The Phlaythong large iron deposit in Shampasak of southern Laos,is located in the Kon Tum microblock （Fig.1A）,central-southern part of the Indo-China block,and the geographic coordinate of the central mining area is...The Phlaythong large iron deposit in Shampasak of southern Laos,is located in the Kon Tum microblock （Fig.1A）,central-southern part of the Indo-China block,and the geographic coordinate of the central mining area is 14°43′04″ N and 106°07′02″ E.展开更多
It is clarified in this paper that the Lower Yangtze depression is a Meso-Cenozoic rift zone formed on thebasement of the Hercynian-Indosinian foreland basins. The rift zone is divided into eastern and western sectors...It is clarified in this paper that the Lower Yangtze depression is a Meso-Cenozoic rift zone formed on thebasement of the Hercynian-Indosinian foreland basins. The rift zone is divided into eastern and western sectorsand is different in northern and southern parts. The rift zone in plane combination comprises parallel.trifurcate or splitting rifts. The North Jiangsu-South Yellow Sea region represents a 'drift-type' rift basinwhose deposition center migrates gradually castward. The formation mechanism and dynamic evolution of therift basin are discussed from a viewpoint of the crustal fine-structure, with evidence in geology and geophysicsand analysis results of dynamic forces given.展开更多
The United Nations Convention on the Law of the Sea entitled the coastal States to naturally extend the continental shelf, which has caused more drastic disputes of maritime delimitation. This paper devotes to clarify...The United Nations Convention on the Law of the Sea entitled the coastal States to naturally extend the continental shelf, which has caused more drastic disputes of maritime delimitation. This paper devotes to clarifying the significant concept of natural prolongation through an effect method combing the legal principles and technical analysis. Firstly, the classic samples with respect of the development of geological features are traced. Based on these samples, the classification with a model is proposed in order to affirm the concept＇s significance under certain geomorphologic situations. Lastly, scientific analysis is used to present two potential prolongation situations and emphasize that all the technical analysis on maritime delimitation should be complied with international law and protect the common interest of all the mankind.展开更多
With the major breakthrough in Sinian-Cambrian gas exploration in the Sichuan Basin,the geologic understanding on this formation has changed.One change concerns the discovery of a nearly SN negative structure in the w...With the major breakthrough in Sinian-Cambrian gas exploration in the Sichuan Basin,the geologic understanding on this formation has changed.One change concerns the discovery of a nearly SN negative structure in the west of Gaoshiti-Moxi area,but there is controversy over the nature,boundary features and distribution scope,sedimentary features,formation stage and evolution of the structure[11e14].Since the negative structure belt is closely related to the formation of the Anyue Sinian-Cambrian giant gasfield,it is necessary to get a better under-standing of its geological features in order to guide the gas exploration in Sinian-Cambrian of the Sichuan Basin in the future.Through an analysis of the drilling data of Sinian-Cambrian in this area,an observation of outcrop profiles and the use of 27000 km 2D seismic data and latest drilling data(Well Gaoshi 17),and in combination with regional structure background,the boundary and distribution scope,sedimentary features and evolution of the Mianzhu-Changning rift in craton were investigated.The results showed that:①the rift in overall SN direction had a steep and fairly stable eastern boundary,and gentler western boundary with variable positions in different stages;②at the end of Sinian Deng2 member,the rift was a nearly symmetrical depression with an area of 3104 km2;③at the end of Deng4 member,it was a fault depression which was steep in the east and gentle in the west controlled by its eastern boundary fault with an area of 8104 km2;and④the evolution of the rift can be divided into four stages:embryonic stage in Deng1-Deng2,formation stage in Deng3-Deng4,filling and subsidence stage in Early Cambrian Maidingping-Qiongzhusi Formation,shrinkage and disappearing stage in Early Cambrian Canglangpu-Longwangmiao Formation.Through the study,it was concluded that both sides of the rift are in good Sinian-Cambrian gas-reservoir-forming conditions,which are major prospects for future exploration.展开更多
The geological features of three types of tropical volcanic rock and soil distributed along Jakarta-Bandung high-speed railway(HSR),including pozzolanic clayey soil,mud shale and deep soft soil,are studied through fie...The geological features of three types of tropical volcanic rock and soil distributed along Jakarta-Bandung high-speed railway(HSR),including pozzolanic clayey soil,mud shale and deep soft soil,are studied through field and laboratory tests.The paper analyzes the mechanism and causes of engineering geological problems caused by tropical volcanic rock and soil and puts forward measures to control subgrade slope instability by rationally determining project type,making side slope stability control and strengthening waterproofing and drainage.The“zero front slope”tunneling technology at the portal,the simplified excavation method of double-side wall heading and the cross brace construction method of arch protection within the semi-open cut row pile frame in the“mountainside”eccentrically loaded soft soil stratum are adopted to control the instability of tunnel side and front slopes,foundation pits and working faces;CFG or pipe piles shall be used to reinforce soft and expansive foundation or replacement measures shall be taken,and the scheme of blind ditch+double-layer water sealing in ballastless track section shall be put forward to prevent arching deformation of foundation;the treatment measures of CFG pile,pipe pile and vacuum combined piled preloading are adopted to improve the bearing capacity of foundation in deep soft soil section and solve the problems of settlement control and uneven settlement.These engineering countermeasures have been applied during the construction of Jakarta-Bandung HSR and achieved good results.展开更多
