A wealth of geological and geochemical evidence indicates that plate tectonics was initiated in the Archean,though its style differing from that in the Phanerozoic,largely due to higher temperatures of convective mant...A wealth of geological and geochemical evidence indicates that plate tectonics was initiated in the Archean,though its style differing from that in the Phanerozoic,largely due to higher temperatures of convective mantle.Understanding the specific characteristics for the operation of ancient plate tectonics is critical for deciphering the formation and evolution of continental crust on early Earth,as well as the progressive development of Earth’s habitability.Through an in-depth analysis of geology and geochemistry for two events of late Archean crustal growth in the North China Craton,this study suggests that Archean plate tectonics would likely undergo the gradual evolution from immature to mature phases.The North China Craton experienced two major episodes of crustal growth at~2.9-2.7 and~2.6-2.5 Ga,respectively,represented by peaks in isotopic model ages of Archean felsic gneisses and widespread mafic rocks in greenstone belts.Although the preserved mafic rocks in greenstone belts generally exhibit arc-like trace element signatures,the early mafic crust formed at~2.9-2.7 Ga is limited in volume,with most of it having been reworked within several hundred million years.Tonalite-trondhjemite-granodiorite(TTG),produced by partial melting of such mafic crust,show zircon Hf-O isotope compositions indicative of sources consisting of seawater-hydrothermally altered oceanic crustal rocks with varying ages,suggesting that the early mafic crust was likely dominated by oceanic basalts.The medium-to low-pressure signatures of TTG rocks further imply that the oceanic crust was not subducted deeply to mantle depths,but instead was accreted to the margin of proto-continental nuclei due to aborted subduction.In contrast,the~2.6-2.5 Ga crustal growth event preserved a greater volume of mafic rocks.For these mafic rocks,the enrichment of incompatible elements correlates with water contents estimated from whole-rock major elements,indicating that their arc-like trace element features were associated with fluid metasomatism of the source region.Integrated with regional geological evidence from~2.5 Ga,such as ophiolites containing ultrahigh-pressure mineral inclusions and eclogite-facies remnants of oceanic crust,these observations suggest that modern-style plate subduction was likely in operation by the end of the Late Archean.Therefore,the modern plate tectonics regime did not emerge abruptly,but underwent a gradual evolution controlled by the thermal state of plate margins.It is this evolving tectonic regime that drove the significant crustal growth during the Archean.The two distinct episodes of crustal growth ultimately led to the formation of the North China Craton.展开更多
Tectonic activities significantly impact deep reservoir properties via sedimentary and diagenetic processes,and this is particularly true for lacustrine rift basins.The tectonic-sedimentary-diageneticreservoir system ...Tectonic activities significantly impact deep reservoir properties via sedimentary and diagenetic processes,and this is particularly true for lacustrine rift basins.The tectonic-sedimentary-diageneticreservoir system is crucial in deep reservoir exploration.This study examined the first member and upper submember of the second member of the Dongying Formation in the Bodong Low Uplift in the Bohai Bay Basin(East China),documenting the petrologic features and physical properties of reservoirs in different tectonic sub-units through integrated analysis of log and rock data,along with core observation.A mechanism for deep reservoir formation in lacustrine rift basins was developed to elucidate the sedimentary and diagenetic processes in complex tectonic settings.The results show that tectonic activities result in the occurrence of provenances in multiple directions and the existence of reservoirs at varying burial depths,as well as the significant diversity in sedimentary and diagenetic processes.The grain sizes of the sandstones,influenced by transport pathways rather than the topography of the sedimentary area,exhibit spatial complexity due to tectonic frameworks,which determine the initial pore content of reservoirs.However,the burial depth,influenced by subsequent tectonic subsidence,significantly impacts pore evolution during diagenesis.Based on the significant differences of reservoirs in slope zone,low uplift and depression zone,we establish different tectonic-diagenetic models in deep complex tectonic units of lacustrine rift basins.展开更多
