DISCOVERY OF RADIOLARIAN FOSSILS IN THE CHERT GRAVELS OF TRIASSIC CONGLOMERATE IN THE WEST OF SOUTH TIANSHAN, NW CHINA

1. Introduction Kurgan, a frontier station in the south foot of the Southwest Tianshan Mountains, is located on the NW margin of the Tarim Basin (Fig. 1). The Mesozoic coal-bearing molasses there is the most west Mesozoic outcrop of the Kuqa Depression, a tectonic unit of Tarim and its adjacent area. It is very difficult for geologist to access there. This results in the lack of geological works in this area. Meanwhile, only a few petroleum exploration works have been accomplished in t…     

SEDIMENTARY FACIES OF THE ZHARTAISHAN GROUP IN THE LANGSHAN-ZHARTAISHAN AREA, INNER MONGOLIA, CHINA

As an important tectono-stratigraphic unit on the northwestern margin of the North China Plate, the Zhartaishan Group of Mid-Proterozoic age is widely exposed in the Langshan-Zhartaishan area, Inner Mongolia (Fig. 1). The underlying basement of it is metamorphic rock series of the Upper Archaean Wulashan Group and the Lower Proterozoic Sertengshan Group. The overlying strata are of Paleozoic, Mesozoic and Cenozoic. The Zhartaishan Group is quite different both from the underlying met…     

GEOCHEMISTRY OF EARLY PRECAMBRIAN K-GRANITE IN THE TIANZHEN-HUAI''''AN AREA AND ITS TECTONIC SIGNIFICANCE

l.GeologicalCharacteristicsThegranitebe1textendsnortheastWardfromBaimashi,FansiinShanxiPr0vincet0XigeyuandErdaolin,XuanhuainHebeiPr0vinceabout2Oto4Okminthewidth(Fig.l).Thestretch0fgranitebeltisnortheastanddipssoutheastWard.Thebeltconsistsmainlyofpotassicgraniteandasmallquantityofgametgranite,greygneiss,gabbroandhigh-pressuregranulite.TherelationshipbetWeenvariouspetrologicalunitsoccwhngasrocksheetsorschiefersischaracterizedbytectonicstacking-Theschistosity,whichischaracterizedbyminerals…     

STRUCTURAL CHARACTERISTICS OF THE TAIHANGSHAN PIEDMONT FAULT ZONE

1. Introduction The Taihangshan piedmont fault zone is located in a transition zone between the Taihang Mountains and the North China Plain, and is an important tectonic zone in North China. It is from the middle of Huairou County of Beijing through Fangshan County of Beijing, Laishui, Baoding, Shijiazhuang, Xingtai, and Handan of Hebei Province, and Anyang and Tangyin of Henan Province to Xinxiang of Henan Province, extending southward about 620 km in a NE-NNE direction (Fig. 1).…     

THE "COPPER SHALE" OF MANSFIELD, GERMANY——A complex deposit of syngenetic and hydrothermal origin

Since about 1300 the Mansfield copper deposits have been the most produ-ctive copper-field in central Europe (Fig. 2). To give you a quantitative ideaabout ite importance I give in the following the production of metals per onemillion tons of handpicked ore in 1941:     

STRATIGRAPHIC SECTION OF TACAN WELL 1,THE DEEPEST ON-LAND WELL IN CHINA: DISCRIPTION AND DISCUSSIONS

1. Introduction Tacan 1 well (TC1 for short) is an important exploration well drilled by Tarim Oil Field Company, PetroChina in the central part of the Tarim Basin, NW China. It is located in the Tazhong Uplift, the Central (Tarim) Rise, 14km southeast of TZ4 well and 3.35km southwest of TZ401 well (Fig. 1). It finished at the depth of 7200m where the granodiorite under the Cambrian was drilled 31 m and the designed geological purpose is reached. Up to now, it is the deepest on-land…     

ORIGIN OF NATURAL GAS IN SHANBEI GASFIELD

l.GeologicalSettingShanbeiGasFieldliesincentralOrdosBasin,northShanxiprovince,withlOolQnwidthfromeasttowestand17Okinlengthfromnorthtosouth(Fig.1).Asthegasreservesisabouthundredsofbillioncubicmeters,ShanbeiGasFieldhasbecomethenatUalgassuPplybaseforBeijing.ThegasreservoirsofShanbeiGasFieldaretheuPperordovicianMajiagougrouP.ThereexisttWosetsofgaspotentialsources,theloweranduPperPaleozoicinOrdosBasin.ThelowerPaleozoicsourcerocksaremarineorlagooncarbonatCs,anditsgasiscalledoil-formedgas…     

