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1.
大兴安岭─燕山地层分区中、新生代地层 总被引：1，自引：0，他引：1
对大兴安岭和燕山北部的中生代地层，进行了系统的总结。侏罗纪早中期为含煤地层，晚期为以兴安岭群为代表的火山堆积；白垩纪早期为火山－沉积含煤地层，晚期为红层。第三纪以二连盆地合大量哺乳动物群的杂色沉积为特征。 相似文献
2.
陆相盆地地层单元在沉积过程中往往呈现一定的规律性,主要显示为地层单元的沉积相（岩相）组合、沉积建造、地层叠加样式和古生物群的渐进演化,对应着煤、油页岩和蒸发盐等经济矿产的潜在沉积。利用含煤、油页岩和蒸发盐特征性地层单元区分辽宁抚顺盆地、河南桐柏盆地和美国绿河盆地充填演化过程中不同地层单元的差异和潜在经济矿产的沉积,并且这些地层单元的沉积演化受气候和构造的联合控制。气候和构造控制了进入盆地中沉积物与水体供给速率以及盆地潜在可容纳空间的变化,造成盆地充填在过补偿、平衡补偿和欠补偿状态之间演化,引起地层单元岩性组合、沉积建造和古生物群的改变,能够合理解释煤、油页岩和蒸发盐的沉积。此外,不同类型盆地中气候和构造条件的差异也可能引起煤、油页岩或者蒸发盐的缺失。 相似文献
3.
陆相红色盆地1∶5万填图的一种新方法———构造—岩性—岩相填图法 总被引：3，自引：0，他引：3
通过吉安—泰和盆地１∶５万区域地质调查实践，提出了构造—岩性—岩相填图法：首先在区域性资料分析的基础上，通过踏勘确立构造不整合面、相变换面，初步划分岩石地层单位的群、组；第二，测制剖面，详细研究构造不整合面、相变换面、同相叠复面等界面特征及被这些界面围限的岩石地层内部结构等，正式划分岩石地层群、组、段，建立岩石地层层序；第三，利用主干地质路线调查，建立盆地地层格架；第四，开展面上地质调查，完成１∶５万地质填图；最后，进行综合分析，选择重点区段、剖面进行详细研究，总结盆地沉积模式 相似文献
4.
走滑环境中陆相盆地充填层序特征以云南先锋盆地为例 总被引：8，自引：3，他引：8
走滑陆相盆地在构造背景、沉积范围、物源供应方式、基底地形特征、沉积物特点和沉积层序特征方面均与大陆边缘海相盆地有重要区别，通常具有多物源、多沉积体系、相带窄、相变快的特点。本文在对云南先锋盆地充填序列、沉积格架、构造格架和区域构造背景分析基础上，讨论了在走滑构造背景下陆相盆地的一系列特征以及走滑型陆相盆地的层序地层特点. 相似文献
5.
陆相坳陷型沉积盆地通常发育在克拉通的内部差异沉降和裂谷盆地后期的热沉降等不同的大地构造阶段,是一类独特而又十分重要的沉积盆地。本文基于该类盆地的特点,提出了综合利用盆地沉积相、残余厚度图、区域构造大剖面及其平衡恢复等多方面资料对其盆地原型进行恢复的方法和流程,具体包括以残余沉积相恢复盆地原始边界、以平衡剖面恢复盆地原始形态、以关键钻井资料与平衡剖面相结合恢复原始沉积厚度。该方法消除了构造运动对盆地形态的改变,真正将盆地原型纳入到其原始形态框架下进行研究。本文还利用该方法对柴达木盆地新生代各地层沉积时的盆地原型分别进行了恢复,并据此对其新生代的沉积演化进行了分析,结果表明柴达木盆地新生代的沉积格局变化与阿尔金断裂的活动息息相关。 相似文献
6.
提出了中、晚三叠世海相沉积和陆内火山－沉积盆地具有一体化的成因联系；对株罗纪至早白恶世海陆交互相的凯北群、龙爪沟群和鸡西群的区域特征作了论述，对白垩纪中晚期火山岩，含油盆地和红层沉积进行了总结。 相似文献
7.
陆相盆地中的海侵层序特征:中欧盆地三叠系与松辽盆地白垩系对比研究 总被引：5，自引：0，他引：5
中欧盆地三叠系是典型的海陆过渡相沉积，松辽盆地白垩系是含有海侵事件记录的陆相河湖盆地。两盆地的共同特点是：①大陆克拉通上长期发育的大型坳陷盆地；②靠近古大洋和（或）有向海通道；③主要由互层状泥岩、粉砂岩、碳酸盐岩和膏盐层组成；④无典型海相化石，可能发育有半咸水和（或）高盐度生物；⑤海侵层中自生矿物的δ^34S,δ^13C,δ^18O同位素比值及介质盐度指数（Sr/Ba）、碱度指数（Ca Mg)／（Si Al）、还原性指标（Zn Ni)/Ga、硫沉积通量指数（归一化硫含量）等显著高于相邻层位背景值。 相似文献
8.
