西北非构造演化与油气成藏组合特征

西北非油气资源丰富,是我国石油公司海外油气勘探的重要区块。受泛非、加里东、海西、阿尔卑斯运动的影响,西北非构造演化经历了泛非期基底形成、古生代稳定陆块演化、中生代裂陷、新生代反转隆升的复杂过程,发育三叠、伊利兹、锡尔特等多个超大型含油气盆地。主要有两套成藏组合:撒哈拉地台为主的古生代成藏组合、北部大陆边缘为主的中新生代成藏组合。     

东非大陆边缘构造演化过程与油气勘探潜力

近年来,东非大陆边缘油气接连获得大突破,已成为世界油气勘探的热点。与西非和北非相比,东非油气勘探和研究程度均很低,尤其经历错综复杂的构造演化过程后,盆地构造、沉积与油气系统及其三者之间的相互作用关系十分复杂,不利于对东非油气勘探前景的分析和判断。本文通过对东非大陆边缘形成与演化过程的探讨,并结合现今盆地结构和油气发现状况,研究认为,东非大陆边缘先后经历了Karoo陆内裂谷、侏罗—白垩纪裂谷两期裂谷和一期被动陆缘作用阶段。两期裂谷发育多套烃源层系,并与被动陆缘阶段的三角洲-深水浊积扇储层时空上构成较好的油储关系,两者均受控于东非复杂构造演化作用,构造对油藏系统的改造或破坏作用影响了东非油气富集规模和类型。     

冀西北怀安地区基底变质岩系构造变形序列研究

怀安地区构造变形强烈,是研究华北克拉通形成和演化的重要窗口。通过对该区基底变质岩系构造形迹进行研究,结合区域地质资料及同位素年龄数据,将该区早前寒武纪构造变形序列划分为4期: 新太古代阜平晚期(D1),桑干岩群韧性变形,形成片麻理、无根褶皱和韧性剪切带; 新太古代五台晚期(D2),在新太古代TTG/花岗岩中形成区域性片麻理和条带状构造,并在桑干岩群中形成近EW向的复式背形和向形构造; 古元古代吕梁中期(D3),集宁岩群沙渠村岩组形成区域性片麻理,并形成与片麻理一致的NE向韧性剪切带,在新太古代地质体中叠加近SN向的开阔复式背形和向形构造; 古元古代吕梁晚期(D4),红旗营子岩群太平庄岩组形成片理和片麻理,尚义—平泉断裂形成。建立了该区早前寒武纪构造演化模式,并将其划分为新太古代陆壳增生阶段和古元古代碰撞造山阶段,对理解华北克拉通的形成及演化具有重要意义。     

Relationships Between the North China Plate and the Tarim Plate

The relationships and boundary between the North China and Tarim plates have been unclear for a long time ; however, the two plates occupy a prominent position in the formation and evolution of the continental lithosphere of China. It is proposed that the Engger Us ophiolitic melange zone discovered recently north of Alaxa is a typical suture between the two plates. The ophiolitic melange zone is composed mainly of a mixture of fragments of ancient oceanic crust and sedimentary rocks of active and passive continental margins. The melange may be divided into tectonic inclusions and matrix. The suture extends northeastwards into the Republic of Mongolia and probably westwards to meet the Altun fault. With the Engger Us ophiolitic melange zone as the boundary the Alaxa area may be divided into two parts: the northern part (AN ) belongs to the Tarim plate, while the southern part (AS) the North China plate. Geological evidence shows that the two plates were amalgamated in the Late Permian or a bit later.     

南非主要成矿区带的划分及成矿特征

南非境内矿产资源种类繁多、储量巨大,其内部的构造单元包括一个太古宙克拉通与一系列元古宙-古生代造山带,以及一个代表弧后前陆沉积系统的卡鲁盆地(狭义)。文章结合区域构造演化与成矿关系,将南非划分为6个Ⅲ级成矿区带:太古宙卡普瓦尔克拉通金-铀、铁-铜-铂族元素、金刚石成矿区,古元古代林波波金-金刚石成矿,古元古代海斯铁-锰成矿带,中元古代那马奎铜-铅-锌多金属成矿,古生代开普褶皱带钨-锡-铜-钼多金属成矿带,古生代-中新生代卡鲁盆地铀-金刚石-砂金成矿区。     

