Rare Earth Element Geochemistry of Late Palaeozoic Coals in North China   总被引：7，自引：0，他引：7  

HUANG Wenhui  YANG Qi  TANG Dazhen China University of Geosciences  Xueyuan Rd.  Haidian District  Beijing TANG Xiuyi  ZHAO Zhigen Huainan Institute of Technology  Huainan  Anhui 《《地质学报》英文版》2000,74(1):74-83

Instrumental Neutron Activation Analysis (INAA) was done to determine the abundances of rare earth elements (REE) of 58 samples of Late Palaeozoic Carboniferous-Permian coals and related rocks in North China. Detailed study of REE geochemistry shows that the ∑REE of most coals studied in this paper is in a normal range between 30×10-6 and 80×10-6 with a mean of 56×10-6. The REE in the Taiyuan Formation in the northern part of North China are much richer than those in the southern part. This is due to the shorter distance to the source area in the north. Moreover, the IREE is in positive correlation to coal ash, especially closely related to the content of clay minerals <2μm in size. This reveals that most REE were carried by terrigenous clastic materials, especially fine clay minerals. In the coals the light REE (LREE) are much richer than the heavy REE (HREE), and the LREE/HREE ratio in coals generally varies from 2 to 8. The LREE/HREE ratio of high-ash, low-sulphur coals is higher than that of lo  相似文献   

Multi-mechanism Orogenic Model of the Su-Jiao Orogenic Belt   总被引：1，自引：0，他引：1  

FAN Jintao  CHEN Jiongda  CHEN Huogen Geological Survey of Jiangsu Province  Nanjing  Jianesu 《《地质学报》英文版》2000,74(2):201-206

The Su-Jiao orogenic belt is the eastern part of the Central Mountain System of China. Recent studies on its erogenic system indicate that the Su-Jiao erogenic belt is a complex orogenic belt which suffered at least 3 orogenies of different mechanisms in the Mesoproterozoic, Neoproterozoic and Triassic respectively. The Meso-Neoproterozoic orogenies belong to the Wilson cycle on the plate margins. The belt is a part of the Late Mesoproterozoic supercontinent Rodinia. The Triassic orogeny belongs to the re-orogeny of the non-Wilson cycle. Delamina-tion of mountain roots occurred after both the Wilson and non-Wilson cycles in the Su-Jiao erogenic belt. The large-amplitude isostatic uplift of mountains, magmatic activities and basin-forming and mountain-making in the upper crust, all indicate the general significance of delamination in the development of erogenic belts.  相似文献   

Quaternary Climate and Environment in the Lop Nur, Xinjiang   总被引：4，自引：0，他引：4  

WANG Mill  PU Qingyu  Geological Society of Chin  Baiwanzhuang Rd.  Beijing LIU Chenglin  CHEN YongzhiInstitute of Mineral Deposits  Chinese Academy of Geological Sciences  Baiwanzhuang Rd.  Beijing 《《地质学报》英文版》2000,74(2):273-278

Since the middle Early Pleistocene (1.20 Ma B.P.), the desert steppe climate and environment have predominated in the Lop Nur area, Xinjiang, characterized by warm humid epochs interrupted by dry cold intervals. The grain-size and magnetic susceptibility curves record 30 climatic oscillations, each with a ca. 40 ka cycle, in the area since 1.2 Ma B.P., which reflects the controlling effects exerted by the astronomic factor on the environment. The Quaternary sedimentary environment in the Lop Nur gradually changed from a fresh lake through a brackish lake to a saline lake, showing a spiral evolution, and finally it evolved into a playa.  相似文献   

Determination of 3-D Velocity Anomalies of the Nanbei Tectonic Zone of China Based on Local Earthquakes     

CHANG Xu  LIU YikeInstitute of Geology  Geophysics  Chinese Academy of Sciences  All  Datun Ro  Chaoyang District  Beijing  E-mail: changxu@mail.c-geos.ac.cn 《《地质学报》英文版》2000,74(1):102-112

In this paper, 3-D velocity images of the crust and upper mantle beneath the Nanbei tectonic zone of China are constructed using P-wave travel time residuals of earthquakes, with the data supplied by China's seismic networks and the International Seismic Centre.During the model parameterization in the tomographic inversion the interpolation function of grid node velocities is used as the space function of velocity, and the velocity function is allowed to be discontinuous. The difficulties caused by large memory demand and high computing cost in solving the system of equations are avoided by utilizing the least squares QR decomposition algorithm. Thus, the stability of the algorithm is ensured. Though resolution images are not derived in the inversion process based on the resolution theory of Backus and Gilbert, a covariance resolution method is put forward by the authors. The resolution analyses have proved the reliability of the image results. 3-D ray tracing is conducted to obtain the ray paths in a s  相似文献   

Qinling Faunal Region-The Third Ordovician Faunal Region: International Correlation   总被引：1，自引：0，他引：1  

PEI FangRegional Geological Survey Party  Henan Bureau of Geology  Mineral Exploration  Development  Pingdingshan  Henan 《《地质学报》英文版》2000,74(2):137-142

