The Eurasian continent was subject to multiphase intensive intracontinental deformation in the Cenozoic(Fig.1A).However,its Cenozoic intra-continental deformation process and the driving force has long been disputed,w...The Eurasian continent was subject to multiphase intensive intracontinental deformation in the Cenozoic(Fig.1A).However,its Cenozoic intra-continental deformation process and the driving force has long been disputed,which is only associated with the Indo-Asian collision(Molnar and Tapponnier,1975;Jolivet et al.,1990;Tapponnier et al.,2001;Yin,2010;Xu et al.,2013;Zhao et al.,2016),is caused by the Pacific-Asian collision(Cui,1997;Schellart and Lister,2005;Fan et al.,2019),or is connected with a combined effect of the Indo-Asian collision and the Pacific-Eurasia convergence(Ren et al.,2002;Li et al.,2013;Shi et al.,2015;Liu et al.,2019).展开更多
In recent years, deep water areas have become popular exploration fields because of their abundant hydrocarbon resource potential. There are only relatively poor planar seismic profiles and no wells for deepwater area...In recent years, deep water areas have become popular exploration fields because of their abundant hydrocarbon resource potential. There are only relatively poor planar seismic profiles and no wells for deepwater areas of the Lingshui Formation in the Qiongdongnan Basin. A lot of faults developed and strata are fragmented due to high temperatures and high pressure, and this has resulted in dim sequence boundaries. Based on seismic data of the deepwater area and well data of bordering shallow water areas, Lingshui Formation was divided into four third class sequences; namely SI, SII, SIII and SIV, and the three-dimensional isochronous stratigraphic framework of the Lingshui Formation in the studied area was shaped. Based mainly on seismic attributes such as amplitude, continuity, internal structure and external shape, six typical seismic facies were identified, including mat-shaped, filling, wedge-shaped, foreset, moundy-shaped and lenticular-shaped, and a seismic facies distribution map was subsequently drawn. With studies on wells of bordering shallow water areas, regional sedimentary characteristics, and isopach map as references, sedimentary planar distribution features were analyzed. The deepwater area of the Lingshui Formation has mainly developed littoral and shallow sea. Sandstone bodies of fan delta, braided river delta, slope fan, basin floor fan, and turbidite fan are at an interdigitate junction to marine hydrocarbon source rocks and thus are favorable prospecting targets.展开更多
The main petroliferous basins in eastern China are Cenozoic fault basins, most of which have experienced two-stage tectonic evolution, i.e., rifting subsidence in the Paleogene and post-rifting thermal subsidence in t...The main petroliferous basins in eastern China are Cenozoic fault basins, most of which have experienced two-stage tectonic evolution, i.e., rifting subsidence in the Paleogene and post-rifting thermal subsidence in the Neogene-Quaternary. The episodic tectonic evolution and syndepositional faulting had significant influence on the fault basins in terms of accommodation space, deposition rate, and depositional facies zones. In this study, the tectonic deformation characteristics and the tectonic-depositional evolution of the Western Sag of the Cenozoic Liaohe Depression were investigated by comprehensive analysis of the available geological and geophysical data using the modern theory of tectonic geology and the balanced section technique. The tectonic deformation of the Cenozoic fault basin was characterized by superimposed faults and depression. In addition, there existed relatively independent but still related extensional tectonic systems and strike-slip tectonic systems. The tectonic evolution of the fault basin involved five stages, i.e., initial rifting stage （E2s4）, intense faulting stage （E2s3）, fault-depression transition stage （E3sl2）, differential uplifting stage （E3d）, and depression stage （N-Q）. According to the characteristics of tectonic development and evolution of the Western Sag, the depositional evolution in the Cenozoic fault basin was divided into two stages, i.e., multi-episodic rifting filling in the Paleogene and post-rifting filling in the Neogene-Quaternary. The former rifting stage was further subdivided into four episodes with different characteristics of depositional development. The episodic faulting controlled the filling process and filling pattern of the Cenozoic Western Sag as well as the development and spatial distribution of associated depositional systems, whereas the syndepositional faults that developed in multiple stages in various tectonic positions controlled the development of depositional systems and sand bodies in the Western Sag. That is, the fault terraces on steep slopes controlled the development of sand bodies, the fault terraces on gentle slopes controlled the development of low-stand fan bodies, and the fault terraces or fault troughs in the central basin controlled the development of fluxoturbidite bodies.展开更多
With increased exploration in the faulted basins of eastern China,petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution,complex reservoir and hydrocarbon enrich...With increased exploration in the faulted basins of eastern China,petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution,complex reservoir and hydrocarbon enrichment patterns,and lacking of suitable exploration techniques.Aiming at resolving these problems,studies on source rocks,reservoirs,hydrocarbon accumulation and geophysical prospection were carried out by laboratory analysis,reservoir anatomy,and seismic analysis.A highlyefficient hydrocarbon generation/expulsion model of source rocks in saline environment was established,which aided in the discovery of a new set of source rocks in the Jiyang Depression.This study also reveals the formation process of high-quality reservoir by alternating acid and alkaline fluids during deposition and diagenesis,and pattern of secondary pores development in deep clastic rocks.Through the fine anatomy of the oil reservoirs,an orderly distribution pattern of the oil reservoirs is established,and the potential exploration targets in the undrilled area are identified.In addition,single-point highdensity seismic acquisition and high-resolution imaging technologies are developed,enabling fine and efficient exploration in areas with high exploration maturity.The research result plays a leading and demonstrative role in the fine and efficient exploration of faulted basins in eastern China.展开更多
