|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | The control of syndepositional faulting on the Eogene sedimentary basin fills of the Dongying and Zhanhua sags, Bohai Bay Basin显示文摘The Dongying and Zhanhua sags are the major hydrocarbon exploration and produc- tion subbasins in the Bohai Bay Basin. Integrated analysis of the sedimentary basin fills has shown that the syndepositional faults and their arrangement styles exerted an important influ- ence on the development and distribution of the Eogene depositional systems. The sedimentary filling evolution of the subbasins reflects the general control of the episodic rifting process. The major long-term active normal faults formed a series of paleogeomorphic accident or slopebreak zones that commonly delineated the subsidiary palaeostructural units and the depositional facies tracts and constrained the general distribution of sedimentary facies zones. The central sag boundary fault slopebreak zones usually determined the distribution of the depocenters of ter- restrial clastic depositional systems, particularly the lowstand fans or deltaic depositional sys- tems, and have proven to be the economically important targets for the exploration of subtle sandstone reservoirs. A variety of syndepositional fault arrangement patterns, including the par- allel, en echelon, combo-like, broom-like fault systems and the fault overlap or transfer zones, have been recognized in the subbasins. They generated distinctive geomorphic features and exerted a direct influence on sediment dispersal and sandbody distribution during the Eogene synrift stage. It is the key for the prediction of depositional systems tracts and reservoir sand- stones to investigate the activity and distribution of the fault slopebreak zones and reconstruct the structural paleogeomorphy in different basin filling stages of the basin evolution. | LIN Changsong1, ZHENG Herong2, REN Jianye1, LIU Jingyan1 & Qiu Yigang1 1. Department of Energy Geology, China University of Geosciences, Beijing 100083, China 2. Petroleum Exploration and Production Institute, Sino-Petroleum and Chemistry Cooperation, Beijing 100083, China | 2004 | Science China Earth Sciences2004,47,9: | 33 |
| 2 | Mesozoic basin evolution and tectonic mechanism in Yanshan, China显示文摘The Mesozoic basins in Yanshan, China underwent several important tectonic transformations, including changes from a pre-Late Triassic marginal cratonic basin to a Late Triassic-Late Jurassic flexural basin and then to a late Late Jurassic-Early Cretaceous rift basin. In response to two violent intraplate deformation at Late Triassic and Late Jurassic, coarse fluvial depositional systems in Xingshikou and Tuchengzi Formations were deposited in front of thrust belts. Controlled by transform and extension faulting, fan deltas and lacustrine systems were deposited in Early Cretaceous basins. The composition of clastic debris in Late Triassic and Late Jurassic flexural basins respectively represents unroofing processes from Proterozoic to Archean and from early deposited, overlying pyroclastic rocks to basement rocks in provenance areas. Restored protobasins were gradually migrated toward nearly NEE to EW-trending from Early Jurassic to early Late Jurassic. The Early Cretaceous basins with a NNE-trending crossed over early-formed basins. The Early-Late Jurassic and Early Cretaceous basins were respectively controlled by different tectonic mechanisms. | LIU Shaofeng1,2, LI Zhong3 & ZHANG Jinfang4 1. Key Laboratory of Lithospheric Tectonics, Deep-Level Process and Explovation, Ministry of Education of P. R. China, Beijing 100083, China 2. School of Geosciences and Resources, China University of Geosciences, Beijing 100083, China 3. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 4. Institute of Software, Chinese Academy of Science, Beijing 100080, China | 2004 | Science China Earth Sciences2004,47,z2: | 24 |
| 3 | Tidal current-induced formation——storm-induced change——tidal current-induced recovery——Interpretation of depositional dynamics of formation and evolution of radial sand ridges on the Yellow Sea seafloor显示文摘The results of simulated tidal current field, wave field and storm-induced current field are employed to interpret the depositional dynamic mechanism of formation and evolution of the radial sand ridges on the Yellow Sea seafloor. The anticlockwise rotary tidal wave to the south of Shandong Peninsula meets the following progressive tidal wave from the South Yellow Sea, forming a radial current field outside Jianggang. This current field provides a necessary dynamic condition for the formation and existence of the radial sand ridges on the Yellow Sea seafloor. The results of simulated 'old current field (holocene)' show that there existed a convergent-divergent tidal zone just outside the palaeo-Yangtze River estuary where a palaeo-underwater accumulation was developed. The calculated results from wave models indicate that the wave impact on the topography, under the condition of high water level and strong winds, is significant. The storm current induced by typhoons landing in the Yangtze River | 张长宽 张东生 张君伦 王震 | 1999 | Science China Earth Sciences1999,42,1: | 17 |