新疆塔里木板块西北缘早二叠世深水遗迹化石的发现及意义

在新疆塔里木板块西北缘下二叠统比尤勒提群中部首次发现了大量深水遗迹化石,主要包括Glockeria Ksiazkiewicz 1968,Helminthoida sp., Megagrapton sp., Paleodictyon sp., Paleodictyon (Glenodictyum) Croaticum Ulchman 1995, Planolites sp., Protopaleodictyon sp., Scalarituba missouriensis Weller 1899, Spirophycus sp.等,代表典型深海环境的Nereites遗迹相。根据对温古尔剖面的研究,比尤勒提群下部为浅海陆棚相砂泥质灰岩、粉砂质泥岩、粉砂岩、泥晶灰岩等;而含丰富遗迹化石的比尤勒提群中部为一套深海海底扇沉积的浊积岩系夹少量硅质岩,并且在浊积扇的不同位置所产遗迹组合类型也明显不同,扇根以觅食迹为主,含大量穿相分子,扇中开始出现牧食迹,扇梢则出现特征的耕作迹;比尤勒提群上部为浅海陆棚－滨海相沉积的硅质灰岩、泥晶灰岩和砂质灰岩及粉砂质泥岩、钙质砂岩等。该套遗迹化石组合与深海浊积事件密切相关,同时表明塔里木板块西北缘早二叠世时期存在一个陆棚浅海－深海盆地沉积环境,晚二叠世时期海水向西退去形成陆相沉积。     

北非地区中生代盆地区域沉积中心发育机制新认识及油气差异富集效应

北非地区为世界上油气富集地区之一,区内油气分布表现出极大的不均匀性,以往研究对这一油气差异性富集控制因素的探讨较为薄弱。本研究重点从中生代期间发育的多个区域沉积中心的演化和形成机制的角度,探讨这一科学问题。对已有的基础地质和油气勘探资料的综合再分析表明,北非地区冈瓦纳大陆北缘发育维德迈尔—佩拉杰、苏尔特、东地中海三个彼此孤立存在的中生代沉积中心,这些沉积中心在空间上处于阿拉拉隆起、苏尔特隆起、黎凡特隆起三个海西运动中形成的NE向古隆起之上,具有“古隆起塌陷反转”的形成机理;沉积中心均靠近新特提斯洋边缘,总体呈现受海西运动形成的古隆起和新特提斯洋开启背景下的伸展作用联合控制。三个中生代沉积中心为中生代优质烃源岩发育区和油气富集区;受海西期塑造的古构造、海西构造剥蚀对砂岩储层的控制以及中生代烃源岩发育等有利因素所控,这些塌陷形成的中生代沉积中心及围区成为最为重要的油气富集区带。中生代盆地的这一形成过程为该区油气差异富集的重要控制因素。     

东非海岸重点盆地渐新世构造事件—沉积体系耦合关系研究

本论文以东非海岸鲁伍马、坦桑尼亚及拉穆盆地为对象，利用钻井、测井及地震资料，揭示了渐新世构造事件—古地貌特征—沉积系统的耦合关系，服务研究区油气勘探选区。结果表明，（1）板块构造事件控制宏观地貌格局及沉积环境变化。随着印度—塞舌尔板块与非洲板块分离，印度洋逐渐扩张，海水南侵，沉积环境由陆相变为海相。由于Afar地幔柱作用及地层抬升等作用，东非海岸整体呈西高东低地貌格局；（2）洋中脊扩展及断层活动控制盆地隆坳格局及沉积体系宏观展布规律。研究区发育西部坳陷带、中部斜坡带及东部深海平原带，东部Davie东及Davie西断层构成Davie构造带。从西向东依次发育 4 大河流—三角洲—海底扇沉积体系；西部坳陷带以三角洲沉积为主，中部斜坡带发育海底扇，东部深海平原带以半深海—深海泥最为常见，沉积体系多发育在Davie构造带以西；（3）次级断层活动影响沉积体系的发育规模及分布。沉积体系多发育在西部坳陷带及中部斜坡带的凹陷中。因凹陷及次级断裂影响，鲁伍马盆地北部、坦桑尼亚盆地南部沉积体系呈北偏特征，而拉穆盆地具南偏趋势。     

