Welcome to visit Geoscience!

Table of Content

    20 February 2004, Volume 18 Issue 2
    Engineering Geology and Environmental Geology
    PETROLEUM PLAY ANALYSIS AND STRIKE SLIP SYSTEM BASIN.MOUNTAIN COUPLING
    LIU He-fu,LI Xiao-qing,LIU Li-qun,LIAO Qun-shan
    2004, 18(2):  139-150. 
    Asbtract ( 1691 )   PDF (678KB) ( 1829 )  
    Related Articles | Metrics

    The bending of the strike slip fault dominated the forming of basin and mountain along the fault.This is so-called strike slip system basin-mountain coupling.The strike slip fault can be divided into three different levels corresponding to the different scales of petroleum exploration targets,such as transform fault dominated the basin forming,transfer fault controlled the play,and tear fault charged the trap.According to the mechanical scenario,the strike slip dominated basins can be divided into three types:(1)transtensional basin;(2)transpressional basin;and(3)transrotational basin.The compound of transfer fault with rift basin or foreland basin can form the linked fault family,which produced the echelon fold or echeIon fault
    bIock.The echelon fold and echelon fault block controlled the plays.The tear fault intersected with low angle normal fault or thrust fault can form some traps,e.g.trap—door structure trap.

    IDENTIFIABLE CRETERIA OF INTRACONTINENTAL FORELAND BASINS lN NORTHEASTERN CHINA
    CHEN Fa-jing,WANG Xin-wen
    2004, 18(2):  151-156. 
    Asbtract ( 3250 )   PDF (274KB) ( 1361 )  
    Related Articles | Metrics

    In this paper,identifiable criteria can be summarized as follows:(1)structural geometry of asymmetric mountain front depression,which is typical of the intracontinental for land basins;(2)subsidence curve of the intercontinental foreland basins consists of two sections which are different from exterlsional fault depressions,the first section is a gentle curve of total subsidence and tectonic subsidence;the second section shows a very steep curve;(3)molasses sediments in the upper part of reverse sedimentary cycle and offlap,intense tectonic movement and intraformational progressive tectonic angular unconfofmity. It is concluded that comprehensive analysis of multiple criteria for identifying intercontinental foreland is very necessary.

    SEALING PROPERTIES OF DIFFERENT DIRECTION FAULTS IN THE BOHAI BAY AREA
    WAN Tian-feng,WANG Ming-ming,YIN Xiu-lan,JIN Xiang-Ian
    2004, 18(2):  157-163. 
    Asbtract ( 1975 )   PDF (338KB) ( 1221 )  
    Related Articles | Metrics

    The sealing property of faults is affected by the combining manner between the maximum principal compressive stress orientation of tectonic stress field and the strike direction of faults at the same stage.When the acute angles of them are larger,the sealing properties of faults are better. If the acute angles of them are smaller,the sealing properties of faults are poorer,the liquid permeability in fault is better and good for the liquid migration. For the reasons given above,we can appraise the sealing property of fault semi-quantitatively used the sealing coefficient calculated by the method of liner algebra.By analyzing the evolving history of the sealing property of faults in the different stages of petroleum migration,the advantaged parts,which can gather oil and gas,are forecasted in some fault zones. By evaluating to the Bohai Bay area synthetically,lt is recognized that the petroleum gathering of fault depressions at east-west or north-south trending are the best,and the parts areas of the northeastward  or northwestward of fault depressions,sometimes are well for petroleum enrichment.Miaoxi-1 fault,Kenli-3 fault and Miaoxi-3 fault are forecasted for beneficial fault depression zones of petroleum exploration in the future.

