平谷地裂缝基本特征与成因分析

平谷地裂缝是平谷盆地内一类重要的地质灾害,近些年来裂隙有所加剧,已经影响到了人们生产生活。本文对平谷地裂缝及隐伏夏垫断裂北段进行勘探研究,总结了平谷地裂缝的基本特征,讨论了地裂缝发育的成因机制及其与隐伏夏垫断裂关系。研究表明：平谷地裂缝主要分布于古白河冲洪积扇地下水溢出带,沿今错河河道分布,主要发育为北东或北西向两组,性质为张裂隙;地裂缝发育长度、深度规模有限,一般埋深约7-8m,无“断裂根”构造;地裂缝浅表层充填震动砂脉,揭示了震动液化的根本成因,而现今呈现裂缝塌陷是早期震动液化裂隙在降水或灌溉淋滤作用下砂土流失表现;隐伏夏垫活动断裂构造可能制约了平谷地裂缝发育位置和地裂缝分布特征,断裂带附近应力集中和节理破裂可能是地裂缝发育的构造基础。     

渤海湾盆地中、新生代构造演化研究

根据中生界上侏罗统和下白垩统地层和控盆断裂分布分析,中生代晚期晚侏罗—早白垩世郯庐断裂带的左旋走滑平移导致郯庐断裂带以西自北向南发育了3个北西向断堑系,即北部的渤海断堑系、中部的济阳断堑系和南部的鲁西南断堑系。从区域资料综合分析,渤海湾盆地的基本格局是早第三纪以来的新生代盆地格局。渤海湾盆地的形态、构造和沉积特征及热流值分布表明该盆地在新生代为拉分盆地。根据渤海湾盆地的各个坳陷内新生代各时期的地层分布、沉积厚度和控盆边界断裂在各时期的空间位置以及活动性质综合分析,恢复了盆地新生代以来的构造演化格局。中、新生代盆地构造和沉积分布特征表明渤海湾盆地是一个中、新生代叠合盆地。     

大同盆地晚新生代环境演化特征

大同盆地是一受北东向主干断裂控制的不对称地堑盆地。盆地基底形态控制了晚新生代沉积的厚度、结构和分布规律。大同盆地古湖泊在上新世早期即已存在,并被盆地中部呈北东走向的玄武岩垅岗分隔成南北两部分;由于构造运动和古气候变化的影响,早更新世早期湖泊发育达到全盛期,然后几经扩张与收缩,于晚更新世早期逐惭消亡。河流与湖泊的相互消长在盆地内沉积了一套河湖相地层,其物质来源主要是东北部火山岩和变质岩分布区。     

北京平谷马坊Zk09钻孔新生代地层格架及其地质意义

本文基于北京平谷马坊地区Zk09钻孔新生代地层岩性岩相分析和沉积物古地磁等测试,建立了北京平原泃河水系中下游冲洪积区完整新生代地层格架。其中,0m～180m为中更新世-全新世陆相辫状河和曲流河沉积,180m～240.5m为中新世-上新世残坡积、湖积和三角洲前缘沉积。Zk09钻孔新生代不连续地层揭示了北京平原区两次重要的抬升构造事件：第一期构造事件发生于中新世,而不是前人研究认定的早更新世或上新世末,其最终结束了大渤海湾盆地古近纪盆-岭构造系统演化;第二次构造事件发生于中更新世早期,其可能是目前以走滑运动为主的最新构造变动形式起始时间。     

合肥盆地逆掩冲断带地质-地球物理综合解释及其大地构造属性

在大量地震剖面综合解释的基础上 ,提出华北板块与北淮阳晚加里东 -早海西期褶皱带的界线应在六安断裂 ,肥中断裂是华北陆壳型基底与其过渡壳型基底的大致分界。首次发现合肥盆地侏罗系之下存在以青白口系刘老碑组泥质岩为主滑脱层的印支期形成的由南向北滑脱冲断、主要卷入华北地台及其被动陆缘上元古 -古生界的完整冲断体系 ,并认为侏罗纪盆地为再生前陆盆地 ,编制了前侏罗系基岩地质图 ,为研究华北、大别及扬子三大块体的相互关系提供了新资料     

柴达木盆地北缘下、中侏罗统古地理及盆地类型研究

柴达木盆地北缘侏罗系后期改造强烈,地层赋存复杂,从地面露头、钻井、地震等资料入手,采用单因素分析多因素综合作图法,对下、中侏罗统岩相古地理进行了定量研究.认为早中、侏罗世时期该区主要发育湖泊相,以滨浅湖-半深湖相为主;现今下、中侏罗统的分布范围并不代表其原始沉积盆地的边界,原始沉积盆地的北边界在南祁连山边界大断裂附近;北缘早、中侏罗世时期为伸展断陷盆地.     