| 4 | Assessment of widely used methods to derive depositional ages from detrital zircon populations显示文摘The calculation of a maximum depositional age(MDA)from a detrital zircon sample can provide insight into a variety of geological problems.However,the impact of sample size and calculation method on the accuracy of a resulting MDA has not been evaluated.We use large populations of synthetic zircon dates(N≈25,000)to analyze the impact of varying sample size(n),measurement uncertainty,and the abundance of neardepositional-age zircons on the accuracy and uncertainty of 9 commonly used MDA calculation methods.Furthermore,a new method,the youngest statistical population is tested.For each method,500 samples of n synthetic dates were drawn from the parent population and MDAs were calculated.The mean and standard deviation of each method ove r the 500 trials at each n-value(50-1000,in increments of 50)were compa red to the known depositional age of the synthetic population and used to compare the methods quantitatively in two simulation scenarios.The first simulation scenario varied the proportion of near-depositional-age grains in the synthetic population.The second scenario varied the uncertainty of the dates used to calculate the MDAs.Increasing sample size initially decreased the mean residual error and standard deviation calculated by each method.At higher n-values(>~300 grains),calculated MDAs changed more slowly and the mean resid ual error increased or decreased depending on the method used.Increasing the p roportion of near-depositional-age grains and lowering measurement uncertainty decreased the number of measurements required for the calculated MDAs to stabilize and decreased the standard deviation in calculated MDAs of the 500 samples.Results of the two simulation scenarios show that the most successful way to increase the accuracy of a calculated M DA is by acquiring a large number of low-uncertainty measurements(300300)approach is used if the calculation of accurate MDAs are key to research goals.Other acquisition method s,such as high-to moderate-precision measurement methods(e.g.,1%-5%,2σ)acquiring low-to moderate-n datasets(50300).Additionally,they are most susceptible to producing erroneous MDAs due to contamination in the field or laboratory,or through disturbances of the youngest zircon’s U-Pb systematics(e.g.,lead loss).More conservative methods that still produce accurate MDAs and are less susceptible to contamination or lead loss include:youngest grain cluster at 1σunce rtainty(YGC 1σ),youngest grain clusterat 2σuncertainty(YGC 2σ),and youngest statistical population(YSP).The ages calculated by these methods may be more useful and appealing when fitting calculated MDAs in to pre-existing chronostratigraphic frameworks,as they are less likely to be younger than the true depositional age.From the results of our numerical models we illustrate what geologic processes(i.e.,tectonic or sedimentary)can be resolved using MDAs derived from strata of different ages. | Daniel S.Coutts William A.Matthews Stephen M.Hubbard | 2019 | Geoscience Frontiers2019,10,4: | 12 |
| 5 | Depositional architecture of the Tertiary tectonic sequences and their response to foreland tectonism in the Kuqa depression, the Tarim Basin显示文摘The Tertiary Kuqa depression is a foreland basin generated by flexural subsidence resulting from the southward thrusting of the southern Tianshan Mountains. Tertiary basin fills of the depression can be classified into four tectonic sequences bounded by gentle angular unconformities. The sequences are composed of two parts, the lower transgressive and the upper progradational successions, which are separated by a regional maximum transgressive surface. The development of these sequences is attributed to the foreland tectonic process from flexural subsidence caused by thrust loading to rebounded uplift due to the erosion and stress release. The generation of the angular unconformities defining the tectonic sequences has been interpreted as the result of the rebounded uplift and the following thrusting. It has been found that there is a significant difference in depositional pattern between the northeastern and the northwestern margins. The relatively strong thrusting and mountain building occurring along the northwestern margin resulted in the development of thick-bedded alluvial fan and angular unconformities. The northeastern margin, in contract, lacks thick alluvial fan accumulation due to weak thrusting. This difference is likely related to the pre-existing east-west partition of the basin basement. | 林畅松 肖建新 刘景彦 陈建强 张燕梅 纪云龙 | 2002 | Science China Earth Sciences2002,45,3: | 11 |