East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines t...East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines ten critical questions of East Asian tectonics,including the thickness of the continental lithosphere,the origin of the North–South Gravity Lineament,and the northern extent of the Indian plate beneath the Tibetan Plateau.Additional questions address the Tibetan Plateau's lateral growth,the Tianshan mountain building,the mantle flow in response to the Indo-Asian collision,and the formation of the Shanxi Rift.The review also explores the subduction along the eastern margins of the East Asian Continent and the origins of the Changbaishan volcanic field,the destruction of the North China Craton,and the development of the Mesozoic Large Granitic Province in South China.Originally presented at the DEEP2024 workshop to stimulate discussion of how SinoProbe-II research initiatives could advance our understanding of Asian tectonics,this review provides context for each question,summarizes current knowledge,and identifies promising research directions.展开更多
The tectonic setting of the Himalaya during the Early Paleozoic has been a subject of enduring debate within the scientific community.Newly discovered bimodal intrusive rocks from comprehensive field geological invest...The tectonic setting of the Himalaya during the Early Paleozoic has been a subject of enduring debate within the scientific community.Newly discovered bimodal intrusive rocks from comprehensive field geological investigation in the central mountain range were subjected to petrology,zircon U-Pb geochronology,zircon Hf isotopes and whole-rock geochemistry analyses.The Palie bimodal intrusive rocks,comprising amphibolite and granitic gneiss,were formed at~489 Ma.The amphibolite exhibits geochemical characteristics consistent with N-MORB,while the granitic gneiss is classified as high potassium calc-alkaline peraluminous S-type granite.Both igneous rocks exhibit negative zirconε_(Hf)(t)values and display ancient T_(DM)^(C)ages.In conjunction with regional geological survey findings,it can be inferred that the formation of the Palie bimodal intrusive rocks occurred within a post-collision extensional tectonic setting.The amphibolite genesis involved partial melting of an enriched lithospheric mantle with some crustal assimilation,whereas the origin of the granitic gneiss can be attributed to partial melting of pre-existing felsic crust.Our data indicate that during the Early Paleozoic,the Himalaya underwent a transition from a pan-African collisional setting to post-collisional extensional tectonics.展开更多
This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on...This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on the Jebel Gustar and Kef Lahmar area,which includes 14 sub-basins,this research uses a DEM-based technique to assess Holocene activities,lineament characteristics,and stream systems.Five geomorphic indices are used to assess relative active tectonics:the stream lengthgradient index(SL),drainage basin asymmetry(AF),valley-floor width to valley height ratio(VF),drainage basin shape(BS),and mountain front sinuosity(SMF).A weighted overlay of these five indices produces the Index of Relative Active Tectonics(IRAT)map.The findings reveal significant neotectonic activity in the study area,supported by profound basement faulting.This research highlights the morpho-structural processes and neotectonics activity in the Jebel Gustar,providing a framework for investigating the evolution of this structure.Additionally,it enhances comprehension of the interactions between the alpine range's internal zones in Eastern Algeria and the Atlasic domain.This study proposes a systematic approach to evaluate the tectonic and geomorphological dynamics of the South Setif region.展开更多
In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using overcoring and hydraulic fracturing stress data,the relation between the stress field and geological...In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using overcoring and hydraulic fracturing stress data,the relation between the stress field and geological tectonics was discussed,and the stability of regional faults under the present-day stress environment was evaluated.The results indicate that the stress level is considerably high,and the distribution of stress intensity is uneven.The stress regime is primarily characterized by σ_(H)>σ_(v)>σ_(h).The σ_(H) orientation is well-oriented in the WNW-ESE,which is roughly identical to other stress indicators.Moreover,theσH direction reflected by joint strikes and inferred based on the fault characteristics agrees fairly with the identified stress orientation.The modern stress field basically inherited the tectonic stress field of the Yanshanian and Himalayan periods but is principally dominated by the Himalayan period.Additionally,the calculatedμm ranges from 0.2 to 0.7,indicating that the possibility of shallow faults across this area being reactivated and experiencing shear failure is small overall under the current stress conditions.μm=0.2 and 0.5 are suggested as the lower and upper limits for predicting and analyzing future fault activity in the area,respectively.展开更多
