THE SIGNIFICANCE OF STRIKE-SLIP FAULTING IN THE BASEMENT OF THE ZAGROS FOLD AND THRUST BELT

Lateral offsets in the pattern of seismicity along the Zagros fold and thrust belt indicate that transverse faults segmenting the Arabian basement are active deep‐seated strike‐slip faults. The dominant NW‐SE trending features of the belt have undergone repeated horizontal displacements along these transverse faults. These reactivated basement faults, which are inherited from the Pan‐African construction phase, controlled both deposition of the Phanerozoic cover before Tertiary‐Recent deformation of the Zagros and probably the entrapment of hydrocarbons on the NE margin of Arabia and in the Zagros area. We have used observations of faulting recognized on Landsat satellite images, in conjunction with the spatial distribution of earthquakes and their focal mechanism solutions, to infer a tectonic model for the Zagros basement. Deformation in the NW Zagros appears to be concentrated on basement thrusts and a few widely‐spaced north‐south trending strike‐slip faults which separate major structural segments. In the SE Zagros, two main structural domains can be distinguished. A domain of NNW‐trending right‐lateral faults in the northern part of the SE Zagros implies that fault‐bounded blocks are likely to have rotated anticlockwise about vertical axes relative to both Arabia and Central Iran. In contrast, the predominance of NNE‐trending left‐lateral faults in the southern part of the SE Zagros implies that fault‐bounded blocks may have rotated clockwise about vertical axes. We propose a tectonic model in which crustal blocks bounded by strike‐slip faults in a zone of simple shear rotate about vertical axes relative to both Arabia and Central Iran. The presence of domains of strike‐slip and thrust faulting in the Zagros basement suggest that some of the convergence between Arabia and Central Iran is accommodated by rotation and possible lateral movement of crust along the belt by strike‐slip faults, as well as by obvious crustal shortening and thickening along thrust faults.     

GEOLOGY OF THE NORTH FALKLAND BASIN

The North Falkland Basin comprises two main structural elements: a north-south trending graben, termed the North Falkland Graben; and a set of subsidiary basins to the west of this graben, also controlled by north-south trending extensional faults, but which have been constrained by NW-SE oriented, reactivated Palaeozoic thrust faults. The North Falkland Graben can be divided, in its northern part, into western and eastern depocentres, which are separated by a north-south trending intra-graben high.
Early syn-rift, late syn-rift, early post-rift and late post-rift successions have been identified within the North Falkland Graben. The subsidiary grabens to the west probably contain only early syn-rift deposits overlain by late post-rift sediments: these basins were possibly uplifted along the shoulder of the main graben during its mainphase of extension in the Late Jurassic to Early Cretaceous.
Although predictions of sediment-infill type have only been made by regional correlations and seismic facies analysis in these undrilled basins, two major deltaic units of early post-rift age are confidently inferred to be present in the North Falkland Graben, and to pass laterally into possible anaerobic mudstones of source-rock quality.
This petroleum system will soon be tested by a number of oil companies sharing production licences for the entire axial area of the North Falkland Graben.     

GEOLOGY OF THE PERMIAN “SUPER-GIANT” GAS RESERVOIRS IN THE GREATER PERSIAN GULF AREA

The Permian Dalan and Khuff Formations contain extensive gas reservoirs in the Greater Persian Gulf area. The Permian transgressive sea covered a vast area in the Middle East, and deposited a fairly thick sequence of shallow, epicontinental carbonates. These carbonates were deposited unconformably on Lower Paleozoic rocks in western Iran and on the basement in Central Arabia. The term “Khuff Formation” has been widely used by oil companies in the region, but its equivalent, the Dalan Formation, is a new name currently being used in Iran. The Permian Basin was an elongate trough, trending NW-SE, parallel to the Cretaceous-Tertiary Zagros geosyncline. The deepest part of the Permian Basin was in the extreme SE portion of the trough, in the vicinity of the present Oman Mountains, in which nearly 6,000 ft (1,830 m) of Permian sediments were deposited. Porosity and permeability are generally low in these carbonates. However, secondary fracture porosity and dolomitization are commonly developed throughout these rocks. Permian reservoirs are capped by impervious strata, and the gas seems to be sourced from within the Permian section.     