| 6 | Sedimentary facies and depositional model of shallow water delta dominated by fluvial for Chang 8 oil-bearing group of Yanchang Formation in southwestern Ordos Basin,China显示文摘A systematic analysis of southwestern Ordos Basin's sedimentary characteristics,internal architectural element association styles and depositional model was illustrated through core statistics,well logging data and outcrop observations in Chang 8 oil-bearing group.This analysis indicates that shallow water delta sediments dominated by a fluvial system is the primary sedimentary system of the Chang 8 oil-bearing group of the Yanchang Formation in southwestern Ordos Basin.Four microfacies with fine grain sizes are identified: distributary channels,sheet sandstone,mouth bar and interdistributary fines.According to the sandbody's spatial distribution and internal architecture,two types of sandbody architectural element associations are identified: amalgamated distributary channels and thin-layer lobate sandstone.In this sedimentary system,net-like distributary channels at the delta with a narrow ribbon shape compose the skeleton of the sandbody that extends further into the delta front and shades into contiguous lobate distribution sheet sandstone in the distal delta front.The mouth bar is largely absent in this system.By analyzing the palaeogeomorphology,the palaeostructure background,sedimentary characteristics,sedimentary facies types and spatial distribution of sedimentary facies during the Chang 8 period,a distinctive depositional model of the Chang 8 shallow water fluvial-dominated delta was established,which primarily consists of straight multi-phase amalgamated distributary channels in the delta plain,net-like distributary channels frequently diverting and converging in the proximal delta front,sheet sandstones with dispersing contiguous lobate shapes in the distal delta front,and prodelta or shallow lake mudstones. | 陈林 陆永潮 吴吉元 邢凤存 刘璐 马义权 饶丹 彭丽 | 2015 | Journal of Central South University2015,22,12: | 11 |
| 7 | Sequence stratigraphic framework and distribution of depositional systems for the Paleogene in Liaodong Bay area显示文摘With a comprehensive geological and geophysical data base,the Paleogene in the Liaodong Bay area,which consists of the Kongdian,Shahejie and Donghying Formations from the base to top,was divided into 4 second-order sequences and 8 third-order sequences based on the characteristics of the se-quence boundaries. Each third-order sequence is subdivided into the lowstand,lake transgressive and highstand systems tracts. The Lowstand systems tract (LST) is mainly composed of progradational parasequence sets,while the lake transgressive systems tract (TST) largely consists of the retrograda-tional parasequence sets and the highstand systems tract (HST) is dominated by the progradational parasequence sets. The main types of depositional systems include the shallow lake,semi-deep lake,deep lake,delta,fan delta,braided fluvial delta and nearshore subaqueous fan. The braided fluvial delta and fan delta depositional systems are mainly confined to the sequences of the lower SEs4-Ek,SEs3 and SEs1+2,while the sequences of SEd3,SEd2 and SEd1 are dominated by the delta and nearshore subaqueous fan depositional systems with the latter being developed at the downthrown side of the basin-bounding fault in each sequence. The evolution of the depositional systems is always con-trolled by the paleo-tectonic setting and the ancient landform in the space and geological time. It is concluded that the most favorable reservoirs are distributed in the Liaoxi low uplift and the central Liaozhong sag. | ZHU XiaoMin1,DONG YanLei1,YANG JunSheng1,ZHANG Qin1,LI DeJiang2,XU ChangGui3 & YU Shui3 1 National Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China 2 Research Institute of Petroleum Exploration and Development——Langfang,PetroChina,Langfang 065007,China 3 Technology Department of CNOOC Tianjin Company,Tianjin 300452,China | 2008 | Science China Earth Sciences2008,51,S2: | 11 |