PHYSICAL ENRICHMENT--A NEW THEORY ON THE GENESIS OF INDUSTRIAL PHOSPHORITE DEPOSITS

Sedimentary mineral deposits were not formed simply as product of simplereactions through a single kind of factors,but were outputs of intricate reactionsamong a complex set of evolutionary natural environmental agents.They were formedat least through three different stages,viz.,the imbibition and concentration ofore forming materials;the geochemical enrichment;and the physical concentrationstages(Fig.1).As to industrial phosphorites,physical enrichmnt is of paramountimportance.It seems,almost all of the world industrial phosphorite deposits wereformed as such.Our idea of physical enrichment was first set up in 1980,during the 2ndNational Symposium on Mineral Deposits at Hongchow.Since then,lots of newevidences had been added up.In this paper,only those of phosphorite deposits are described.     

DETERMINATION OF THE FORMING PERIOD OF DIABASE IN THE NORTHERN SLOPE OF GAOYOU SAG AND IT''''S PETROLEUM GEOLOGIC SIGNIFICANCE

1.IfltroductionAlotofworkhasbeendoneonthequestionaboutthediabasefoeingperiodinnorthernslopeofGaoyousag.Duetomanyreasons,reliableresultisn'tavailablebyisotopicdating.Therefore,peoplehaven'tgotreliableabsoluteagedataasyet.Judgingfromdiabaseoccwrence,distributionhorizonandwhetherfaultdisplacesdiabaseindifferentperiods,geologistoftenconsiderthatthetWosetSofdiabaseofthetopandthebottommostlyinvadedinWubaoandSanduoevents.ThebottomdiabaserockbodydistributesmostlyinSegmentFu2(E,f2)andSegmentFu3(E,…     

APPLICATION OF THE DC RESISTIVITY METHODS TO THE STUDY OF GROUNWATER IN THE WESTERN PART OF AMMAN BASIN, JORDAN

1. Introduction In many parts of the world, the technique of electrical sounding has been used effectively for solving subsurface water problems in order to minimize drilling costs (e.g. Breusse 1963; Zohdy and Jackson, 1969; Zohdy, 1969; Zohdy et. al. 1984). During June 1999, resistivity surveys was made at the western Amman basin to provide some information about the thickness, lithology and tectonics of the subsurface layers and then to locate suitable drilling sites for water wells. T…     

Origin of Oils in “Subtle pools” in the Dongying Depression, Bohai Bay Basin, China

Subtle traps or oil pools have become an important exploration play in the Dongying Depression, Bohai Bay Basin, east China. Despite recent successes in exploration, the formation mechanisms of subtle traps are still not well understood. The majority of subtle oil pools in the Dongying Depression are developed in the middle interval of the Es3 Member of the Paleogene Shahejie Formation with the subtle traps being primarily of lenticular basin-floor turbidite sands encompassed in mudstones. Oil in the subtle traps was previously thought to have migrated directly from the surrounding source rocks of the same formation （Es3）. Detailed geochemical investigation of 41 oils and 41 rock samples from the depression now indicates that the oils from the subtle traps cannot be correlated well with the surrounding Es3 source rocks, which are characterized by high Pr/ Ph （〉1）, low Gammacerane/C30hopane, representing a freshwater lacustrine setting. In contrast the oils features low Pr/Ph （〈1） and relatively high Gammacerane content, showing a genetic affinity with the underlying Es4 source rocks, which also have the same qualities, indicating a brackish lacustrine setting. Oils in the Es3 subtle traps are probably derived from mixed sources with the contribution from the upper Es4 source rocks predominating. Therefore unconventional oil migration and accumulation mechanisms need to be invoked to explain the pooling of oils from the ES4 source rocks, which probably came through a thick low interval of the Es3 source rocks with no apparent structural or stratigraphic pathways. We suggest that the subtle oil migration pathway probably plays an important role here. This finding may have significant implications for future exploration and the remaining resource evaluation in the Dongying Depression.     