A systematic study of early Paleozoic S-type granites in Pinghe enhances our understanding of the tectonic evolution of proto-Tethys and provides a foundation for exploring rare metal deposits in the region.The Pinghe...A systematic study of early Paleozoic S-type granites in Pinghe enhances our understanding of the tectonic evolution of proto-Tethys and provides a foundation for exploring rare metal deposits in the region.The Pinghe granites consist of monzogranite and leucogranite.Zircon U-Pb dating shows that the emplacement ages of the monzogranite and leucogranite are 502.0 Ma and 500.9 Ma,respectively.All samples have high SiO_(2) content and a weakly to strongly peraluminous character(A/CNK=1.08-1.23),consistent with S-type granites.The monzogranite has relatively high CaO,Sr,Ba,and CaO/Na_(2)O ratios but lower Rb.In contrast,the leucogranite has lower CaO,Sr,Ba,and CaO/Na_(2)O ratios but higher Rb.The similar ε_(Nd)(t)values(−9.3 to−8.4)and Pb isotopic compositions((^(206)Pb/^(204)Pb)t=18.03-19.36,(^(207)Pb/^(204)Pb)t=15.66-15.76,(^(208)Pb/^(204)Pb)t=37.97-38.55)suggest that the monzogranite formed through partial melting of crustal greywacke,while the leucogranite originated from partial melting of crustal pelite.Regional geological studies suggest that these S-type granites in Pinghe were emplaced in an active continental margin setting,associated with the westward subduction of the proto-Tethys oceanic slab.The geochemical characteristics of leucogranite are consistent with those of tungsten-tin-related granites,indicating significant metallogenic potential for W and Sn deposits.展开更多
Fractal geometry quantitatively analyzes the irregular distribution of geological features,highlighting the dynamic aspects of tectonics,seismic heterogeneity,and geological maturity.This study analyzed the active fau...Fractal geometry quantitatively analyzes the irregular distribution of geological features,highlighting the dynamic aspects of tectonics,seismic heterogeneity,and geological maturity.This study analyzed the active fault data along the Kuhbanan fault zone in southeastern Iran by applying the boxcounting method and observing the changes in Coulomb stress and tried to find the potential triggering parts.The entire region was divided into 16subzones with the box-counting method,and then the fractal dimension(D)in each zone was calculated.The analysis of the fractal dimension for active faults and earthquake epicenters along with the seismicity parameter(b)and their ratio in the Kuhbanan region indicates an imbalance between seismic fractals and faults.This finding suggests that the area may have the potential for future earthquakes or hidden faults.In conjunction with b-value and changes in Coulomb stress change,D-value analysis reveals intense tectonic activity and stress accumulation,particularly within the Ravar,Zarand,and Kianshahr sections.It may be considered a potential location for future earthquakes.The changes in Coulomb stress resulting from the 2005Dahuieh earthquake have also placed this region within the stress accumulation zone,potentially triggering the mentioned areas.This integrative approach,backed by historical earthquake data,highlights the impact of fault geometry and stress dynamics,offering an enhanced framework for earthquake forecasting and seismic risk mitigation applicable to other tectonically active areas within the Iranian plateau.展开更多
Deterministic, probabilistic and composite-grading methods are used to get the possible locations of strong earth-quakes in the future in Norwest Beijing and its vicinity based on the quantitative data and their accur...Deterministic, probabilistic and composite-grading methods are used to get the possible locations of strong earth-quakes in the future in Norwest Beijing and its vicinity based on the quantitative data and their accuracy about active tectonics in the research area and by ordering, some questions in the results are also discussed. It shows that the most dangerous fault segments for strong earthquakes in the future include: segments B and A of the southern boundary fault of the Yangyuan basin, the southern boundary fault of the Xuanhua basin, the east segment of the southern Huaian fault and the east segment of the northern YanggaoTianzhen fault. The most dangerous area is YangyuanShenjing basin, the second one is TianzhenHuaianXuanhua basin and the third dangerous areas are WanquanZhangjiakou and northeast of Yuxian to southwest of Fanshan.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42472258)the Shandong Provincial Natural Science Foundation for Excellent Young Scholars(Grant No.ZR2023YQ036).