| 8 | The formation and evolution of Chepaizi-Mosuowan paleo-uplift and its control on the distributions of sedimentary facies in the Junggar Basin显示文摘The Chepaizi-Mosuowan paleo-uplift is a large-scale uplift stretching across the Junggar Basin formed during the Yanshanian. It has experienced four evolutionary stages: the initial forming stage (J1), the intense development stage (J2+3), the waning and burial stage (K-E), and the tilting and extinction stage (N-Q). The most intense period of activities is the Middle Jurassic. Dur-ing the Early Jurassic, the Chepaizi-Mosuowan paleo-structure was a low amplitude uplift. Because of the subsequent strong uplifting during Middle-Late Jurassic, the Middle and Upper Jurassic were eroded. With the evolution of the Chepaizi-Mosuowan paleo-uplift, the sedimentary pattern of the basin changed, and the paleo-uplift separated the northern depositional systems from those in the south side. As a result, the basin tectonics controlled the distribution and evolution of the depositional systems. During Early Jurassic, while the paleo-uplift was low, its controlling effect on depositional systems was limited and sediments coming from the northwest could reach the central and southern parts of the basin. With the strong uplifting of the Chepaizi-Mosuowan paleo-structure during Middle-Late Jurassic, sediments from the northwest provenance could only deposit in the northern graben of the paleo-uplift. The intense erosion of the Middle-Upper Jurassic also changed the former sedimentary center of the basin into a source area, supplying sediments for grabens on both sides of the paleo-uplift. In the Cretaceous, regional subsidence caused the paleo-uplift to be buried again and subsequently sediments accumulated on top of it. The depositional facies are dominated by fluvial in the Early Cretaceous and shallow lacustrine to deltaic in the Late Cretaceous. In the history of the long-lasting development of this paleo-uplift, large-scale erosions of the paleohigh not only provided sufficient sediments to the center of the Junggar Basin, but also created favorable conditions for the formation of various subtle traps such as lithologic and stratigraphic traps. | JI YouLiang ZHOU Yong KUANG Jun WAN Lu ZHANG Rui LU ChunHong | 2010 | Science China Earth Sciences2010,53,6: | 10 |
| 9 | Mesozoic-Cenozoic tectonic transition in Kuqa Depression-Tianshan,Northwest China:Evidence from sandstone detrital and geochemical records显示文摘Similar to compositional evolution of sandstone modes and detrital heavy minerals from different profiles in the Kuqa Depression, Northwest China, major element analysis of whole sandstones from the same profiles shows four discontinuous depositional interfaces or periods, respectively corresponding to Lower Triassic\Middle Triassic, Upper Jurassic\Lower Cretaceous, Lower Cretaceous\Paleogene and Miocene\Pliocene, and indicates five-phase evolution during Mesozoic-Cenozoic: (1) From the first to fifth phase, a depositional suite changes from maroon and coarse clastic, through grey-dark grey and fine, red and coarse, red-mottled, interlayered by gypsum, to brown and coarse clastic assemblages, accompanying detrital component evolution in unstable-stable-unstable-very unstable-very unstable assem- blages. It is indicated that carbonate and complex detritus gradually dominate in sandstones in post-Late Jurassic, with rapid reduction of compositional maturity. (2) For major element geo- chemical parameters of whole sandstones, CaO and Fe2 O * 3+MgO contents show a change sequence in high-low-high-higher-highest values, with rapid increasing in post-Late Jurassic. (3) Contra some aggregative indicators for weathering indexes of sandstone detrital component, Al2O3/(CaO+Na2O) and ln(Q/(L+CE)), show a change sequence in low-high-low-lower-lowest ratios, with rapid decreasing in post-Late Jurassic. It is found that sandstone samples of the first, second and later three phases may be distinguished from the A-CN-K and A-CNK-FM diagrams respectively. Therefore, in the Kuqa Depression-Tianshan, the most important discontinuous depositional interface recording paleotectonic and paleoclimatic transition occurred in Early Triassic\Middle Triassic and Late Jurassic\Early Cretaceous, respectively, and, however, tec- tonic differentiations of basin-range system finally result in distinct depositional systems but similar detrital weathering indexes across the Lower Cretaceous\Paleogene and Miocene\ Plio- cene interfaces, respectively. | LI Zhong1, GUO Hong2, WANG Daoxuan3 & LIN Wei1 1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Tarim Oilfield Branch, CNPC, Korla 841000, China 3. Hefei University of Industry, Tunxilu 193, Hefei 230009, China | 2005 | Science China Earth Sciences2005,48,9: | 9 |
