赣东北鹅湖岭组的再认识   总被引：9，自引：2，他引：7  

巫建华 《地层学杂志》1996,20(2):153-160

在分析赣东北鹅湖岭组及有关地层的地质特征、地层划分现状及产生分岐的原因的基础上,提出以岩性、岩相为划分依据,将鹅湖岭组与喷发相相对应,将其下界、上界分别置于沉积喷发相与喷发相、喷发相与喷发沉积相的相变界面上。从而将北京地质学院指定的打鼓顶组建组剖面上的"打鼓顶组"并入鹅湖岭组;将赣东北其它地区的鹅湖岭组下界由安山岩层顶界处上移至安山岩层之上灰绿色砂岩层的顶界处,将铅山一上饶一带鹅湖岭组上界下移至原鹅湖岭组上部的底界处。  相似文献   

厚层切叠砂体自然层描述方法:以北一区断东葡一组1-4小层为例     

吴迪  马世忠  景丽娟  周志国 《世界地质》2020,39(1):106-112

将多期切叠河道砂体归类合并,建立一个“垂向连续,横向联通的表外砂岩空间体”(其中砂岩间夹层厚度≤0.4 m)的自然层概念来控制多期河道复合切叠厚砂体。以北一匹断东萄一组1-4小层为例,利用自然层间砂体厚度、切叠程度、测井曲线形态、相叠加类型及砂体叠加期次将自然层分为5类;再依据砂体间切叠位置、切叠程度和切叠形态的差异建立自然层剖面表征方法;依据砂体叠加期次,建立自然层在平面上表征模式。  相似文献   

STRUCTURAL GEOLOGY     

《Abstract of Chinese Geological Literature》2014,(3)

正20141283 Bai Daoyuan(Hunan Institute of Geological Survey,Changsha 410016,China);Zhong Xiang Nature,Origin and Tectonic Setting of Jinzhou Basin in the South Segment of Xuefeng Orogen(Geology in China,ISSN1000-3657,CN11-1167/P,40(4),2013,p.1079-1091,10 illus.,47 refs.)Key words:foreland basins,strike-slip faults,Hunan Province  相似文献   

贵州开阳地区澄江组第二段砂岩粒度分析与沉积环境          下载免费PDF全文

乔卫涛  陈仁  胡歆睿  吕留彦  周武 《贵州地质》2020,37(1):59-65

对开阳地区金中背斜及翁昭地区澄江组第二段砂岩的进行了粒度分析,得出了其粒度参数特征。以粒度参数为基础,根据萨胡粒度判别函数、离散图解及粒度概率累积曲线及Sr/Ba测试分析,显示其沉积环境为河流相沉积。结合砂岩岩石学特征综合判断金中地区为辫状河沉积而翁昭地区为曲流河沉积。整体证实了贵州南华系澄江晚期古地理格局为北西高,南东低的特征。  相似文献   

Carbonate slope re-sedimentation in a tectonically-active setting (Western Sicily Cretaceous Escarpment,Italy)     

Vincenzo Randazzo  Johan Le Goff  Pietro Di Stefano  John Reijmer  Simona Todaro  Maria Simona Cacciatore 《Sedimentology》2020,67(5):2360-2391

Tectonic processes are widely considered as a mechanism causing carbonate platform margin instabilities leading to the emplacement of mass transport deposits and calciturbidites. However, only few examples establishing a clear link between tectonics and re-sedimentation processes are known from the literature. The two-dimensional and three-dimensional wire-cut walls of hundreds of quarries extracting ornamental limestones (for example, Perlato di Sicilia) from the Western Sicily Cretaceous Escarpment in Italy expose a series of mass transport deposits. The depositional architecture, spatial facies distribution and sedimentary features of these deposits were studied in detail. Thin section analysis was used to define the microfacies characteristics and to determine the age of the re-sedimented limestones. Eleven facies types grouped into four facies associations were recognized that defined specific depositional processes and environments. The stratigraphic architecture of the slope was reconstructed using four composite facies successions based on the detailed analysis and correlation of the field sections. The palaeoslope orientation was reconstructed based on the analysis of synsedimentary faults, slump scars and pinch-out geometries. The Western Sicily Cretaceous Escarpment was strongly influenced by synsedimentary transtensional tectonics in combination with magmatic processes, as suggested by the presence of tuffites and pillow lava intercalations within the re-sedimented carbonate series. These volcanics point to a major role of crustal shear as a trigger for mass transport deposit emplacement. The facies distribution along the Western Sicily Cretaceous Escarpment delivers new insights into the deformation processes accompanying the crustal extension of the Cretaceous western Tethys realm.  相似文献   

GEOPHYSICAL EXPLORATION     

《Abstract of Chinese Geological Literature》2014,(2)

正20141074Bao Xijie(Research Institute of Exploration and Development,Daqing Oilfield Company,PetroChina,Daqing 163712,China)Gather Optimal Processing and Application Effect of Prestack AVA Instantaneous Inversion  相似文献   