GEOLOGY OF THE PERMIAN "SUPER-GIANT" GAS RESERVOIRS IN THE GREATER PERSIAN GULF AREA

The Permian Dalan and Khuff Formations contain extensive gas reservoirs in the Greater Persian Gulf area. The Permian transgressive sea covered a vast area in the Middle East, and deposited a fairly thick sequence of shallow, epicontinental carbonates. These carbonates were deposited a fairly thick sequence of shallow, epicontinental carbonates. These carbonates were deposited unconformably on Lower Paleozoic rocks in western Iran and on the basement in Central Arabia. The term "Khuff Formation" has been widely used by oil companies in the region, but its equivalent, the Dalan Formation, is a new name currently being used in Iran.
The Permian Basin was an elongate trough, trending NW-SE, parallel to the Cretaceous-Tertiary Zagros geosyncline. The deepest part of the Permian Basin was in the extreme SE portion of the trough, in the vicinity of the present Oman Mountains, in which nearly 6,000 ft (1,830 m) of Permian sediments were deposited.
Porosity and permeability are generally low in these carbonates. However, secondary fracture porosity and dolomitization are commonly developed throughout these rocks. Permian reservoirs are capped by impervious strata, and the gas seems to be sourced from within the Permian section.     

TECTONIC EVOLUTION OF THE SOUTHERN - CENTRAL IRISH SEA BASIN

Interpretation of 2D seismic reflection data combined with correlation of five wells in the southern part of the Central Irish Sea Basin show a NE-SW trending graben, whose bounding faults are considered to be reactivated lineaments of Precambrian age. The basin-fill comprises mainly Carboniferous and Triassic successions, with localised and thin occurrences of Lower Jurassic and Tertiary rocks, all of which are unconformably overlain by Quaternary sediments. Due to poor data quality, the structural evolution of the area during the Late Palaeozoic is poorly understood. During the Triassic, the basin was subjected to thermal subsidence with a phase of minor uplift in the Anisian. The major phase of extension in the basin took place during the ?Middle - Late Jurassic and had a NW-SE orientation. Subsequent Late Jurassic sinistral shear along the NE-SW trending basin bounding fault is suggested to have taken place, giving rise to a series of north-south intra-basinal faults. The present-day structure of the basin is a broad anticline, inherited from a Cretaceous - Early Tertiary compressional phase. During the Palaeocene the area was subjected to regional uplift, followed by minor extension along the NW boundary fault during the Eocene - Oligocene. A Late Tertiary phase of transpression is postulated to have occurred, which inverted north-south trending faults and folded the base-Tertiary unconformity.     