中新生代天山及其两侧盆地性质与演化

天山两侧中新生代盆地中的沉积记录、沉积中心展布及其迁移特征反映了盆地演化特征,天山地区的年代学数据则是构造活动的响应。这些沉积学记录、年代学记录及山前构造变形与天山地区的构造演化、天山快速隆升和区域地壳缩短相对应,反映晚侏罗世晚期—早白垩世早期、晚新生代是天山快速隆升的2个时期,也是盆地性质发生转变的重要时期。综合分析认为,天山两侧盆地早中侏罗世为陆内断陷坳陷盆地阶段,晚侏罗世—早白垩世早期盆地开始进入挤压背景下的陆内坳陷盆地阶段,晚新生代开始发育再生前陆盆地。天山晚新生代构造变形总体显示西强东弱的特点,这种变形差异可能与帕米尔构造结的向北推挤有关。     

福州盆地的形成与演变

福州盆地是在早更新世周围山地剧烈上升过程中,相对下沉而形成的一个山间断陷盆地。中更新世时期盆地长期稳定,并发育了完整的红色风化壳;晚更新世时期持续沉降,并在玉木上、下亚间冰期中两度遭受海侵;全新世以来,经历了规模空前的长乐海侵而长期处于海湾环境之中,直至1500aBP才脱离海水影响。水负荷和沉积物负荷导致的均衡作用,使盆地全新世中期以来沉降速度成倍增加。     

三门峡盆地重力异常特征与构造格局

三门峡盆地位于汾渭地堑系东南端,秦岭纬向构造带和新华夏构造的交汇部位。研究其构造格局对盆地油气勘探具有重要意义。本文综合利用布格重力资料和野外观测资料,刻画盆地断裂特征并划分了构造单元。研究结果表明,三门峡盆地主要发育近EW向、NE向和NW向三组断裂系,包括4条边界断裂和13条盆地内次级断裂,且边界断裂多以断裂带形式呈现。盆地断裂多形成于前新生代,至第四纪趋于稳定,具有延伸长、切割深的特点。盆地西部布格重力异常值相对较高,剩余重力场盆内自北向南呈近EW向低-高-低的条带分布,且存在多个异常值不同的区域,表明新生代沉积地层较厚,并受断裂控制出现了沉降差异。受中条山南断裂、文底-宫前断裂、灵宝-三门峡断裂和三门峡-硖石断裂等断裂控制,三门峡盆地可划分为3个二级构造单元和9个三级构造单元,盆地自北向南依次为北部坳陷带、中部低隆起和南部坳陷带。整体表现为南北分带、凹隆相间的构造格局。     

共和盆地地貌发育与环境演化探讨

本文讨论了青藏高原东北部一个大型断陷盆地晚新生代期间地貌发育与环境演化问题,中新世至中更新世为盆地沉陷阶段,其中晚第三纪为青海东部内陆古湖的一部分,第四纪早期黄河发育,形成河湖交替环境,中更新世之后为盆地上升阶段,促使水系演化并形成最多达13级的黄河阶地与龙羊峡谷,气候从温暖湿润向干燥寒冷发展,特别自晚更新世晚期以来,在数次干寒环境下形成多种冰缘形态和风沙堆积,并促使湖泊退缩和咸化。     