? The intensive extensional deformation in the eastern part of the Chinese continent in Late Mesozoic time (J3-K1) caused the formation of largescale fault basin system in Northeastern China block, metamorphic core ...? The intensive extensional deformation in the eastern part of the Chinese continent in Late Mesozoic time (J3-K1) caused the formation of largescale fault basin system in Northeastern China block, metamorphic core complexes in North China block and widespread volcanic eruption and granitic intrusive in eastern China. Generally, the deformation has been interpreted as subduction tectonics along the eastern continental margin. We suggest that the combination effect of the subduction and collision in Tethys domain and the subduction from Pacific side and the mantle upwelling beneath the lithosphere. This event controlled the Late Jurassic to Early Cretaceous tectonic history in eastern China.展开更多
The types,evolution processes,formation mechanisms,and depositional models of deep-water gravity flow deposits in a lacustrine rift basin are studied through core observation and systematic analysis.Massive transport ...The types,evolution processes,formation mechanisms,and depositional models of deep-water gravity flow deposits in a lacustrine rift basin are studied through core observation and systematic analysis.Massive transport of slide and slump,fluid transport of debris flow and turbidity currents are driven by gravity in deep-water lacustrine environment.The transformation between debris flow and turbidity current,and the transformation of turbidity current between supercritical and subcritical conditions are the main dynamic mechanisms of gravity flow deposits in a lake basin.The erosion of supercritical turbidity current controls the formation of gravity-flow channel.Debris flow deposition gives rise to tongue shape lobe rather than channel.Deep-water gravity flow deposits are of two origins,intrabasinal and extrabasinal.Intrabasinal gravity flow deposits occur as single tongue-shape lobe or fan of stacking multiple lobes.Extrabasinal gravity-flow deposits occur as sublacustrine fan with channel or single channel sand body.However,the nearshore subaqueous fan is characterized by fan of stacking multiple tongue shape lobes without channel.The differential diagenesis caused by differentiation in the nearshore subaqueous fan facies belt results in the formation of diagenetic trap.The extrabasinal gravity flow deposits are one of the important reasons for the abundant deep-water sand bodies in a lake basin.Slide mass-transport deposits form a very important type of lithologic trap near the delta front often ignored.The fine-grained sediment caused by flow transformation is the potential"sweet spot"of shale oil and gas.展开更多
Lijiang-Daju fault, the seismogenic fault of the 1996 Lijiang M=7.0 earthquake, can be divided into Lijiang-Yuhu segment in the south and Yuhu-Daju segment in the north. The two segments show clear difference in geolo...Lijiang-Daju fault, the seismogenic fault of the 1996 Lijiang M=7.0 earthquake, can be divided into Lijiang-Yuhu segment in the south and Yuhu-Daju segment in the north. The two segments show clear difference in geological tectonics, but have the similar dynamic features. Both normal dip-slip and sinistral strike-slip coexist on the fault plane. This kind of movement started at the beginning of the Quaternary (2.4~2.5 Ma B.P.). As to the tectonic types, the detachment fault with low angle was developed in the Early Pleistocene and the normal fault with high angle only after the Mid-Pleistocene (0.8 Ma B.P.). Based on the horizontal displacements of gullies and the vertical variance of planation surfaces cross the Lijiang-Daju fault at east piedmont of Yulong-Haba range, the average horizontal and vertical slip rates are calculated. They are 0.84 mm/a and 0.70 mm/a since the Quaternary and 1.56 mm/a and 1.69 mm/a since the Mid-Pleistocene. The movements of the nearly N-S-trending Lijiang-Daju fault are controlled not only by the regional stress field, but also by the variant movement between the Yulong-Haba range and Lijiang basin. The two kinds of dynamic processes form the characteristics of seismotectonic environment of occurring the 1996 Lijiang earthquake.展开更多
Tectonic movements in the North Slope of Biyang Depression are comparatively mild and stable, thus generating two categories of deltas. Elementary reasons for the coexistence of deltas are the existence of the palaeod...Tectonic movements in the North Slope of Biyang Depression are comparatively mild and stable, thus generating two categories of deltas. Elementary reasons for the coexistence of deltas are the existence of the palaeodrainage pattern and the effect of palaeotopography. The sedimentary facies is the most elementary factor controlling the physical property of reservoirs. The layout and spatial combination model of the sand body and faults are the major influential factors on the occurrence of hydrocarbons. Comparative study on Houzhang and Yanglou Braided Deltas as well as Zhangchang and Gucheng Meandering Deltas suggests that the hydrocarbons distribute primarily in the mouth bar subfacies and secondarily in the distal bar subfacies of the braided delta, while the oil-water and aqueous layers are mainly found in the subaquatic distributary channel. Although the sand body of the meandering delta has excellent stratification and high porosity, the thickness is far less than that of the braided delta. Therefore, the yield of hydrocarbon is relatively low. The mudstone of the delta front subfacies is a kind of source rock with a high content of organic matter. The conducting system for oil/gas migration in the North Slope is a composite one comprising faults and sand- stone reservoirs. A large amount of oil/gas from the deep depression first migrated towards the slope along the sand body which stretches and connects with the source rocks, and then redistributed along the faults in the slope. After the movement reached a standstill, the faults formed the occlusion in the up-dip direction of the sand body, generating a great quantity of fault block hydrocarbon reservoirs in the Noah Slope.展开更多
