样子哨盆地地质特征及其成矿作用

样子哨盆地位于龙岗隆起北西部,具有多时代叠加沉积,多期次构造演化特征。地层主要由上元古界、古生界、中生界、新生界组成,沉积中心由北东向南西转移;区内褶皱构造发育,上元古界褶皱构造以全形紧密褶皱为主,古生界褶皱构造以全开阔线形复式褶皱为主;盆地找矿前景较好,在南西部具备形成矽卡岩型多金属矿的地质条件,南东部沿盆缘断裂具备形成浅成低温热液型金矿的地质条件,盆地中部中生界煤系地层也较发育。     

潮水盆地北缘构造演化特征及其与砂岩型铀成矿关系初析

系统阐述了潮水盆地的区域地质构造背景、构造演化动力学特征、盆地北缘目的层构造特征，综合分析了构造与铀成矿的关系，指出早中侏罗世伸展构造环境下形成找矿目的层，晚第三纪以来的挤压抬升为渗入型自流水盆地形成提供必要条件，多期次构造运动使盆地北缘形成平缓的构造斜坡带，而断块构造运动既有利于层问氧化带的发育。又限制其发展规模。     

地震相关的软沉积物构造变形及其在盆地演化中的意义

以两类新发现的软沉积物变形构造——同沉积拉张构造和同沉积挤压构造为例,探讨其成因机理和在盆地构造演化中的意义。同沉积拉张构造类似于沉积布丁构造,同沉积挤压构造类似挤压岩枕,分别记录了拉张和挤压背景下处于地震活动带的沉积盆地所受到的应力状态及其方向,揭示了盆地分别处于威尔逊旋回的裂谷盆地和残余盆地阶段。同沉积布丁构造发现于内蒙古白云鄂博东南约25km的腮林忽洞群下部的薄层石灰岩中。这些构造只在某些特定的层段中顺层发育,薄层青灰色泥质微晶灰岩条带几乎层层都被密集的同生小断裂错开,而与之相间分布的浅黄灰色薄层微…     

南海南部礼乐盆地构造热演化研究

礼乐盆地位于南海海域南部,是一个形成于中新生代的叠合盆地,长期以来缺乏构造热演化方面研究。本文在认识礼乐盆地构造演化的基础上,选用盆地内地震测线(L2剖面),应用二维横向不均匀拉张模型对礼乐盆地构造热演化史进行了模拟研究。模拟结果揭示了盆地在新生代的构造热演化特征:(1)盆地经历了两次连续的拉张过程,第一期拉张幅度较小,拉张系数在1.05左右,第二次拉张程度较第一次拉张强烈,深水地区拉张系数达到1.3;(2)礼乐盆地两次拉张使得盆地逐步升温,第二次拉张结束时达到历史最高温时期,之后热流持续下降;(3)盆地不同构造部位热流史具有差异性,其中深水区经历的古热流最高,达75mW/m2,礼乐滩最低,仅为63mW/m2。     

青藏高原东北部贵德盆地新生代沉积演化与构造隆升

通过对高原东北部贵德盆地新生代地层研究,为恢复高原隆升历史提供依据。贵德盆地形成于渐新世末,其新生代地层可划分出深水砾砂质网状河流、泥石流质网状河流、砾质网状河流、山麓洪积、三角洲、半深湖与浅湖、水下扇三角洲七个沉积相组合体系。根据其沉积相组合和沉积演化揭示出高原隆升过程先后经历了:早期隆升期 (渐新世末 )、较稳定剥蚀夷平期 (早中新世 )、小幅隆升期 (早中新世末 )、稳定剥蚀夷平期 (中中新世至晚中新世 )、持续逐步较快速隆升期 (8.2～ 3.6Ma)、急剧强烈阶段性隆升期 (3.6～ 0Ma) ;其中 3.6Ma±的隆升是新生代构造运动的一个重要分水岭,此前盆地海拔应不超过 10 0 0m,此后构造活动速度明显加速,地形高差显著增大。可见青藏高原的隆升是一个多阶段、不等速和非均变的复杂过程     