Deep-seated catastrophic landslides,particularly rock or debris avalanches,travel extremely rapidly for long distances,causing severe damage over wide areas.This paper summarizes the geological and geomorphological fe...Deep-seated catastrophic landslides,particularly rock or debris avalanches,travel extremely rapidly for long distances,causing severe damage over wide areas.This paper summarizes the geological and geomorphological features of such events,which were induced by earthquakes and rainstorms in Asia,and then uses these features to predict future potential sites of failures.Most of the rock avalanches are preceded by gravitational slope deformation with topographic features,in which small scarps along future head of landslide are the most representative;the scarps can be identified in topographic images made by highresolution airborne LiDAR DEMs and may suggest the instability just before catastrophic failure.展开更多
0 INTRODUCTION Changbaishan volcanism,located on the border of China and North Korea,has been a subject of extensive research due to its unique geological features and active volcanic history(Wan et al.,2024).Two prim...0 INTRODUCTION Changbaishan volcanism,located on the border of China and North Korea,has been a subject of extensive research due to its unique geological features and active volcanic history(Wan et al.,2024).Two primary models have been proposed to explain the origin of Changbaishan volcanism(CV).展开更多
Tight oil has become the focus in exploration and development of unconventional oil in the world, especially in North America and China. In North America, there has been intensive exploration for tight oil in marine. ...Tight oil has become the focus in exploration and development of unconventional oil in the world, especially in North America and China. In North America, there has been intensive exploration for tight oil in marine. In China, commercial exploration for tight oil in conti- nental sediments is now steadily underway. With the dis- covery of China＇s first tight oil field--Xin＇anbian Oilfield in the Ordos Basin, tight oil has been integrated officially into the category for reserves evaluation. Geologically, tight oil is characterized by distribution in depressions and slopes of basins, extensive, mature, and high-quality source rocks, large-scale reservoir space with micro- and nanopore throat systems, source rocks and reservoirs in close contact and with continuous distribution, and local ＂sweet area.＂ The evaluation of the distribution of tight oil ＂sweet area＂ should focus on relationships between ＂six features.＂ These are source properties, lithology, physical properties, brittleness, hydrocarbon potential, and stress anisotropy. In North America, tight oil prospects are distributed in lamellar shale or marl, where natural fractures are fre- quently present, with TOC 〉 4 %, porosity 〉 7 %, brittle mineral content 〉 50 %, oil saturation of 50 %-80 %, API 〉 35~, and pressure coefficient 〉 1.30. In China, tight oil prospects are distributed in lamellar shale, tight sand- stone, or tight carbonate rocks, with TOC 〉 2 %, poros- ity 〉 8 %, brittle mineral content 〉 40 %, oil saturation of 60 %-90 %, low crude oil viscosity, or high formation pressure. Continental tight oil is pervasive in China and its preliminary estimated technically recoverable resources are about （20-25） × lO8^ t.展开更多
Geological Characteristics and Prospecting Indicators of Senji Molybdenum Ore Body in Urad Houqi, Inner Mongolia Based on geological mapping, soil geochemical survey, surface trough exploration and deep drilling verif...Geological Characteristics and Prospecting Indicators of Senji Molybdenum Ore Body in Urad Houqi, Inner Mongolia Based on geological mapping, soil geochemical survey, surface trough exploration and deep drilling verification and control, the Senji Molybdenum deposit was discovered. Geological characteristics of the molybdenum ore body are described. The host lithology of molyb</span><span style="font-family:Verdana;">denum ore body is mainly in the cataclastic carbonated black plagioclase </span><span style="font-family:Verdana;">gneiss of the second rock member of the Paleoproterozoic Baoyintu Group, followed by Early Carboniferous monzogranite. The genetic type of the </span><span style="font-family:Verdana;">deposit is preliminarily deduced to be a hydrothermal filling vein-type</span><span style="font-family:Verdana;"> molybdenum </span><span style="font-family:Verdana;">deposit. The significance of this paper is to summarize the prospecting</span><span style="font-family:Verdana;"> marks of the molybdenum ore body in this area, so as to further guide the exploration work in this area, and at the same time provide a useful reference for the exploration work of similar deposits in other areas.展开更多
As petroleum exploration advances and as most of the oil-gas reservoirs in shallow layers have been explored, petroleum exploration starts to move toward deep basins, which has become an inevitable choice. In this pap...As petroleum exploration advances and as most of the oil-gas reservoirs in shallow layers have been explored, petroleum exploration starts to move toward deep basins, which has become an inevitable choice. In this paper, the petroleum geology features and research progress on oil-gas reservoirs in deep petroliferous basins across the world are characterized by using the latest results of worldwide deep petroleum exploration. Research has demonstrated that the deep petroleum shows ten major geological features. （1） While oil-gas reservoirs have been discovered in many different types of deep petroliferous basins, most have been discovered in low heat flux deep basins. （2） Many types of petroliferous traps are developed in deep basins, and tight oil-gas reservoirs in deep basin traps are arousing increasing attention. （3） Deep petroleum normally has more natural gas than liquid oil, and the natural gas ratio increases with the burial depth. （4） The residual organic matter in deep source rocks reduces but the hydrocarbon expulsion rate and efficiency