High-yielding oil wells were recently found in the first member of Paleogene Shahejie Formation,the Binhai area of Qikou Sag,providing an example of medium-and deep-buried high-quality reservoirs in the central part o...High-yielding oil wells were recently found in the first member of Paleogene Shahejie Formation,the Binhai area of Qikou Sag,providing an example of medium-and deep-buried high-quality reservoirs in the central part of a faulted lacustrine basin.By using data of cores,cast thin sections,scanning electron microscope and physical property tests,the sedimentary facies,physical properties and main control factors of the high-quality reservoirs were analyzed.The reservoirs are identified as deposits of slump-type sub-lacustrine fans,which are marked by muddy fragments,slump deformation structure and Bouma sequences in sandstones.They present mostly medium porosity and low permeability,and slightly medium porosity and high permeability.They have primary intergranular pores,intergranular and intragranular dissolution pores in feldspar and detritus grains,and structural microcracks as storage space.The main factors controlling the high quality reservoirs are as follows:(1)Favorable sedimentary microfacies of main and proximal distributary gravity flow channels.The microfacies with coarse sediment were dominated by transportation and deposition of sandy debris flow,and the effect of deposition on reservoir properties decreases with the increase of depth.(2)Medium texture maturity.It is shown by medium-sorted sandstones that were formed by beach bar sediment collapsing and redepositing,and was good for the formation of the primary intergranular pores.(3)High content of intermediate-acid volcanic rock detritus.The reservoir sandstone has high content of detritus of various components,especially intermediate-acid volcanic rock detritus,which is good for the formation of dissolution pores.(4)Organic acid corrosion.It was attributed to hydrocarbon maturity during mesodiagenetic A substage.(5)Early-forming and long lasting overpressure.A large-scale overpressure compartment was caused by under-compaction and hydrocarbon generation pressurization related to thick deep-lacustrine mudstone,and is responsible for the preservation of abundant primary pores.(6)Regional transtensional tectonic action.It resulted in the structural microcracks.展开更多
The easternmost Tian Shan lies in eastern Xinjiang, Central Asia. The South Barkol basin fault（SBF） in the northern part of the easternmost Tian Shan is a major tectonic structure in this orogenic region. The late Q...The easternmost Tian Shan lies in eastern Xinjiang, Central Asia. The South Barkol basin fault（SBF） in the northern part of the easternmost Tian Shan is a major tectonic structure in this orogenic region. The late Quaternary activity, paleoseismology, and deformation characteristics of the fault provide important clues for understanding the tectonic process of the eastern Tian Shan orogen and implementing seismic mitigation. Through interpretation of high-resolution satellite images, unmanned aerial vehicle measurements, and detailed geological and geomorphic investigations, we suggest that the fault exhibits clear left-lateral slip along its western segment. Paleoseismic trenches dug near Xiongkuer reveal evidence of six large paleoearthquakes. The four latest paleoearthquakes were dated： the oldest event occurred at 4663 BC–3839 BC. Data on the horizontal offsets along the probable 1842 Barkol earthquake coseismic rupture suggest clear multiple relationships between cumulative offsets and possible ~4 m of coseismic left-lateral slip per event. From the cumulative offsets and 14 C sample ages, we suggest an average Holocene left-lateral slip rate of 2.4–2.8 mm/a on the SBF, accounting for ~80% of lateral deformation within the entire eastern Tian Shan fault system. This result is comparable with the shortening rate of 2–4 mm/a in the whole eastern Tian Shan, indicating an equal role of strike-slip tectonics and compressional tectonics in this orogen, and that the SBF may accommodate substantial lateral tectonic deformation.展开更多
This paper gives a study of 3 D crustal seismic velocity changes in the Weihe fault depression basin, in which the overlapping sphere iterative reconstruction method of tomographic image was used in connection with ...This paper gives a study of 3 D crustal seismic velocity changes in the Weihe fault depression basin, in which the overlapping sphere iterative reconstruction method of tomographic image was used in connection with the two point fast ray tracing technique. By means of theoretical modeling, the monitoring function of the observatory network system of Shaanxi Province was tested. Using the seismic data of the network, seismic tomographic inversion imaging of the crustal seismic velocity in the Weihe fault basin was studied. The results are as follows: In the Tongchuan Yaoxian area to the north of Jingyang, there is a high velocity region extending nearly in NS direction, the highest velocity value is around Tongchuan. To the southwest of Shangxian and Lantian, there is a low velocity zone about 100 km long and about 50 km wide, inside which there are two regions of the lowest velocity 50 km apart. The epicenters of historical strong earthquakes are mainly on the boundary of high velocity regions or in regions of fairly high velocity. In the eastern and western parts of the south margin of the Qinling Mountains, there is an obvious lateral nonhomogeneity of seismic velocity.展开更多
Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The s...Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The sedimentary characteristics of this epoch and the tectono-paleogeography of the basin were expounded.The results show that in its early stages,the Songliao Basin was characterized by a detached faulted basin in which mainly lake facies developed among mountains.It became gradually one lake during the late stages of the Early Cretaceous.During this period,the fault activity in the Songliao Basin changed from a turbulent to a quiet development,the water area from small separated lakes to one large lake,in which the sedimentary facies were divided into asymmetric eastern and western parts.In the basin a volcanic clastic rock-alluvial fan system developed and a fan delta-lake-small delta-river system was mainly deposired.Our research also shows that the basement rifts not only controlled the distribution of fault depressions and the tectonic development in the Early Cretaceous,but had also an effect on the orientation of sedimentation,source area and river system,which determine the tectonopaleogeography of the Early Cretaceous.展开更多
The role of authigenic clay growth in clay gouge is increasingly recognized as a key to understanding the mechanics of berittle faulting and fault zone processes,including creep and seismogenesis,and providing new ins...The role of authigenic clay growth in clay gouge is increasingly recognized as a key to understanding the mechanics of berittle faulting and fault zone processes,including creep and seismogenesis,and providing new insights into the ongoing debate about the frictional strength of brittle fault(Haines and van der Pluijm,2012).However,neither the conditions nor the processes which展开更多
