首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 944 毫秒
1.
This study provides the results of the first integrated study of Oligocene–Pliocene basins around Norway.Within the study area, three main depocentres have been identified where sandy sediments accumulated throughout the Oligocene to Early Pliocene period. The depocentre in the Norwegian–Danish Basin received sediments from the southern Scandes Mountains, with a general progradation from north to south during the studied period. The depocentre in the basinal areas of the UK and Norwegian sectors of the North Sea north of 58°N received sediments from the Scotland–Shetland area. Because of the sedimentary infilling there was a gradual shallowing of the northern North Sea basin in the Oligocene and Miocene. A smaller depocentre is identified offshore northern Nordland between Ranafjorden (approximately 66°N) and Vesterålen (approximately 68°N) where the northern Scandes Mountains were the source of the Oligocene to Early Pliocene sediments. In other local depocentres along the west coast of Norway, sandy sedimentation occurred in only parts of the period. Shifts in local depocentres are indicative of changes in the paleogeography in the source areas.In the Barents Sea and south to approximately 68°N, the Oligocene to Early Pliocene section is eroded except for distal fine-grained and biogenic deposits along the western margin and on the oceanic crust. This margin was undergoing deformation in a strike-slip regime until the Eocene–Oligocene transition. The Early Oligocene sediments dated in the Vestbakken Volcanic Province and the Forlandssundet Basin represent the termination of this strike-slip regime.The change in the plate tectonic regime at the Eocene–Oligocene transition affected mainly the northern part of the study area, and was followed by a quiet tectonic period until the Middle Miocene, when large compressional dome and basin structures were formed in the Norwegian Sea. The Middle Miocene event is correlated with a relative fall in sea level in the main depocentres in the North Sea, formation of a large delta in the Viking Graben (Frigg area) and uplift of the North and South Scandes domes. In the Norwegian–Danish Basin, the Sorgenfrei-Tornquist Zone was reactivated in the Early Miocene, possibly causing a shift in the deltaic progradation towards the east. A Late Pliocene relative rise in sea level resulted in low sedimentation rates in the main depositional areas until the onset of glaciations at about 2.7 Ma when the Scandes Mountains were strongly eroded and became a major source of sediments for the Norwegian shelf, whilst the Frigg delta prograded farther to the northeast.  相似文献   

2.
Using recently gathered onland structural and 2D/3D offshore seismic data in south and central Palawan (Philippines), this paper presents a new perspective in unraveling the Cenozoic tectonic history of the southeastern margin of the South China Sea. South and central Palawan are dominated by Mesozoic ophiolites (Palawan Ophiolite), distinct from the primarily continental composition of the north. These ophiolites are emplaced over syn-rift Eocene turbidites (Panas Formation) along thrust structures best preserved in the ophiolite–turbidite contact as well as within the ophiolites. Thrusting is sealed by Early Miocene (∼20 Ma) sediments of the Pagasa Formation (Isugod Formation onland), constraining the younger limit of ophiolite emplacement at end Late Oligocene (∼23 Ma). The onset of ophiolite emplacement at end Eocene is constrained by thrust-related metamorphism of the Eocene turbidites, and post-emplacement underthrusting of Late Oligocene – Early Miocene Nido Limestone. This carbonate underthrusting at end Early Miocene (∼16 Ma) is marked by the deformation of a seismic unit corresponding to the earliest members of the Early – Middle Miocene Pagasa Formation. Within this formation, a tectonic wedge was built within Middle Miocene (from ∼16 Ma to ∼12 Ma), forming a thrust-fold belt called the Pagasa Wedge. Wedge deformation is truncated by the regionally-observed Middle Miocene Unconformity (MMU ∼12 Ma). A localized, post-kinematic extension affects thrust-fold structures, the MMU, and Late Miocene to Early Pliocene carbonates (e.g. Tabon Limestone). This structural set-up suggests a continuous convergent regime affecting the southeastern margin of the South China Sea between end Eocene to end Middle Miocene. The ensuing structures including juxtaposed carbonates, turbidites and shallow marine clastics within thrust-fold belts have become ideal environments for hydrocarbon generation and accumulation. Best developed in the Northwest Borneo Trough area, the intensity of thrust-fold deformation decreases towards the northeast into offshore southwest Palawan.  相似文献   