文摘A wealth of geological and geochemical evidence indicates that plate tectonics was initiated in the Archean,though its style differing from that in the Phanerozoic,largely due to higher temperatures of convective mantle.Understanding the specific characteristics for the operation of ancient plate tectonics is critical for deciphering the formation and evolution of continental crust on early Earth,as well as the progressive development of Earth’s habitability.Through an in-depth analysis of geology and geochemistry for two events of late Archean crustal growth in the North China Craton,this study suggests that Archean plate tectonics would likely undergo the gradual evolution from immature to mature phases.The North China Craton experienced two major episodes of crustal growth at~2.9-2.7 and~2.6-2.5 Ga,respectively,represented by peaks in isotopic model ages of Archean felsic gneisses and widespread mafic rocks in greenstone belts.Although the preserved mafic rocks in greenstone belts generally exhibit arc-like trace element signatures,the early mafic crust formed at~2.9-2.7 Ga is limited in volume,with most of it having been reworked within several hundred million years.Tonalite-trondhjemite-granodiorite(TTG),produced by partial melting of such mafic crust,show zircon Hf-O isotope compositions indicative of sources consisting of seawater-hydrothermally altered oceanic crustal rocks with varying ages,suggesting that the early mafic crust was likely dominated by oceanic basalts.The medium-to low-pressure signatures of TTG rocks further imply that the oceanic crust was not subducted deeply to mantle depths,but instead was accreted to the margin of proto-continental nuclei due to aborted subduction.In contrast,the~2.6-2.5 Ga crustal growth event preserved a greater volume of mafic rocks.For these mafic rocks,the enrichment of incompatible elements correlates with water contents estimated from whole-rock major elements,indicating that their arc-like trace element features were associated with fluid metasomatism of the source region.Integrated with regional geological evidence from~2.5 Ga,such as ophiolites containing ultrahigh-pressure mineral inclusions and eclogite-facies remnants of oceanic crust,these observations suggest that modern-style plate subduction was likely in operation by the end of the Late Archean.Therefore,the modern plate tectonics regime did not emerge abruptly,but underwent a gradual evolution controlled by the thermal state of plate margins.It is this evolving tectonic regime that drove the significant crustal growth during the Archean.The two distinct episodes of crustal growth ultimately led to the formation of the North China Craton.
基金funded by the Open Fund of Key Laboratory of Marine Geology and Environment,Chinese Academy of Sciences(Grant No.MGE2020KG10)the Open Fund of Key Laboratory of Submarine Geosciences,Ministry of Natural Resources(Grant No.KLSG 2208)+2 种基金the Natural Science Basic Research Program of Shaanxi(Grant No.2024JC-YBMS-227,2023-JC-QN-0287)the Postgraduate Innovation and Practice Ability Development Fund of Xi'an Shiyou University(No.YCS23113046)the National Natural Science Foundation of China(Grant No.41802128,42076219)。
文摘Tectonic activities significantly impact deep reservoir properties via sedimentary and diagenetic processes,and this is particularly true for lacustrine rift basins.The tectonic-sedimentary-diageneticreservoir system is crucial in deep reservoir exploration.This study examined the first member and upper submember of the second member of the Dongying Formation in the Bodong Low Uplift in the Bohai Bay Basin(East China),documenting the petrologic features and physical properties of reservoirs in different tectonic sub-units through integrated analysis of log and rock data,along with core observation.A mechanism for deep reservoir formation in lacustrine rift basins was developed to elucidate the sedimentary and diagenetic processes in complex tectonic settings.The results show that tectonic activities result in the occurrence of provenances in multiple directions and the existence of reservoirs at varying burial depths,as well as the significant diversity in sedimentary and diagenetic processes.The grain sizes of the sandstones,influenced by transport pathways rather than the topography of the sedimentary area,exhibit spatial complexity due to tectonic frameworks,which determine the initial pore content of reservoirs.However,the burial depth,influenced by subsequent tectonic subsidence,significantly impacts pore evolution during diagenesis.Based on the significant differences of reservoirs in slope zone,low uplift and depression zone,we establish different tectonic-diagenetic models in deep complex tectonic units of lacustrine rift basins.
基金supported by grants from the National Science Foundation of the USA.