THE GEOLOGY AND HYDROCARBON HABITAT OF THE BRISTOL CHANNEL BASIN

The Bristol Channel Basin forms an early Mesozoic ((?Permo-) Triassic-Jurassic) basin development with a relatively thin cover of Cretaceous and Tertiary sediments. On the basis of structural trends and stratigraphy, the Basin can be divided into two sub-basins: the ENE-WSW trending Main Bristol Channel Basin and the E-W trending East Bristol Channel Basin. In between them there is an Intermediate Area which incorporates features of the sub-basins on either side. This subdivision appears to be the result of the presence of major NW-SE basement faults which intersect the Bristol Channel area in several places. As a result of intermittent periods of tectonic activity three main stages of basin development can be recognised: (1) a (?Permo-) Triassic- Middle Jurassic stage terminated by mid-Kimmerian epeirogenetic movements, (2) an Upper Jurassic—Lower Cretaceous stage terminated by a Lower Cretaceous (late Berriasian-pre-Aptian) period of deformation, (3) an Upper Cretaceous—Tertiary stage. The bulk of the preserved sedimentary fill in the main Bristol Channel Basin consists of up to 11,000 ft of (?Permo-) Triassic-Jurassic sediments. The section is severely truncated by the overlying late Lower Cretaceoussediments or, in theirabsence, by Upper Cretaceous strata. Below the unconformity, the Upper Jurassic and, depending on their structural position, parts or the whole of the Middle and Lower Jurassic are missing. The East Bristol Channel Basin hasapreserved fill of some 7,500 ft of Triassic-Jurassic sediments. The Middle and Upper Jurassic are completely preserved in the centre of this Eastern Basin, contrasting with the situation found in the main Basin. The basin fill of both sub-basins consists largely of Triassic continental red-beds, mainly silty claystones and evaporites and Jurassic marine calcareous siltstonesand claystones. Structures are essentiully the result of the Lower Cretaceous tectonic phase(s) and are therefore mainly confined to the Triassic—Jurassic—early Lower Cretaceous sections. A number of structural traps of interest to exploration have been delineated and (unsuccessfully) tested in the Main Bristol Channel and Intermediate Area. Evaluation of the currently available data indicates that the absence of significant hydrocarbon indications in these wells is probably due to insufficient and untimely hydrocarbon generation. The possible generation is thought to have occurred prior to the main phases(s) of structural deformation, during a period of temporarily increased heatflow (Middle Jurassic—Lower Cretaceous). An additional unfavourable aspect for hydrocarbon prospects is the lack of good quality reservoir developments. From a megateetonic point of view the Bristol Channel Basin formspart of a regional rift basin development which also includes the Celtic Sea and Western Approaches Basins. The different basins and blocks of this area can, according to their behaviour during the Mesozoic, be grouped as follows: (a) the East Bristol Channel, E. of the zone of majorNWSE faults (e.g. Sticklepath fault), (b) a Central Fault Block, comprising the Cornubian Platform, the Main Bristol Channel and Haig Fras Basins, (c) Flanking Basins, such as the Intermediate Area, the Celtic Sea and Western Approaches Basins.     

STRUCTURAL DEVELOPMENT IN THE NORTHERN NORTH SEA

The Northern North Sea basin is a relatively narrow, grabenal or half-grabenal, northsouth trending feature. The trapping structures are tilted fault blocks. In the southern part of the basin these are mainly westwards tilted blocks formed by down to the east throw faults trending north-south, parallel to the basin margins. This could fit with general plate tectonic theory, but in the northern part of the area this faulting is complicated by a pronounced NE-SW trend. This is parallel to the old Caledonian trend and it is postulated that strike-slip faulting may have been reactivated during the Mesozoic. This strike-slip movement on the NE-SW fault trend gave a tendency for individual fault block rotation resulting in a variety of block tilt directions in the northern part of the basin.
The overall half-graben feature probably started forming in early Triassic, but the faulting leading to the individual fault block formation mainly started during the Middle Jurassic, continuing through the Upper Jurassic. A further period of fault movement occurred during the Upper Cretaceous, but this is not associated with any tilt.     