海南岛周邻新生代沉积盆地构造与差异性演化特征

海南岛周邻发育有4个重要的新生代沉积盆地,即莺歌海盆地、北部湾盆地、琼东南盆地和珠江口盆地珠三凹陷。根据最新的地球物理数据,重新厘定这些盆地的构造与沉积演化及其与海南岛陆上构造的关联。这些盆地发育NE和NW向断裂构造,但存在极大差异性。前者受红河哀牢山断裂构造影响,表现为张扭性的拉分盆地。而后三个盆地则总体表现为裂陷盆地,夹于江绍 博白断裂与丽水 南澳断裂南段之间。伸展始于古新世,具有四次裂陷作用,并发育NW向走滑伸展断层。晚期岩浆对沉积盆地具有一定改造作用,表现岩浆喷发、热流值高。我们厘定了这些NE向断裂在海南岛延伸,滨海断裂可能延至海南岛东南缘,并表现出明显的地震活动性,推断海南岛新生代构造演化与南海北部陆缘演化具有一致性。     

中国东南部中、新生代盆地特征与构造演化

中国东南部中、新生代盆地与花岗岩构成了复杂的盆岭镶嵌体系--华南盆岭构造.根据盆地的几何学、运动学、动力学与构造演化特征,将研究区中、新生代盆地划分为类前陆盆地、裂谷盆地和断陷盆地三大类型.对晚三叠世以来各个时代盆地的规模、产状、边界、岩石组合、指相矿物、沉积构造进行了分析.不同时代盆地的特征和重点区段盆区岩层的节理测量-统计结果表明,晚三叠世以来研究区的盆-岭格局至少经历过4期地球动力学演化.该盆-岭体系具有密切的时空和成因联系,二者时间相近,空间相伴,成因相关.研究表明,永定-龙南-始兴是一个中侏罗世陆内裂谷带,武夷山是晚中生代的古地理与气候分隔带,赣江带是晚中生代的火山岩界线.     

中国东南部中、新生代盆地特征与构造演化

中国东南部中、新生代盆地与花岗岩构成了复杂的盆岭镶嵌体系--华南盆岭构造.根据盆地的几何学、运动学、动力学与构造演化特征,将研究区中、新生代盆地划分为类前陆盆地、裂谷盆地和断陷盆地三大类型.对晚三叠世以来各个时代盆地的规模、产状、边界、岩石组合、指相矿物、沉积构造进行了分析.不同时代盆地的特征和重点区段盆区岩层的节理测量-统计结果表明,晚三叠世以来研究区的盆-岭格局至少经历过4期地球动力学演化.该盆-岭体系具有密切的时空和成因联系,二者时间相近,空间相伴,成因相关.研究表明,永定-龙南-始兴是一个中侏罗世陆内裂谷带,武夷山是晚中生代的古地理与气候分隔带,赣江带是晚中生代的火山岩界线.     

地震反射剖面揭示的苏北盆地北缘构造特征及其演化

苏北盆地位于下扬子板块东北部鲁苏隆起的南侧,由于构造位置特殊,其构造演化比较复杂。利用高分辨率反射剖面资料,得到苏北盆地北缘清晰的地下结构和断裂形态。结果表明,整个剖面以大东凸起为对称轴,两侧箕状凹陷近似对称发育,涟南凹陷呈南深北浅的形态,涟北凹陷呈南浅北深的形态,该凹陷内正断层发育。这些研究成果为建立研究区的构造演化模式提供了重要的信息,推测自白垩纪末期以来,研究区在印度板块碰撞和太平洋板块碰撞影响下,拉张裂隙和挤压隆起2种作用交替进行,形成了对称箕状凹陷。     

样子哨盆地北缘找矿前景

样子哨盆地北缘构造岩浆活动强烈,成矿地质条件有利。盆地北西北东向韧性剪切带叠加有后期脆性构造,带内发育有串珠状Au元素化探异常,且与已知金矿床（点）吻合较好,类比认为韧性剪切带型金矿具有良好的找矿前景;南东侧盆缘断裂表现为多期次活动叠加的特点,沿断裂带充填有含金硅化蚀变岩,应注意寻找中低温热液型金矿;盆地中早侏罗世闪长岩、花岗斑岩侵入灰岩中,在其周围相应伴随有Au、Ag、Cu、Pb、Zn、W、Mo等元素化探异常,矽卡岩型铜钼矿找矿前景较好。     

