The timing of salt structure growth in the Southern Permian Basin (Central Europe) and implications for basin dynamics     

Michael Warsitzka  Fabian Jhne‐Klingberg  Jonas Kley  Nina Kukowski 《Basin Research》2019,31(2):337-360

In this paper, a literature‐based compilation of the timing and history of salt tectonics in the Southern Permian Basin (Central Europe) is presented. The tectono‐stratigraphic evolution of the Southern Permian Basin is influenced by salt movement and the structural development of various types of salt structures. The compilation presented here was used to characterize the following syndepositional growth stages of the salt structures: (a) “phase of initiation”; (b) phase of fastest growth (“main activity”); and (c) phase of burial’. We have also mapped the spatial pattern of potential mechanisms that triggered the initiation of salt structures over the area studied and summarized them for distinct regions (sub‐basins, platforms, etc.). The data base compiled and the set of maps produced from it provide a detailed overview of the spatial and temporal distribution of salt tectonic activity enabling the correlation of tectonic phases between specific regions of the entire Southern Permian Basin. Accordingly, salt movements were initiated in deeply subsided graben structures and fault zones during the Early and Middle Triassic. In these areas, salt structures reached their phase of main activity already during the Late Triassic or the Jurassic and were mostly buried during the Early Cretaceous. Salt structures in less subsided sub‐basins and platform regions of the Southern Permian Basin mostly started to grow during the Late Triassic. The subsequent phase of main activity of these salt structures took place from the Late Cretaceous to the Cenozoic. The analysis of the trigger mechanisms revealed that most salt structures were initiated by large‐offset normal faults in the sub‐salt basement in the large graben structures and minor normal faulting associated with thin‐skinned extension in the less subsided basin parts.  相似文献   

Flexural deformation controls on Late Quaternary sediment dispersal in the Garo-Rajmahal Gap,NW Bengal Basin     

Jean-Louis Grimaud  Celine Grall  Steven Goodbred  Michael S. Steckler  Ryan Sincavage  Jennifer L. Pickering  Chris Paola  Leonardo Seeber  Md. Saddam Hossain 《Basin Research》2020,32(5):1242-1260

Subsurface deformation is a driver for river path selection when deformation rates become comparable to the autogenic mobility rate of rivers. Here we combine geomorphology, soil and sediment facies analyses, and geophysical data of the Late Quaternary sediments of the central Garo-Rajmahal Gap in Northwest Bengal to link subsurface deformation with surface processes. We show variable sedimentation characteristics, from slow rates (<0.8 mm/year) in the Tista megafan at the foot of the Himalaya to nondeposition at the exposed surface of the Barind Tract to the south, enabling the development of mature soils. Combined subsidence in the Tista fan and uplift of the Barind Tract are consistent with a N-S flexural response of the Indian plate to loading of the Himalaya Mountains given a low value of elastic thickness (15–25 km). Provenance analysis based on bulk strontium concentration suggests a dispersal of sediment consistent with this flexural deformation—in particular the abandonment of the Barind Tract by a Pleistocene Brahmaputra River and the current extents of the Tista megafan lobes. Overall, these results highlight the control by deeply rooted deformation patterns on the routing of sediment by large rivers in foreland settings.  相似文献   

小兴安岭-张广才岭铁力地区侏罗纪辉绿岩年代学、地球化学、锆石Hf同位素特征及其构造意义   总被引：1，自引：0，他引：1  

葛茂卉  张进江  刘恺 《岩石学报》2020,36(3):726-740

小兴安岭-张广才岭地区中生代岩浆活动的成因及动力学背景对于揭示古太平洋的构造演化具有重要意义。本文选取小兴安岭-张广才岭铁力地区出露的辉绿岩墙为研究对象,进行锆石LA-ICP-MS U-Pb年代学、全岩地球化学和锆石Hf同位素等分析,对该基性岩的形成时代、岩石成因、岩浆源区以及形成的大地构造背景进行讨论。研究表明:辉绿岩锆石具有高Th/U比值( 0.3),CL图像显示微弱的振荡环带结构,具有岩浆锆石特征,~(206)Pb/~(238)U加权平均年龄为187±2Ma,即形成于早侏罗世;该岩体主要经历了橄榄石和单斜辉石的分离结晶作用,未遭受明显的地壳混染作用,并且具有Rb、Ba、U、Pb、K和Sr等流体活动元素相对富集,Th、Nb和Ta等非流体活动性元素相对亏损的地球化学特征,暗示其形成于被俯冲流体富集交代的亏损地幔部分熔融,源区可能为尖晶石-石榴石二辉橄榄岩,部分熔融程度约为6%～20%。结合该地区同时代的岩浆岩、变形构造、矿床特征和黑龙江蓝片岩的相关报道,本文认为小兴安岭-张广才岭地区在中生代期间处于活动大陆边缘环境,其岩浆岩的形成主要是由于存在于佳木斯地块和松嫩-小兴安岭地块间的牡丹江洋西向俯冲造成的。  相似文献   