CENOZOIC GEOLOGY OF THE WENHO-SSUSHUI DISTRICT OF CENTRAL SHANTUNG

1. Syclinal warping at the end of the Cretaceous time?(Phase Ⅲof Yenshan Movement?).Intermont sedimentation.Deposition of the lowerand middle portions of the Kuanchuang Series during the Eocene(and earlyOligocene?)time. 2. Block-faulting and progressive tilting during the late Oligocenetime(Nanling Movement).Accumulation of the "bajada breccias" in con-nection with the faulting and the inauguration of the Tanghsien consequentdrainage system. 3. Tanghsien erosion to full maturity during the Miocene time. 4. Prolonged period of chemical weathering.Fossil soils withmanganese-iron pisolites and karst surfaces formed(Pliocene). 5. Deposition of gravels(Late Pliocene?). 6. "Z erosion" of moderate dissection followed by the accumula-tion of the Concretionary Reddish Loams (Lower Pleis cene). 7. Chingshui dissection along old lines,followed by the deposition ofbrownish-gray loams and loess of the Malan epoch(Upper Pleistocene). 8. Present cycle of erosion and deposition.     

东濮凹陷古近纪断裂活动的幕式特征及控盆作用

通过对东濮凹陷古近纪的沉降史分析,揭示了该区古近纪断裂活动的幕式特征:探讨了断裂活动的幕式特征对盆地沉积、构造演化的控制作用,并指出:①古近纪的断裂活动具有明显的五幕式特征,即初始活动期(Es2)、快速活动期(Es,34)、衰减期(Es33)、再活化期(Es32-Es2'2)及收缩期(Es,2'1-Ed);②断裂活动的幕式特征直接控制着盆地古近系的三级层序界面和沉积演化特征;③断裂活动的五幕式特征直接控制着盆地构造演化阶段,相应形成初始断陷期(Ek～Es,4)、快速断陷期(Es,3'4)、衰减期(Es,3'3)、再活化期(Es,32-Es,2'2)和收缩期(Es,21～Ed).     

Ocean-Continent Subduction within the Paleotethyan Archiopeligic Ocean from Mineralogical Evidence of Muztag Ophiolite, Eastern Kunlun Mountain, China

TheMuztagophioliteisdistributeddiscontinu ouslyalongthewest easttrendingMuztag Jingyuhu faultzoneintheEasternKunlunMountainofXin jiangUygurAutonomousRegion(Fig.1).The mountainiscomposedoftwoprincipalunitsofmeta morphicperidotitesandcumulates(Molnaretal.,1…     

STRESS FIELD ALONG THE REVOLUTION AXIS AND THE FORMATION OF QINGHAI—TIBET PLATEAU

STRESS FIELD ALONG THE REVOLUTION AXIS AND THE FORMATION OF QINGHAI—TIBET PLATEAU1　SunZhaoyuan .TheStar (Nebular)HypothesisoftheStressField[M ].Beijing :PetroleumIndustryPress,1996 . 2　SunZhaoyuan ,SunJuan .Thestartheoryofthestressfieldofthepoletheecliptic[J].AdvanceinEarthSciences.Beijing :Sciencepress,1999,14(3) . 3　JiangMei,XuZhiqin ,etal.SeismicprofilingbetweenMangai,QinghaiandRuoqiangXinjiangandinfrastructurestudy[J].Beijing ,ActaGeologi…     

Composition and Provenance of Sandstones and Siltstones in Paleogene, Huimin Depression, Bohai Bay Basin, Eastern China