The Burkinian orogenic cycle,precursor of the Eburnian orogeny in West Africa

In the best known areas of the West African craton structural, petrographic, and geochronological data provide a distinction between two separate units of the Lower Proterozoic in West Africa. A lower unit was metamorphosed from low to medium grade around 2170 Ma by horizontal shearing. This unit is mainly composed of dominantly basic bimodal magmatic rocks, and some trondhjemitic to tonalitic anatectic gneisses, and locally mesozonal mica schists known in Ivory Coast as the ‘Kounoukou formation’ which has been dated as 2183 Ma old. An upper unit, which frequently begins with polygenic conglomerates, also shows important bimodal vulcanism, but in contrast to the lower unit is dominantly silicic. This unit is affected by lower grade conditions of metamorphism and is weakly deformed. These two units correspond to the classic Eburnian I/Eburnian II succession. However, a clearer distinction is possible, with the recognition of two successive orogenic cycles. In the basal part of each of the two units a major episode of tholeiitic magmatism is evidence for separate periods of lithospheric thinning and fracturing. This was followed by the deposition of various lithological sequences, then by one or more tectonometamorphic events. Later uplift led to the emplacement of anorogenic subvolcanic granitic massifs which are displayed occasionally as ring complexes. This suggests that ‘Eburnian I’ is actually an independent orogenic cycle appearing in the West African formations between 2400 and 2150 Ma, for which we propose the name ‘Burkinian cycle’. This cycle has affected the lower magmatic and sedimentary formations, which we designate Dabakalian. This implies a restricted time span for the Eburnian cycle from 2100–2150 to 1800 Ma. The stratigraphic term ‘Birimian’ is applied to the sedimentary and magmatic formations of the upper unit. This scheme proposed for the Lower Proterozoic in West Africa is probably applicable to other Lower Proterozoic terranes in Africa.     

华北地块北缘中新元古界沉积构造演化

根据文献资料及对研究区8 条实测剖面资料的综合分析结果表明,Columbia 超级大陆的裂解导致华北陆块北缘大陆裂 谷盆地的形成。随着大陆进一步伸展和洋壳的形成,华北地块北缘逐渐发展为被动大陆边缘。在1400 Ma 左右,即铁岭组 沉积后,华北地块北缘转变为活动大陆边缘。早期洋壳向华北地块低角度的俯冲造成弧后地区发生挤压（芹峪上升）,导致 铁岭组抬升和剥蚀,而后期洋壳高角度的俯冲又造成弧后区域发生强烈的伸展和断陷,沉积了下马岭组,并伴随辉绿岩的 侵入。华北地块与相邻地体之间的碰撞导致下马岭组的抬升（或蔚县抬升）以及碰撞花岗岩的形成,挤压构造发生的时间 对应于Rodinia 超级大陆的形成期。新元古代沉积是Rodinia 超级大陆裂解的结果。龙山组石英砂岩和海绿石砂岩是Rodinia 超级大陆裂解后的最早期沉积,记录了海侵初期的超覆过程。     

Relationships Between the North China Plate and the Tarim Plate1

Abstract The relationships and boundary between the North China and Tarim plates have been unclear for a long time; however, the two plates occupy a prominent position in the formation and evolution of the continental lithosphere of China. It is proposed that the Engger Us ophiolitic mélange zone discovered recently north of Alaxa is a typical suture between the two plates. The ophiolitic mélange zone is composed mainly of a mixture of fragments of ancient oceanic crust and sedimentary rocks of active and passive continental margins. The mélange may be divided into tectonic inclusions and matrix. The suture extends northeastwards into the Republic of Mongolia and probably westwards to meet the Altun fault. With the Engger Us ophiolitic mélange zone as the boundary the Alaxa area may be divided into two parts: the northern part (AN) belongs to the Tarim plate, while the southern part (AS) the North China plate. Geological evidence shows that the two plates were amalgamated in the Late Permian or a bit later.     

Zircon U-Pb geochronology,geochemistry and Sr-Nd-Pb isotopes from the metamorphic basement in the Wuhe Complex:Implications for Neoarchean active continental margin along the southeastern North China Craton and constraints on the petrogenesis of Mesozoic g

We report zircon U-Pb geochronology,geochemistry and Sr-Nd-Pb isotope data from mafic granulites and garnet amphibolites of the Wuhe Complex in the southeastern margin of the North China Craton (NCC).In combination with previous data,our results demonstrate that these rocks represent fragments of the ancient lower crust,and have features similar to those of the granulite basement in the northern margin of the NCC.A detailed evaluation of the Pb isotope data shows that Pb isotopes cannot effectively distinguish the role of the Yangtze Craton basement from that of the NCC basement with regard to the source and generation of magmas,at least for southeastern NCC.The age data suggest that the protoliths of the granulites or amphibolites in the Wuhe Complex were most likely generated in Neoarchean and that these rocks were subjected to Paleoproterozoic(1.8-1.9 Ga) high-pressure granulite facies metamorphism. This study also shows that the Precambrian metamorphic basement in the southeastern margin of the NCC might have formed in a tectonic setting characterized by a late Neoarchean active continental margin.     