Main active faults and seismic activity along the Yangtze River Economic Belt: Based on remote sensing geological survey     

《China Geology》2020,3(2):314-338

The Yangtze River Economic Belt (YREB) spans three terrain steps in China and features diverse topography that is characterized by significant differences in geological structure and present-day crustal deformation. Active faults and seismic activity are important geological factors for the planning and development of the YREB. In this paper, the spatial distribution and activity of 165 active faults that exist along the YREB have been compiled from previous findings, using both remote-sensing data and geological survey results. The crustal stability of seven particularly noteworthy typical active fault zones and their potential effects on the crustal stability of the urban agglomerations are analyzed. The main active fault zones in the western YREB, together with the neighboring regional active faults, make up an arc fault block region comprising primarily of Sichuan-Yunnan and a “Sichuan-Yunnan arc rotational-shear active tectonic system” strong deformation region that features rotation, shear and extensional deformation. The active faults in the central-eastern YREB, with seven NE-NNE and seven NW-NWW active faults (the “7-longitudinal, 7-horizontal” pattern), macroscopically make up a “chessboard tectonic system” medium-weak deformation region in the geomechanical tectonic system. They are also the main geological constraints for the crustal stability of the YREB.  相似文献   

南海北部琼东南海域活动冷泉特征及形成模式   总被引：3，自引：0，他引：3       下载免费PDF全文

杨力  刘斌  徐梦婕  刘胜旋  关永贤  顾元 《地球物理学报》2018,61(7):2905-2914

近年来，活动冷泉的研究越来越受到关注.本文利用多波束数据、多道地震数据以及底质取样结果研究琼东南海域活动冷泉系统，分析活动冷泉的羽状流特征、海底地貌与底质特征以及流体活动构造特征.多波束水体数据上，观测到多个延伸高度超过750 m的气泡羽状流，海底流体活动非常强烈；多道地震上识别出麻坑、流体运移通道、气烟囱等流体渗漏相关的构造，与其他海域观测到的反射特征不同，羽状流的下方流体运移通道呈强振幅"串珠"反射；重力活塞取样在两个站位上获得浅表层块状天然气水合物.其中一个站位位于活动冷泉附近，天然气水合物赋存于海底以下8 m左右.基于以上三方面的数据，笔者提出了一个用于描述活动冷泉系统的形成模式，游离气通过气烟囱向上运移到达浅层，一部分在天然气水合物稳定带内形成天然气水合物，另一部分穿透天然气水合物稳定带到达海底，形成活动冷泉的羽状流.  相似文献   

基于浅层反射地震勘探技术的大庆地区近地表构造特征研究          下载免费PDF全文

赵斌  刘财  韦庆海  鹿琪  石金虎  余中元  孙海峰 《地球物理学报》2018,61(8):3385-3399

目前，对于大庆地区的地质构造研究成果仅局限在深部构造上，该地区从未开展过针对近地表隐伏断裂的探查工作.本文采用浅层反射地震勘探方法，查明了克山—大安断裂嫩江组以上地层的详细地层信息以及断裂的展布形态；同时，在主干断裂上覆的背斜构造中，发现了许多次级断裂，这些次级断裂在前人的成果中并未提出过，并且在本区的断裂-褶皱构造体系中，次级断裂的活动特性同样受主干断裂活动的影响；然后通过钻孔验证，证实了浅层反射地震勘探结果的可靠性，并且确定了次级断裂的最新活动时代；最后综合编制了松辽盆地长垣隆起地区浅层地质模型，并讨论了本地区的构造体系受晚白垩纪以来太平洋板块俯冲方向变化的影响而形成的构造特征.本次研究中的方法和成果可为大庆市城市发展规划、重大工程建设选址和大庆油田安全高效生产等提供科学依据，可为其他地区开展近地表断裂探查提供借鉴和参考，为本地区浅层地质构造后续研究提供了基础资料，填补该地区近地表地球物理勘探构造研究的空白.  相似文献   

3D P-WAVE VELOCITY STRUCTURE AT THE NORTHEASTERN MARGIN OF ORDOS BLOCK     

HAN Xiao-ming  Liu Fang  ZHANG Fan  CHEN Li-feng  LI Juan  LI Shuan-hu  YANG Hong-ying 《地震地质》2018,40(1):215-231

Using the 7 100 absolute first arrivals of P waves and 91 513 relative P arrival times of 726 events at the northeastern margin of the Ordos block since 2009, the 3D fine structure of P wave velocity within the depth of 15km in the crust was inverted by the double difference seismic tomography method. The results show that there exist obvious high-speed continuous bodies in the northwest of the study area, and their lateral areas increase gradually with depth, while the velocity of east and south is relatively low. The velocity inhomogeneity exists and differs at different depths. The lateral differences of velocity are related to seismicity and faults. The 5~15km depth profile shows that earthquakes tend to occur in the area with relatively high velocity or high speed transition zones, which to some extent reflects the fragility of regional crustal media and the strong differential movement of faults in vertical and horizontal directions where the crust body is easy to absorb and store strain energy and generate major earthquakes. A "Y"-shape low-velocity channel is present in the lower crust around Liangcheng, corresponding to the NW-trending Heilaoyao-Shahukou fault set, which may reveal the migration path of the Late Tertiary-Quaternary basalt eruption. The Helingeer M6.2 earthquake in 1976 was related to the formation of the locking section of the thermal welding in this area. The three-dimensional fine structure of P wave velocity presented in this paper provides intuitive seismological evidence for physical and chemical properties of crustal media and the deep tectonic environment of earthquake preparation.  相似文献   