3.
The petroleum system of the Kunsan Basin in the Northern South Yellow Sea Basin is not well known, compared to other continental rift basins in the Yellow Sea, despite its substantial hydrocarbon potential. Restoration of two depth-converted seismic profiles across the Central Subbasin in the southern Kunsan Basin shows that extension was interrupted by inversions in the Late Oligocene-Middle Miocene that created anticlinal structures. One-dimensional basin modeling of the IIH-1Xa well suggests that hydrocarbon expulsion in the northeastern margin of the depocenter of the Central Subbasin peaked in the Early Oligocene, predating the inversions. Hydrocarbon generation at the dummy well location in the depocenter of the subbasin began in the Late Paleocene. Most source rocks in the depocenter passed the main expulsion phase except for the shallowest source rocks. Hydrocarbons generated from the depocenter are likely to have migrated southward toward the anticlinal structure and faults away from the traps along the northern and northeastern margins of the depocenter because the basin-fill strata are dipping north. Faulting that continued during the rift phase (∼ Middle Miocene) of the subbasin probably acted as conduits for the escape of hydrocarbons. Thus, the anticlinal structure and associated faults to the south of the dummy well may trap hydrocarbons that have been charged from the shallow source rocks in the depocenter since the Middle Miocene.  相似文献   

4.
Most of the basins developed in the continental core of SE Asia (Sundaland) evolved since the Late Cretaceous in a manner that may be correlated to the conditions of the subduction in the Sunda Trench. By the end of Mesozoic times Sundaland was an elevated area composed of granite and metamorphic basement on the rims; which suffered collapse and incipient extension, whereas the central part was stable. This promontory was surrounded by a large subduction zone, except in the north and was a free boundary in the Early Cenozoic. Starting from the Palaeogene and following fractures initiated during the India Eurasia collision, rifting began along large faults (mostly N–S and NNW–SSE strike-slip), which crosscut the whole region. The basins remained in a continental fluvio-lacustrine or shallow marine environment for a long time and some are marked by extremely stretched crust (Phu Khanh, Natuna, N. Makassar) or even reached the ocean floor spreading stage (Celebes, Flores). Western Sundaland was a combination of basin opening and strike-slip transpressional deformation. The configuration suggests a free boundary particularly to the east (trench pull associated with the Proto-South China Sea subduction; Java–Sulawesi trench subduction rollback). In the Early Miocene, Australian blocks reached the Sunda subduction zone and imposed local shortening in the south and southeast, whereas the western part was free from compression after the Indian continent had moved away to the north. This suggests an important coupling of the Sunda Plate with the Indo-Australian Plate both to SE and NW, possibly further west rollback had ceased in the Java–Sumatra subduction zone, and compressional stress was being transferred northwards across the plate boundary. The internal compression is expressed to the south by shortening which is transmitted as far as the Malay basin. In the Late Miocene, most of the Sunda Plate was under compression, except the tectonically isolated Andaman Sea and the Damar basins. In the Pliocene, collision north of Australia propagated toward the north and west causing subduction reversal and compression in the short-lived Damar Basin. Docking of the Philippine Plate confined the eastern side of Sundaland and created local compression and uplift such as in NW Borneo, Palawan and Taiwan. Transpressional deformation created extensive folding, strike-slip faulting and uplift of the Central Basin and Arakan Yoma in Myanmar. Minor inversion affected many Thailand rift basins. All the other basins record subsidence. The uplift is responsible for gravity tectonics where thick sediments were accumulated (Sarawak, NE Luconia, Bangladesh wedge).  相似文献   

5.
The provenance of the Danish Miocene sands has been deduced from zircon ages and heavy minerals integrated with an existing detailed stratigraphic model of the fluvio-deltaic sand successions that prograded into the North Sea Basin in large delta lobes. The stratigraphic model allowed interpretation of the depositional ages of the samples, which were used to reconstruct the outline of the river pathway system for each time slice. The contribution from individual source areas to a specific position in the Miocene succession was controlled by depositional environment and tectonics. The major rivers each flowed separately to the sea, so mixing between supplies from different sources could only have occurred in the marine environment, where a wave-induced shallow current and a tidally-induced deeper current transported the sediment along the shore in opposite directions. Changes in grain size parameters and mineral assemblages across Denmark showed that the overall sediment transport direction for southern Scandinavia was to the south-west. They also showed that the sediments are immature with regards to transport length, so the high maturity of the heavy mineral suite suggests that kaolinisation has been a widespread phenomenon in the source areas. Rapid uplift and/or extensive denudation may have been revealed by an apparent eastward migration of the dominating provenance area, which was observed in the zircon age data for two consecutive time spans; the early Miocene first tectonic pulse and the intra-early Miocene tectonic phase. Comparison of the zircon age distributions with age markers defined using the published ages of the Scandinavian basement terranes shows that most of the sand came from several Sveconorwegian source areas in south-eastern Norway and south-western Sweden. Contributions from the Svecofennian Orogen, the Caledonian belt and the Oslo Rift are also found and the presence of Archaean zircon grains suggests that contributions to the river systems came from as far away as Finland.  相似文献   