准噶尔盆地的原型和构造演化

文中讨论了以下三个问题:(1)洋-陆转换时限和中、晚石炭世盆地原型。根据准噶尔盆地及其邻区的构造演化及岩浆活动研究,洋-陆转换时限应为早石炭世末,中、晚石炭世裂陷槽是由于造山期后伸展塌陷作用产生的;(2)二叠纪—早更新世陆内盆地的原型。根据陆内盆地的鉴别标志,提出了二叠纪盆地为陆内裂谷—裂谷期后弱伸展坳陷—弱缩短挠曲坳陷,三叠纪、侏罗纪、白垩纪和第三纪为弱伸展或稳定大陆内坳陷和陆内前陆坳陷或弱缩短挠曲坳陷交替的叠合盆地;(3)准噶尔盆地原型和构造演化对油气分布的控制作用。     

Structural characteristics and evolution of the South Yellow Sea Basin since Indosinian

Based on the seismic data gathered in past years and the correlation between the sea and land areas of the Lower Yangtze Platform, the structural characteristics of the South Yellow Sea Basin since the Indosinian tectonic movement is studied in this paper. Three stages of structural deformation can be distinguished in the South Yellow Sea Basin since the Indosinian. The first stage, Late Indosinian to Early Yanshanian, was dominated by foreland deformation including both the uplifting and subsidence stages under an intensively compressional environment. The second stage, which is called the Huangqiao Event in the middle Yanshanian, was a change for stress fields from compression to extension. While in the third stage (the Sanduo Event) in the Late Himalayan, the basin developed a depression in the Neogene-Quaternary after rifting in the Late Cretaceous-Paleogene. The long-time evolution controlled 3 basin formation stages from a foreland basin, then a fault basin to a final depression basin. In conclusion, since the Indosinian, the South Yellow Sea Basin has experienced compressional fold and thrust, collisional orogen, compressional and tensional pulsation, strike-slip, extensional fault block and inversion structures, compression and convergence. The NE, NEE, nearly EW and NW trending structures developed in the basin. From west to east, the structural trend changed from NEE to near EW to NW. While from north to south, they changed from NEE to near EW with a strong-weak-strong zoning sequence. Vertically, the marine and terrestrial facies basins show a “seesaw” pattern with fold and thrust in the early stages, which is strong in the north and weak in the south and an extensional fault in later stages, which is strong in the north and weak in the south. In the marine facies basin, thrust deformation is more prevailing in the upper structural layer than that in the lower layer. The tectonic mechanism in the South Yellow Sea Basin is mainly affected by the collision between the Yangtze and North China Block, while the stress environment of large-scale strike-slip faults was owing to subduction of the Paleo-Pacific plate. The southern part of the Laoshan uplift is a weak deformation zone as well as a stress release zone, and the Meso-Paleozoic had been weakly reformed in later stages. The southern part of the Laoshan uplift is believed, therefore, to be a promising area for oil and gas exploration.     

Late Mesozoic rift evolution and crustal extension in the central Songliao Basin,northeastern China: constraints from cross-section restoration and implications for lithospheric thinning

The Songliao Basin, the largest oil-producing basin in China, was the centre of late Mesozoic rifting and lithospheric thinning in northeastern China. However, the rifts are still poorly revealed due to a thick cover of subsidence successions. By structural interpretation and sequential restoration of cross-sections based on new 2D seismic data and well data, this study presents the structural style, basin evolution, and horizontal crustal extension of the central Songliao Basin. We have developed a novel method to retrieve the regional extension principal strains. The results enable an assignment of rifting into two episodes. The earlier episode (ca. 157–130 Ma) was dominated by distributed faulting of numerous planar normal faults trending NNE–SSW, NNW–SSE, or near NS, probably reflecting pre-existing basement fabrics; in contrast, the later episode (ca. 130–102 Ma) was controlled by localized extension along several major listric faults. Horizontal crustal extension during rifting is estimated to have been 11–28 km (10.6%–25.5%), with the long-term average rate varying from 0.20 to 0.51 mm yr^–1. Regional horizontal strains show a gradual evolution from biaxial extension at the beginning of rifting to WNW–ESE uniaxial stretching during the later rifting episode. Brittle crustal extension is interpreted to have been associated with vertical strain due to tectonic stretching, which is estimated to have contributed more in thinning the lower crust than the mantle lithosphere. Accordingly, a two-episode dynamic model is proposed to explain rifting in the Songliao Basin. We suggest that the earlier event was dominated by delamination of the thickened continental lithosphere, whereas the later event was probably controlled by regional crustal detachment due to slab subduction and stagnancy of the Izanagi lithospheric plate.     