本文对胶莱盆地万家—蓝村一带浅覆盖区白垩纪陆相“红层”中火山岩夹层流纹质熔结凝灰岩进行同位素年代学研究,揭示火山岩形成时代,划分岩石地层单位。通过LA- ICP- MS锆石 U- Pb测年,获得了24个测点构成的谐和线上交点年龄数值为11832±073Ma(MSWD=100),该年龄代表了流纹质熔结凝灰岩的形成时间,指示白垩纪陆相“红层”的沉积时代为早白垩世。将这套以紫、红色为主,以细—粉砂岩、泥岩为主,夹少量砂砾岩、灰岩的河流- 湖泊相沉积“红层”划归为王氏群辛格庄组。火山活动大致与区域上石前庄旋回相当。本研究为胶莱盆地王氏群辛格庄组沉积时限提供了年代依据,同时揭示了该时期火山活动的特点,为胶莱盆地白垩纪原型盆地恢复和古地理演化提供了参考。 相似文献
9.
10.
伊犁盆地南缘侏罗系水西沟群特征及沉积环境分析 总被引：3，自引：0，他引：3
利用成因地层分析的方法，对伊犁盆地南缘侏罗系水西沟群进行沉积特征及沉积环境的分析，并对其沉积旋回进行了统一划分和对比，认为水酉沟群自下而上，可划为8个旋回；I—Ⅳ旋回属于冲积扇沉积；V-Ⅳ旋回属于扇三角洲沉积 相似文献
11.
《International Geology Review》2012,54(14):1649-1672
More than 285 carbonate-hosted Zn–Pb deposits occur in Iran, including world-class deposits such as Mehdiabad and Irankuh. Cretaceous carbonates are the most common host rock for these deposits, which are largely concentrated in the Malayer-Esfahan metallogenic belt (MEMB) and the Yazd-Anarak metallogenic belt (YAMB) and, to a lesser extent, in the Central Iranian geological and structural gradual zone and in the Central Alborz metallogenic belt. To erect a broad metallogenic framework for Cretaceous-hosted Zn–Pb resources in Iran, we integrated a geographic information system data base, including all reported deposits and occurrences of this affinity. A significant correspondence between the distribution of these deposits and the main suture zones in the Iran plate is clearly indicated. In addition, stratiform laminated sulphides are common features in most of the Early Cretaceous deposits (e.g. Irankuh, Ravanj, and Anjireh-Tiran), indicating a synsedimentary origin of these deposits. Most of the Cretaceous-hosted orebodies cluster around the Nain-Baft and Sabzevar Cretaceous suture zones and are associated with two major tectonic events: (1) extensive Early Cretaceous back-arc basin formation, producing, for instance, the Nain-Baft mineralized basin and (2) compressive Late Cretaceous closure of the back-arc basins, reflecting the Laramide orogenesis, for example, around the Nain-Baft and Sabzevar sutures in the west and north of the Central Iranian Microcontinent. Related to the back-arc basin formation and evolution, stratiform sedimentary exhalative (SEDEX)-like (e.g. Irankuh, Vejin, Robat, Takiyeh, and stratiform Ravanj) and Irish-type (e.g. Mehdiabad) Zn–Pb ± Ba deposits formed, whereas basin closure and plate collision triggered basinal fluid flow from the suture towards both sides of the MEMB and the YAMB, thus causing the formation of Late Cretaceous-hosted Mississippi Valley-type provinces (e.g. Nakhlak, stratabound Ravanj, Khanjar-e-Reshm, Chahriseh, and Lapalang deposits) on both sides of the Nain-Baft suture zone. These two different geotectonic scenarios and their evolution explain the distribution pattern of most of the Zn–Pb deposits hosted by Cretaceous sedimentary rocks in Iran. On the other hand, the formation of these deposits is not related to the collision between the Arabian and Iran plates (including the Sanandaj-Sirjan zone), inasmuch as no spatial relationship exists between this tectonic event and the distribution pattern of the deposits, which occurs far away from the collision front. The occurrence of SEDEX-like deposits in continental back-arc basins of the Iran plate confirms that an extensional setting favourable for regional Zn–Pb metallogenesis prevailed during the Early Cretaceous. In addition, Irish-type Zn–Pb mineralization took place in carbonate platforms developed on the passive margins that surrounded the Nain-Baft back-arc oceanic basin (e.g. Mehdiabad deposit). 相似文献
12.