6.
The Central Trough of the North Sea is not a simple rift graben. It is an elongated area of regional subsidence which was initiated in mid Cretaceous times and continued to subside through to the late Tertiary. Its form is not representative of pre-mid Cretaceous tectonics.In Late Permian times the North Sea was divided into a northern and southern Zechstein basin by the E-W trending Mid North Sea-Ringkøbing-Fyn High. The latter was dissected by a narrow graben trending NNW through the Tail End Graben and the Søgne Basin. The Feda Graben was a minor basin on the northern flank of the Mid North Sea High at this time. This structural configuration persisted until end Middle Jurassic times when a new WNW trend separated the Tail End Graben from the Søgne Basin. Right lateral wrench movement on this new trend caused excessive subsudence in the Tail End and Feda Grabens while the Søgne Basin became inactive.Upper Jurassic subsidence trends continued during the Early Cretaceous causing the deposition of large thicknesses of sediments in local areas along the trend. From mid Cretaceous times the regional subsidence of the Central Trough was dominant but significant structural inversions occurred in those areas of maximum Early Cretaceous and Late Jurassic subsidence.  相似文献   

7.
Onshore and offshore seismic and geologic-morphologic evidence from the wider region of the ?anakkale Basin indicates that this area has been widely exposed to transpressional tectonism, which already commenced in the Pliocene. During this transpressional tectonism, the Gelibolu Fault and the Anafartalar Shear Zone on the Gelibolu Peninsula, as well as the Bozcaada-Biga Shear Zone on the Biga Peninsula were activated. As a consequence, the northern part of the Gelibolu Peninsula, and a broad zone between Bozcaada Island and the Karaburun Peninsula were uplifted to form the northern and southern boundaries of the ?anakkale Basin, respectively. This remained a low-elevation intermontane basin between these two highlands. The original morphology of the ?anakkale Basin may have developed as a coastal and shelf section of the large extensional Marmara Sea Basin at the end of the Late Miocene. This tectonic phase was followed in the Pliocene by the transpressional tectonism of the North Anatolian Fault Zone, which destroyed the initial morphology and formed the present V-shaped basin. The activity of the Gelibolu Fault and the Anafartalar Shear Zone along the northern boundary of the ?anakkale Basin ended in the late Pleistocene with the initiation of the northern segment of the North Anatolian Fault Zone. The tectonism along the northern boundary of the ?anakkale Basin thus shifted from a transpressional to a transtensional regime. Seismic data indicate that the Bozcaada-Biga Shear Zone continues to be active to the present day.  相似文献   

8.
Marine geological and geophysical data together with drilling information indicate that the North African passive continental margin has been subjected to extension and wrenching after it collided with the northern part of Sicily. The area of the Tripolitania Basin, Jarrafa Trough, Melita and Medina Bank and the Ragusa-Malta Plateau has formed part of a sinking passive margin since the dispersal of Gondwanaland at about 180 My ago as observed from geohistory diagrams. A record of rifting in a NW-SE direction accompanied by dextral shear along the southern troughs is observed in seismic reflection data. The rifting started during the Neocomian and lasted until the Eocene when activity became minor. A pre-Middle Miocene period of northward subduction of oceanic crust is inferred from the geology in NE Sicily. Uplift of the northern part of the African margin after collision in the Middle Miocene is seen in wells in southern Sicily. After the Messinian a rift and dextral shear zone established itself across the African Margin from the Strait of Sicily to the Medina Ridge in the lonian Basin. The zone is marked by up to 1.7 km deep grabens, narrow active wrench faulted channels, volcanic fissures and local uplifted ‘Keilhorsts’ such as Malta. This zone, which varies in width from 100 to 35 km, forms the southern boundary of a microplate which includes Sicily. We speculate that the present motion of this microplate is partly due to the eastward movement of the Calabrian Arc with the Sicilian block over the last remaining oceanic lithosphere in the Eastern Mediterranean.  相似文献   