increase with the burial depth. （5） There are many types of rocks in deep hydrocarbon reservoirs, and most are clastic rocks and carbonates. （6） The age of deep hydrocarbon reservoirs is widely different, but those recently discovered are pre- dominantly Paleogene and Upper Paleozoic. （7） The porosity and permeability of deep hydrocarbon reservoirs differ widely, but they vary in a regular way with lithology and burial depth. （8） The temperatures of deep oil-gas reservoirs are widely different, but they typically vary with the burial depth and basin geothermal gradient. （9） The pressures of deep oil-gas reservoirs differ significantly, but they typically vary with burial depth, genesis, and evolu- tion period. （10） Deep oil-gas reservoirs may exist with or without a cap, and those without a cap are typically of unconventional genesis. Over the past decade, six major steps have been made in the understanding of deep hydrocarbon reservoir formation. （1） Deep petroleum in petroliferous basins has multiple sources and many dif- ferent genetic mechanisms. （2） There are high-porosity, high-permeability reservoirs in deep basins, the formation of which is associated with tectonic events and subsurface fluid movement. （3） Capillary pressure differences inside and outside the target reservoir are the principal driving force of hydrocarbon enrichment in deep basins. （4） There are three dynamic boundaries for deep oil-gas reservoirs; a buoyancy-controlled threshold, hydrocarbon accumulation limits, and the upper limit of hydrocarbon generation. （5） The formation and distribution of deep hydrocarbon res- ervoirs are controlled by free, limited, and bound fluid dynamic fields. And （6） tight conventional, tight deep, tight superimposed, and related reconstructed hydrocarbon reservoirs formed in deep-limited fluid dynamic fields have great resource potential and vast scope for exploration. Compared with middle-shallow strata, the petroleum geology and accumulation in deep basins are more complex, which overlap the feature of basin evolution in different stages. We recommend that further study should pay more attention to four aspects： （1） identification of deep petroleum sources and evaluation of their relative contributions; （2） preservation conditions and genetic mechanisms of deep high-quality reservoirs with high permeability and high porosity; （3） facies feature and transformation of deep petroleum and their potential distribution; and （4） economic feasibility evaluation of deep tight petroleum exploration and development.展开更多
In this study, we analyzed the gravity and, magnetic characteristics, and the occurrence of a fault zone and discussed the relationships between the two locations. The results reveal that the subsurface structures str...In this study, we analyzed the gravity and, magnetic characteristics, and the occurrence of a fault zone and discussed the relationships between the two locations. The results reveal that the subsurface structures strikes are different compared with those in the research region. In other words, the geophysical advantageous directions from the gravity and magnetic anomalies are not the same as those caused by the surface structures. The local horizontal gradient results from the gravity and magnetic anomalies show that the majority of earthquakes occur along an intense fault zone, which is a zone of abrupt gravity and negative magnetic change, where the shapes match very well. From the distribution of earthquakes in this area, we find that it has experienced more than 11 earthquake events with magnitude larger than Ms7.0. In addition, water development sites such as Jinshajiang, Lancangjiang, and the Red River and Pearl River watersheds have been hit ten times by earthquakes of this magnitude. It is observed that strong earthquakes occur frequently in the Holocene active fault zone.展开更多
The modern laterite gold deposits in southern China, which belong to reworked laterite deposits, can be further divided into three subclasses and seven types. Their geological features, ore-forming conditions and regu...The modern laterite gold deposits in southern China, which belong to reworked laterite deposits, can be further divided into three subclasses and seven types. Their geological features, ore-forming conditions and regularities are discussed. A geologic-geochemical metallogenic model for laterite gold deposits has been established.展开更多
Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of eac...Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are different.The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body.It is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace elements.Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou.The results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei coalfield.The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors.The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.展开更多
Iron oxide copper-gold （IOCG） deposits are a research focus of the current ore deposit geology, and have attracted much attention among the worldwide geologists and exploration experts due to their shallow depth, a ...Iron oxide copper-gold （IOCG） deposits are a research focus of the current ore deposit geology, and have attracted much attention among the worldwide geologists and exploration experts due to their shallow depth, a wide variety of mineral species and large scale. This paper presents a review of the present IOCG deposits research, which includes the definition of IOCG deposits, temporal and spatial distribution, ore-forming environments, ore-forming magmatic rocks, their geological features, ore-controlling structures and ore-bearing rocks, mineralized alteration zoning, and their genesis and ore-forming process. This work also proposed the ore prospecting direction of IOCG deposits from a trinity model of metaUogenic geological bodies, metallogenic structure surface and metailogenic information signs, and discussed the existing problems of the IOCG deposits research.展开更多
This report first gives a general description of Cambodia and then discusses its topographic and geological features. Finally, the current situation concerning erosion and sediment disasters is discussed.