COMPRESSIVE NEOGENE-QUATERNARY TECTONICS IN THE HINTERLAND AREA OF THE NORTHERN APENNINES

The NW-SE trending Northern Apennine Mountains consist of a series of allochthonous units which were thrust generally to the NE during Neogene crustal shortening, in the direction of a foreland basin to the east andNE. On the hinterland (internal) side of this fold-and-thrust belt, a series of small-scale sedimentary basins developed from the late Miocene and were deformed at the same time. The late Tortonian-Pleistocene evolution of the Northern Apennines has previously been considered by most authors in terms of a classical model of a NE-migrating compressional front, which was followed in time and space by a hinterland extensional regime related to the development of the Tyrrhenian Basin. This paper presents new structural data from both the external parts of the Northern Apennines and the late Tortonian-Pleistocene basins located in the internal sector. In the Northern Apennine thrust belt, reactivation and out-of-sequence geometries for the thrust faults have been recorded. In the hinterland basins, compressional deformation has been documented and is usually associated with thrust ramps and regional unconformities. The timing of both thrust reactivation and of the major compressional phases affecting the hinterland basins is closely correlated with periods of magmatic quiescence, and with compressional phases detected in the external margin of the Northern Apennines (the Padan-Adriatic foredeep). Data presented in this paper indicate that compressional deformation has played a major role in the recent evolution of the Northern Apennines. The mechanism envisaged to explain this tectonic framework takes account of the piggy-back emplacement of basement thrusts from internal to external sectors, which occurred in post-Serravallian time. Activity on basement thrusts may have caused reactivation of thrusts in the internal cover sequence, giving rise to out-of-sequence geometries and controlling the development and/or deformation of the hinterland basins. This type of structural evolution has resulted in a complex geometry for the thrust sheets, and this must be taken into consideration during re-interpretation of the structure of the Northern Apennines. It may also have important implications for petroleum exploration.     

THE EFFECT OF BASEMENT FAULT REACTIVATION ON THE TRIASSIC – RECENT GEOLOGY OF KURDISTAN,NORTH IRAQ

The Zagros orogenic belt is underlain by a complex faulted Precambrian basement. Major fault trends originating in this basement have been invoked to explain large‐scale structural changes along the strike of the orogen, e.g. the development of the Kirkuk Embayment (Kurdistan, Iraq) and the Lurestan Salient (Iran). However, within the Kirkuk Embayment, these structural trends have not previously been considered as an interacting group of faults which are periodically reactivated. This contribution first presents a revised basement fault map for the Kirkuk Embayment, created from interpreted gravity data, existing fault maps and remote sensing lineament analyses. This map is then compared to surface structure maps, published facies maps and source rock maturity data using GIS techniques. The object is to define the relationship between the basement faults and surface structures, fades and source‐rock maturity through time. Surface anticline orientation and location, as well as a number of major facies changes within the cover sequence, and the maturity of Triassic source rocks, are constrained by the interaction of the Najd and Transverse fault trends. A third basement trend, the Nabitah trend, has a more subtle effect on Phanerozoic geology. The Kirkuk Embayment can be divided into a series of semi‐independent basement blocks, defined by these basement fault trends. The interaction of these semi‐independent blocks has created local but predictable differences in surface structures, sediment thickness and facies, and variations in the maturity of Triassic source units across the Kirkuk Embayment. An understanding of the location and behaviour of basement faults within this hydrocarbon province is therefore a valuable predictive tool in exploration.     

STRUCTURAL AND TECTONIC SYNTHESIS FOR THE PERTH BASIN, WESTERN AUSTRALIA

The Perth Basin is localised by reactivation of Neoproterozoic shear zones on the western margin of the Archaean Yilgarn Craton in Western Australia. While Ordovician to Silurian sandstones were deposited in the northern Perth Basin, the earliest sediments elsewhere are Middle Carboniferous to Permian in age. A sinistral transtensional regime, during which the main architecture of the basin was established, developed during NE-SW extension between Greater India and Western Australia in the Permo-Triassic. NW-SE shortening with continued NE-SW extension resulted in sinistral transpression in the late-Early to Middle Triassic. Sag-phase sedimentation in the LateTriassic followed this oblique rifting event. An analogy may be made between the Perth Basin and the Permo-Carboniferous to Jurassic Karoo basins in southern and central Africa and Madagascar. Deposition of the Karoo sequence took place within pull-apart and transtensional basins resulting from sinistral reactivation of basement shear zones. The Indian Gondwana Supergroup, and an equivalent sequence in Antarctica, were deposited within normal fault-bounded graben. The Late Paleozoic to Early Mesozoic formation of the Perth Basin, the Karoo basins of Africa and Madagascar, and the Gondwana basins of India was due to intraplate stress resulting from convergence along the Panthalassa margin of Gondwanaland. Late-Early to Middle Triassic compressional events in all basins mark terminal collision along the Panthalassa margin. The latest Triassic to Early Jurassic marks a new rifting event due to regional east-west to WNW-ESE extension, producing dextralplus normal displacements on many NW-to NNW-striking structures, and essentially normal displacements on north- to NNE-striking faults. NW-SE extension during the Upper Jurassic culminated in the NW separation of Greater India and the formation of oceanic crust in the Neocomian, and resulted in the superposition of structures developed in a dextral transtensional regime. Conjugate strike-slip faults and minor thrust faults formed during the post-Neocomian, with approximately north-south compression and east-west extension. Precambrian gneisses, granitoids and metasediments of SW Western Australia have been deformed during basin development, and dole rite dyke intrusion during the Carboniferous to Middle Triassic is restricted to these terranes. The sequence of events proposed herein for the Perth Basin is in agreement with the tectonic framework of a large portion of Gondwanaland. A better knowledge of the structural history of the Perth Basin may aid the interpretation of seismic and remote-sensing data in the search for further hydrocarbon occurrences.     