文摘East Asian continental tectonics challenges the plate tectonics paradigm with its diffuse intraplate deformation,magmatism,and earthquakes.Despite extensive studies,fundamental questions persist.This review examines ten critical questions of East Asian tectonics,including the thickness of the continental lithosphere,the origin of the North–South Gravity Lineament,and the northern extent of the Indian plate beneath the Tibetan Plateau.Additional questions address the Tibetan Plateau's lateral growth,the Tianshan mountain building,the mantle flow in response to the Indo-Asian collision,and the formation of the Shanxi Rift.The review also explores the subduction along the eastern margins of the East Asian Continent and the origins of the Changbaishan volcanic field,the destruction of the North China Craton,and the development of the Mesozoic Large Granitic Province in South China.Originally presented at the DEEP2024 workshop to stimulate discussion of how SinoProbe-II research initiatives could advance our understanding of Asian tectonics,this review provides context for each question,summarizes current knowledge,and identifies promising research directions.
基金supported by the China Geological Survey Program(Grant No.DD20220989)the National Natural Science Foundation of China(Grant No.41972118)。
文摘The tectonic setting of the Himalaya during the Early Paleozoic has been a subject of enduring debate within the scientific community.Newly discovered bimodal intrusive rocks from comprehensive field geological investigation in the central mountain range were subjected to petrology,zircon U-Pb geochronology,zircon Hf isotopes and whole-rock geochemistry analyses.The Palie bimodal intrusive rocks,comprising amphibolite and granitic gneiss,were formed at~489 Ma.The amphibolite exhibits geochemical characteristics consistent with N-MORB,while the granitic gneiss is classified as high potassium calc-alkaline peraluminous S-type granite.Both igneous rocks exhibit negative zirconε_(Hf)(t)values and display ancient T_(DM)^(C)ages.In conjunction with regional geological survey findings,it can be inferred that the formation of the Palie bimodal intrusive rocks occurred within a post-collision extensional tectonic setting.The amphibolite genesis involved partial melting of an enriched lithospheric mantle with some crustal assimilation,whereas the origin of the granitic gneiss can be attributed to partial melting of pre-existing felsic crust.Our data indicate that during the Early Paleozoic,the Himalaya underwent a transition from a pan-African collisional setting to post-collisional extensional tectonics.
文摘This research investigates dynamic earth processes within the South Setifian allochthonous ensemble,providing insights into landscape evolution and seismotectonic activity within the Tellian mountain chain.Focusing on the Jebel Gustar and Kef Lahmar area,which includes 14 sub-basins,this research uses a DEM-based technique to assess Holocene activities,lineament characteristics,and stream systems.Five geomorphic indices are used to assess relative active tectonics:the stream lengthgradient index(SL),drainage basin asymmetry(AF),valley-floor width to valley height ratio(VF),drainage basin shape(BS),and mountain front sinuosity(SMF).A weighted overlay of these five indices produces the Index of Relative Active Tectonics(IRAT)map.The findings reveal significant neotectonic activity in the study area,supported by profound basement faulting.This research highlights the morpho-structural processes and neotectonics activity in the Jebel Gustar,providing a framework for investigating the evolution of this structure.Additionally,it enhances comprehension of the interactions between the alpine range's internal zones in Eastern Algeria and the Atlasic domain.This study proposes a systematic approach to evaluate the tectonic and geomorphological dynamics of the South Setif region.
基金supported by the National Natural Science Foundation of China(52204084)the Open Research Fund of The State Key Laboratory of Coal Resources and safe Mining,CUMT(SKLCRSM23KF004)+3 种基金the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities)(FRF-IDRY-GD22-002)the Fundamen〓〓tal Research Funds for the Central Universities and the Youth Teacher International Exchange and Growth Program(QNXM20220009)the National Key R&D Program of China(2022YFC2905600 and 2022YFC3004601)the Science,Technology&Innovation Proj〓〓ect of Xiongan New Area(2023XAGG0061).
文摘In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using overcoring and hydraulic fracturing stress data,the relation between the stress field and geological tectonics was discussed,and the stability of regional faults under the present-day stress environment was evaluated.The results indicate that the stress level is considerably high,and the distribution of stress intensity is uneven.The stress regime is primarily characterized by σ_(H)>σ_(v)>σ_(h).The σ_(H) orientation is well-oriented in the WNW-ESE,which is roughly identical to other stress indicators.Moreover,theσH direction reflected by joint strikes and inferred based on the fault characteristics agrees fairly with the identified stress orientation.The modern stress field basically inherited the tectonic stress field of the Yanshanian and Himalayan periods but is principally dominated by the Himalayan period.Additionally,the calculatedμm ranges from 0.2 to 0.7,indicating that the possibility of shallow faults across this area being reactivated and experiencing shear failure is small overall under the current stress conditions.μm=0.2 and 0.5 are suggested as the lower and upper limits for predicting and analyzing future fault activity in the area,respectively.