| 10 | The relationship between methylated chromans and maturity of organic matter in the source rocks from Jianghan hypersaline basin显示文摘The distribution,the relative composition,and their variation of methylated chromans(MTTC) with maturation of organic matter in the source rocks from Mingjia 1 well,Jianghan hypersaline basin,have been analyzed and studied. There is a close relationship between the distribution of methylatd chromans and paleosalinity of depositional environment. In the Eq1-Eq3 source rocks deposited under hypersaline environment with lower Pr/Ph ratio,higher gammacerane index and abundant organic sulfur-containing compounds,methyl MTTC and dimethyl MTTC are main components,but in the Eq4 source rocks deposited non-hypersaline environment with relatively higher Pr/Ph ratio,lower gammacerane index and organic sulfur-containing compounds,trimethyl MTTC is a major compound in methylate chromans. Obviously,the distributions and the compositions of methylated chromans in the source rocks are in harmony with biomarker indicators indicating the paleaosalinity and redox of depositional environment. The relationship between the ratio of 5,8-dimethyl MTTC to 7,8-dimethyl MTTC(dimethyl MTTC ratio) and the maturity of organic matter in the source rocks from Mingjia 1 well has been discussed. The results show that dimethyl MTTC ratio increased with the burial depth and the maturation of organic matter in the source rocks,especially in immature level. It is noteworthy that this ratio is very susceptible to small variation in the maturity of organic matter in the source rocks when vitrinite reflectance Ro is less than 0.65%. It may imply that this ratio is a good and susceptible aromatic maturity indicator for the relative maturity of organic matter in immature source rocks. | BAO JianPing1,ZHU CuiShan1 & MA AnLai2 1 Key Laboratory of Oil & Gas Resource and Exploration Technology,Ministry of Education,Geochemistry Department,Yangtze University,Jingzhou 434023,China 2 Institute of Petroleum Exploration and Development,Sinopec,Beijing 100083,China | 2009 | Science China Earth Sciences2009,52,S1: | 8 |
| 11 | Sedimentary Characteristics of the Cretaceous in the Songliao Basin显示文摘The rupture of the lithosphere in Late Jurassic brought about the eruption of basaltic magma in the Songliao Basin. The evolution of the basin in Cretaceous progressed through six stages: pre-rift doming, extensional fracturing, fault subsidence, fault downwarping, downwarping and shringkage, resulting in the deposition of terrstrial facies nearly 10,000 m thick. There are different depositional sequences in these stages: the depositional period of the Early Cretaceous Shahezi and Yincheng Formations is the development stage of the down-faulted basin, forming a volcanic rock-alluvial fan-fan delta-lacustrine (intercalated with episodic turbidites)-swamp facies sequences; the period of the Early Cretaceous Dengluku Formation is the transformation stage of fault subsidence into fault downwarping of the basin, forming a sequence mainly of alluvial plain-lacustrine facies; the depositional period of the Early Cretaceous Quantou Formation-Late Cretaceous Nenjiang Formation is the downwarping stage of the basin, forming an alluvial plain-delta-lacustrine facies sequence; the period of the Late Cretaceous Sifangtai Formation-Mingshui Formation is the shringkage stage of the basin, forming again a sequence mainly of alluvial plain-alluvial fan and small relict lacustrine facies. These vertical depositional sequences fully display the sedimentary characteristics of a failed continental rift basin. Many facts indicate that the two large-scale lake invasions, synchronous with the global rise of sea level, which took place in the downwarping stage of the basin development, led to the connection between the lake and sea. | Liu Zhaojun, Wang Dongpo, Liu Li, Liu Wanzhu, Wang Pujun, Du Xiaodi and Yang Guang Changchun University of Earth Sciences, Changchun, Jilin Sun Sheping | 1993 | Acta Geologica Sinica(English Edition)1993,67,2: | 7 |