三江盆地是我国黑龙江省东北部重要的中—新生代盆地。本文从三江盆地铀源条件、中—新生代构造演化、构造格局、中—新生代古气候演化、主要盖层沉积建造特征及后生蚀变特征等方面进行研究,以砂岩型铀矿成矿理论为指导,对三江盆地砂岩型铀矿成矿条件进行了综合分析,在此基础上对盆地找矿方向进行了探讨。研究认为：盆地西部具有较好的铀源条件,好于盆地其他地段;盆地中生代以来存在早白垩世末—晚白垩世早期和古近纪末—新近纪早期两期构造反转,在构造反转作用的控制下形成了盆地的主要找矿目标层下白垩统猴石沟组和古近系宝泉岭组含煤碎屑岩;猴石沟组、宝泉岭组及富锦组在盆地内发育有良好的地层结构和岩性岩相条件,同时在局部地区发育有氧化带,其是砂岩型铀矿找矿的重要线索。盆地砂岩型铀成矿条件总体较好,其中西部坳陷为重点工作区,猴石沟组和宝泉岭组为重点找矿层位。 相似文献
13.
Chen Pei-ji 《Cretaceous Research》1983,4(2):123-143
A review of the stratigraphy of the continental Cretaceous sequences is given. Conchastracans, ostracods and charophytes have proved useful in biostratigraphy, with additional aid from pelecypods, gastropods, larger plant fossil and, locally, dinosaur remains.The continental Lower Cretaceous deposits are considered to fall into three domains: the Circum-Pacific, the Tethyan and the NW Chinese. The continental Upper Cretaceous sediments occur mainly in the three domains: NW Chinese, SE Chinese and NE Chinese. 相似文献
14.
研究区位于酒东盆地东北缘红山地区。通过对下白垩统新民堡群后生氧化改造作用的研究,认为灰白色弱氧化、强水解蚀变带是层间氧化带的一部分。铁和有机质是沉积岩中常见的色素,当含氧水进入目的层砂体时,砂体中的有机质、低价铁(Fe2+)等化合物被氧化,导致岩石褪色;同时氧化作用导致砂岩中长石水解,形成以高岭石为主的白色黏土矿物,使岩石增白。增白与褪色的双重作用是砂岩总体上变白的重要原因,其所形成的灰白色蚀变岩位于强氧化的紫红色-黄色蚀变亚带与灰色原生岩石带之间的一定范围内。铀矿化(体)产在弱氧化、强水解灰白色砂岩与原生灰色砂岩界面附近偏灰色岩石一侧[1-2]。灰白色蚀变带与铀成矿关系密切,可作为区域性白垩系砂岩型铀矿的找矿标志之一。 相似文献
15.
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
16.
Daniel Paul Le Heron Micha M. Buslov Clare Davies Keith Richards Inna Safonova 《Sedimentary Geology》2008,208(1-2):45-60
The Mesozoic stratigraphy in the subsurface of the West Siberian Basin contains prolific hydrocarbon accumulations, and thus the depositional environments of marine and marginal marine Jurassic and Cretaceous age sediments are well-established. However, no information is currently available on strata of equivalent age that crop out along the SE basin margin in the Mariinsk–Krasnoyarsk region, despite the potential of these exposures to supply important information on the sediment supply routes into the main basin. Detailed sedimentological analysis of Jurassic–Cretaceous clastic sediments, in conjunction with palaeo-botanical data, reveals five facies associations that reflect deposition in a range of continental environments. These include sediments that were deposited in braided river systems, which were best developed in the Early Jurassic. These early river systems infilled the relics of a topography that was possibly inherited from earlier Triassic rifting. More mature fluvial land systems evolved in the Mid to Late Jurassic. By the Mid Jurassic, well-defined overbank areas had become established, channel abandonment was commonplace, and mudrocks were deposited on floodplains. Coal deposition occurred in mires, which were subject to periodic incursions by crevasse splay processes. Cretaceous sedimentation saw a renewed influx of sand-grade sediment into the region. It is proposed that landscape evolution throughout the Jurassic was driven simply by peneplanation rather than tectonic processes. By contrast, the influx of sandstones in the Cretaceous is tentatively linked to hinterland rejuvenation/ tectonic uplift, possibly coeval with the growth of large deltaic clinoform complexes of the Neocomian in the basin subsurface. 相似文献
17.