    PETROLEUM PLAY ANALYSIS AND BASIN-MOUNTAIN COUPLING IN EASTERN PART OF THE TARIM BASIN,NORTHWESTERN CHINA
    LI xiao-jun,LI Jing-ming,LIU Li-qun,LIU He-fu
    2004, 18(2):  164-170. 
    Asbtract ( 3116 )   PDF (287KB) ( 952 )  
    Related Articles | Metrics

    The evolution of the Tarim Basin waS dominated by the plate tectonic cycling:(1)divergent cycle phase:Tarim plate was separated from super-continent,and the rift basin was formed in the eastern part of the Tarim Basjn in Nanhua-Sinian time;(2)drifting cycle phase:Tarim plate was experienced the drifting and thermal subsidence. The Paleozoic craton and its related petroleum pIays were formed there,such as the paleo-uplift play and continental shelf break play;(3) convergent cycle phase:Tarim plate and its surrounding areas were converted from basin to mountain.The hiatus of Permian-Triassic sequences was in the eastern part of the Tarim Basin;(4)continental cycle phase:The rift basin was formed since preliminary of the post-orogeny extension phase in Jurassic time.The intra-continent orogeny started since Cenozoic
    time,the basin-mountain coupling system was developed there. The strike-slip foreland basin was formed in the eastern part of the Tarim Basin,and its related orogenic type petroleum system was formed.The thrust fold and strike-slip fold type play were formed.

    A STUDY ON THE DISTRIBUTION MODEL OF THE SEQUENCE STYLE ON CRATON BASIN IN THE MID-YANGTZE AREA
    ZHOU Yan,CHEN Hong-de,WANG Cheng-shan,JIN Zhi-jun,TANG Liang-jie
    2004, 18(2):  171-179. 
    Asbtract ( 1542 )   PDF (457KB) ( 1005 )  
    Related Articles | Metrics

    As an example in the Mid-Yangtze area,the basic catalogues and characteristics of sequence style in craton basin have been studied,the mainly key factors for sequence style forming have been discussed,and the sequence styIe distribution model calIed as F,S,R and P has been improved.As a resuIt,there are three styles in craton basin mainy which are called as T,H,and TH styles,in which the H styles is the most one. Relative sea-level change is the most key factor controlling tertiary sequence style forming and distribution, and FSR model is chief one for tertiary sequence style in the Mid-Yangtze area.The sequence style character in the Mid-Yangtze area is similar to the other craton basins in the world,the result in the Mid-Yangtze area may be regarded as a representation conclusion.

    THE PRIMARY STUDY ON HOW TO DIVIDE SQUENCES AND SYSTEM TRACTS OF THE LACUSTRINE DEEP WATER ENVIRONMENTAL STRATA —— A CASE STUDY OF WELL NIU 38 IN DONGYING DEPRESSION
    WANG Yong,CAO Ying-chang,ZHENG Wen-tao,ZHAO Jian,CHEN xiao-hong
    2004, 18(2):  180-186. 
    Asbtract ( 1459 )   PDF (270KB) ( 1108 )  
    Related Articles | Metrics

    Certain properties of sedimentary rocks are a function of the depths of waterbody in shallow water environment.However they are not sensitive to the variation of the depth of waterbody in deep water environment. It is still a weak point in sequence stratigraphy to recognize the sedimentary cycles of lacustrine strata formed in deep water environment.Well Niu 38 with fairly full data,located in the Niuzhuang region,Dongying depression,is chosen to study in this paper.Some indexes sensitive to the variations of the depth of water,such as TOC,acoustic time,REE,etc., combined with Fisher plot,are used to recognize the sequences and system tracts of deep water envimnment,and good results have been obtained.As shown in thisnpaper,low contents of TOC and REE,together with the variation of the slopes of acoustic time curves and  Fisher plot,appear on the boundaries of sequences and system tracts.

    STUDY ON THE SULFUR-LEAD lSOTOPE OF ZHAOYUAN GOLD MINERALIZATION AREA AND WALL ROCKS
    LI Jin-xiang,DENG Jun,WU wen-gen,WANG Yin-hong,CHENG Dun-wu,LI Jian
    2004, 18(2):  187-192. 
    Asbtract ( 4412 )   PDF (280KB) ( 1596 )  
    Related Articles | Metrics