非洲大陆构造单元划分

非洲大陆地质演化历史悠久,矿产资源丰富.综合已有研究成果,对非洲大陆地质背景、构造单元划分及主要构造单元特征进行简要总结.非洲大陆跨特提斯和冈瓦纳两大构造域,大部分属于冈瓦纳构造域,主要由太古宙—古元古代结晶基底、上覆盖层和泛非构造带组成.根据非洲大陆地质背景和构造演化,在前人研究的基础上,将非洲大陆划分为2个一级构造...     

特提斯构造演化对西北非地区油气成藏的控制作用

特提斯构造带油气资源丰富,从特提斯演化来分析盆地油气成藏具有重要的意义。西北非位于特提斯构造带西段,具有三叠、锡尔特、伊利兹等多个超大型含油气盆地,主要有以撒哈拉地台为主的古生界成藏组合和北部大陆边缘为主的中新生界成藏组合。特提斯构造演化对西北非油气成藏具有明显的控制作用:特提斯洋开启以及海侵阶段,控制盆地烃源岩、盖层发育;特提斯洋关闭阶段,构造运动活跃,发育含油气圈闭,控制油气运移及分布。     

桂西北南丹-荔波地区中、新生代构造演化:来自古构造应力场的证据

桂西北南丹-荔波地区是我国重要的锡多金属矿床富集地,近年来油气勘探显示该区亦具有极大的海相页岩气成藏潜力。因此,深入探讨和认识该区中、新生代构造应力场特征及其构造演化是成矿规律研究和页岩气勘探过程中不可或缺的重要环节。本文以南丹-荔波地区广泛发育的褶皱、共轭节理和断层为研究对象,在详细野外观测的基础上,利用叠加褶皱、共轭节理分析以及断层滑动矢量等方法,反演了研究区中、新生代构造应力场变化。构造解析表明,该区中、新生代共经历了四期构造应力场的交替和演化,分别为NNE-SSW 向挤压、NW-SE 向挤压、NEE-SWW 向伸展和近E-W 向挤压。结合区域构造演化特征,推测NNE-SSW 向挤压应力场的形成可能与印支期华南大陆南北边缘与印支/华北板块碰撞闭合有关;NW-SE 向挤压应力场和NEE-SWW 向伸展应力场可能分别对应于燕山早期古太平洋板块向华南大陆之下的俯冲消减以及燕山晚期发生的弧后伸展作用;近E-W 向挤压应力场可能形成于喜山期印度?欧亚板块陆陆碰撞所产生远程效应的构造背景之下。     

华北陆台基底构造格局研究现状一瞥

专家们对华北陆台早前寒武纪基底构造格局形成与演化的认识既有共同点又有分歧。共同点是太古宙为形成刚性小陆块的时期 ,其成因可能与地幔柱的垂直增生有关 ,如TTG质岩类的大量增生与侵位。小陆块的构造拼合形成华北克拉通的主体。分歧焦点是陆块拼合的时代 :第一种认为小陆块的拼合发生在新太古代 ,即华北陆台在新太古代就已克拉通化 ,到古元古代时在伸展构造体制作用下 ,形成了一系列的裂谷或拗拉谷。第二种认为拼合发生在古元古代 ,即华北陆台是吕梁运动才克拉通化的。形成裂谷或拗拉谷的时期在中元古代     

新疆塔里木板块西北缘早二叠世深水遗迹化石的发现及意义

在新疆塔里木板块西北缘下二叠统比尤勒提群中部首次发现了大量深水遗迹化石,主要包括Glockeria Ksiazkiewicz1968,Helminthoida sp.,Megagrapton sp.,Paleodictyon sp.,Paleodictyon(Glenodictyum)Croaticum Ulchman1995,Planolites sp.,Protopaleodictyon sp.,Scalaritubamissouriensis Weller1899,Spirophycus sp.等,代表典型深海环境的Nereites遗迹相。根据对温古尔剖面的研究,比尤勒提群下部为浅海陆棚相砂泥质灰岩、粉砂质泥岩、粉砂岩、泥晶灰岩等;而含丰富遗迹化石的比尤勒提群中部为一套深海海底扇沉积的浊积岩系夹少量硅质岩,并且在浊积扇的不同位置所产遗迹组合类型也明显不同,扇根以觅食迹为主,含大量穿相分子,扇中开始出现牧食迹,扇梢则出现特征的耕作迹;比尤勒提群上部为浅海陆棚-滨海相沉积的硅质灰岩、泥晶灰岩和砂质灰岩及粉砂质泥岩、钙质砂岩等。该套遗迹化石组合与深海浊积事件密切相关,同时表明塔里木板块西北缘早二叠世时期存在一个陆棚浅海-深海盆地沉积环境,晚二叠世时期海水向西退去形成陆相沉积。     