东北地区拉布达林盆地的构造特征及早白垩世变形序列

拉布达林盆地为内蒙-大兴安岭古生代碰撞造山带之上的中生代断陷盆地,主要发育下白垩统和第四系.拉布达林盆地的构造特征复杂,主要发育NE向、NEE向和NW向构造,其中NE向构造主要为一系列NE向犁式正断层及其与之相伴的同向正断层组合,NEE向构造具有剪切正断层的性质,NE向和NEE向断层都是形成于塔木兰沟组-伊列克得组沉积时期的控陷断层,它们是形成于同一应力场具有不同力学性质的构造.NW向断层形成较晚,切割了NE向和NEE向断层,具有左行走滑的特征.在大磨拐河组沉积时期经历了较大规模的挤压作用,不仅使部分早期NE向控陷正断层发生正反转作用,而且形成断层转折褶皱和断层传播褶皱.依据反射地震资料及相关地质资料,确定拉布达林盆地在早白垩世经历了3期变形作用,即塔木兰沟组-伊列克得组沉积时期的NW-SE向的伸展作用、大磨拐河组沉积时期的NW-SE向挤压作用和伊敏组沉积时期的近EW向伸展作用.     

Tectonic framework of Tiburon Basin,Gulf of California,from seismic reflection evidence

Tiburon Basin is characterized by a thick sedimentary fill that records the evolution of one of the rift segments of the East Pacific Rise. Its structure corresponds to an echelon pull-apart basin bounded by two dextral-oblique faults. Unlike basins in the southern Gulf of California that are underlain by oceanic crust, rift basins in the northern Gulf of California contain sedimentary thickness (up to 6 km) that masks the structure of the crust. To study the architecture of the Tiburon Basin, two-dimensional, multichannel seismic reflection data collected by Petróleos Mexicanos (PEMEX) in the early 1980s were used. The data base is a grid of lines, 5–20 km apart, with 6 s of record in 48 channels. Additional seismic data of the Ulloa 99 project were also interpreted. Our results indicate that the general structural pattern of the Tiburon Basin is controlled by two dextral-oblique faults: De Mar and Tiburon. De Mar lies to the east and ends in elevated basement transferring the stress to the Desemboque fault. The latter borders the incoming basement from the Sonora and Tiburon faults to the west, ending to the north in an antiform. Four structural domains are recognized: (1) the northern Tiburon domain is a high basement that divides the Delfin Basin to the northeast and exhibits extensional folds with their axes parallel to the basement and its flanks; (2) the Libertad domain is a sheared basement high along the margin of Sonora and forms the right step of the Tepoca Basin to the north; (3) the Tiburon central domain defines a broad sag cut by a dense NE-striking pattern of normal faults with opposed dips in the depocentre and abruptly ends to the west against the Tiburon fault; and (4) the southern Tiburon domain forms a basement ramp offshore Isla Tiburon and is controlled by a pattern of NNE-striking normal faults on the south that likely connect at an oblique angle (?60°) to the De Mar fault. We propose a rhombochasm basin model with more than 6 s of sedimentary record in the depocentre, in which the basement is not recorded. The NW-trending faults in the Libertad domain possibly continue towards the Sonora coastal plain. The principal NW-trending dextral faults and the secondary NNE-striking pattern of normal faults cut the shallow strata of this domain.     