On Jan.31 of 2010,the Suining earthquake occurred at Suining City whch is located the center of Sichuan Basin.It is unusual for the strong earthquake to occur at the center of Sichuan Basin with a stable geotectonic e...On Jan.31 of 2010,the Suining earthquake occurred at Suining City whch is located the center of Sichuan Basin.It is unusual for the strong earthquake to occur at the center of Sichuan Basin with a stable geotectonic environment and a low-level historical seismicity.The macro-epicenter of the earthquake is located at Moxi town of Suining city,Sichuan province,China.The earthquake intensity of the epicenter area is degree VII,and the long axis of the isoseismal line trends in NE orientation.The Suining earthquake caused the collapse or destruction of 460 family houses.The earthquake focal mechanism solution and records of the near-field seismographic stations showed the earthquake occurred at the reverse fault at a depth 34 km.Based on the waveform and focal mechanism,we consider the Suning earthquake is triggered by the reverse fault and not by the gravitational collapse or man-made explosive sources.Basing on seismic refraction profile and borehole,we consider that the earthquake is triggered by the backthrust fault of Moxi anticline rooted in detachments at a depth 3-4 km.Furthermore,we infer that tectonic mechanism of the Suining(Ms5.0) Earthquake is driven by the horizontal crustal shortening and stress adjustment on a shallow detachment after the Wenchuan(Ms 8.0) earthquake.展开更多
The Erlian fault basin group, a typical Basin and Range type fault basin group, was formed during Late Jurassic to Early Cretaceous, in which there are rich coal, oil and gas resources. In the present paper the abund...The Erlian fault basin group, a typical Basin and Range type fault basin group, was formed during Late Jurassic to Early Cretaceous, in which there are rich coal, oil and gas resources. In the present paper the abundant geological and petroleum information accumulated in process of industry oil and gas exploration and development of the Erlian basin group is comprehensively analyzed, the structures related to formation of basin are systematically studied, and the complete extensional tectonic system of this basin under conditions of wide rift setting and low extensional ratio is revealed by contrasting study with Basin and Range Province of the western America. Based on the above studies and achievements of the former workers, the deep background of the basin development is treated.展开更多
Through petroleum exploration of 20 years, a new petroleum production area has been constructed in Hailar Basin. Their petroleum geological characteristics and hydrocarbon distribution has been known in detail. The Ha...Through petroleum exploration of 20 years, a new petroleum production area has been constructed in Hailar Basin. Their petroleum geological characteristics and hydrocarbon distribution has been known in detail. The Hailar Basin is a basin group consisted of many scattered sub-basins with similar structural developed history. Each sub-basin has unique hydrocarbon distributing rules, including (1) oil/gas reservoir distribution is controlled by the oil/gas sag, and the oil/gas bearing in big sag is rich; (2) underwater fan and turbidity fan are the most favorable reservoirs; structure zone controlled by main fault is favorable zone of forming composite oil/gas accumulation; (3) lower fault-block in higher rise and higher fault-block in lower rise are favorable to oil/gas accumulation; (4) deep fault and granite body are closely re-lated to oil/gas reservoir, its distributing area is favorable area of oil and mantle source non-hydrocarbon gas formation; (5) higher geothermal area is favorable oil/gas bearing area.展开更多
As the west boundary fault of the Songliao Basin and the eastern margin of the Da Hinggan Mountains, the Nenjiang-Balihan fault is located in the central part of Northeast China. It is traditionally considered to be a...As the west boundary fault of the Songliao Basin and the eastern margin of the Da Hinggan Mountains, the Nenjiang-Balihan fault is located in the central part of Northeast China. It is traditionally considered to be a huge deep-seated NNE-striking fault, characterized by a normal fault or detachment fault displacement. The field investigation resulted in the finding of ductile shear zones in the Lingxia and Louzidian areas, the middle and southern sectors of the fault system. The authors conducted meas- urements of structural elements in the field, micro-structural studies, finite strain measurements, a study on preferred crystal orientations of quartz determined by Electron Back Scatter Diffraction and muscovite 40Ar/9Ar chronology of the deformed rocks in the ductile shear zone. The results show that the deformation features of the Lingxia and Louzidian ductile shear zones are similar, and that they represent one continuous fault, i.e., the middle-southern segment of the Nenjiang-Balihan Fault, which experienced a sinistral strike-slip ductile shearing in the Early Cretaceous （-130 Ma）. By measuring the displacement of the Xar Moron River suture and Wolegen Group on both sides of the Nenjiang-Balihan Fault, it is found that the cumulative strike-slip offset of the fault is about 40-50 km.展开更多
Based on the case history study of sequence stratigraphic framework,sequence model,and the controlling factors on sequence formation in the southern Junggar foreland basin,a contrasting comparison of the characteristi...Based on the case history study of sequence stratigraphic framework,sequence model,and the controlling factors on sequence formation in the southern Junggar foreland basin,a contrasting comparison of the characteristics among the foreland basin,the faulted basin,and the sag basin is made in the aspects of sequence architecture,filling style,the controlling factors on sequence development,the migrations of basin center and depocenter,etc..The current study results show that there are major differences and these are documented as follows.（1） The accommodation space in foreland basin is mainly created by the subsidence caused by thrusting and napping in the foothill belt,resulting in progradational-dominated parasequence sets in the foothill area and retrogradational parasequence sets in the ramp region.（2） The accommodation space in an open-lake system in faulted basin is mainly created by the activities of the basin margin faults;thus,tectonic sequences are formed.However,in the closed-lake system,the subaqueous accommodation is mainly controlled by climatic-influenced lake-level fluctuations,and climatic sequence is formed.（3） In sag basin,a closed-lake system is easily formed due to its generation often within the cratons and isolation from the sea,and its accommodation space creation is mainly controlled by climatic lake-level fluctuations;thus,the sequence architecture in sag basin is similar to that formed on the passive continental margin.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41672203)China Geological Survey(CGS)(Grant Nos.DD20190018,DD20160060,1212011120099,1212011120100,1212011220259).