Global oil and gas consumption continues to rise and new strategies are required to meet the growing demand.Carbonate gas reservoirs are an important natural gas resource that are often accompanied by water intrusion ...Global oil and gas consumption continues to rise and new strategies are required to meet the growing demand.Carbonate gas reservoirs are an important natural gas resource that are often accompanied by water intrusion during the development process.The efficient development of such reservoirs has therefore been extensively studied and met with difficulty.This paper summarizes the basic geological and water invasion characteristics of water-bearing carbonate gas reservoirs and correlates the two.A method for identifying water invasion types by production dynamics is introduced.The variation curve of the production water to gas ratio is shown to correspond with the reservoir geological characteristics.Typical development methods and the advantages/disadvantages of different water control techniques are summarized.The findings are used to propose a full-cycle water control plan for water-bearing carbonate gas reservoirs,and the development strategies of“early preparation,early discovery,and early treatment”and“re-analyze,re-assess,and re-adjust”are implemented to organically combine water control,drainage,and water blocking methods.The results provide a reference for formulating efficient and scientific development plans of waterbearing carbonate gas reservoirs.展开更多
Geological features and hazards have no geographical and political boundaries.The North Atlantic Treaty Organization(NATO)has been funding several international Earth Science research projects in Central Asia and the ...Geological features and hazards have no geographical and political boundaries.The North Atlantic Treaty Organization(NATO)has been funding several international Earth Science research projects in Central Asia and the Caucasus over the last ten years.The projects are aimed at improving the security of people and the safety of infrastructures,and fostering peaceful scientific collaboration between scientists from NATO and non-NATO countries.In the present work,we show how Earth Science can contribute to improving scientific collaboration also among countries that are politically in tension,and how it can also play a key role in preventing situations that may escalate into conflicts.This paper showcases the main results,partially unpublished,of three different research projects that have been aimed at assessing,through an interdisciplinary approach,different geohazards affecting important infrastructure and lifelines of a number of countries in Central Asia and the Caucasus.For each region,we also describe the societal relevance of the research,considering possible geopolitical issues that might be brought about by natural disasters.展开更多
The predictions by drilling-related mechanical and geological models are in some degree inaccurate due to non-unique solution of seismic velocity model.To address this problem,a new drilling technology guided by well-...The predictions by drilling-related mechanical and geological models are in some degree inaccurate due to non-unique solution of seismic velocity model.To address this problem,a new drilling technology guided by well-seismic information integration is proposed which consists of seismic velocity update of drilled formations,seismic velocity prediction of the formation ahead of drilling bit,and the prediction of geological feature and drilling geological environmental factors ahead of bit.In this technology,real information(velocity,formation and depth)behind the drilling bit and local pre-stack seismic data around the wellbore being drilled are used to correct the primitive seismic velocity field for a re-migration of seismic data and to update geological features and drilling geological environmental factors ahead of the drilling bit.Field application shows that this technology can describe and predict the geological features,drilling geological environmental factors and complex drilling problems ahead of the bit timely and improve the prediction efficiency and accuracy greatly.These new updated results are able to provide scientific basis for optimizing drilling decisions.展开更多
In order to promote the exploration and development of continental shale gas reservoirs in China further,we systematically summarized the geological features of typical continental shale,such as the Ordos Basin.Then,t...In order to promote the exploration and development of continental shale gas reservoirs in China further,we systematically summarized the geological features of typical continental shale,such as the Ordos Basin.Then,the shale gas reservoir characteristics,geochemical charac-teristics and fracturing performance of the Lower Cretaceous Shahai Fm in the Fuxin Basin were analyzed by using the data of TOC contents,rock specific surface,pore size distribution and X-ray diffraction analysis of the whole rock.Based on this,it was compared with the marine/continental shale gas reservoirs from the aspect of geological feature.Finally,the shale gas reservoir and resource potential of the Shahai Fm were evaluated.And the following research results were obtained.First,the formation age of China's continental shale is later,its TOC contents vary in a large range,and its organic matters are mainly of a mixed-humic type.And it is characterized by low thermal evolution degree,low quartz content,high feldspar content,high carbonate content,and comparability of total brittle mineral content to marine shale.Second,shale in the Shahai Fm has shallow burial depth and its mineral composition is dominated by quartz,feldspar and carbonate minerals.Its pores are mainly mesopores with an average porosity of 3.47%.There are diverse reservoir spaces,which is favorable for the accumulation of shale gas.Third,the TOC content of the Shahai Fm shale is mainly above 2%,with a moderate thermal evolution degree of organic matter and high gas content.Fourth,the total brittle mineral content of Shahai Fm shale is up to 60%,indicating a good fracturing performance.Fifth,shale reservoirs in the Shahai Fm can be classified into three categories.Type Ⅰ is target reservoirs of exploration and development,and Type Ⅱ is favorable reservoirs.It is estimated that the amount of shale gas resources are in the range of 232.2-286.2 billion m^(3).It is concluded that the Shahai Fm shale in the Fuxin Basin has both resource potential in geology and fracturing performance in engineering,and its exploration and development prospect is broad.What's more,the potential of commercial shale gas development is great in the sweet-point areas.展开更多
Over the past decade,great progresses have been made in natural gas exploration in the Sichuan Basin,where several large gas fields(such as Anyue)have been discovered.With the increase of data and the deepening of exp...Over the past decade,great progresses have been made in natural gas exploration in the Sichuan Basin,where several large gas fields(such as Anyue)have been discovered.With the increase of data and the deepening of exploration,new knowledges have been gained in geological theory,thus it is necessary to further analyze the distribution characteristics and main controlling factors of large gas fields,thus to put forward new exploration directions for large gas fields.Therefore,based on the statistics on the geological parameters of 20 large gas fields discovered in this basin,the distribution rules,formation conditions and main controlling factors of large gas fields were analyzed,and the follow-up exploration directions were proposed.The following results were achieved.(1)Large gas fields are developed in different tectonic regions in the Sichuan Basin,mostly in the low and gentle tectonic belts in the central Sichuan Basin.Large gas fields are developed in seven series of strata in longitudinal stratigraphic sequences,which are dominated by the reef-shoal large gas fields formed in the Upper Permian ChangxingeLower Triassic Feixianguan Fms.(2)There are four sets of source rocks contributing to the formation of large gas fields,mostly from the assemblage of Xujiahe Fm source rocks.(3)Reservoirs in the large gas fields are dominated by porous carbonates and tight sandstones;large gas fields are mostly structuralelithological ones and normal pressure ones.(4)The development of marine large gas fields are mainly controlled by intracratonic rifts and paleo-uplifts.The controlling effect of intracratonic rifts is mainly from three aspects,namely the hydrocarbon generation center of source rocks,high-energy facies belts on the platform edges,and lateral sealing for hydrocarbon accumulation.The controlling effect of the paleo-uplifts mainly acts from another three aspects:intra-platform high-energy facies belts,karstic dolomite reservoirs and long-term hydrocarbon accumulation.The structures of foreland basins controlled the development of the continental large gas fields from four aspects:tectonic setting,source and reservoir assemblage,trap type and fracture distribution.In conclusion,a total of 5 domains with 14 favorable zones are the follow-up exploration directions of large gas fields in the Sichuan Basin.展开更多
基金financially supported by the Special fund for Foreign Mineral Resources Risk Exploration (Grant No.Sichuan Financial Investment (2010)331)China Geological Survey (Grant No.12120114012501)
文摘The Phlaythong large iron deposit in Shampasak of southern Laos,is located in the Kon Tum microblock （Fig.1A）,central-southern part of the Indo-China block,and the geographic coordinate of the central mining area is 14°43′04″ N and 106°07′02″ E.