    The wall rocks of gold deposits located in Zhaoyuan gold mineralization area were rooted in metamo‘phic rocks in Jiaodong rock group in Archaean era and granites in Mesozoic era.The average values of δ34S in Jiaodong rock group,granites and gold deposits are 7.4‰,6.9‰and 8.1‰respectively.
    Three positive values increase successively,so they have sulfur homologue and continuity in evolvement.Lead isotope is similar to sulfur isotope,the average values of 207Pb/204Pb in Jiaodong rock group,granites and gold deposits are 15.381,15.562 and 15.475 respectiveb,and it is very clear that their values are all less than the average value of basalt rooted in mantle 18.269.The μ values in lead isotope are all less than their critical value 9.58, so it is indicated that lead was rooted in rocks formed at the same structural settings.In addition,it is also indicated by contact relations among them that Jiaodong rock group,granites and gold deposits are the evolutive results at the different geological stages with the same mineral source rock.

    METALLOGENIC EPOCH OF HULUNXIBAI GOLD DEPOSIT IN ALASHAN AREA.INNER MONGOLIA  AUTONOMOUS REGION
    LI Jun-jian,LUO Hui,ZHOU Xue-wu,ZHOU Hong-ying,SUN zheng-pin,WANG shou-guang
    2004, 18(2):  193-196. 
    Asbtract ( 1778 )   PDF (170KB) ( 1162 )  
    Related Articles | Metrics

    In Alashan area,Inner Mongolia Autonomous Region,the Hulunxibai gold deposit locates in the inner and outer contact belts of Hulunxibai granite.The ore boods are controlled by the zones of fracturs,and consist of altered disseminated ore bodies and Au-bearing quartz vein lens.By single zircon U-Pb and quartz 40Ar/39Ar methods,the ages of Au-bearing quanz vein were directly detected.The results shown that themetallogenic epoch of Hulunxibai gold deposit is 319.5 Ma to 348.84 Ma,that is middle Variscan period.

    STUDY ON THE METALLOGENIC FEATURE AND ORE GENESIS OF HONGQILING COPPER-NICKEL DEPOSIT,JILIN PROVINCE
    DONG Yao-song,FAN Ji-zhang,YANG Yan-chen,SUN De-you
    2004, 18(2):  197-202. 
    Asbtract ( 7065 )   PDF (308KB) ( 1723 )  
    Related Articles | Metrics

    Copper—nickel deposit of Hotlgqihng is located in Huifahe fault which is contacting zone of North China platform and Jihei geosyncline,it is a large scale deposit.In mineral area,the stratum which is crop out is Hulan group’s metamorphic rocks. Huifahe fault is characteristic of cutting deeply and frequent inheriting activity,its stretch is norrtheast.The northwest faults are derived from Huifahe fault,they are important the structure of controlling-rock and controlling-ore, controlled the distribution of mafic, ultramafic rocks and ore-body of copper-nickel sulfide.The rock-body which have the relation of mtallogenic of copper—nickel ore have the characteristic of compound rock-body.They belong to mafic, ultramafic rocks which type are gabbro,pyroxenite and peridotite.The ore-bodys of copper-nickel are seated in mafic,ultramafic rocks,the shape are similar slaty, nervation, lentiform and cystiform. The characteristic of microelement and REE geochemical have proved the ore-bodys come from mantle liquation.Mine and mafic,ultrafic rocks have consanguinity.The authors ascertained the genesis of ore deposits are deep magmaticand differentiation.
    Key words:mtallogenic feature:g∞chemical characteristic:ore genesis:Hongqiling copper—11ickel deposit

    GEOLOGICAL AND MICROELEMENT GEOCHEMICAL STUDY OF YANGSHAN GOLD DEPOSIT,GANSU PROVINCE
    LUO Xi-ming,QI Jin-zhong,YUAN Shi-song,LI Zhi-hong
    2004, 18(2):  203-209. 
    Asbtract ( 6339 )   PDF (288KB) ( 1016 )  
    Related Articles | Metrics