文摘The Eurasian continent was subject to multiphase intensive intracontinental deformation in the Cenozoic(Fig.1A).However,its Cenozoic intra-continental deformation process and the driving force has long been disputed,which is only associated with the Indo-Asian collision(Molnar and Tapponnier,1975;Jolivet et al.,1990;Tapponnier et al.,2001;Yin,2010;Xu et al.,2013;Zhao et al.,2016),is caused by the Pacific-Asian collision(Cui,1997;Schellart and Lister,2005;Fan et al.,2019),or is connected with a combined effect of the Indo-Asian collision and the Pacific-Eurasia convergence(Ren et al.,2002;Li et al.,2013;Shi et al.,2015;Liu et al.,2019).
基金sponsored by Ministry of Science and Technology of China (grant No. 2009CB219400)
文摘In recent years, deep water areas have become popular exploration fields because of their abundant hydrocarbon resource potential. There are only relatively poor planar seismic profiles and no wells for deepwater areas of the Lingshui Formation in the Qiongdongnan Basin. A lot of faults developed and strata are fragmented due to high temperatures and high pressure, and this has resulted in dim sequence boundaries. Based on seismic data of the deepwater area and well data of bordering shallow water areas, Lingshui Formation was divided into four third class sequences; namely SI, SII, SIII and SIV, and the three-dimensional isochronous stratigraphic framework of the Lingshui Formation in the studied area was shaped. Based mainly on seismic attributes such as amplitude, continuity, internal structure and external shape, six typical seismic facies were identified, including mat-shaped, filling, wedge-shaped, foreset, moundy-shaped and lenticular-shaped, and a seismic facies distribution map was subsequently drawn. With studies on wells of bordering shallow water areas, regional sedimentary characteristics, and isopach map as references, sedimentary planar distribution features were analyzed. The deepwater area of the Lingshui Formation has mainly developed littoral and shallow sea. Sandstone bodies of fan delta, braided river delta, slope fan, basin floor fan, and turbidite fan are at an interdigitate junction to marine hydrocarbon source rocks and thus are favorable prospecting targets.
基金supported by the National Basic Research Program of China (973 Program) (No. 2006CB202300)the Major Scientific and Technical Project of China National Petroleum Corporation (No. 07-01C-01-04)
文摘The main petroliferous basins in eastern China are Cenozoic fault basins, most of which have experienced two-stage tectonic evolution, i.e., rifting subsidence in the Paleogene and post-rifting thermal subsidence in the Neogene-Quaternary. The episodic tectonic evolution and syndepositional faulting had significant influence on the fault basins in terms of accommodation space, deposition rate, and depositional facies zones. In this study, the tectonic deformation characteristics and the tectonic-depositional evolution of the Western Sag of the Cenozoic Liaohe Depression were investigated by comprehensive analysis of the available geological and geophysical data using the modern theory of tectonic geology and the balanced section technique. The tectonic deformation of the Cenozoic fault basin was characterized by superimposed faults and depression. In addition, there existed relatively independent but still related extensional tectonic systems and strike-slip tectonic systems. The tectonic evolution of the fault basin involved five stages, i.e., initial rifting stage （E2s4）, intense faulting stage （E2s3）, fault-depression transition stage （E3sl2）, differential uplifting stage （E3d）, and depression stage （N-Q）. According to the characteristics of tectonic development and evolution of the Western Sag, the depositional evolution in the Cenozoic fault basin was divided into two stages, i.e., multi-episodic rifting filling in the Paleogene and post-rifting filling in the Neogene-Quaternary. The former rifting stage was further subdivided into four episodes with different characteristics of depositional development. The episodic faulting controlled the filling process and filling pattern of the Cenozoic Western Sag as well as the development and spatial distribution of associated depositional systems, whereas the syndepositional faults that developed in multiple stages in various tectonic positions controlled the development of depositional systems and sand bodies in the Western Sag. That is, the fault terraces on steep slopes controlled the development of sand bodies, the fault terraces on gentle slopes controlled the development of low-stand fan bodies, and the fault terraces or fault troughs in the central basin controlled the development of fluxoturbidite bodies.
基金This study is funded by the National major science&technology special project entitled Critical Technologies for Fine Exploration in the Bohai Bay Basin(No.2011ZX0500).