9.
The Late Miocene Zeit Formation is exposed in the Red Sea Basin of Sudan and represents an important oil-source rock. In this study, five (5) exploratory wells along Red Sea Basin of Sudan are used to model the petroleum generation and expulsion history of the Zeit Formation. Burial/thermal models illustrate that the Red Sea is an extensional rift basin and initially developed during the Late Eocene to Oligocene. Heat flow models show that the present-day heat flow values in the area are between 60 and 109 mW/m2. The variation in values of the heat flow can be linked to the raise in the geothermal gradient from margins of the basin towards offshore basin. The offshore basin is an axial area with thick burial depth, which is the principal heat flow source.The paleo-heat flow values of the basin are approximately from 95 to 260 mW/m2, increased from Oligocene to Early Pliocene and then decreased exponentially prior to Late Pliocene. This high paleo-heat flow had a considerable effect on the source rock maturation and cooking of the organic matter. The maturity history models indicate that the Zeit Formation source rock passed the late oil-window and converted the oil generated to gas during the Late Miocene.The basin models also indicate that the petroleum was expelled from the Zeit source rock during the Late Miocene (>7 Ma) and it continues to present-day, with transformation ratio of more than 50%. Therefore, the Zeit Formation acts as an effective source rock where significant amounts of petroleum are expected to be generated in the Red Sea Basin.  相似文献   

10.
There are many large-scale Cenozoic sedimentary basins with plentiful river deltas, deep-water fans and carbonate platforms in the southern South China Sea. The Crocker Fan was deposited as a typical submarine fan during the late Eocene–early Miocene, and stretches extensively across the entire Sarawak–Sabah of the northern Borneo area. However, systematic analyses are still lacking regarding its sediment composition and potential source suppliers. No consensus has been reached yet on the provenance evolution and sedimentary infilling processes, which seriously impeded the oil-and-gas exploration undertakings. By combining with sedimentary-facies identification, heavy mineral assemblages, elemental geochemistry and detrital zircon U-Pb dating, this paper aims to generalize an integrated analysis on the potential provenance terranes and restore source-to-sink pathways of the Crocker Fan. In general, the Crocker Fan was initially formed over the Cretaceous–lower/middle Eocene Rajang Group by an angular Rajang unconformity. The continual southward subduction of the proto-South China Sea resulted in magmatic activities and subsequent regional deformation and thrusting along the Lupar Line in the northern Borneo. The lowermost Crocker sequence is featured by a thick conglomerate layer sourced from in-situ or adjacent paleo-uplifts. From the late Eocene to the early Miocene, the Crocker Fan was constantly delivered with voluminous detritus from the Malay Peninsula of the western Sundaland. The Zengmu Basin was widely deposited with delta plain and neritic facies sediments, while the Brunei-Sabah Basin, to the farther east, was ubiquitously characterized by turbiditic sequences. The Crocker Fan successions are overall thick layers of modest-grained sandstones, which formed high-quality reservoirs in the southern South China Sea region.  相似文献   

11.
A digitally recorded and processed multichannel seismic profile between Cromer (England) and Sylt (Germany) has provided the first continuous section through the Miocene to Middle Pleistocene delta complex of the southern North Sea Basin. The profile depicts the progressive westward expansion of deltaic sedimentation that eventually filled in this gently subsiding epicontinental basin. Significant basinward shifts in seismic facies occur above all but one of 14 seismic sequence boundaries that punctuate the deposition of up to 830 m of deltaic sediments on the profile. These sequence boundaries and the morphology of prodelta, delta front, delta top and fluvio-deltaic seismic facies record the interaction between subsidence, cyclic fluctuation in sediment supply to, and cyclic change of relative sea level within the basin. Two submarine slides were developed within delta front facies in the Pliocene section and the profile has intersected a swarm of Elsterian (Middle Pleistocene) glacial palaeovalleys that have been incised into the upper part of the delta complex.  相似文献   