    The Yangshan gold deposit,located in south Gansu Province,is a supper large fine-grained disseminated goId deposit recently found in China.Four discovered ore blocks of  the deposit all occur in Devonian epimetamorphised sandstone,phyllite or limestone.The ore belt is controlled by Anchanghe-Guanyinba fault as well as its secondary faults. The orebodies,being in lenticular or veinlike forms,are spatially related to plagiogranite. Pyrite and arsenopyrite are the main metallic minerals and native gold usually occurs in pyrite,arsenopyrite and clay minerals as micrograined inclusions(2~3μm).Enrichment of Au,Hg,As,Bi,Sb in the ore is obvious and such elements show positive correlations with each other,
    indicating that the forming of the Yangshan gold deposit is associated with the activity of hypothermal ore fluid containing Au,Hg,As,Bi,Sb.The decrease of these elements from the upper part to the lower part of the deposit show that the activity of the ore fluid becorne weak along with the depth.The δD value of quartz from the ore ranges from-60‰ to-72‰,andδ18OH2O value ranges from 8.O‰~10.1‰,indicating the ore fiuid is mainIy composed of magmatic water.The δ34S value of pyrite from the ore ranges from-2.2‰ to-0.7‰,which is greatly different  from that of pyrite in Devonian phyllite,suggesting the magmatic origin of the sulfur,therefore it is proposed that the Yangshan gold deposit is genetically related to
    the magmatic thermal activity.

    RELATIONSHIP BETWEEN METALLOGENESIS AND MAGMATIC ACTIVITIES IN THE NAONIUSHAN—-JULIHE COPPER POLYMETALLIC ORE BELT, EASTERN INNER MONGOLIA
    KNAG Ming,CEN Kuang,Luo xian-rong,CHEN Xiang
    2004, 18(2):  210-216. 
    Asbtract ( 5171 )   PDF (289KB) ( 1470 )  
    Related Articles | Metrics

    Magmatic activities in the Naoniushan-Julihe copper polymetallic ore belt are mainly composed of two structural cycles,i.e.structural cycle in late Variscan period and early Yanshanian period.The ore-forming ages of the discovered copper polymetallic deposits are dominantly early Yanshanian period,and metallogenesis are related to intrusive rocks in early Yanshanian period,especially to hypabyssal-supper hypabyssal intermediate-acidic and acidic rocks. Total content of rare earth elements in volcanic-subvolcanic rocks in the area is low,and the ratio of ΣCe toΣY is high(2.7 to 14.1),and Eu anomaly is little.These rocks,which originated from upper mantle to lower crust,belong to calcic-alkalic rock series
    that are rich in Si,K and poor in Fe,Mg. Ore-forming elements and associated elements,such as Bi,W,
    Sn,Ag,Pb,Cu are characterized by high abundance value,which provide ore-forming material sources for
    the copper polymetallic ore belt.

    PETROLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF CENOZOIC ALKALI—RICH PORPHYRIES AND XENOLITHS
    HOSTED IN WESTERN YUNNAN PROVINCE
    ZHAO xin,YU Xue-hui,Mo xuan-xue,ZHANG Jin,LU Bo-xi
    2004, 18(2):  217-228. 
    Asbtract ( 1798 )   PDF (522KB) ( 1639 )  
    Related Articles | Metrics

    A set of Tertiary alkali—rich porphyries occurs in the Jinshajiang River—Ailao Mountain fault belt,western Yunnan Province. And many types of deep—derived xenoliths have been discovered in some of the alkali—rich porphyries. Research on the porphyries and xenoliths is very important for understanding the composition and evolution of the mantle and the interaction between the mantIe and the crust in western Yunnan. In this paper,rock types and petrographic characteristics of the porphyries and xenoliths in Liuhe,Xinhua,Dianxin and Xiaoqiaotou are introduced and the analysis results of major elements,trace elements,rare earth elements and Pb-Sr-Nd isotopes are presented.Based on these analyses,geochemical discrimination diagrams and studies of experimental petrology and phase equilibrium,the followirlg conclusions have been
    reached:Most of the alkali-rich porphyries are shoshonitic and formed in post-collision arc settings;magmas of alkali—rich porphyries originated near the bottom(about 55 km in depth)of the thickened crust in western Yunnan;the source rocks may be those of eclogite phase;the geochemical characteristics of EMⅡenriched mantle in the source region is likely related to the mixing of the lower crust and the mantle with fingerprints of subducted ocean crust.