| 12 | The response of deltaic systems to climatic and hydrological changes in Daihai Lake rift basin,Inner Mongolia,northern China显示文摘Delta systems are ubiquitous around lacustrine rift basins. Its peripheral ge-ometry, progradation structures and sedimentary successions were controlled by both tec-tonic settings and climatic changes. Peripheral geometry of a delta was strongly influenced by depositional gradients which formed the fan-shape delta on the steep slopes and developed the lobe-shape delta on the gentle slopes. Due to the discharge feed rivers can change rapidly driven by climatic variations, and the nearshore area of deltas display considerable facies variability. The rise of annual rainfall, which suggests the rivers feeding deltas are continuous, and result in distributary mouth bars that are prevalent in the front of deltas since the down-slope flows are greater than the along-slope currents. On the contrary, when the annual rainfall decreases and evaporation increases, the rivers only can feed deltas ephemerally. If the along-slope currents were in a dominant position, the distal bars were deposited. Progra-dation structure and sedimentary successions of deltas were controlled by the gradients of slopes. On gentle depositional slopes, shingle foreset beds predominate with fine sediments and small-scale sedimentary structures or vice versa. | Yu Xinghe Li Shunli Tan Chengpeng Xie Jing Chen Bintao Yang Fan | 2013 | Journal of Palaeogeography2013,2,1: | 6 |
| 13 | Geochemical Constraints of Sediments on the Provenance, Depositional Environment and Tectonic Setting of the Songliao Prototype Basin显示文摘The geochemistry of sediments is primarily controlled by their provenances, and different tectonic settingshave distinctive provenance characteristics and sedimentary processes. So, it is possible to discriminate provenances,depositional environments and tectonic settings in the development of a sedimentary basin with the geochemistry of theclastic rocks. The analytical results of the present paper demonstrate that sediments in the Songliao prototype basin areenriched in silica (SiO2=66.48-80.51%), and their ΣREE are 30-130 times of that of chondrite with remarkable Euanomalies. In discriminating diagrams of Eu/Eu* vs ΣREE and (La/Yb)N vs ΣREE, most samples locate above the line Eu/Eu*=1, on the right of the line Eu/Eu*/ΣREE=1 and under the line La/Yb)N/ΣREE=1/8, which indicates that thedepositional environment of sediments in the basin was oxidizing. In addition, variations of MgO, TiO2, A12O3,FeO+Fe2O3, Na2O and CaO vs SiO2 reflect a tendency of increasing mineral maturity of sediments in the basin. Analysesalso show that the protolytes of the sediments in the basin were felsic igneous rocks, and the Songliao prototype basin wasin a tectonic setting of an island arc on an active continental margin, with violent sinistral strike-slip. | 阎全人 高山林 王宗起 李继亮 肖文交 侯泉林 阎臻 陈海泓 | 2002 | Acta Geologica Sinica(English Edition)2002,76,4: | 5 |
| 14 | Immature crude oils in the salt lake depositional environment are related to organic matter precipitated at stage of carbonate in salt lake sedimentation sequences显示文摘The present paper studies the mineralogy and geochemistry of a geological section in Jianghan basin. Widely distributed immature oils in this basin have been shown to relate to the carbonate depositional stage of salt lake sedimentation cycle. It is concluded that only when the content of organic carbon in the rocks is taken into account, is it meaningful to calculate the immature oil in the source rocks. | PENG Ping’an SHENG Guoying FU Jiamo JIANG Jiagang | 2000 | Chinese Science Bulletin2000,45,S1: | 5 |
| 15 | Influence of depositional environment on coalbed methane accumulation in the Carboniferous-Permian coal of the Qinshui Basin, northern China显示文摘Based on analyses of the lithofacies palaeo-geography of the Taiyuan and the Shanxi Formations in the Qinshui Basin, the spatial variations of the coal seam thickness, coal maceral composition, coal quality, and gas content, together with the lithofacies of the surrounding rocks in each palaeogeographic unit were investigated. The results show that the thick coals of the Taiyuan Formation are mainly distributed in delta and barrier island depositional units in the Yangquan area in the northern part of the basin and the Zhangzi area in the southeastern part of the basin. The thick coals of the Shanxi Formation are located within transitional areas between delta plain and delta front depositional units in the central southern part of the basin. The Taiyuan Formation generally includes mudstone in its lower part, thick, continuous coal seams and limestones in its middle part, and thin, discontinuous coal seams and limestone and sand-mud interbeds in its top part. The Shanxi Formation consists of thick, continuous sandstones in its lower part, thick coal seams in its middle part, and thin coal seams, sandstone, and thick mudstone in its upper part. From the perspective of coal-bearing sedimentology and coalbed methane (CBM) geology, the lithology and thickness of the surrounding rocks of coal seams play more significant roles in controlling gas content variation than other factors such as coal thickness, coal macerals, and coal quality. Furthermore, it is found that the key factors influencing the gas content variation