巴西坎波斯盆地A区块盐下构造特征及其对油气分布的影响

位于巴西深海坎波斯（Campos）盆地南部的A区块,自晚侏罗世以来经历了多期构造运动,盐下构造特征复杂。结合最新3D地震资料和钻井资料,对该区盐下地层的地质属性、断裂发育及构造演化进行了分析。A区块盐下地层识别出4个地震反射层和3套地震层序;经历了裂谷阶段、倾斜和剥蚀阶段以及热沉降阶段3个构造演化阶段,主要发育正断层,在平面上呈NE向和NNE向展布,受构造运动影响发育了一条NW—SE向转换断层,控制着正断层展布。最后探讨了构造运动对该区油气分布的影响,以期为A区块和坎波斯盆地盐下油气勘探提供科学依据。      

BASIN EVOLUTION OF THE LURESTAN REGION IN THE ZAGROS FOLD-AND-THRUST BELT, IRAN

The evolution of the central part of the Lurestan region in the Zagros fold-and-thrust belt has been studied using newly generated isopach maps for different time intervals between the Late Cretaceous and the Miocene. The study was based on existing geological maps, gravity data, measured stratigraphic surface sections, original field work and well data. Understanding the processes which have influenced facies and thickness variations in the study area will have a significant impact on future hydrocarbon exploration.
Cenomanian carbonates assigned to the Sarvak Formation, the main reservoir unit in the study area, are composed of both pelagic and neritic facies. These facies occur along the roughly north-south trending "Anaran lineament", interpreted to represent a palaeohigh, which influenced patterns of sedimentation in the Cretaceous-Tertiary. The palaeohigh formed as a result of the reactivation of a basement lineament in the Late Cretaceous. The continuing influence of this lineament on patterns of sedimentation during Oligocene — early Miocene time is indicated by a range of evidence including the presence of clinoform geometries.
Analysis of sedimentary thicknesses in the Zagros foreland basin between the Late Cretaceous and the early Miocene indicates progressive SWward migration of the depocentre. Late Cretaceous ophiolite obduction and plate margin convergence exerted a major influence on stratigraphic architecture, and controlled depocentre migration and foreland basin evolution.     

渤海湾复式盆地动力学探讨

渤海湾盆地是中国东部较为典型的中新生代复式断陷盆地.本文根据渤海湾盆地构造格架、构造样式、构造分带迁移和深部构造背景,探讨了其盆地动力学.文章认为渤海湾盆地的形成与演化是两大动力系统在时空上叠加复合的结果.一个动力系统是NW-SE区域性伸展拉张;另一动力系统是由郯庐断裂带平移所引起的近NS向拉分或走滑变形.这两大动力系统是相对独立且在空间上共存.因此渤海湾地区是中新生代区域性伸展拉张叠加上郯庐断裂带平移拉分和走滑所形成的复式盆地.      