    DISCOVERY OF THE WENJIASHI OPHIOLITIC MELANGE BELT IN NORTHEASTERN HUNAN AND ITS IMPLICATIONS
    JIA Bao-hua,PENG He-qiu,TANG xiao-shan,HE Jiang-nan,Guo Le-qun
    2004, 18(2):  229-236. 
    Asbtract ( 1432 )   PDF (345KB) ( 1364 )  
    Related Articles | Metrics

    This is the first report on the ophiolite suite,which consists of metasediment,meta-basalt,metadiabase,metagabbro,metapyroxene and metasilicith,in the Wenjiashi area, northeastern Hunan.Based on geology,petrology,geochemistry and isotope chronologic data issued in this work,it is suggested that the Wenjiashi ophiolite be developed under the tectonic setting of a restricted small ocean basin.Tectono -rock assemblages such as ophiolite melange belt,foreland basin,molasse formation and“S—type”granitoid recorded the whole process of collisinal orogenesis of Wuling epoch and confirm that the
    Jiangnan—Xuefeng Block should belong to Protemzoic orogens.The discovery of the ophiolitic melange belt in the Wenjiashi area provides information about the Precambrian geotectonic framework and crust evolution of South China,and therefore,this area would become one of key areas to study the early evolution(the Wuling Movement)of South China continental crust.

    GEOCHEMISTRY AND TECTONIC SETTING OF OPHIOLITES IN WEST OF NAMCO LAKE, TIBET
    YE Pei-sheng,WU Zhen-han,HU Dao-gong,JIANG Wan,YANG Xin-de
    2004, 18(2):  237-243. 
    Asbtract ( 5149 )   PDF (299KB) ( 1828 )  
    Related Articles | Metrics

    Ophiolites in west of the Namco Lake in Tibet are mainly composed of metamorphic peridotites,gabbro—diabases and basalts.From the analysis of major and trace elements of ophiolite in west of Namco,the charactenstics of the metamorphic peridotite are high content in Mg,and low content in Ti and ΣREE.The diabases and basalts are the transitional IAB/MORB-type basalt,which have the characteristic of depletion in high field elements(Nb,Ta,Zr,Hf)and comparable enrichment in large ion lithosperic elements(Rb,Sr,Ba),and on the other hand,theREE/chondrite pattern displays a flat-model with LREE
    depletion and without Eu anomaly. It is concluded that the geotectonic setting of ophiolite in Namco is formed in back arc basin by the comparison with the ophiolite of typical areas and discrimination diagrams of the tectonlc setting.

    SEISMIC ATTRIBUTE TECHNOLOGY APPLICATION IN PROGRESSIVE DEVELOPMENT OF LITHOLOGlC RESERVOIR,THE DUNTANG AREA
    JU Chun-rong
    2004, 18(2):  244-248. 
    Asbtract ( 1442 )   PDF (375KB) ( 1177 )  
    Related Articles | Metrics

    Seismic attribute technology is used in this article to discuss the types and scales of reservoirs of E2d1 in the Duntang 3D

    development area of the Jinhu sag in Subei basin.Full 3D interpretation is used by taking full advantage of seismic technologiesfault complex and elaborate interpretation of structure are studied by using time slideforward modeling(AIMS)is used to research generated mechanism of seismic wave of objective and analyze the relationship between the onlap 

    point of T52 reflection and that of realobjective.ISIS multi-channeled inversion system is used to predict the sand 

    body in objective intervalsand define the possible distribution bound of the sand body and possible oil domain. 