Earthquake-related Tectonic Deformation of Soft-sediments and Its Constraints on Basin Tectonic Evolution

The authors introduced two kinds of newly found soft-sediment deformation-synsedimentary extension structure and syn-sedimentary compression structure, and discuss their origins and constraints on basin tectonic evolution. One representative of the syn-sedimentary extension structure is syn-sedimentary boudinage structure, while the typical example of the syn-sedimentary compression structure is compression sand pillows or compression wrinkles. The former shows NW-SE-trendlng contemporaneous extension events related to earthquakes in the rift basin near a famous Fe-Nb-REE deposit in northern China during the Early Paleozoic （or Mesoproterozoic as proposed by some researches）, while the latter indicates NE-SW-trending contemporaneous compression activities related to earthquakes in the Middle Triassic in the Nanpanjiang remnant basin covering south Guizhou, northwestern Guangxi and eastern Yunnan in southwestern China. The syn-sedimentary boudinage structure was found in an earthquake slump block in the lower part of the Early Paleozoic Sailinhudong Group, 20 km to the southeast of Bayan Obo, Inner Mongolia, north of China. The slump block is composed of two kinds of very thin layers-pale-gray micrite （microcrystalline limestone） of 1-2 cm thick interbedded with gray muddy micrite layers with the similar thickness. Almost every thin muddy micrite layer was cut into imbricate blocks or boudins by abundant tiny contemporaneous faults, while the interbedded micrite remain in continuity. Boudins form as a response to layer-parallel extension （and/or layer-perpendicular flattening） of stiff layers enveloped top and bottom by mechanically soft layers. In this case, the imbricate blocks cut by the tiny contemporaneous faults are the result of abrupt horizontal extension of the crust in the SE-NW direction accompanied with earthquakes. Thus, the rock block is, in fact, a kind of seismites. The syn-sedimentary boudins indicate that there was at least a strong earthquake belt on the southeast side of the basin during the early stage of the Sailinhudong Group. This may be a good constraint on the tectonic evolution of the Bayan Obo area during the Early Paleozoic time. The syn-sedimentary compression structure was found in the Middle Triassic flysch in the Nanpanjiang Basin. The typical structures are compression sand pillows and compression wrinkles. Both of them were found on the bottoms of sand units and the top surface of the underlying mud units. In other words, the structures were found only in the interfaces between the graded sand layer and the underlying mud layer of the flysch. A deformation experiment with dough was conducted, showing that the tectonic deformation must have been instantaneous one accompanied by earthquakes. The compression sand pillows or wrinkles showed uniform directions along the bottoms of the sand layer in the flysch, revealing contemporaneous horizontal compression during the time between deposition and diagenesis of the related beds. The Nanpanjiang Basin was affected, in general, with SSW-NNE compression during the Middle Triassic, according to the syn-sedimentary compression structure. The two kinds of syn-sedimentary tectonic deformation also indicate that the related basins belong to a rift basin and a remnant basin, respectively, in the model of Wilson Cycle.     

吉南老岭地区早白垩世铝质A型花岗岩的厘定及其构造意义

主微量元素分析和LA-ICP-MS锆石U-Pb年龄显示吉南老岭地区的头道、老岭、上绿水桥和高台子岩体为一套早白垩世铝质A型花岗岩.主要岩性为钾长花岗岩、晶洞钾长花岗岩、花岗斑岩和花岗岩.LA-ICP-MS锆石U-Pb年龄为121~125Ma.主量元素具有富Si、alk, 贫Fe、Mg、Ca、Ti的特征; 微量元素亏损Ba、Sr、Ti、Nb、Ta、P, 富集K、Rb、Th等不相容元素; 稀土元素具有中等到强烈的负铕异常及右倾海鸥型的球粒陨石标准化稀土配分模式.元素地球化学特征表明岩体为铝质A型花岗岩(A/CNK=0.82~1.15, A/NK=1.00~1.28).岩石具有较低的不相容元素Ce/Nb、Y/Nb、Yb/Ta比值, 为A₁型非造山花岗岩.研究表明吉南老岭地区早白垩世时处于非造山的伸展构造环境, 是华北板块东部早白垩世伸展地球动力学背景在吉林南部地区的岩浆活动体现.      

准噶尔西部陆内盆地构造演化与油气聚集

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