西湖凹陷黄岩区地质演化及断层对油气运聚的影响

西湖凹陷黄岩区的地质演化大致可以分为四个阶段 :古新世 -始新世伸展阶段 ,基底断层控制了地垒式断块构造发育 ;渐新世 -中中新世坳陷沉降阶段 ,在渐新世早中期存在继承性断块活动 ;晚中新世构造反转阶段 ,形成大型反转背斜、北北东向和近东西向盖层断层 ;上新世 -第四纪区域沉降阶段 ,东西向断层再次活动。晚中新世和上新世 -第四纪的断层活动对花港组油气运聚有重要的影响。     

珠江口盆地陆丰凹陷断裂构造特征及“人”字型构造成因

陆丰凹陷位于珠江口盆地珠一坳陷东北部，被陆丰中央低凸起分隔成为南、北两个洼陷带，可进一步划分出惠州5洼、惠州11洼、陆丰7洼、陆丰13西洼、陆丰13东洼、陆丰15洼等次级构造单元。地震资料解释表明，不同构造单元内发育的主要构造样式具有差异性。其中"人"字型构造样式发育在陆丰中央低凸起的西部，向东逐渐演化为共轭式（"X"型）构造样式。理论模型表明，只有在基底地垒顶面之上盖层的厚度大于共轭断层倾向交叉点的高度时，盖层中才能发育地堑，形成地堑叠加在地垒之上的"X"型构造样式，否则形成盖层地垒叠加基底地垒的构造样式。平衡演化剖面和构造物理模拟实验表明，"人"字型构造样式受先存走向非平行的基底隐伏断层控制，其经历了文昌组沉积期强烈断陷、恩平组沉积期弱断陷、珠海组沉积期断坳转换、新近纪裂后差异沉降等构造演化阶段。基底隐伏断层差异活动是导致盖层变形差异的主控因素，伸展应力方向的顺时针转变及其与基底隐伏断层之间的交角变化是产生基底断层活动差异的主要原因。     

THE GEOLOGY AND HYDROCARBON POTENTIAL OF THE PEEL AND SOLWAY BASINS, EAST IRISH SEA

Data from recent exploration campaigns by Elf Exploration UK plc and partners in the Peel and Solway Basins (East Irish Sea) have provided significant new information on the geology and hydrocarbon potential of these previously unexplored areas. In this paper, I present a regional geological framework for the basins based on outcrop studies, potential field data and regional seismic lines. The dominant NE-SW and NW-SE structural trends are probably inherited from the Caledonian Orogeny and show evidence of repeated reactivation. Seismic interpretation indicates that the NE-SW trending faults were important in controlling Early Carboniferous basin development, and that transpressional movement along these faults in response to N-S compression led to basin inversion during the Variscan Orogeny. New well data indicate that both the Peel and Solway Basins were subjected to major erosion at this time, causing the entire Upper Carboniferous stratigraphy to be removed. Preserved Dinantian facies comprise shallow-marine sandstones, shales and carbonates in the NE, passing into shallow-water, high energy carbonates in the SW. A change to E-W extension during the Permo-Triassic led to renewed extensional motion on the underlying Caledonian faults, and to the creation of a new system of faults oriented N-S. The Permian and Triassic sections present in the wells in the Peel and Solway Basins are very similar to those in the numerous exploration wells in the East Irish Sea Basin to the SE. Liassic rocks are partly preserved in both the Peel and Solway Basins. The intra-basinal highs which separate the basins in this region are thought to have been initiated during Late Cimmerian uplift, and to have been enhanced by Laramide and Alpine phases of uplift. Laramide uplift was also accompanied by the emplacement of WNW-ESE trending dykes. Regional stratigraphic information has been combined with apatite fission-track data and vitrinite reflectance data to constrain these phases of uplift. These data suggest that at the present day, the Peel and Solway Basins are isolated remnants of a previously more extensive cover of Mesozoic rocks. The three exploration wells drilled in the Peel and Solway Basins by Elf Exploration UK plc tested valid Triassic fault-block traps, but failed to encounter any significant hydrocarbon shows. Variable, but generally good quality reservoirs exist at the top of the Sherwood Sandstone Group. The main control on reservoir quality is the primary sedimentological character of the sandstones, with cementation and compaction locally reducing quality. Over most of the area, evaporites and shales in the Mercia Mudstone Group form a viable top and lateral seal. The main factor preventing development of a viable petroleum system appears to be the absence of significant Carboniferous source rocks.     