    It yields very good development effect

    ANALYSES FOR THE SEDIMENTARY ENVIRONMENT OF CRETACEOS STRATA AND IT’S CAUSES OF FORMATION IN THE KUQA DEPRESSION
    LIU Jian-qing,LAI Xing-yun,YU Bing-song
    2004, 18(2):  249-255. 
    Asbtract ( 3023 )   PDF (365KB) ( 1459 )  
    Related Articles | Metrics

    In recent years,large-scaIe gas fields have been found in the Kala 2 area of the Kuqa depression,and show well prospects in gas and oiI exploration.Basjqke Formation and Baxgai Formation are the main resefvoirs.The researches for the causes of their formation can establish scientific predicting system;therefore have a profound significance.Based on the analyses of tectonic,the source of the deposits,the microstructure of the sandstone,the paIaeontoIogical species,the trace elements,the granularmetric character,the sedimentary structure and system,we can see that the strata are under arid—oxidizing climate during their formation,that the lithology of the reservoirs show a Iow—grade compositional maturity and structural maturity character, that the strata are a typical sedimentary structure and sedimentary sequence from bottom to top.It is concluded that the Cretaceous strata should be included in a braided delta,meandering river and lacustrine sedimentary system.One of the most important characters in Upper Cretaceous strata is that granularmetric character shows a transitional peculiarity,which is not only different to fluvial sediment,but also different to alluvial fan,all of which constitute a manifest character of the Cretaceous strata.

    RESERVOIR CHARACTERISTICS AND INFLUENCE FACTORS OF THE TURBIDITE SANDBODY SHASAN INTERMEDIATE MEMBER IN THE NIUZHUANG SAG,DONGYING DEPRESSlON,SHANDONG PROVINCE
    RAO Meng-yu,ZHONG Jian-hua.WANG Hai-qiao,GUO Ze-qing
    2004, 18(2):  256-262. 
    Asbtract ( 9375 )   PDF (319KB) ( 3046 )  
    Related Articles | Metrics

    Turbidite sandbody reservoir of the Shasan intermediate member at the Niuzhuang sag of Dongying in Shandong Province, mainly consists of feldspathic packsand,litharenite and silstone with low compositional maturity and textural maturity. An investigation for micoscopic reservoir characteristics shows that the type of the reservoir pore space include primary pore, micro-pore of clay mineral matrix,intergranuIar dissolution pore,intragranular dissolution pore and micro-fissure,and the pore structure is mainly characterized by low permeability-fine throat,and that the reservoir have medium-low porosity and
    low permeability and poor physical properties. Through the study on the factors which affect the reservoir physical properties,the authors of this paper think that rock composition and texture,sedimentary micro-facies,diagenesis and the generation and distribution of the abnormal high pressure systems are the main factors to control the reservoir physical properties.The carbonate cement,siliceous cement and authigenic clay mineral are the main causes of the poor physical properties; The dissolution of organic acid produced in wide hydrocarbon generation and transformation of clay minerals may produce substantial secondary porosity in reservoir,and the existence of the abnomal high pressure,high geothermal field and early hydrocarbon invasion are a crucial requirement for partial original porosity and secondary porosity to be preserved.

    RESERVIOR CHARACTERISTICS OF LOWER PALEOZOIC CARBONATE BURIED HILL IN CHEZHEN ZONE, SHENGLI OIL FIELD, SHANDONG PROVINCE
    SONG Lai-ming,PENG Shi-mi,LI Guo-rong,JIA Da-ji
    2004, 18(2):  263-268. 
    Asbtract ( 5139 )   PDF (343KB) ( 2171 )  
    Related Articles | Metrics

    The reservoir investigation of carbonate buried hill is characterized by its complexity and difficulty in the fieId of petroleum geology. Based on the thoroughly observation of core datum and thin section,the petrological characteristics of the study area was described,and thus five storage spaces were proposed:corroded pore,corroded cavity,cave,weathering fissure and structural fissure.The five storage spaces formed five reservoir types: weathering fissure, fissure-cavity, corroded cavity, structural fissure and cavern,in which the first three types are the most important ones.Combined with the drilling,mud
    logging,well logging and well test data,the five reservoir types were analyzed and the carbonate buried hill reservoir was evaIuated to be divided into three types. The result indicates that the carbonate reservoirs distribute as stripes in the direction from northeast to southwest.