天山北缘河流阶地形成及构造变形定量分析

新生代以来,北天山山前发育了3排冲断褶皱带。新生代晚期一系列河流普遍穿过这3排冲断褶皱带并发育了三级河流阶地。在最新构造活动的影响下,河流阶地普遍发生变形,遭受抬升。利用光释光及14C年代学方法确定了塔西河三级阶地的形成年龄,并实际测量了三级阶地的高程。结果表明吐谷鲁背斜的构造抬升速率在32．85-28．75 ka问为9．50-12．57 mm／a,12-13 ka间为9．67-14．5 mm／a,全新世则增至10．79-23．44mm／a,天山基底的平均隆升速率达到3．39-3．86mm／a。通过对天山最高一级夷平面、野外实测侏罗纪地层高程及天山发育的煤层的相对隆升速率的研究则表明天山自24 Ma以来平均的隆升速率约为0．085-0．146 mm／a。结合对北天山其他主要河流阶地的观察及研究可以看出自晚更新世一全新世以来,天山北缘的最新构造活动具有不断加快的特征。     

The transition from passive to active margin tectonics: a case study from the zone of Samedan (eastern Switzerland)

The Zone of Samedan is part of a fossil, early Mesozoic rift system originally situated in the distal, Lower Austro-Alpine domain of the Adriatic passive continental margin. An early Mesozoic configuration of asymmetrical rift basins bounded by relative structural highs compartmentalized Late Cretaceous active margin tectonics; Jurassic half-grabens were folded into arcuate synclines, whereas relative structural highs engendered thin, imbricated thrust sheets. West-directed thrusting and folding initiated at the surface and continued to depths favoring mylonitization under lower greenschist-facies conditions. At this time Liguria-Piemontese ophiolites were accreted to Lower Austro-Alpine units directly underlying the Zone of Samedan. Late Cretaceous orogenic collapse of the Adriatic active margin involved the reactivation of west-directed thrusts as low-angle, top-to-the-east, normal faults. These faults accommodated extensional uplift of Liguria-Piemontese ophiolites and Lower Austro-Alpine units beneath and within the Zone of Samedan. During Paleogene collision, some Late Cretaceous faults in the Zone of Samedan were reactivated under lower anchizonal conditions as north-directed thrusts. The latter stages of this early Tertiary thickening were transitional to brittle, high-angle normal faulting associated with top-to-the-east extension and spreading above the warm, uplifting Lepontine dome.     

Rift propagation at craton margin.: Distribution of faulting and volcanism in the North Tanzanian Divergence (East Africa) during Neogene times

A revised kinematic model is proposed for the Neogene tectono-magmatic development of the North Tanzanian Divergence where the axial valley in S Kenya splits southwards into a wide diverging pattern of block faulting in association with the disappearance of volcanism. Propagation of rifting along the S Kenya proto-rift during the last 8 Ma is first assumed to have operated by linkage of discrete magmatic cells as far S as the Ngorongoro–Kilimanjaro transverse volcanic belt that follows the margin of cratonic blocks in N Tanzania. Strain is believed to have nucleated throughout the thermally-weakened lithosphere in the transverse volcanic belt that might have later linked the S Kenya and N Tanzania rift segments with marked structural changes along-strike. The North Tanzanian Divergence is now regarded as a two-armed rift pattern involving: (1) a wide domain of tilted fault blocks to the W (Mbulu) that encompasses the Eyasi and Manyara fault systems, in direct continuation with the Natron northern trough. The reactivation of basement fabrics in the cold and intact Precambrian lithosphere in the Mbulu domain resulted in an oblique rift pattern that contrasts with the orthogonal extension that prevailed in the Magadi–Natron trough above a more attenuated lithosphere. (2) To the E, the Pangani horst-like range is thought to be a younger (< 1 Ma) structure that formed in response to the relocation of extension S of the Kilimanjaro magmatic center. A significant contrast in the mechanical behaviour of the stretched lithosphere in the North Tanzanian diverging rift is assumed to have occurred on both sides of the Masai cratonic block with a mid-crustal decoupling level to the W where asymmetrical fault-basin patterns are dominant (Magadi–Natron and Mbulu), whereas a component of dynamical uplift is suspected to have caused the topographic elevation of the Pangani range in relation with possible far-travelled mantle melts produced at depth further N.