鄂尔多斯盆地正宁地区三叠系延长组长9油层组成岩作用^*          下载免费PDF全文

沈默  朱筱敏  李程善  张文选  程逸凡  江梦雅 《古地理学报》2020,22(3):539-554

综合利用岩心、铸体薄片、扫描电镜等多种资料,对鄂尔多斯盆地正宁地区三叠系延长组长9油层组储集层的岩石类型、成岩作用类型、成岩相分布特征及主控因素进行了系统研究。延长组长9油层组储集层的岩石类型为细—中粒岩屑质长石砂岩和长石质岩屑砂岩,成岩作用类型主要为压实作用,同时还有绿泥石、方解石、铁方解石及硅质胶结作用,方解石交代作用和少量的溶蚀作用,储集层目前处于中成岩A期。根据层理频率和塑性颗粒含量将岩石划分为高频层理富片状塑性颗粒粉—细砂岩岩石相和低频层理富刚性矿物细—中砂岩岩石相,前者分布于水下分流河道边部,发育压实致密成岩相;后者形成于水下分流河道主河道和河口坝。根据砂体结构可划分为厚层单砂体和厚层多砂体。厚层单砂体为单期形成的河道或河口坝砂体,上部以方解石充填胶结成岩相为特征,下部以绿泥石衬边胶结成岩相为特征;厚层多砂体为多期砂体冲刷叠置形成,发育方解石绿泥石充填胶结成岩相。塑性颗粒含量对压实作用强度影响最大,叠加碳酸盐胶结致使储集层质量变差,而早期绿泥石环边胶结抑制压实作用,是有利储集层发育的重要条件。综合评价表明,延长组长9油层组有利储集层发育于绿泥石衬边胶结相,其次为绿泥石和方解石充填胶结相,最差储集层为方解石充填胶结相和压实致密相。  相似文献   

Clinoform architecture and along‐strike facies variability through an exhumed erosional to accretionary basin margin transition     

Miquel Poyatos‐Mor  George D. Jones  Rufus L. Brunt  Daniel E. Tek  David M. Hodgson  Stephen S. Flint 《Basin Research》2019,31(5):920-947

Exhumed basin margin‐scale clinothems provide important archives for understanding process interactions and reconstructing the physiography of sedimentary basins. However, studies of coeval shelf through slope to basin‐floor deposits are rarely documented, mainly due to outcrop or subsurface dataset limitations. Unit G from the Laingsburg depocentre (Karoo Basin, South Africa) is a rare example of a complete basin margin scale clinothem (>60 km long, 200 m‐high), with >10 km of depositional strike control, which allows a quasi‐3D study of a preserved shelf‐slope‐basin floor transition over a ca. 1,200 km² area. Sand‐prone, wave‐influenced topset deposits close to the shelf‐edge rollover zone can be physically mapped down dip for ca. 10 km as they thicken and transition into heterolithic foreset/slope deposits. These deposits progressively fine and thin over tens of km farther down dip into sand‐starved bottomset/basin‐floor deposits. Only a few km along strike, the coeval foreset/slope deposits are bypass‐dominated with incisional features interpreted as minor slope conduits/gullies. The margin here is steeper, more channelized and records a stepped profile with evidence of sand‐filled intraslope topography, a preserved base‐of‐slope transition zone and sand‐rich bottomset/basin‐floor deposits. Unit G is interpreted as part of a composite depositional sequence that records a change in basin margin style from an underlying incised slope with large sand‐rich basin‐floor fans to an overlying accretion‐dominated shelf with limited sand supply to the slope and basin floor. The change in margin style is accompanied with decreased clinoform height/slope and increased shelf width. This is interpreted to reflect a transition in subsidence style from regional sag, driven by dynamic topography/inherited basement configuration, to early foreland basin flexural loading. Results of this study caution against reconstructing basin margin successions from partial datasets without accounting for temporal and spatial physiographic changes, with potential implications on predictive basin evolution models.  相似文献   

Carboniferous eclogite and garnet–omphacite granulite from northeastern Hainan Island,South China: Implications for the evolution of the eastern Palaeo‐Tethys     

Xiaochun Liu  Yi Chen  Wei‐ Wang  Mengmeng Xia  Juan Hu  Yibing Li  Daogong Hu  Biao Song 《Journal of Metamorphic Geology》2021,39(1):101-132

High‐P (HP) eclogite and associated garnet–omphacite granulite have recently been discovered in the Mulantou area, northeastern Hainan Island, South China. These rocks consist mainly of garnet, omphacite, hornblende, quartz and rutile/ilmenite, with or without zoisite and plagioclase. Textural relationships, mineral compositions and thermobarometric calculations demonstrate that the eclogite and garnet–omphacite granulite share the same three‐stage metamorphic evolution, with prograde, peak and retrograde P?T conditions of 620–680°C and 8.7–11.1 kbar, 820–860°C and 17.0–18.2 kbar, and 700–730°C and 7.1–8.5 kbar respectively. Sensitive high‐resolution ion microprobe U–Pb zircon dating, coupled with the identification of mineral inclusions in zircon, reveals the formation of mafic protoliths before 355 Ma, prograde metamorphism at c. 340–330 Ma, peak to retrograde metamorphism at c. 310–300 Ma, and subsequent pegmatite intrusion at 295 Ma. Trace element geochemistry shows that most of the rocks have a MORB affinity, with initial ε_Nd values of +2.4 to +6.7. As with similar transitional eclogite–HP granulite facies rocks in the thickened root in the European Variscan orogen, the occurrence of relatively high P?T metamorphic rocks of oceanic origin in northeastern Hainan Island suggests Carboniferous oceanic subduction leading to collision of the Hainan continental block, or at least part of it, with the South China Block in the eastern Palaeo‐Tethyan tectonic domain.  相似文献   

COAL GEOLOGY     

《Abstract of Chinese Geological Literature》2014,(3)

正20141574 Chen Hao(Exploration and Development Research Institute,Daqing Oilfield Company,Daqing 163712,China)High-Resolution Sequences and Coal Accumulating Laws in Nantun Formation of Huhe Lake Sag(Petroleum GeologyOilfield Development in Daqing,ISSN1000-3754,CN23-1286/TQ,32(4),2013,p.15-19,5 illus.,15 refs.)Key words:coal accumulation regularity,coal  相似文献