基金funded by the Science and Technology Department of Yunnan Province(202303AA080006)the National Natural Science Foundation of China(41972312 and 41672329).
文摘A systematic study of early Paleozoic S-type granites in Pinghe enhances our understanding of the tectonic evolution of proto-Tethys and provides a foundation for exploring rare metal deposits in the region.The Pinghe granites consist of monzogranite and leucogranite.Zircon U-Pb dating shows that the emplacement ages of the monzogranite and leucogranite are 502.0 Ma and 500.9 Ma,respectively.All samples have high SiO_(2) content and a weakly to strongly peraluminous character(A/CNK=1.08-1.23),consistent with S-type granites.The monzogranite has relatively high CaO,Sr,Ba,and CaO/Na_(2)O ratios but lower Rb.In contrast,the leucogranite has lower CaO,Sr,Ba,and CaO/Na_(2)O ratios but higher Rb.The similar ε_(Nd)(t)values(−9.3 to−8.4)and Pb isotopic compositions((^(206)Pb/^(204)Pb)t=18.03-19.36,(^(207)Pb/^(204)Pb)t=15.66-15.76,(^(208)Pb/^(204)Pb)t=37.97-38.55)suggest that the monzogranite formed through partial melting of crustal greywacke,while the leucogranite originated from partial melting of crustal pelite.Regional geological studies suggest that these S-type granites in Pinghe were emplaced in an active continental margin setting,associated with the westward subduction of the proto-Tethys oceanic slab.The geochemical characteristics of leucogranite are consistent with those of tungsten-tin-related granites,indicating significant metallogenic potential for W and Sn deposits.
基金financial support received through a grant from the Vice-President's Research Office at Bu-Ali Sina University,Iran(Grant Number 09.99)。
文摘Fractal geometry quantitatively analyzes the irregular distribution of geological features,highlighting the dynamic aspects of tectonics,seismic heterogeneity,and geological maturity.This study analyzed the active fault data along the Kuhbanan fault zone in southeastern Iran by applying the boxcounting method and observing the changes in Coulomb stress and tried to find the potential triggering parts.The entire region was divided into 16subzones with the box-counting method,and then the fractal dimension(D)in each zone was calculated.The analysis of the fractal dimension for active faults and earthquake epicenters along with the seismicity parameter(b)and their ratio in the Kuhbanan region indicates an imbalance between seismic fractals and faults.This finding suggests that the area may have the potential for future earthquakes or hidden faults.In conjunction with b-value and changes in Coulomb stress change,D-value analysis reveals intense tectonic activity and stress accumulation,particularly within the Ravar,Zarand,and Kianshahr sections.It may be considered a potential location for future earthquakes.The changes in Coulomb stress resulting from the 2005Dahuieh earthquake have also placed this region within the stress accumulation zone,potentially triggering the mentioned areas.This integrative approach,backed by historical earthquake data,highlights the impact of fault geometry and stress dynamics,offering an enhanced framework for earthquake forecasting and seismic risk mitigation applicable to other tectonically active areas within the Iranian plateau.
基金National major basic-theory planning project Mechanism and Prediction of Strong Earthquake (95130105) and the Key Project from China Seismological Bureau (95040803).
文摘Deterministic, probabilistic and composite-grading methods are used to get the possible locations of strong earth-quakes in the future in Norwest Beijing and its vicinity based on the quantitative data and their accuracy about active tectonics in the research area and by ordering, some questions in the results are also discussed. It shows that the most dangerous fault segments for strong earthquakes in the future include: segments B and A of the southern boundary fault of the Yangyuan basin, the southern boundary fault of the Xuanhua basin, the east segment of the southern Huaian fault and the east segment of the northern YanggaoTianzhen fault. The most dangerous area is YangyuanShenjing basin, the second one is TianzhenHuaianXuanhua basin and the third dangerous areas are WanquanZhangjiakou and northeast of Yuxian to southwest of Fanshan.