文摘It is clarified in this paper that the Lower Yangtze depression is a Meso-Cenozoic rift zone formed on thebasement of the Hercynian-Indosinian foreland basins. The rift zone is divided into eastern and western sectorsand is different in northern and southern parts. The rift zone in plane combination comprises parallel.trifurcate or splitting rifts. The North Jiangsu-South Yellow Sea region represents a 'drift-type' rift basinwhose deposition center migrates gradually castward. The formation mechanism and dynamic evolution of therift basin are discussed from a viewpoint of the crustal fine-structure, with evidence in geology and geophysicsand analysis results of dynamic forces given.
基金The National Social Science Foundation of China under contract No.16CFX069China Postdoctoral Science Foundations under contract Nos 2015M581913 and 2016T90531the Fundamental Research Funds for the Central Universities
文摘The United Nations Convention on the Law of the Sea entitled the coastal States to naturally extend the continental shelf, which has caused more drastic disputes of maritime delimitation. This paper devotes to clarifying the significant concept of natural prolongation through an effect method combing the legal principles and technical analysis. Firstly, the classic samples with respect of the development of geological features are traced. Based on these samples, the classification with a model is proposed in order to affirm the concept＇s significance under certain geomorphologic situations. Lastly, scientific analysis is used to present two potential prolongation situations and emphasize that all the technical analysis on maritime delimitation should be complied with international law and protect the common interest of all the mankind.
基金National Science and Technology Major Project(ID:2011ZX05007).
文摘With the major breakthrough in Sinian-Cambrian gas exploration in the Sichuan Basin,the geologic understanding on this formation has changed.One change concerns the discovery of a nearly SN negative structure in the west of Gaoshiti-Moxi area,but there is controversy over the nature,boundary features and distribution scope,sedimentary features,formation stage and evolution of the structure[11e14].Since the negative structure belt is closely related to the formation of the Anyue Sinian-Cambrian giant gasfield,it is necessary to get a better under-standing of its geological features in order to guide the gas exploration in Sinian-Cambrian of the Sichuan Basin in the future.Through an analysis of the drilling data of Sinian-Cambrian in this area,an observation of outcrop profiles and the use of 27000 km 2D seismic data and latest drilling data(Well Gaoshi 17),and in combination with regional structure background,the boundary and distribution scope,sedimentary features and evolution of the Mianzhu-Changning rift in craton were investigated.The results showed that:①the rift in overall SN direction had a steep and fairly stable eastern boundary,and gentler western boundary with variable positions in different stages;②at the end of Sinian Deng2 member,the rift was a nearly symmetrical depression with an area of 3104 km2;③at the end of Deng4 member,it was a fault depression which was steep in the east and gentle in the west controlled by its eastern boundary fault with an area of 8104 km2;and④the evolution of the rift can be divided into four stages:embryonic stage in Deng1-Deng2,formation stage in Deng3-Deng4,filling and subsidence stage in Early Cambrian Maidingping-Qiongzhusi Formation,shrinkage and disappearing stage in Early Cambrian Canglangpu-Longwangmiao Formation.Through the study,it was concluded that both sides of the rift are in good Sinian-Cambrian gas-reservoir-forming conditions,which are major prospects for future exploration.
文摘The geological features of three types of tropical volcanic rock and soil distributed along Jakarta-Bandung high-speed railway(HSR),including pozzolanic clayey soil,mud shale and deep soft soil,are studied through field and laboratory tests.The paper analyzes the mechanism and causes of engineering geological problems caused by tropical volcanic rock and soil and puts forward measures to control subgrade slope instability by rationally determining project type,making side slope stability control and strengthening waterproofing and drainage.The“zero front slope”tunneling technology at the portal,the simplified excavation method of double-side wall heading and the cross brace construction method of arch protection within the semi-open cut row pile frame in the“mountainside”eccentrically loaded soft soil stratum are adopted to control the instability of tunnel side and front slopes,foundation pits and working faces;CFG or pipe piles shall be used to reinforce soft and expansive foundation or replacement measures shall be taken,and the scheme of blind ditch+double-layer water sealing in ballastless track section shall be put forward to prevent arching deformation of foundation;the treatment measures of CFG pile,pipe pile and vacuum combined piled preloading are adopted to improve the bearing capacity of foundation in deep soft soil section and solve the problems of settlement control and uneven settlement.These engineering countermeasures have been applied during the construction of Jakarta-Bandung HSR and achieved good results.
文摘Deep-seated catastrophic landslides,particularly rock or debris avalanches,travel extremely rapidly for long distances,causing severe damage over wide areas.This paper summarizes the geological and geomorphological features of such events,which were induced by earthquakes and rainstorms in Asia,and then uses these features to predict future potential sites of failures.Most of the rock avalanches are preceded by gravitational slope deformation with topographic features,in which small scarps along future head of landslide are the most representative;the scarps can be identified in topographic images made by highresolution airborne LiDAR DEMs and may suggest the instability just before catastrophic failure.
基金support from the National Natural Science Foundation of China(No.42276049)。
文摘0 INTRODUCTION Changbaishan volcanism,located on the border of China and North Korea,has been a subject of extensive research due to its unique geological features and active volcanic history(Wan et al.,2024).Two primary models have been proposed to explain the origin of Changbaishan volcanism(CV).
