of basin subsidence and step-wise expansion by outward faulting within Late Proterozoic mobile belts. The position of successive basin margins can be related to specific lineament structures in the underlying basement. Asymmetric expansion of the Paraná Basin occurred along the northern and southern basin margins during deposition of the Itararé Group; this expansion probably reflects shallow crustal adjustments activated by collisional movements along the Andean margin of South America during the Hercynian Orogeny.  相似文献   

11.
李理  赵利  刘海剑  房贤云 《地质科学》2015,50(2):446-472
渤海湾盆地是一个在早白垩世被动裂陷盆地基础上发育起来的新生代主动裂陷盆地, 走滑作用贯穿始终, 特别是在兰聊-盐山断层以东, 使这个裂陷盆地具有鲜明的走滑特征。伸展和走滑作用此消彼长, 伸展构造和走滑构造相互叠加、转换, 垂向上相互叠置、交切, 并由此导致变换带的产生。晚中生代以来太平洋板块向欧亚板块俯冲的方向和速度变化、后撤以及板片窗效应、中始新世印欧板块碰撞导致的地幔上涌是控制盆地形成的深部背景, 郯庐断裂带早白垩世强烈的左行走滑、古新世-早始新世弱的左行走滑以及中始新世后的右行走滑活动也深刻地控制和影响着盆地的发育, 盆地内晚中生代-新生代的伸展和走滑构造的演化则是其浅部响应, 并由此控制着岩浆活动以及油气生成、运聚和分布的时空迁移。  相似文献   

12.
《Sedimentary Geology》2006,183(3-4):297-319
Using palynostratigraphy combined with analysis of lithostratigraphy and sedimentary facies of discontinuous outcrops and selected drillholes, we have investigated whether the Eocene sequences and their boundaries in the Eucla Basin of South Australia were synchronous with major sea-level events. The correlation of Eocene sequences and their boundaries in the eastern nearshore and onshore Eucla Basin indicates that these complex marine–nonmarine strata fall into four sequences or allostratigraphic packages that can be seen from the offshore basin to nearshore and onshore basin, including palaeovalleys. Key sedimentary surfaces (disconformities, a tidal/wave ravinement surface, transgressive surfaces, maximum flooding surfaces) bound the packages (including three new revised units) and are coincident with four third-order sequence boundaries. The eastern Eucla Basin stratigraphy accords with the general view of Eocene sea-level patterns and elucidates a stepwise evolution of marine and nonmarine environments.  相似文献   

13.
以最新的地质 地球物理资料和北黄海盆地构造几何学特征为基础,采用盆地反演模拟与宏观分析相结合的方法,系统解析了北黄海盆地的构造运动学特征。研究表明,北黄海盆地在中、新生代时期经历了水平伸展、水平挤压、相对平移(走滑)以及垂直差异升降等几种运动型式,其中,水平伸展运动和垂直差异升降运动是北黄海盆地构造运动及形成演化的主体。水平伸展运动可以划分为J3-K1、E2和E3三个主要“伸展事件”,并控制着盆地的成盆演化,其南北向伸展强度均东强西弱,东西向最大伸展强度自中生代到新生代由东向西迁移。水平挤压运动主要有晚白垩世和渐新世末-中新世初期两期。相对平移(走滑)运动伴随水平伸展运动和水平挤压运动发生,使多数NNE向、NW向断裂具有相对压扭或张扭平移(走滑)性质,其中尤以NNE向断裂更为明显。垂直差异升降运动具有“幕式”渐进之特点,晚侏罗世、早白垩世、始新世、渐新世以及中新世中晚期以来为沉降期,其中尤以始新世的沉降速率最大,晚白垩世、古新世、中新世早期为抬升剥蚀期;盆地的中、新生代沉降作用具有明显的自东向西迁移规律:东部坳陷以中生代沉降作用最为显著,中部坳陷主沉降期为始新世,而西部坳陷的快速沉降主要发生在始新世,并一直持续到渐新世。  相似文献   

14.
Recent free-air gravity data covering the Makassar Straits is integrated with Bouguer gravity data from onshore East Kalimantan to provide new insights into the basement structure of the region. Onshore Kalimantan, gravity highs on the northern margin of the Kutai Basin trend NNE–SSW and N–S and correspond with the axes of inverted Eocene half-grabens. NW–SE trending lows correspond to deep seated basement weaknesses reactivated as normal faults during the Tertiary. An intra-basin gravity high trending NNE–SSW, the Kutai Lakes Gravity High, is modelled as folded high density Paleogene sediments flanked by syn-inversion synclines infilled with low density sediments. Offshore Kalimantan, the Makassar Straits include two basins offset by an en-echelon fault zone, suggestive of an extensional origin. The regional signature of the free-air anomaly data mirrors the bathymetry, but this effect can be reduced by the use of filters in order to examine the basin architecture. The free-air gravity minimum in the Makassar Strait is only −20 mGal, much smaller than that appropriate for a foreland basin, and more indicative of an extensional basin. The steepness of the gradients on the flanks of the basins indicates fault control of their margins. A regional 2D profile across the North Makassar Basin suggests the presence of attenuated crust (<14 km) in the basin axis at the present day, whereas flexural backstripping implies the presence of oceanic crust of middle Eocene age. The presence of oceanic crust in the North Makassar Straits Basin has implications for regional plate tectonic models.  相似文献   

15.
1IntroductionThis paper is focused on the Southamerican geo-logical history of the Chaco Paran偄Basin rift system inthe last75-65Ma,including some Quaternary phe-nomena(Fig.1).The study presents a new interpre-tation to its evolution and stratigraphy.The …  相似文献   