This study was conducted to distinguish the compositions and provenance of sandstones and siltstones in the Ek1-Es3 members of Huimin (惠民) depression. The samples have been analyzed for petrographic, major element and selected trace element compositions (including REE). The results show that the sandstones from the first member of Kongdian (孔店) Formation (Ek1) have higher quartz compositions than those from the fourth member (Es4) and the third member (Es3) of Shahejie (沙河街) Formation. The alkali feldspar/plagioclase ratio in the A-CN-K diagrams decreases in the order Ek1>Es4>Es3, which suggests that the Ek1 member had a more alkali feldspar-rich granitoid source and more intense weathering of the source than the Es4 and Es3 members. The mineral distributions in the A-CN-K diagrams also indicate that the sandstones and slltstones in the three members underwent K-metasomatism. Extrapolation of the sandstones and siltstones back to the plaginclase-alkali feldspar line in the A-CN-K diagram suggests a high average plagioclase to alkali feldspar ratio in the provenance (tonalite to granite). In addition, the chemical index of weathering (CIW) and chemical index of alteration (CIA) parameters of the sandstones and siltstones suggest that the weathering of the first cycle material was intense, and the CIW decreases in the order Ek1>Es4>Es3. Trace element ratios suggest all the sedimentary rocks were mostly derived from granitoids. Elemental ratio plots (e.g., Th/Sc vs. Eu/Eu*) of sandstones and siltstones suggest a mix of a granodiorite-tonalite source as a source of the sandstones and siltstones. The sandstones and siltstones of Es3 and Es4 members also contain higher Eu/Eu* and lower Th/Sc ratios than the sandstones and siltstones of Ek1 member. As is consistent with the petrography, it suggests that the sandstones and siltstones of Es3 and Es4 members are derived from a source with less granite and more granodiorite-tonalite than the sandstones and siltstones of Ek1 member.     

DIFFERENT LITHOLOGIC PETROLEUM POOLSDUE TO THE SAME SUDDEN GEOLOGICAL EVENT IN AREA BIN 3, BIN NAN OILFIELD,CHINA

1.IntroductionThecurrentmainexploratorytargetSaresubtlereservoirsbecauseofhighexplorationInaturityinEastChina.AreaBin3inBinnanoilfield,locatedinthecountyBin,Shandongprovince,isstruct'UrallysituatedinthewestpartofBinnan--LainfractUredzoneofnorthwestDongyingDepression,nearcountyBinuplifttothenorth(Fig.l).ThereservoircharacteristicsshowthattWotypesofpoolssuchasvolcaniceffusiveandtUrbiditesandstonereservoirscoexistinlowerShahejie3Member(inshortS,')inareaBin3.Twompesofsubtlepoolscoexistins…     

东濮断陷含油气系统分析与勘探发现

运用含油气系统理论研究了东濮断陷含油气系统,提出了"纵向分层、横向分洼、洼中分层"的新思路,将东濮断陷含油气系统精细划分为4个级别:东濮断陷含油气系统为一级,是以古近系沙河街组(Es)为烃源岩,以三叠系(T)和Es为储层,即Es—T、Es的含油气系统。指出二级系统Es3—T、Es4、Es3、Es2为主力含油气系统,前梨园、濮城等主力生油洼陷中Es3—T、Es4、Es3、Es2三级含油气系统是油气勘探的靶区。油气勘探实践在一度认为没有油的地方取得了突破,发现了新层系、新类型和高产稳产区块。在濮城洼陷以Es43亚段为烃源岩的Es43-T、Es4、Es3、Es2四级含油气系统中,位于北部中央隆起带的文明寨、卫城地垒上新探明了三叠系致密砂岩裂缝油气田,其裂缝含油,基质不含油,裂缝的规模具有一定的尺度,既为油气渗流通道,也能作为油气的储集空间,探明规模储量数百万吨,突破了渤海湾盆地的找油模式,丰富了油气藏类型,该勘探和研究对东部老油区的挖潜勘探将会有所借鉴。     

BULLETIN OF THE GEOLOGICAL SOCIETY OF CHINA——PROCEEDINGS OF THE EIGHTH ANNUAL MEETING OF THE GEOLOGICAL SOCIETY OF CHINA HELD IN NANKING,MAY 2,3,4,1931

The Annual Meetings of the past years were all held in Peiping. This was the first meeting held at Nanking at the invitation of National Central University. Fifty-four members were present, including Director W. H. Wong of the National Geological Survey, Prof. Y. C. Sun of National University, Peiping, Mr. T. O. Chu, acting Director of Geological Survey of Kwangtung and     

GEOCHEMISTRY OF EARLY CRETACEOUS TRACHYTES OF DONGLINGTAI FORMATION FROM THE XISHAN AREA, BEIJING： CONSTRAINTS ON MELTING OF LOWER MAFIC CRUST

Felsic igneous rocks are of widespread magma types in continental orogenic belt, the petrologic genesis of which provides very important indication for understanding crustal evolution and melting geodynamic process within orogenic belt. Because of the differences of meltingdynamic condition, e.g. (1) composition of source rock; (2) physical chemistry conditions such as temperature, pressure etc.; (3) composition of residual phases and so on, felsic igneous rocks exhibit distinctly diverse petro…