12.
南沙海区万安盆地构造演化与成因机制   总被引:2,自引:1,他引:1  
本文基于地震、钻井和区域地质资料,运用回剥法和平衡剖面技术定量研究了万安盆地的构造沉降和伸展程度,重建盆地的构造演化史并探讨其成因机制。模拟结果表明,万安盆地构造沉降曲线为多段式,其南北部构造沉降差异明显,且沉降中心逐渐向南发展的趋势。晚始新世-渐新世(37.8~23.03 Ma BP)盆地中、北部快速沉降,存在两个沉降中心;早中新世(23.03~16.0 Ma BP)盆地南部也发生快速沉降,整个盆地存在3个沉降中心;中中新世(约16.0~11.63 Ma BP)沉降作用减弱,盆地进入裂后热沉降期。万安盆地的伸展和形成演化呈现北早南晚的特征,与南海海底扩张密切相关,同时受控于万安断裂带交替地右旋-左旋走滑作用,是伸展和走滑双重作用的结果。盆地的构造演化过程可细分为4个阶段:初始裂谷期、主要裂谷期、走滑改造期和裂后加速沉降期。  相似文献   

13.
Previously undocumented, migrating submarine canyons have developed in the Pearl River Mouth Basin along the northern continental margin of the South China Sea from the middle Miocene to present. A grid of high-resolution, 2-D multi-channel seismic profiles calibrated by borehole information permits documentation of these northeastward migrating submarine canyons, as the result of the interplay of gravity flows and bottom currents. The modern canyons have lengths of 30–60 km, widths of 1–5.7 km, and relief of 50–300 m in water depths of 450–1500 m. Buried ancient submarine canyon successions were originally eroded by basal erosional discontinuities and partially filled by canyon thalweg deposits. These are overlain by lateral inclined packages and hemipelagic drape deposits. Basal erosional discontinuities and thalweg deposits are probably created principally by turbidity currents and filled with turbidites. Lateral inclined packages likely were formed by along-slope bottom currents. The evolution of these migrating submarine canyons reveals that northeastward bottom currents have consistently occurred at least from the middle Miocene to present in the study area. It might further imply that thermohaline intermediate water circulation of the South China Sea has been anti-cyclonic from the middle Miocene to present. The initiation of migrating submarine canyons possibly signals commencement of strong bottom currents after the middle Miocene in the South China Sea. The intensification of bottom currents also possibly may reflect shoaling of the major ocean seaways and increased vigor in oceanic circulation forced by global cooling after the middle Miocene.  相似文献   

14.
The results of the complex study of the sedimentary cover (continuous seismic profiling and diatom analysis) in the northeastern part of the Sea of Japan, including the Bogorov Rise, the adjacent part of the Japan Basin, and the continental slope, are presented. Two varied-age complexes were distinguished in the sedimentary cover of Primorye’s continental slope, namely, the Middle Miocene and Late Miocene-Pleistocene; these complexes were formed in a stable tectonic environment with no significant vertical movements. The depression in the acoustic basement is located along the continental slope and it is divided from the Japan Basin by a group of volcanic structures, the most uplifted part of which forms the Bogorov Rise. The depression was formed, probably, before the Middle Miocene. In the Middle Miocene, the Bogorov Rise was already at the depths close to the modern ones. In the sedimentary cover near the Bogorov Rise, buried zones were found, which probably were channels for gas transportation in the pre-Pleistocene. Deformations of sediments that occurred in the beginning of the Pleistocene are established in the basin.  相似文献   

15.
Particular features of the tectonic structure and anomalous distribution of the geothermal, geomagnetic, and gravity fields in the region of the Sea of Okhotsk are considered. On the basis of heat flow data, the ages of large-scale structures in the Sea of Okhotsk are estimated at 65 Ma for the Central Okhotsk Rise and 36 Ma for the South Okhotsk Basin. The age of the South Okhotsk Basin is confirmed by the data on the kinematics and corresponds to a 50-km thickness of the lithosphere. This is in accordance with the thickness value obtained by magnetotelluric soundings. A comparative analysis of the model geothermal background and the measured heat flow values on the Akademii Nauk Rise is performed. The analysis points to an abnormally high (by approximately 20%) measured heat flow, which agrees with the high negative gradient of gravity anomalies. The estimates of the deep heat flow and the basement age of the riftogenic basins in the Sea of Okhotsk were carried out in the following areas: the Deryugin Basin (18 Ma, Early Miocene), the TINRO Basin (12 Ma, Middle Miocene), and the West Kamchatka Basin (23 Ma, Late Oligocene). The temperatures at the boundaries of the main lithological complexes of the sedimentary cover are calculated and the zones of oil and gas generation are defined. On the basis of geothermal, magnetic, structural, and other geological-geophysical data, a kinematic model of the region of the Sea of Okhotsk for a period of 36 Ma was calculated and constructed.  相似文献   