中非裂谷盆地构造演化差异性与构造动力学机制

分析了不同空间位置盆地的构造演化差异性，并结合区域构造事件探讨了中非裂谷盆地的构造动力学成因机制。中非裂谷盆地包括两个分支体系：西非裂谷系主要呈左旋走滑双断式结构；中非裂谷系主要表现为单断式右旋走滑结构。研究区内有走滑盆地和伸展盆地两种类型：前者位于走滑断裂带内部，近似平行于走滑断裂带展布，走滑作用强，构造反转明显；后者位于走滑断裂带端部，与走滑断裂带斜交，伸展作用强，构造反转较弱。中非裂谷盆地发育3期裂陷—拗陷构造旋回：早白垩世，中非盆地同时发生强烈的裂陷作用；晚白垩世，不同空间位置盆地的裂谷作用强度差异明显并且经历构造反转；古近纪，只有近NW-SE向盆地发生第三期裂谷作用，而其他盆地处于拗陷期。中非裂谷盆地是非洲陆缘板块构造运动在非洲陆内3个块体差异应力作用的陆内响应，3期裂谷作用的构造动力来源不同：早白垩世中大西洋扩张、晚白垩世南大西洋快速扩张和印度洋扩张双重作用、古近纪非洲板块与欧洲板块主要碰撞及西北印度洋中脊扩张影响。     

基于绕射波的碳酸盐岩储层缝洞识别方法及应用

在塔里木盆地北部奥陶系碳酸盐岩储层中,沿断裂发育的溶洞和裂缝是重要的油气储集空间.因此,对于缝洞型油藏的地震识别关键在于断裂、裂缝和溶洞的刻画.溶洞和裂缝等储集空间存在形态多样性、多尺度性和非规则性,导致其地震响应通常表现为复杂的绕射波特征.基于绕射波的识别方法可从地震数据中去除反射波,只利用地震波场中的绕射信息进行分析.为此,首先基于平面波破坏滤波和均值滤波技术,从常规反射波数据中分离出绕射波数据;然后对比了不同分离程度的绕射波数据对溶洞的刻画能力;最后基于绕射波实际资料,对比分析相干属性和最大似然属性对断裂和裂缝的识别能力.实际资料的应用表明,绕射波信息能够有效地识别溶洞、小尺度断裂和裂缝等地质体,对碳酸盐岩缝洞型油气藏研究具有重要意义.     

Discussion on marine source rocks thermal evolvement patterns in the Tarim Basin and Sichuan Basin, west China

Taking marine source rocks of lower Paleozoic in the Tarim Basin and Paleozoic ones in the Sichuan Basin as examples, their sedimentation process could be classified into four styles continuous subsldence with deep sedimentation in early stage, continuous subsidence with deep sedimentation in later stage, that deeply buried-uplift-shallowly buried, and that shallowly buried-uplift-deeply buried.Unlike that in East China, the marine source rocks evolvement patterns did not accord with sedimentation styles one by one in superimposed basins in west China. Taking local geothermal field into account, four types of source rock evolvement patterns were built that evolved fast in early stage,evolved fast in middle stage, evolved continuously and evolved in multistage. Among them, the 1st pattern contributed little to the present industrial oil pools directly, but paleo-oil reservoirs and gases cracked from crude oils were main exploration targets. Although some gases were found in the 2nd pattern, the scale was not big enough. For the 3rd and 4th patterns, the hydrocarbon potential depended on organic matters maturity in early stage. For relatively low mature rocks, it was possible to generate some oils in later stage; otherwise the main products were gases. Paleo-oil reservoirs remained fairly well in the Sichuan Basin, and most source rocks underwent kerogen-oil-gas processes,which was useful reference to gas exploration in the Tarim Basin.     

Episodic rifting of continental marginal basins and tectonic events since 10 Ma in the South China Sea

Integrated study on the tectonic, basin filling and thermal evolution of the Tertiary basins on the northern margin of the South China Sea has indicated that the rift continental margin on the northern South China Sea is not a passive margin and that the western margin is characteristic of the transform-extension. Episodic rifting and the thermal events since 10 Ma in the area have been documented by the integrated analysis of dynamic process. It has been clarified that the tectono-thermal events have exerted a significant influence on basin features and hydrocarbon accumulation, and particularly, the westward collision of the Lusong Island Arc, the generation of densely spaced faults in the Pearl River Mouth Basin, the rapid subsidence, high heat flow and large-scale over pressure and thermal-fluid breakthrough in the Yinggehai and the Qiongdongnan basins have proved to be the important factors determining the formation of oil and gas in these basins.     