are the thicknesses of mudstone and limestone overlying a coal seam. At similar burial depths, the gas content of the Taiyuan coal seams decreases gradually in the lower delta plain, barrier-lagoon,delta front, barrier-tidal flat, and carbonate platform depositional units. The CBM enrichment areas tend to be located in zones of poorly developed limestone and well-developed mudstone. In addition, the gas content of the Shanxi Formation is higher in the coals of the delta front facies compared to those in the lower delta plain. The CBM enrichment areas tend to be associated with the thicker mudstones. Therefore, based on the lithologic distribution and thickness of the rocks overlying the coal seam in each palaeogeographic unit of the Taiyuan and Shanxi Formations, the areas with higher gas content are located in the north-central basin for the Taiyuan coals and in the southern basin for the Shanxi coals. Both of these areas should be favorable for CBM exploration in the Qinshui Basin. | Haihai HOU Longyi SHAO Shuai WANG Zhenghui XIAO Xuetian WANG Zhen LI | 2019 | Frontiers of Earth Science2019,13,3: | 4 |
| 16 | Organic geochemical characterization and depositional paleoenvironments of the Devonian strata in Guizhong region,Guangxi,China显示文摘Devonian strata in the Guizhong region,Guangxi,China consist mainly of marine deposition carbonates(limestones and dolomites) as well as restricted clastic rocks. The strata thickness is measured as 2041m and classified into 14 formations. An integrated field geological,petrographic,sedimentological,palaeobiological,and geochemical study of these strata reveals that the depositional paleoenvironments were carbonate tidal flat,restricted platform,open platform,shelf,platform margin slop,and algal herm. The total organic carbon(TOC) of sedimentary organic matter ranges between 0.07% and 1.96% with average of 0.21%. The organic matter types are Type ? and Type II1. The vitrinite reflectance(R0) of kerogen ranges between 0.99% and 2.03%,indicating the maturated and highly maturated stages. The analytical results of the representative samples collected from shelf and subtidal facies show that the differences of organic matter type and biological diagnostic compounds are related to the types of source rocks deposited in different paleoenvironments. | MAO ZhiChao1,2,DU YuanSheng1,ZHANG Min2,YAN JiaXin1 & ZENG Fang2 1 Key Laboratory of Biogeology and Environment Geology of Education Ministry,Wuhan 430074,China 2 Department of Geochemistry,Yangtze University,Jingzhou 434023,China | 2009 | Science China Earth Sciences2009,52,S1: | 4 |
| 17 | Depositional model of Permian Luodianian volcanic island and its impact on the distribution of fusulinid assemblage in southern Qinghai,Northwest China显示文摘Pan-riftizational tectonic activity reached climax at Luodianian (Permian) in the East Tethyan Domain, Qinghai-Tibet Plateau. Because of eruptive volcanics and influence of terrigenous materials, a complex volcanic-sedimentary landform formed on the sea floor in southern Qinghai. Four sedimentary facies types were recognized based on detailed field mapping. Spatially, platform facies volcanic-limestone type was located at the center belt approximately trending NWW, surrounded by shallow water slope facies tuff/tuffite type at the two flanks and deep water slope facies breccia/calcirudite at the most outside. The depression facies sandstone-mudstone type, which comprised mainly mudstone, de-posited between volcanic islands (platform facies volcanic-limestone type). Based on the field map-ping and stratigraphic section data, seven rift-related sedimentary facies were recognized and a depo-sitional model for volcanic island was proposed. It is revealed that some volcanic island chain formed quickly and intermittently in the Qamdo Block during violent eruption, and small carbonate reef, shoal, platform occurred above or on edge of volcanic island, and some slope sedimentary facies surrounded volcano island chain during dormant period of volcanic activities. Three types of fusulinid assemblages were distinguished in the carbonate rocks, which deposited in varied positions of a palaeo-volcanic island: (1) Misellina-Schwagerina assemblage occurred above or on edge of volcanic island, (2) Para-fusulina assemblage was located at restricted depression facies among volcanic islands or carbonate platform, and (3) the reworked Pseudofusulina-Schwagerina assemblage occurred at slope facies near margin of volcanic island, which originally deposited in the shallow-water carbonate platform, then collapsed along the volcanic island margin with fusulinid-bearing grain-supported carbonate con-glomerate or