鄂尔多斯盆地中新生代构造应力场与油气聚集

在前人研究的基础上,通过大量野外、井下节理、断层和褶皱观测以及构造形成序列确定,开展了鄂尔多斯盆地中新生代构造应力场研究,并分析了构造应力场与油气聚集的关系。鄂尔多斯盆地印支期主压应力场主要呈NW—SE向、NNE—SSW向和SN向,控制了古生界油气的第一次运聚与成藏;燕山期主压应力场主要呈NW—SE向,盆地西南缘呈NE—SW向,控制了古生界油气的第二次运聚与成藏;喜马拉雅期主压应力场主要呈NNE—SSW向,该时期为油气运聚调整和最终就位期。      

珠江口盆地东部和台湾西部海域中生界地质构造特征

珠江口盆地东部和台湾西部海域广泛分布的海相中生界发育 3个方向的 4种断层 :NE向逆断层、NE向正断层、WNW—EW向正断层和NW向左行平移断层。区内各构造单元之间的接界关系有所不同 ,珠一坳陷、台西南盆地与隆起均呈断裂接界关系 ,潮汕坳陷与东沙隆起之间为渐变过渡关系 ,而东沙隆起与澎湖北港隆起、潮汕坳陷与台西南盆地均以平移断层为界。本区中、新生代构造演化主要表现为两次大的构造沉降与挤压隆升的旋回     

西北太平洋边缘新生代盆地成因(下):后裂谷期构造演化

西北太平洋边缘形成连锁右行拉分裂谷系统后,在后裂谷期它们虽然基本上继承了原来盆地格架,但遭到一定程度的改造。其中改造作用最显著的盆地是菲律宾海盆地。在中新世,由于北移澳大利亚板块新几内亚块体的楔入,菲律宾海盆地反转成转换挤压型盆地;与菲律宾海沟断裂公轭剪切而形成的西菲律宾海盆中央断裂,小角度切割原NW-W向密集的R′断裂;四国海盆和帕里西维拉海盆转为“撞击”裂谷;马里亚纳海盆则为马里亚纳洋脊弯曲裂开的产物;班达海盆受到近NS向挤压而变形;东海盆地也随琉球岛弧形成受压而变形。中新世末台湾岛开始形成。在上新世至第四纪,太平洋板块向西的挤压较澳大利亚板块向北的挤压强烈,新几内亚海沟具明显左行位移;印度板块强烈推挤欧亚板块,大多数盆地叠加有弱右行拉分作用(由西向东减弱)。全球构造上,新第三纪和第四纪澳大利亚板块和欧亚板块北移均可造成东太平洋边缘圣安德列斯断裂等右行平移。     

南黄海北部盆地晚白垩世以来构造变形与盆地成因

南黄海盆地是中国近海的主要含油气盆地之一,油气勘探多年但成效不大。盆地结构不清、断裂体系多样与构造演化复杂的因素致使勘探潜力不明。为探讨南黄海北部盆地晚白垩世以来的构造变形特征与断陷盆地形成机理,通过近年最新二维地震资料解释及钻井等地质记录,结合相关地质背景和前人研究成果,对北部盆地的断裂特征和盆地结构开展综合研究,形成北部盆地晚白垩世以来不同时期断裂发育模式和地层沉积充填特征的认识。通过研究认为,中生界-古生界海相地层在印支期遭受挤压变形而形成逆冲断裂,该断裂系构成晚白垩世以来盆地的重要基底断裂系。在后期伸展应力状态下,基底断裂复活,控制着盆地内断层的活动范围和活动方式,同时控制着晚白垩世以来的地层沉积格局和构造样式,形成以伸展构造变形为主的多凹组成的断陷群,反映出“深层约束浅层”的关系。