16.
柴达木第三纪转换裂陷盆地形成演化及动力学   总被引:6,自引:0,他引:6       下载免费PDF全文
运用沉积体系组合,构造地层分析和岩浆热流体标志综合分析的方法,探讨了柴达木第三纪转换换裂陷盆地形成演化及动力学过程,笔者认为:柴达木第三纪盆地是以扩展裂陷为主的单型盆地,可划分为扇三角洲沉积体系,水下洪积扇-近岸浊流沉积体系,辫状河三角洲沉积体系,常态湖三角洲体系和湖泊沉积体系在湖盆演化的不同阶段,形成冲积扇-扇三角洲-滨浅湖-砾质辫状河沉积,近岸水下重力流-中深湖-扇三角洲,扇三角洲-中浅湖-河流三种湖盆充填形式。依据古构造运动界面和相应整合界面,将第三纪盆地划分为三个构造层序。分别对应于台裂陷,伸展扩张裂陷和转换坳陷三个发展过程。柴达木第三纪转换争盆地形成演化主要受控于地幔热柱的形成和衰减作用,同时喜马拉雅运动等运程应力作用对盆地的演化至关重要。  相似文献   

17.
东北亚断陷盆地系与北美西部盆岭省伸展作用对比   总被引:2,自引:0,他引:2  
与北美西部盆岭省相比,东北亚新陷盆地系是一独具有特色的大陆裂陷作用区,该断陷盆地系发育于晚中生代期间,以巨大的规模,复杂的动力学背景和伴有一套大陆边缘扩张型火山岩组合为特征。东北亚断陷盆地系发育于宽裂陷作用背景之下,盆地拉伸率较低,但沉降较深,蕴藏有巨大的能源资源,是我国东部重要的煤和油气探领域。  相似文献   

18.
The Sakoa Group is the lowermost stratigraphical succession of the Karoo Supergroup and the oldest sedimentary unit in Madagascar, spanning the Late Carboniferous through Early Permian epochs. The Sakoa Group is exposed in the southern Morondava Basin. It is predominantly a siliciclastic sequence comprising seven lithofacies associations: (1) diamictites; (2) conglomeratic sandstones; (3) sandstones; (4) interbedded thin sandstones and mudstones; (5) mudstones; (6) coals; and (7) limestones. These facies represent deposition in the early extensional stages of continental rift development. The sediments were deposited predominantly on alluvial fans, and in braided to meandering stream and overbank environments. Locally lacustrine and coal swamp environments formed in low areas of the basin floor during rift initiation. Subsidence rates remained fairly constant throughout the Early Permian and were accompanied by a gradual reduction in relief of the basin margins and an increased geomorphic maturity of the fluvial systems flowing across the basin floor. Near the end of the Early Permian the southern Morondava Basin was inundated by a marine transgression , which resulted in deposition of the Vohitolia Limestone. Subsequent tectonic uplift and erosion resulted in a regional unconformity between the Sakoa Group and the overlying Sakamena Group.  相似文献   

19.
中国北方从东到西绵延3000 km范围上的华北克拉通、塔里木克拉通及其中间微地块上都保存有埃迪卡拉纪冰川沉积记录,但有关它的年代学、冰川规模、古地理重建和大地构造背景等存有争论。本文基于中国北方埃迪卡拉纪冰碛岩空间分布、地层与沉积层序,沉积环境与沉积相等,结合以往国内外文献,系统分析了埃迪卡拉纪冰川上述有关问题。研究揭示,埃迪卡拉纪时期,国内外应存在年轻于(Gaskiers)580 Ma的冰期;中国北方埃迪卡拉纪冰川时限约562.5~551 Ma,堆积了冰下、冰缘和冰前沉积相(物),构成垂向上(由下至上)从冰下至冰前与海相冰碛物沉积层序,符合大陆冰川(盖)沉积响应样式;此外,国内外埃迪卡拉纪冰碛岩及冰川剥蚀地貌均十分发育;部分冰碛岩之上还可见盖帽白云岩,并呈现与成冰纪盖帽白云岩类似的沉积构造,但彼此碳同位素剖面却不尽相同;本研究推测,埃迪卡拉纪时期,原特提斯洋及周缘大陆(群)可能普遍存在至少是洲际性大陆冰盖,甚至是全球性的冰期。研究认为,埃迪卡拉纪时期的亚洲陆块群应与冈瓦纳大陆缺乏构造亲缘性的若干重要证据。本文研究结果在埃迪卡拉纪大陆及其古地理重建和大地构造背景恢复方面具有重要科学意义...  相似文献   

20.
采用古生态学及沉积学方法, 对南海北部深水区BY7-1-1井及L29井特定层段进行细致研究.通过有孔虫、孢粉藻类分析及沉积学分析, 证实南海北部白云深水区在晚始新世即出现滨浅海相沉积环境, 确定了南海北部最早接受海相沉积的时间.始新世海相地层在南海北部主要分布在台西及台西南盆地中, 并在晚始新世扩展到珠江口盆地白云凹陷.在南部分布较广, 曾母盆地、北康盆地、礼乐盆地及巴拉望盆地中均有始新世海相地层分布.南海始新世海相地层的分布受制于新南海扩张及古南海的消退, 以晚始新世为时间节点发生显著变化, 总体上分布范围增大, 反映该时期南海拉张和断裂活动的加剧.南海始新世海相地层具有良好的油气潜力, 在部分盆地中形成了优质的烃源岩与储层, 珠江口盆地白云深水区晚始新世海相地层的发现, 对南海深水海相油气勘探具有积极的参考作用.   相似文献   

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