文摘With increased exploration in the faulted basins of eastern China,petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution,complex reservoir and hydrocarbon enrichment patterns,and lacking of suitable exploration techniques.Aiming at resolving these problems,studies on source rocks,reservoirs,hydrocarbon accumulation and geophysical prospection were carried out by laboratory analysis,reservoir anatomy,and seismic analysis.A highlyefficient hydrocarbon generation/expulsion model of source rocks in saline environment was established,which aided in the discovery of a new set of source rocks in the Jiyang Depression.This study also reveals the formation process of high-quality reservoir by alternating acid and alkaline fluids during deposition and diagenesis,and pattern of secondary pores development in deep clastic rocks.Through the fine anatomy of the oil reservoirs,an orderly distribution pattern of the oil reservoirs is established,and the potential exploration targets in the undrilled area are identified.In addition,single-point highdensity seismic acquisition and high-resolution imaging technologies are developed,enabling fine and efficient exploration in areas with high exploration maturity.The research result plays a leading and demonstrative role in the fine and efficient exploration of faulted basins in eastern China.
文摘? The intensive extensional deformation in the eastern part of the Chinese continent in Late Mesozoic time (J3-K1) caused the formation of largescale fault basin system in Northeastern China block, metamorphic core complexes in North China block and widespread volcanic eruption and granitic intrusive in eastern China. Generally, the deformation has been interpreted as subduction tectonics along the eastern continental margin. We suggest that the combination effect of the subduction and collision in Tethys domain and the subduction from Pacific side and the mantle upwelling beneath the lithosphere. This event controlled the Late Jurassic to Early Cretaceous tectonic history in eastern China.
基金Supported by the National Natural Science Foundation of China(41802127,U1762217)China National Science and Technology Major Project(2016ZX05006-003)。
文摘The types,evolution processes,formation mechanisms,and depositional models of deep-water gravity flow deposits in a lacustrine rift basin are studied through core observation and systematic analysis.Massive transport of slide and slump,fluid transport of debris flow and turbidity currents are driven by gravity in deep-water lacustrine environment.The transformation between debris flow and turbidity current,and the transformation of turbidity current between supercritical and subcritical conditions are the main dynamic mechanisms of gravity flow deposits in a lake basin.The erosion of supercritical turbidity current controls the formation of gravity-flow channel.Debris flow deposition gives rise to tongue shape lobe rather than channel.Deep-water gravity flow deposits are of two origins,intrabasinal and extrabasinal.Intrabasinal gravity flow deposits occur as single tongue-shape lobe or fan of stacking multiple lobes.Extrabasinal gravity-flow deposits occur as sublacustrine fan with channel or single channel sand body.However,the nearshore subaqueous fan is characterized by fan of stacking multiple tongue shape lobes without channel.The differential diagenesis caused by differentiation in the nearshore subaqueous fan facies belt results in the formation of diagenetic trap.The extrabasinal gravity flow deposits are one of the important reasons for the abundant deep-water sand bodies in a lake basin.Slide mass-transport deposits form a very important type of lithologic trap near the delta front often ignored.The fine-grained sediment caused by flow transformation is the potential"sweet spot"of shale oil and gas.
基金Joint Seismological Science Foundation of China (198023) and National Natural Science Foundation (40272087).
文摘Lijiang-Daju fault, the seismogenic fault of the 1996 Lijiang M=7.0 earthquake, can be divided into Lijiang-Yuhu segment in the south and Yuhu-Daju segment in the north. The two segments show clear difference in geological tectonics, but have the similar dynamic features. Both normal dip-slip and sinistral strike-slip coexist on the fault plane. This kind of movement started at the beginning of the Quaternary (2.4~2.5 Ma B.P.). As to the tectonic types, the detachment fault with low angle was developed in the Early Pleistocene and the normal fault with high angle only after the Mid-Pleistocene (0.8 Ma B.P.). Based on the horizontal displacements of gullies and the vertical variance of planation surfaces cross the Lijiang-Daju fault at east piedmont of Yulong-Haba range, the average horizontal and vertical slip rates are calculated. They are 0.84 mm/a and 0.70 mm/a since the Quaternary and 1.56 mm/a and 1.69 mm/a since the Mid-Pleistocene. The movements of the nearly N-S-trending Lijiang-Daju fault are controlled not only by the regional stress field, but also by the variant movement between the Yulong-Haba range and Lijiang basin. The two kinds of dynamic processes form the characteristics of seismotectonic environment of occurring the 1996 Lijiang earthquake.
文摘Tectonic movements in the North Slope of Biyang Depression are comparatively mild and stable, thus generating two categories of deltas. Elementary reasons for the coexistence of deltas are the existence of the palaeodrainage pattern and the effect of palaeotopography. The sedimentary facies is the most elementary factor controlling the physical property of reservoirs. The layout and spatial combination model of the sand body and faults are the major influential factors on the occurrence of hydrocarbons. Comparative study on Houzhang and Yanglou Braided Deltas as well as Zhangchang and Gucheng Meandering Deltas suggests that the hydrocarbons distribute primarily in the mouth bar subfacies and secondarily in the distal bar subfacies of the braided delta, while the oil-water and aqueous layers are mainly found in the subaquatic distributary channel. Although the sand body of the meandering delta has excellent stratification and high porosity, the thickness is far less than that of the braided delta. Therefore, the yield of hydrocarbon is relatively low. The mudstone of the delta front subfacies is a kind of source rock with a high content of organic matter. The conducting system for oil/gas migration in the North Slope is a composite one comprising faults and sand- stone reservoirs. A large amount of oil/gas from the deep depression first migrated towards the slope along the sand body which stretches and connects with the source rocks, and then redistributed along the faults in the slope. After the movement reached a standstill, the faults formed the occlusion in the up-dip direction of the sand body, generating a great quantity of fault block hydrocarbon reservoirs in the Noah Slope.