calcirudite, and finally re-deposited on the deeper slope. The sedimentary sequence re-sulting from calm shallow water was deposited at the interior of the Qamdo Block from the Devonian to early Early Permian. At the beginning of the peak period of activity of pan-riftzation (Luodianian), al-ternate volcanic island and shallow marine environment within continent crust came into being. Uni-form and stable shallow-water carbonate platform was formed during the Xiangboan. This suggested that the activity of rift basin was evidently weakened. Subsequently the instability of the basin appre-ciably increased with the occurrence of basalt in late Kuhfengian. At last the whole Qamdo Block turned into the closure period of rift during the Late Permian. | NIU ZhiJun XU AnWu WANG JianXiong DUAN QiFa ZHAO XiaoMing YAO HuaZhou | 2008 | Science China Earth Sciences2008,51,4: | 4 |
| 18 | Chronostratigraphy and Stratigraphic Classification of the Cretaceous of the Songliao Basin显示文摘Isotopic ages of synsedimentary clay minerals were directly determined with the ultrasonicscattering-settlement separation-K-Ar dilution technique. The apparent age of black mudstoneis 123 Ma for the Quantou Formation, 111.9-89.0 Ma for the Qingshankou Formation and77.6-76.8 Ma for the upper part of the Nenjiang Formation. The Rb-Sr isochrone age of themuddy limestone-mudstone sequence of the lower part of the Nenjiang Formation is 81 Ma andthat of the muddy evaporite of the middle part of the Quantou Formation is 122.2 Ma. On thebasis of the above isotopic ages, the authors propose a modified scheme of stratigraphic classifi-cation of the Cretaceous of the Songliao basin. | Wang Pujun Du Xiaodi Wang Jun and Wang Dongpo 1)Geoenergy Department, Changchun University of Earth Sciences, Changchun, Jilin 2)Earth Sciences Department,Nanjing University,Nanjing,Jiangsu | 1996 | Acta Geologica Sinica(English Edition)1996,70,2: | 4 |
| 19 | Aeolian Facies Belts in the Taklimakan Desert显示文摘At least at the beginning of the last glacial epoch, the facies belts of dune sand, sandy loam and loess formed by winds had existed in the Taklimakan desert and areas south of it. There were no appreciable changes in the NE and NW wind systems and their wind fqrces that deposited dune sand, sandy loam and loess in the global cold stage since the last glacial epoch (accordingly no marked shifts of the boundaries of these aeolian facies belts took place. In the global warm stage since then, the climate in the Taklimakan desert and areas south of it became warm and dry, resulting in ablation of substantial volumes of ice and snow in their surrounding mountains and thus forming alluvial and diluvial deposits in the region. The alluvial-diluvial actions, however, failed to change the general framework of aeolian facies belts. | Li Baosheng, Dong Guangrong, Zhang Jiasheng, Li Sen,Jin Heling, Chen Huizhong, Wen Xiangle, Wang Yao, Lanzhou Desert Research Institute, Chinese Academy of Sciences, Lamhou, Gansuand Zhu YizhiXi’an Open Laboratory of Loess and Quaternary Geology, Chinese Academy of Sciences, Xi’an, Gansu Fei Zhenbi | 1995 | Acta Geologica Sinica(English Edition)1995,69,3: | 4 |
| 20 | On the Carboniferous Sequence Stratigraphy in the Tazhong Area, Xinjiang——A Model of the Sequence Stratigraphy Framework of Intracratonic Depressional Basins显示文摘The Carboniferous prototype sedimentary basin in the Tazhong (Central Tarimbasin) area is recognized as a compressive intracratonic depressional one. Three type Ⅰ sequenceboundaries and three type Ⅱ sequence boundaries can be identified in the CarboniferousSystem, which can accordingly be divided into five sedimentary sequences. These sequencespossess stratigraphic characters of the standard sequence and correspond to the depositionalstratigraphic unit of a third-order eustatic cycle. They can be regionally or globally correlatedwith each other. The framework of sequence stratigraphy of the intracratonict basin in thestudy area distinctly differs from that of the passive continental-margin basin in the lack ofdepositional systems of early-middle lowstand, poor development of the deeply incised valleyand condensed section of the maximum sea-flood, good development of type Ⅱ sequenceboundaries and coastal plain depositional systems coexisting with shelf-type fan deltas underwet climatic conditions, Which consequently led to the formation of a paralic lithofacies frame-work. | Guo Jianhua Zeng Yunfu Zhai Yonghong and Gao Zhenzhong Jianghan Petroleum Institute, Jingsha, Hubei Chengdu Institute of Technology, Chengdu, Sichuan Jianghan Petroleum Institute, Jingsha, Hubei Liu Xinzhu | 1997 | Acta Geologica Sinica(English Edition)1997,71,3: | 4 |