基金supported by the National Key Basic Research and Development Program (973 Program), China (Grant 2014CB239000)China National Science and Technology Major Project (Grant 2011ZX05001)
文摘Tight oil has become the focus in exploration and development of unconventional oil in the world, especially in North America and China. In North America, there has been intensive exploration for tight oil in marine. In China, commercial exploration for tight oil in conti- nental sediments is now steadily underway. With the dis- covery of China＇s first tight oil field--Xin＇anbian Oilfield in the Ordos Basin, tight oil has been integrated officially into the category for reserves evaluation. Geologically, tight oil is characterized by distribution in depressions and slopes of basins, extensive, mature, and high-quality source rocks, large-scale reservoir space with micro- and nanopore throat systems, source rocks and reservoirs in close contact and with continuous distribution, and local ＂sweet area.＂ The evaluation of the distribution of tight oil ＂sweet area＂ should focus on relationships between ＂six features.＂ These are source properties, lithology, physical properties, brittleness, hydrocarbon potential, and stress anisotropy. In North America, tight oil prospects are distributed in lamellar shale or marl, where natural fractures are fre- quently present, with TOC 〉 4 %, porosity 〉 7 %, brittle mineral content 〉 50 %, oil saturation of 50 %-80 %, API 〉 35~, and pressure coefficient 〉 1.30. In China, tight oil prospects are distributed in lamellar shale, tight sand- stone, or tight carbonate rocks, with TOC 〉 2 %, poros- ity 〉 8 %, brittle mineral content 〉 40 %, oil saturation of 60 %-90 %, low crude oil viscosity, or high formation pressure. Continental tight oil is pervasive in China and its preliminary estimated technically recoverable resources are about （20-25） × lO8^ t.
文摘Geological Characteristics and Prospecting Indicators of Senji Molybdenum Ore Body in Urad Houqi, Inner Mongolia Based on geological mapping, soil geochemical survey, surface trough exploration and deep drilling verification and control, the Senji Molybdenum deposit was discovered. Geological characteristics of the molybdenum ore body are described. The host lithology of molyb</span><span style="font-family:Verdana;">denum ore body is mainly in the cataclastic carbonated black plagioclase </span><span style="font-family:Verdana;">gneiss of the second rock member of the Paleoproterozoic Baoyintu Group, followed by Early Carboniferous monzogranite. The genetic type of the </span><span style="font-family:Verdana;">deposit is preliminarily deduced to be a hydrothermal filling vein-type</span><span style="font-family:Verdana;"> molybdenum </span><span style="font-family:Verdana;">deposit. The significance of this paper is to summarize the prospecting</span><span style="font-family:Verdana;"> marks of the molybdenum ore body in this area, so as to further guide the exploration work in this area, and at the same time provide a useful reference for the exploration work of similar deposits in other areas.
基金the National Basic Research Program of China (973 Program, 2011CB201100)‘‘Complex hydrocarbon accumulation mechanism and enrichmentregularities of deep superimposed basins in Western China’’ National Natural Science Foundation of China (U1262205) under the guidance of related department heads and experts
文摘As petroleum exploration advances and as most of the oil-gas reservoirs in shallow layers have been explored, petroleum exploration starts to move toward deep basins, which has become an inevitable choice. In this paper, the petroleum geology features and research progress on oil-gas reservoirs in deep petroliferous basins across the world are characterized by using the latest results of worldwide deep petroleum exploration. Research has demonstrated that the deep petroleum shows ten major geological features. （1） While oil-gas reservoirs have been discovered in many different types of deep petroliferous basins, most have been discovered in low heat flux deep basins. （2） Many types of petroliferous traps are developed in deep basins, and tight oil-gas reservoirs in deep basin traps are arousing increasing attention. （3） Deep petroleum normally has more natural gas than liquid oil, and the natural gas ratio increases with the burial depth. （4） The residual organic matter in deep source rocks reduces but the hydrocarbon expulsion rate and efficiency increase with the burial depth. （5） There are many types of rocks in deep hydrocarbon reservoirs, and most are clastic rocks and carbonates. （6） The age of deep hydrocarbon reservoirs is widely different, but those recently discovered are pre- dominantly Paleogene and Upper Paleozoic. （7） The porosity and permeability of deep hydrocarbon reservoirs differ widely, but they vary in a regular way with lithology and burial depth. （8） The temperatures of deep oil-gas reservoirs are widely different, but they typically vary with the burial depth and basin geothermal gradient. （9） The pressures of deep oil-gas reservoirs differ significantly, but they typically vary with burial depth, genesis, and evolu- tion period. （10） Deep oil-gas reservoirs may exist with or without a cap, and those without a cap are typically of unconventional genesis. Over the past decade, six major steps have been made in the understanding of deep hydrocarbon reservoir formation. （1） Deep petroleum in petroliferous basins has multiple sources and many dif- ferent genetic mechanisms. （2） There are high-porosity, high-permeability reservoirs in deep basins, the formation of which is associated with tectonic events and subsurface fluid movement. （3） Capillary pressure differences inside and outside the target reservoir are the principal driving force of hydrocarbon enrichment in deep basins. （4） There are three dynamic boundaries for deep oil-gas reservoirs; a buoyancy-controlled threshold, hydrocarbon accumulation limits, and the upper limit of hydrocarbon generation. （5） The formation and distribution of deep hydrocarbon res- ervoirs are controlled by free, limited, and bound fluid dynamic fields. And （6） tight conventional, tight deep, tight superimposed, and related reconstructed hydrocarbon reservoirs formed in deep-limited fluid dynamic fields have great resource potential and vast scope for exploration. Compared with middle-shallow strata, the petroleum geology and accumulation in deep basins are more complex, which overlap the feature of basin evolution in different stages. We recommend that further study should pay more attention to four aspects： （1） identification of deep petroleum sources and evaluation of their relative contributions; （2） preservation conditions and genetic mechanisms of deep high-quality reservoirs with high permeability and high porosity; （3） facies feature and transformation of deep petroleum and their potential distribution; and （4） economic feasibility evaluation of deep tight petroleum exploration and development.