基金Supported by the CNPC Science and Technology Major Project(2018E-11)
文摘High-yielding oil wells were recently found in the first member of Paleogene Shahejie Formation,the Binhai area of Qikou Sag,providing an example of medium-and deep-buried high-quality reservoirs in the central part of a faulted lacustrine basin.By using data of cores,cast thin sections,scanning electron microscope and physical property tests,the sedimentary facies,physical properties and main control factors of the high-quality reservoirs were analyzed.The reservoirs are identified as deposits of slump-type sub-lacustrine fans,which are marked by muddy fragments,slump deformation structure and Bouma sequences in sandstones.They present mostly medium porosity and low permeability,and slightly medium porosity and high permeability.They have primary intergranular pores,intergranular and intragranular dissolution pores in feldspar and detritus grains,and structural microcracks as storage space.The main factors controlling the high quality reservoirs are as follows:(1)Favorable sedimentary microfacies of main and proximal distributary gravity flow channels.The microfacies with coarse sediment were dominated by transportation and deposition of sandy debris flow,and the effect of deposition on reservoir properties decreases with the increase of depth.(2)Medium texture maturity.It is shown by medium-sorted sandstones that were formed by beach bar sediment collapsing and redepositing,and was good for the formation of the primary intergranular pores.(3)High content of intermediate-acid volcanic rock detritus.The reservoir sandstone has high content of detritus of various components,especially intermediate-acid volcanic rock detritus,which is good for the formation of dissolution pores.(4)Organic acid corrosion.It was attributed to hydrocarbon maturity during mesodiagenetic A substage.(5)Early-forming and long lasting overpressure.A large-scale overpressure compartment was caused by under-compaction and hydrocarbon generation pressurization related to thick deep-lacustrine mudstone,and is responsible for the preservation of abundant primary pores.(6)Regional transtensional tectonic action.It resulted in the structural microcracks.
基金funded by foundation of seismic risk assessment of active faults,China Earthquake Administration(Grant no.1521044025)
文摘The easternmost Tian Shan lies in eastern Xinjiang, Central Asia. The South Barkol basin fault（SBF） in the northern part of the easternmost Tian Shan is a major tectonic structure in this orogenic region. The late Quaternary activity, paleoseismology, and deformation characteristics of the fault provide important clues for understanding the tectonic process of the eastern Tian Shan orogen and implementing seismic mitigation. Through interpretation of high-resolution satellite images, unmanned aerial vehicle measurements, and detailed geological and geomorphic investigations, we suggest that the fault exhibits clear left-lateral slip along its western segment. Paleoseismic trenches dug near Xiongkuer reveal evidence of six large paleoearthquakes. The four latest paleoearthquakes were dated： the oldest event occurred at 4663 BC–3839 BC. Data on the horizontal offsets along the probable 1842 Barkol earthquake coseismic rupture suggest clear multiple relationships between cumulative offsets and possible ~4 m of coseismic left-lateral slip per event. From the cumulative offsets and 14 C sample ages, we suggest an average Holocene left-lateral slip rate of 2.4–2.8 mm/a on the SBF, accounting for ~80% of lateral deformation within the entire eastern Tian Shan fault system. This result is comparable with the shortening rate of 2–4 mm/a in the whole eastern Tian Shan, indicating an equal role of strike-slip tectonics and compressional tectonics in this orogen, and that the SBF may accommodate substantial lateral tectonic deformation.
文摘This paper gives a study of 3 D crustal seismic velocity changes in the Weihe fault depression basin, in which the overlapping sphere iterative reconstruction method of tomographic image was used in connection with the two point fast ray tracing technique. By means of theoretical modeling, the monitoring function of the observatory network system of Shaanxi Province was tested. Using the seismic data of the network, seismic tomographic inversion imaging of the crustal seismic velocity in the Weihe fault basin was studied. The results are as follows: In the Tongchuan Yaoxian area to the north of Jingyang, there is a high velocity region extending nearly in NS direction, the highest velocity value is around Tongchuan. To the southwest of Shangxian and Lantian, there is a low velocity zone about 100 km long and about 50 km wide, inside which there are two regions of the lowest velocity 50 km apart. The epicenters of historical strong earthquakes are mainly on the boundary of high velocity regions or in regions of fairly high velocity. In the eastern and western parts of the south margin of the Qinling Mountains, there is an obvious lateral nonhomogeneity of seismic velocity.
文摘Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The sedimentary characteristics of this epoch and the tectono-paleogeography of the basin were expounded.The results show that in its early stages,the Songliao Basin was characterized by a detached faulted basin in which mainly lake facies developed among mountains.It became gradually one lake during the late stages of the Early Cretaceous.During this period,the fault activity in the Songliao Basin changed from a turbulent to a quiet development,the water area from small separated lakes to one large lake,in which the sedimentary facies were divided into asymmetric eastern and western parts.In the basin a volcanic clastic rock-alluvial fan system developed and a fan delta-lake-small delta-river system was mainly deposired.Our research also shows that the basement rifts not only controlled the distribution of fault depressions and the tectonic development in the Early Cretaceous,but had also an effect on the orientation of sedimentation,source area and river system,which determine the tectonopaleogeography of the Early Cretaceous.