16.
The Brae oilfield reservoir in the North Sea comprises Upper Jurassic resedimented conglomerates and sandstones interbedded with organic-rich silstone and mudstone thin-bedded turbidites. The system represents a series of small overlapping fans that form a thick (300 m) slope-apron accumulation of sediments deposited in a narrow (<10 km wide) belt along an active fault zone. The complex lateral and vertical distribution of facies was due mainly to variable tectonic activity, and partly also to sediment supply and sea-level changes. Margin setting represents fan and/or source area  相似文献   

17.
The evolution of the North Aegean Sea is studied through the development of three deep basins: the North Aegean Trough, the North Skyros Basin and the Ikaria Basin. Bathymetric data, a 2D seismic dataset and the well-investigated stratigraphic records of the onshore deep basins of northern Greece and Western Turkey were used to make structural and seismic stratigraphic interpretations. The study area shows two sharp unconformities that correspond to the Eocene-Oligocene transition and the Miocene-Pliocene shift. These discontinuities were used as marker horizons for a more detailed structural and seismic stratigraphic interpretation resulting in the identification of several seismic units. A general seismic signature chart was established using onshore basin stratigraphy and well data, which was then used to constrain the ages of the different seismic units. The main features observed in the basins are interpreted as: 1) trans-tensional growth patterns in Pliocene and Quaternary sediments that combine NE–SW trending and steeply dipping fault zones that likely correspond to strike-slip corridors and E-W/WNW-ESE trending normal faults, 2) regional erosional truncations of Miocene sediments, likely related to the Messinian Salinity Crisis (MSC), 3) thick delta-turbidite deposits of Neogene age. Only the North Aegean Trough shows evidence of earlier development and polyphase deformation through inversion structures, and additional seismic units. Extension processes in the Aegean region have been driven by the Hellenic slab rollback since the middle Eocene. The widespread development of Neogene basins at the whole Aegean scale attests to a major tectonic change due to an acceleration of the trench retreat in the middle Miocene. The present study shows that the Neogene basins of the North Aegean Sea developed in dextral transtension with the northward migration of the associated NE-SW trending strike-slip faults. At regional scale, this tectonic pattern indicates that the westward escape of Anatolia started to interact with the trench retreat in the middle Miocene, around 10 Myr before the arrival of the North Anatolian Fault in the North Aegean Sea.  相似文献   

18.
The paper presents the results of a study on the geomorphic structure, tectonic setting, and volcanism of the volcanoes and volcanic ridges in the deep Central Basin of the Sea of Japan. The ridges rise 500–600 m above the acoustic basement of the basin. These ridges were formed on fragments of thinned continental crust along deep faults submeridionally crossing the Central Basin and the adjacent continental part of the Primorye. The morphostructures of the basin began to submerge below sea level in the Middle Miocene and reached their contemporary positions in the Pliocene. Volcanism in the Central Basin occurred mostly in the Middle Miocene–Pliocene and formed marginal-sea basaltoids with OIB (ocean island basalt) geochemical signatures indicating the lower-mantle plume origin of these rocks. The OIB signatures of basaltoids tend to be expressed better in the eastern part of the Central Basin, where juvenile oceanic crust has developed. The genesis of this crust is probably related to rising and melting of the Pacific superplume apophyse.  相似文献   

19.
台西南盆地的构造演化与油气藏组合分析   总被引:14,自引:2,他引:14  
本文根据台西南盆地的地质、地球物理资料,对台西南盆地的地壳结构、基底特征、沉积厚度、断裂构造等基本地质构造特征^[1]作了研究,探讨了台西南盆地的构造发展演化及及油气藏组合。认为该盆地的构造演化为幕式拉张。幕式拉张可分为三大张裂幕,相应的热沉降作用使盆地在不同的张裂幕时期发展为断陷,裂陷,裂拗-拗陷。它们分别与板块作用下的区域构造运动阶段相对应,说明区域构造运动不但控制了盆地的发展演化,同时也制约  相似文献   

20.
Sedimentary rocks from the northern margin of the Trobriand Platform, the north wall of the New Britain Trench, and the floor of the Solomon Sea Basin are volcaniclastics, mudrocks, and neritic and bathyal limestones. Arc-volcanic debris from calc-alkaline or high-K magmatic sources is present at each locality. A minor metamorphic component occurs at one site on the Trobriand Platform which yielded Early Eocene to Middle Miocene material, and at the New Britain Trench site, which yielded Miocene or older and post-Miocene samples. Solomon Sea Basin samples are mudrocks which are apparently no older than Late Pliocene.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号