Basin filling evolution of the central basins of Mallorca since the Pliocene     

Antonio Cap  Celso Garcia 《Basin Research》2019,31(5):948-966

A new compilation of data from 436 drill cores using decompaction and backstripping techniques was used to reconstruct the basin filling history from the Pliocene until the present day in the Palma, Inca and Sa Pobla Basins on the island of Mallorca (Spain). Calcareous rocks dominate the source area and provide a limited amount of clastic input to the basins that has resulted in an average accumulation rate of between 5 and 20 m/Ma during the last 5.3 Ma. Carbonate sediment production dominated the basin filling history during early‐mid Pliocene, but during the Quaternary, the sedimentation processes in the Palma Basin were probably enhanced by an evolution in the drainage network that increased the sediment supply and the accumulated thickness caused by stream capture. However, the maximum sedimentation rate filling the depocentres of the three basins has been decreasing since the Pliocene, showing that not only the catchment transport efficiency but also the relative sea level have been controlling the sediment accumulation in these carbonate basins. The isopach cross‐sections support the idea that a palaeorelief was generated during the Messinian sea level drop and that heterogeneities were filled in from the Pliocene to the Quaternary. We conclude that the central basins of Mallorca were filled heterogeneously due to tectonic and geomorphic processes that controlled sediment transport and production, resulting in different average sedimentation thicknesses that decreased since the Pliocene as the accommodation space became filled and the relative sea level dropped.  相似文献   

《东北地区1：150万大地构造相图》的编制     

刘英才  付俊彧  赵春荆  那福超  宋维民 《地质与资源》2020,29(1):1-6

东北地区1：150万大地构造相图是2018年出版的一份区域性大地构造图.该图依据不断积累和丰富的基础地质资料，将大地构造理论研究与综合应用汇总和集成，是东北地区科技创新成果和技术方法进步转化应用的重要体现.此次编图以板块构造理论和大陆动力学思维为指导，以多岛洋、弧-盆系发展演化观点为切入点，运用大地构造相分析方法，研究东北地区地壳形成、演化历史，以及大地构造环境及其与成矿作用的时空关系.较系统地阐述了东北地区的岩石构造组合、建造构造与构造演化阶段的宏观背景.  相似文献   

Ancient deep roots for Mesozoic world-class gold deposits in the north China craton:An integrated genetic perspective     

Cheng-Xue Yang  M.Santosh 《地学前缘(英文版)》2020,11(1):203-214

The North China Craton(NCC)hosts some of the world-class gold deposits that formed more than 2 billion years after the major orogenic cycles and cratonization.The diverse models for the genesis of these deposits remain equivocal,and mostly focused on the craton margin examples,although synchronous deposits formed in the interior domains.Here we adopt an integrated geological and geophysical perspective to evaluate the possible factors that contributed to the formation of the major gold deposits in the NCC.In the Archean tectonic framework of the NCC,the locations of the major gold deposits fall within or adjacent to greenstone belts or the margins of micro-continents.In the Paleoproterozoic framework,they are markedly aligned along two major collisional sutures-the Trans North China Orogen and the Jiao-Liao-Ji Belt.Since the Mesozoic intrusions hosting these deposits do not carry adequate signals for the source of gold,we explore the deep roots based on available geophysical data.We show that the gold deposits are preferentially distributed above zones of uplifted MOHO and shallow LAB corresponding to thinned crust and eroded sub-lithospheric mantle,and that the mineralization is located above regions of high heat flow representing mantle upwelling.The NCC was at the center of a multi-convergent regime during the Mesozoic which intensely churned the mantle and significantly en riched it.The geophysical data on Moho and LAB upwarp from the centre towards east of the craton is more consistent with paleo-Pacific slab subduction from the east exerting the dominant control on lithospheric thinning.Based on these results,and together with an evaluation of the geochemical and isotopic features of the Mesozoic magmatic intrusions hosting the gold mineralization,we propose a genetic model that invokes reworking of ancient Au archives preserved in the lower crust and metasomatised upper mantle and which were generated through multiple subduction,underplating and cumulation events associated with cratonization of the NCC as well as the subduction-collision of Yangtze Craton with the NCC.The heat and material input along zones of heterogeneously thinned lithosphere from a rising turbulent mantle triggered by Mesozoic convergent margins surrounding the craton aided in reworking the deep roots of the ancient Au reservoirs,leading to the major gold metallogeny along craton margins as well as in the interior of the NCC.  相似文献