基金financed by the National Youth Sciences Foundation of China (No. 41502044)
文摘The role of authigenic clay growth in clay gouge is increasingly recognized as a key to understanding the mechanics of berittle faulting and fault zone processes,including creep and seismogenesis,and providing new insights into the ongoing debate about the frictional strength of brittle fault(Haines and van der Pluijm,2012).However,neither the conditions nor the processes which
基金the National Natural Science Foundation of China (Grant No. 40841010,40972083,41172162)the National Science and Technology Support Program (Grant nNo. 2006BAC13B02-107,2006BAC13B01-604) for the funding
文摘On Jan.31 of 2010,the Suining earthquake occurred at Suining City whch is located the center of Sichuan Basin.It is unusual for the strong earthquake to occur at the center of Sichuan Basin with a stable geotectonic environment and a low-level historical seismicity.The macro-epicenter of the earthquake is located at Moxi town of Suining city,Sichuan province,China.The earthquake intensity of the epicenter area is degree VII,and the long axis of the isoseismal line trends in NE orientation.The Suining earthquake caused the collapse or destruction of 460 family houses.The earthquake focal mechanism solution and records of the near-field seismographic stations showed the earthquake occurred at the reverse fault at a depth 34 km.Based on the waveform and focal mechanism,we consider the Suning earthquake is triggered by the reverse fault and not by the gravitational collapse or man-made explosive sources.Basing on seismic refraction profile and borehole,we consider that the earthquake is triggered by the backthrust fault of Moxi anticline rooted in detachments at a depth 3-4 km.Furthermore,we infer that tectonic mechanism of the Suining(Ms5.0) Earthquake is driven by the horizontal crustal shortening and stress adjustment on a shallow detachment after the Wenchuan(Ms 8.0) earthquake.
文摘The Erlian fault basin group, a typical Basin and Range type fault basin group, was formed during Late Jurassic to Early Cretaceous, in which there are rich coal, oil and gas resources. In the present paper the abundant geological and petroleum information accumulated in process of industry oil and gas exploration and development of the Erlian basin group is comprehensively analyzed, the structures related to formation of basin are systematically studied, and the complete extensional tectonic system of this basin under conditions of wide rift setting and low extensional ratio is revealed by contrasting study with Basin and Range Province of the western America. Based on the above studies and achievements of the former workers, the deep background of the basin development is treated.
文摘Through petroleum exploration of 20 years, a new petroleum production area has been constructed in Hailar Basin. Their petroleum geological characteristics and hydrocarbon distribution has been known in detail. The Hailar Basin is a basin group consisted of many scattered sub-basins with similar structural developed history. Each sub-basin has unique hydrocarbon distributing rules, including (1) oil/gas reservoir distribution is controlled by the oil/gas sag, and the oil/gas bearing in big sag is rich; (2) underwater fan and turbidity fan are the most favorable reservoirs; structure zone controlled by main fault is favorable zone of forming composite oil/gas accumulation; (3) lower fault-block in higher rise and higher fault-block in lower rise are favorable to oil/gas accumulation; (4) deep fault and granite body are closely re-lated to oil/gas reservoir, its distributing area is favorable area of oil and mantle source non-hydrocarbon gas formation; (5) higher geothermal area is favorable oil/gas bearing area.
基金supported by National Natural Science Foundation of China (Grant No. 40739905)Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 200801830041)+2 种基金Science and Technology Project of Sinopec (Grant No. G0800-06-ZS-327)China Scholarship Council (Grant No. 2008617114)the Opening Foundation of the State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration
文摘As the west boundary fault of the Songliao Basin and the eastern margin of the Da Hinggan Mountains, the Nenjiang-Balihan fault is located in the central part of Northeast China. It is traditionally considered to be a huge deep-seated NNE-striking fault, characterized by a normal fault or detachment fault displacement. The field investigation resulted in the finding of ductile shear zones in the Lingxia and Louzidian areas, the middle and southern sectors of the fault system. The authors conducted meas- urements of structural elements in the field, micro-structural studies, finite strain measurements, a study on preferred crystal orientations of quartz determined by Electron Back Scatter Diffraction and muscovite 40Ar/9Ar chronology of the deformed rocks in the ductile shear zone. The results show that the deformation features of the Lingxia and Louzidian ductile shear zones are similar, and that they represent one continuous fault, i.e., the middle-southern segment of the Nenjiang-Balihan Fault, which experienced a sinistral strike-slip ductile shearing in the Early Cretaceous （-130 Ma）. By measuring the displacement of the Xar Moron River suture and Wolegen Group on both sides of the Nenjiang-Balihan Fault, it is found that the cumulative strike-slip offset of the fault is about 40-50 km.
基金supported by the National Science and Technology Major Project (Nos. 2011ZX05003-002 and 2011ZX05009-003-01)the National Basic Research Program of China (No. 2006CB202302)
文摘Based on the case history study of sequence stratigraphic framework,sequence model,and the controlling factors on sequence formation in the southern Junggar foreland basin,a contrasting comparison of the characteristics among the foreland basin,the faulted basin,and the sag basin is made in the aspects of sequence architecture,filling style,the controlling factors on sequence development,the migrations of basin center and depocenter,etc..The current study results show that there are major differences and these are documented as follows.（1） The accommodation space in foreland basin is mainly created by the subsidence caused by thrusting and napping in the foothill belt,resulting in progradational-dominated parasequence sets in the foothill area and retrogradational parasequence sets in the ramp region.（2） The accommodation space in an open-lake system in faulted basin is mainly created by the activities of the basin margin faults;thus,tectonic sequences are formed.However,in the closed-lake system,the subaqueous accommodation is mainly controlled by climatic-influenced lake-level fluctuations,and climatic sequence is formed.（3） In sag basin,a closed-lake system is easily formed due to its generation often within the cratons and isolation from the sea,and its accommodation space creation is mainly controlled by climatic lake-level fluctuations;thus,the sequence architecture in sag basin is similar to that formed on the passive continental margin.