基金supported by the Chinese Earthquake Administration,Institute of Seismology Foundation(IS201326126)Chinese earthquake scientific array exploration northern section of North South Seismic Belt gravity profile Foundation(201308011)
文摘In this study, we analyzed the gravity and, magnetic characteristics, and the occurrence of a fault zone and discussed the relationships between the two locations. The results reveal that the subsurface structures strikes are different compared with those in the research region. In other words, the geophysical advantageous directions from the gravity and magnetic anomalies are not the same as those caused by the surface structures. The local horizontal gradient results from the gravity and magnetic anomalies show that the majority of earthquakes occur along an intense fault zone, which is a zone of abrupt gravity and negative magnetic change, where the shapes match very well. From the distribution of earthquakes in this area, we find that it has experienced more than 11 earthquake events with magnitude larger than Ms7.0. In addition, water development sites such as Jinshajiang, Lancangjiang, and the Red River and Pearl River watersheds have been hit ten times by earthquakes of this magnitude. It is observed that strong earthquakes occur frequently in the Holocene active fault zone.
文摘The modern laterite gold deposits in southern China, which belong to reworked laterite deposits, can be further divided into three subclasses and seven types. Their geological features, ore-forming conditions and regularities are discussed. A geologic-geochemical metallogenic model for laterite gold deposits has been established.
基金supported by National Natural Science Foundation of China(No.51964009)。
文摘Coal seams can enrich a variety of harmful trace elements under specific geological conditions.The spatial distribution of harmful trace elements in coal is extremely uneven,and the distribution characteristics of each element content are different.The harmful elements released in the process of coal mining and utilization will cause serious harm to the environment and the human body.It is of great resource significance to study the geochemistry of coal that affects the enrichment and distribution characteristics of harmful trace elements.Based on the domestic and foreign literature on coal geochemistry in Guizhou published by previous investigators,this study counted 1097 sample data from 23 major coal-producing counties in Guizhou Province,systematically summarized the relevant research results of harmful trace elements in the coal of Guizhou,and revealed the overall distribution and enrichment characteristics of harmful trace elements in the coal of Guizhou.The results show that the average contents of Cd,Pb,Se,Cu,Mo,U,V,As,Hg,and Cr in coal of Guizhou are higher than those in Chinese coal and world coal.A variety of harmful trace elements in the coal of Guizhou have high background values,especially in Liupanshui,Xingyi and Qianbei coalfield.The enrichment of various harmful trace elements in the Late Permian coal in Guizhou is mainly related to the combined action of various geological and geochemical factors.The supply of terrigenous debris and sedimentary environment may be the basic background of the enrichment of harmful elements in western Guizhou,while low-temperature hydrothermal activity and volcanic ash deposition may be the main reasons for the enrichment of harmful elements in southwestern Guizhou.
基金financially supported by the investment and financing strategy research of the international mining capital market
文摘Iron oxide copper-gold （IOCG） deposits are a research focus of the current ore deposit geology, and have attracted much attention among the worldwide geologists and exploration experts due to their shallow depth, a wide variety of mineral species and large scale. This paper presents a review of the present IOCG deposits research, which includes the definition of IOCG deposits, temporal and spatial distribution, ore-forming environments, ore-forming magmatic rocks, their geological features, ore-controlling structures and ore-bearing rocks, mineralized alteration zoning, and their genesis and ore-forming process. This work also proposed the ore prospecting direction of IOCG deposits from a trinity model of metaUogenic geological bodies, metallogenic structure surface and metailogenic information signs, and discussed the existing problems of the IOCG deposits research.
文摘This report first gives a general description of Cambodia and then discusses its topographic and geological features. Finally, the current situation concerning erosion and sediment disasters is discussed.
基金the financial support of the Science and Technology Cooperation Project of the CNPC-SWPU Innovation Alliance,the National Natural Sci-ence Foundation of China(Grant no.U19A2043)the National Natural Science Foundation of China(Grant no.52174033).
文摘Global oil and gas consumption continues to rise and new strategies are required to meet the growing demand.Carbonate gas reservoirs are an important natural gas resource that are often accompanied by water intrusion during the development process.The efficient development of such reservoirs has therefore been extensively studied and met with difficulty.This paper summarizes the basic geological and water invasion characteristics of water-bearing carbonate gas reservoirs and correlates the two.A method for identifying water invasion types by production dynamics is introduced.The variation curve of the production water to gas ratio is shown to correspond with the reservoir geological characteristics.Typical development methods and the advantages/disadvantages of different water control techniques are summarized.The findings are used to propose a full-cycle water control plan for water-bearing carbonate gas reservoirs,and the development strategies of“early preparation,early discovery,and early treatment”and“re-analyze,re-assess,and re-adjust”are implemented to organically combine water control,drainage,and water blocking methods.The results provide a reference for formulating efficient and scientific development plans of waterbearing carbonate gas reservoirs.