The most intense area of Mesozoic volcanism and main region of hydrothermal-type uranium deposits is located in Eastern China. From the northern to the southern part, it can be divided into seven volcanic belts of Great Xing’an Range, Lesser Xing’an-Zhangguangcai Ranges, Northern Hebei-Western Liaoning, the Lower Yangtze Region, Ganhang areas, Wuyi Mountain areas,the Southeast Coastal areas, five uranium metallogenic belts of Guyuan-Hongshanzi, Qinglong-Xingcheng, Luzong-Qixia, Ganhang, Wuyi Mountain, and Three uranium metallogenic perspective belts of Manzhouli-Erguna, Zhalantun, Yichun. The volcanism of all these volcanic belts can be subdivided into six stages: The Early Jurassic to early Middle Jurassic, late Middle Jurassic to early Late Jurassic, early Early Cretaceous, middle Early Cretaceous, late Early Cretaceous and early Late Cretaceous. High-K calc-alkaline rhyolite-alkali trachyte rock assemblage of the early Early Cretaceous has a close connection with the explored uranium deposits. High-K calc-alkaline rhyolites have high content of uranium, and can provide the epithermal ore forming system with uranium; Alkali trachyte associated with mantle-derived magmatism can provide alkaline ore-forming fluid of rich uranium for deep temperature mineralizing system or act as pioneers of alkaline ore-forming fluid of rich uranium. 相似文献
18.
辽东南地区中生代受到三期构造运动的影响且各具特色:①三叠纪的印支运动以形成东西向构造线及较多的"S"型花岗岩为特征;②侏罗纪的早燕山运动以近东西向挤压为主,在辽南地区以形成线理走向为北西西向的推覆构造为特征;③晚侏罗世晚期到早白垩世的晚燕山运动产生大量北东、北北东向断裂,同时发生了强烈的左行走滑。上述三期构造运动对金矿的形成均有一定的影响,三个时期均有一定规模的金矿化作用,金矿化的主要时期是在晚侏罗世晚期到早白垩世。 相似文献
19.
大兴安岭西坡及邻区银铅锌矿床成矿作用若干问题的讨论 总被引：4，自引：0，他引：4
本文概述了大兴安岭西坡及邻区陆相火山岩型银铅锌矿床的基本特征,讨论了该类矿床成矿作用和成矿规律研究中的成矿物质来源、成矿系列和成矿控制因素几个重要问题。认为大兴安岭西坡及俄、蒙邻区的银铅锌矿床,实际上构成了一个与燕山期火山一次火山岩浆活动具有成因联系的银铅锌矿床成矿系列。大兴安岭西坡及邻区燕山中晚期大规模中酸性富碱的火山一次火山岩浆作用是该区这一时期或稍晚银铅锌矿床（可能还包括铜、铝、锡等矿产）集中出现的本质原因和物质基础,它也反映了深部壳慢作用过程中物质分异、聚集和演化的地球化学过程。关键词大… 相似文献
20.
Geological and Geochemical Characteristics of the Hydrothermal Clay Alteration in South Korea 总被引：1，自引：1，他引：0
Sang-Mo KOH Tetsuichi TAKAGI Moon–Young KIM Kazuki NAITO Sei–Sun HONG Sadahisa SUDO 《Resource Geology》2000,50(4):229-242
Abstract: Hydrothermally altered areas forming pyrophyllite‐kaolin‐sericite‐alunite deposits are distributed in Chonnam and Kyongsang areas, Cretaceous volcanic field of the Yuchon Group. The Chonnam alteration area is located within depression zone which is composed of volcanic and granitic rocks of late Cretaceous age. The clay deposits of this area show the genetic relationship with silicic lava domes. The Kyongsang alteration area is mainly distributed within Kyongsang Basin comprising volcanic, sedimentary and granitic rocks of Cretaceous and Tertiary age. Most of the clay deposits of this area are closely related to cauldrons. Paleozoic clay deposit occurs in the contact zone between Precambrian Hongjesa granite gneiss and Paleozoic Jangsan quartzite of Choson Supergroup. Cretaceous igneous rocks of the both alteration areas belong to high K calc‐alkaline series formed in the volcanic arc of continental margin by subduction‐related magmatism. Chonnam igneous rocks show more enrichment of crustal components such as K, La, Ce, Sm, Nd and Ba, higher (La/Yb)cn ratio, and higher initial 87Sr/86Sr ratio (0. 708 to 0. 712) than those of Kyongsang igneous rocks. This might be due to the difference of degree of crustal contamination during Cretaceous magmatism. The most characteristic alteration minerals of Chonnam clay deposits are alunite, kaolin, quartz, pyrophyllite and diaspore which were formed by acidic solution. Those of Kyongsang clay deposits are sericite, quartz and pyrophyllite which were formed by weak acid and neutral solution. The formation ages of the clay deposits of two alteration areas range from 70. 1 to 81. 4 Ma and 39. 7 to 79. 4 Ma, respectively. The Daehyun clay deposit in Ponghwa area of Kyongsang province shows the alteration age range from 290 to 336 Ma. This result shows the different alteration episode from the hydrothermal alteration of Cretaceous to early Tertiary in the Kyongsang and Chonnam alteration areas. These data indicate, at least, three hydrothermal activities of Tertiary (middle to late Eocene), late Cretaceous (Santonian to Maastrichtian) and Paleozoic Carboniferous Periods in South Korea. 相似文献