The Ordovician conodont faunal provinces were previously divided into the Midcontinent and Atlantic Faunal Regions situated respectively in low and high latitudes, where warm- and cold-water type conodont faunas flourished respectively. According to the international correlation this paper proposes the third Ordovician conodont faunal region-Qinling Faunal Region, in which cold-water conodont faunas were well developed in the Early to middle Middle Ordovician and warm-water conodont faunas were well developed in the late Middle and Late Ordovician, indicating that the Qinling Region was situated in high latitudes earlier and in low latitudes later. The origin was only due to plate movement In the Qinling Region the time interval of the change of the conodont fauna from the cold- to warm-water type was 4 Ma (from 474 to 470 Ma), during which the fauna geographically spanned 40° of latitudes, with a movement velocity of nearly 1.12 m/a, indicating that the high-latitude plates were divorced and reduced i  相似文献   

Application of the Landsat-5TM Image Data in the Feasibility Study of Mudflow Hazards in the Southern Taihang Mountains     

QIAO Yanxiao  LI Miwen Remote Sensing Center of Hebei Province  Huaizhong Rd.  Shijiazhuang  Hebei 《《地质学报》英文版》2000,74(2):334-338

The Taihang Mountains area is an area in North China where serious mudflow hazards take place frequently. The hazards often obstrust traffic and make it difficult to carry out conventional ground investigations of the mudflow hazards. This paper introduces the feasibility study of mudflow hazards by using Landsat-5TM data. The study has achieved a great success through adopting both the faint spectral enhancement technique for mudflow fans (or other depositional areas) and comprehensive study of the environmental background of pregnant mudflows. Thus, remote sensing as a fast, convenient, low-cost and effective technical method can be used to recognise the situation of mudflow hazards so that effective rescue can be provided.  相似文献   

The Effect of Geologic Structures on the Control of Floods in the Middle Yangtze River Valley     

Tong Qianming Hunan Institute of Geology  Furong Zhonglu  Changsh  Hunan 《《地质学报》英文版》2000,74(2):344-348

This paper discusses the role of geologic structures in the occurrence of floods and how to prevent flood in the middle reaches of the Yangtze River, and gives the author's suggestion that the Luoshan Qiakou be expanded and the land reclaimed from Dongting Lake be returned to the lake in compliance with the law of geology. .  相似文献   

Evolution-Motion of Crustobodies and Geotectonic Metallogeny     

CHEN Guo  PENG Shenglin  DAI Tagen Geology Department  Central South University of Technology  Changsh  Hunan 《《地质学报》英文版》2000,74(3):433-438

Following the paper entitled A Preliminary Proposal on Crustobody Geotectonics presented by the first author to the 30th IGC in 1996, this paper further extends and elucidates the concept of crustobody in order to make a unifying study of the evolution and motion of crustal structures and to understand the law governing the formation and development of the earth' crust. In this paper the characteristics of crustobody evolution-motion are given. The authors lay emphasis on the relationship between crustobody evolution-motion and tectonic metallogeny. In the end, a multiple dynamic system of the crustobody evolution-motion is discussed from internal and external dynamic forces, and the mantle creep in internal dynamic factors is paid special attention to.  相似文献   

Emanation-Sedimentary Metallogenic Series and Models of the Proterozoic Rift in the Kangdian Axis     

QIN Dexian  LIU ChunxueKunming University of Science  Engineering  Kunming  Yunnan 《《地质学报》英文版》2000,74(3):466-472

The Kangdian axis basement can be divided into two tectonic layers. The lower tectonic layer is the crystalline basement which is made up of the Archaean Dibadu Formation and early Proterozoic Dahongshan Group. The former is a kata-metamorphic basic volcano-sedimentary formation of the old geosyncline (old continental nucleus), and the latter is a medium-grade metamorphosed alkali-rich basic volcanic (emanation)-sedimentary formation of the Yuanjiang-Dahongshan marginal rift. They are in disconformable contact. The upper tectonic layer is the folded basement, and made up of the middle-late Proterozoic Kunyang Group. It is the result of Dongchuan-Yuanjiang intercontinental rifting with discordant contract with the underlying and overlying strata. Along with the evolution of Proterozoic from early to late, four types of emanation-sedimentary deposits in the Kangdian axis rift were formed in turn: (1) emanation-sedimentary iron-copper-gold deposits related to basic volcanic rocks in the Yuanmou-Dahongshan  相似文献   

Study of Pyrolysis Kinetics of Asphaltenes in Silurian Oilsands in the Tarim Basin   总被引：3，自引：0，他引：3  

LIAO Zewen  GENG AnsongThe State Key Laboratory of Organic Geochemistry  Guangzhou Institute of Geochemistry  Chinese Academy of Sciences  Guangzhou  Guangdong 《《地质学报》英文版》2000,74(3):680-684

It is a special petroleum geological phenomenon that Silurian oilsands are extensively distributed in the central and northeast Tarim basin. Some geochemical studies of the oilsands have been carried out, but there is still great controversy over the hydrocarbon-regenerating potential of oilsands and the possibility of Silurian oilsands as hydrocarbon source rocks. In this study, the kinetics of asphaltenes pyrolysis was directly used to simulate the potential of Silurian oilsands for regenerating hydrocarbons. According to the experimental results, combined with other related organic geochemical analysis, it is considered that Silurian oilsands in the Tarim basin have a high hydrocarbon-regenerating potential and are latent hydrocarbon source rocks.  相似文献