基金funding from NATOSFP project G4934funding from NATOSFP project 983142funding from NATO project CLG 982957。
文摘Geological features and hazards have no geographical and political boundaries.The North Atlantic Treaty Organization(NATO)has been funding several international Earth Science research projects in Central Asia and the Caucasus over the last ten years.The projects are aimed at improving the security of people and the safety of infrastructures,and fostering peaceful scientific collaboration between scientists from NATO and non-NATO countries.In the present work,we show how Earth Science can contribute to improving scientific collaboration also among countries that are politically in tension,and how it can also play a key role in preventing situations that may escalate into conflicts.This paper showcases the main results,partially unpublished,of three different research projects that have been aimed at assessing,through an interdisciplinary approach,different geohazards affecting important infrastructure and lifelines of a number of countries in Central Asia and the Caucasus.For each region,we also describe the societal relevance of the research,considering possible geopolitical issues that might be brought about by natural disasters.
基金Supported by the Sinopec Scientific Research Project(P17030-4)
文摘The predictions by drilling-related mechanical and geological models are in some degree inaccurate due to non-unique solution of seismic velocity model.To address this problem,a new drilling technology guided by well-seismic information integration is proposed which consists of seismic velocity update of drilled formations,seismic velocity prediction of the formation ahead of drilling bit,and the prediction of geological feature and drilling geological environmental factors ahead of bit.In this technology,real information(velocity,formation and depth)behind the drilling bit and local pre-stack seismic data around the wellbore being drilled are used to correct the primitive seismic velocity field for a re-migration of seismic data and to update geological features and drilling geological environmental factors ahead of the drilling bit.Field application shows that this technology can describe and predict the geological features,drilling geological environmental factors and complex drilling problems ahead of the bit timely and improve the prediction efficiency and accuracy greatly.These new updated results are able to provide scientific basis for optimizing drilling decisions.
基金Project supported by the National Major Science and Technology Projects of China Project“Evaluation method and expert system for commercial shale gas production zone”(No.:2017ZX05035004-003).
文摘In order to promote the exploration and development of continental shale gas reservoirs in China further,we systematically summarized the geological features of typical continental shale,such as the Ordos Basin.Then,the shale gas reservoir characteristics,geochemical charac-teristics and fracturing performance of the Lower Cretaceous Shahai Fm in the Fuxin Basin were analyzed by using the data of TOC contents,rock specific surface,pore size distribution and X-ray diffraction analysis of the whole rock.Based on this,it was compared with the marine/continental shale gas reservoirs from the aspect of geological feature.Finally,the shale gas reservoir and resource potential of the Shahai Fm were evaluated.And the following research results were obtained.First,the formation age of China's continental shale is later,its TOC contents vary in a large range,and its organic matters are mainly of a mixed-humic type.And it is characterized by low thermal evolution degree,low quartz content,high feldspar content,high carbonate content,and comparability of total brittle mineral content to marine shale.Second,shale in the Shahai Fm has shallow burial depth and its mineral composition is dominated by quartz,feldspar and carbonate minerals.Its pores are mainly mesopores with an average porosity of 3.47%.There are diverse reservoir spaces,which is favorable for the accumulation of shale gas.Third,the TOC content of the Shahai Fm shale is mainly above 2%,with a moderate thermal evolution degree of organic matter and high gas content.Fourth,the total brittle mineral content of Shahai Fm shale is up to 60%,indicating a good fracturing performance.Fifth,shale reservoirs in the Shahai Fm can be classified into three categories.Type Ⅰ is target reservoirs of exploration and development,and Type Ⅱ is favorable reservoirs.It is estimated that the amount of shale gas resources are in the range of 232.2-286.2 billion m^(3).It is concluded that the Shahai Fm shale in the Fuxin Basin has both resource potential in geology and fracturing performance in engineering,and its exploration and development prospect is broad.What's more,the potential of commercial shale gas development is great in the sweet-point areas.
基金supported by the National Science and Technology Major Project of China(No.2016ZX05007-002).
文摘Over the past decade,great progresses have been made in natural gas exploration in the Sichuan Basin,where several large gas fields(such as Anyue)have been discovered.With the increase of data and the deepening of exploration,new knowledges have been gained in geological theory,thus it is necessary to further analyze the distribution characteristics and main controlling factors of large gas fields,thus to put forward new exploration directions for large gas fields.Therefore,based on the statistics on the geological parameters of 20 large gas fields discovered in this basin,the distribution rules,formation conditions and main controlling factors of large gas fields were analyzed,and the follow-up exploration directions were proposed.The following results were achieved.(1)Large gas fields are developed in different tectonic regions in the Sichuan Basin,mostly in the low and gentle tectonic belts in the central Sichuan Basin.Large gas fields are developed in seven series of strata in longitudinal stratigraphic sequences,which are dominated by the reef-shoal large gas fields formed in the Upper Permian ChangxingeLower Triassic Feixianguan Fms.(2)There are four sets of source rocks contributing to the formation of large gas fields,mostly from the assemblage of Xujiahe Fm source rocks.(3)Reservoirs in the large gas fields are dominated by porous carbonates and tight sandstones;large gas fields are mostly structuralelithological ones and normal pressure ones.(4)The development of marine large gas fields are mainly controlled by intracratonic rifts and paleo-uplifts.The controlling effect of intracratonic rifts is mainly from three aspects,namely the hydrocarbon generation center of source rocks,high-energy facies belts on the platform edges,and lateral sealing for hydrocarbon accumulation.The controlling effect of the paleo-uplifts mainly acts from another three aspects:intra-platform high-energy facies belts,karstic dolomite reservoirs and long-term hydrocarbon accumulation.The structures of foreland basins controlled the development of the continental large gas fields from four aspects:tectonic setting,source and reservoir assemblage,trap type and fracture distribution.In conclusion,a total of 5 domains with 14 favorable zones are the follow-up exploration directions of large gas fields in the Sichuan Basin.