Discussion on marine source rocks thermal evolvement patterns in the Tarim Basin and Sichuan Basin,west China

Taking marine source rocks of lower Paleozoic in the Tarim Basin and Paleozoic ones in the Sichuan Basin as examples, their sedimentation process could be classified into four styles: continuous subsidence with deep sedimentation in early stage, continuous subsidence with deep sedimentation in later stage, that deeply buried-uplift-shallowly buried, and that shallowly buried-uplift-deeply buried. Unlike that in East China, the marine source rocks evolvement patterns did not accord with sedimentation styles one by one in superimposed basins in west China. Taking local geothermal field into account, four types of source rock evolvement patterns were built: that evolved fast in early stage, evolved fast in middle stage, evolved continuously and evolved in multistage. Among them, the 1st pattern contributed little to the present industrial oil pools directly, but paleo-oil reservoirs and gases cracked from crude oils were main exploration targets. Although some gases were found in the 2nd pattern, the scale was not big enough. For the 3rd and 4th patterns, the hydrocarbon potential depended on organic matters maturity in early stage. For relatively low mature rocks, it was possible to generate some oils in later stage; otherwise the main products were gases. Paleo-oil reservoirs remained fairly well in the Sichuan Basin, and most source rocks underwent kerogen-oil-gas processes, which was useful reference to gas exploration in the Tarim Basin.     

Natural gas geochemistry of low evolutionary stage of medium- and small-sized basins in Yunnan Province, southwestern China

The biogenic gas and premature-low mature associated gases in some medium and small-sized basins of Yannan Province, such as Luliang, Yanglin, Baoshan and Jinggu basins, have beed researched. The results show that the biogenic-gas consists mainly of methane which is more than 99% in gasous hydrocarbons and of lighter carbon isotopic composition with δ13C1 values from -60.0‰ to - 75.4‰. The methane carbon isotopic compositions in the Baoshan Basin is relatively heavy (δ13C1 - 60‰- - 65‰), but those in Luliang and Yanglin basins are lighter (δ13C1, less than -70‰), which implies that the gas field of the Baoshan Basin formed earlier than the others. In the Jinggu Basin, where crude oil is premature-lower mature, the natural gas of associated oil relatively wet and the relative content of methane about 58%-95% in gasous hydrocarbons. Constituently the gas composition is much similar to associated one, but the methane carbon isotopic compositions from - 53.8‰ to - 57.8‰ are obviously richer in 12C than those of general oil fields and similarly characterize the biothermo-catalytic transitional zone gas. Their ethane carbon isotopic compositions from - 34.6‰ to -29.0‰ show that they may be derived from type Ⅰ or Ⅱ source rock. But for the associated gas from lower evolutionary stage, the heavier ethane carbon isotopic composition as well as the reversed order among the carbon isotopic composition of ethane, propylane and butane also implies that some gases from the type Ⅲ organic matter are mixed. The δ13CCo2 of the samples essentially less than - 10‰ may be generated from organic matter.     

K-Ar age of the Cenozoic volcanic rocks in the Nangqen Basin, Qinghai Province and its geological significance

The Nangqen Basin is one of the typical shearing-extensional basins situated in the north part of the Hengduan Mts. Nine ages of the Cenozoic volcanic rocks from the basin by K-Ar isotope-dilution technique have been reported in the note. The apparent ages of whole rock and separated biotite range from 32.04 to 36.50 Ma. The₄₀Ar-K (%) correlation isochronal line shows that there existed neither argon excessing, nor radiogenetic argon loosing, i.e. the age represents the true diagenetic time. Volcanic activity in this area occurred in the post-collision environment and is controlled by lithosphere substantial thickening and violent intercontinental shearing-strike slip faults. There is age difference of the magmatic activity in the east, the west and the north Tibet. The multi-periodic eruption-intrusion of the magmatic melt since Cenozoic is a tracer showing the pulsating uplift of the Tibetan Plateau.     

秦岭东段红色盆地地层

认为随着古生物资料的不断发展和丰富,秦岭东段一些红色盆地中的地层可以明确的划分为下白垩统、上白垩统、第三系古新统、始新统、中新统、上新统及第四系。它们多能与其他地区的相关地层进行对比,此外,还可根据地层的发育情况,推断盆地发育史及各时期的沉积环境。     

鲁中南盆地内部构造地貌与第四纪地壳运动

鲁中南盆地内的地貌受次级断裂构造的严格控制。盆地中的剥蚀面—临城期剥蚀面在第四纪时被抬升。通过对这些形成于第三纪末至第四纪早期的临城期剥蚀面抬升程度的对比,可估计抬升量并确定地壳抬升轴。这种结论可以对蒙阴县金刚石砂矿的探寻提供线索。