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2011, Volume 18 Issue 3
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Continental geology, tectonics and dynamics. 2011, 18(3): 1-12.  Abstract ( 2143 )   PDF (3038KB) ( 2938 )   The development of modern geosciences and the deep study of continental geology by applying plate tectonics have made continental geological problems the frontier, hotspot and key issues for earth science research in 21st century. This paper, now, after the “Continental Dynamics” study has been proposed for more than 20 years, presents new thinking on relevant concepts, questions, and characteristics of continental geology, introduces typical examples of the intracontinental tectonics in China continent and implements a brief comparison with analogues in the world. On the basis of these, the paper suggests some key scientific questions on the study of continental geology and dynamics for further discussion in the geological circle. Furthermore, the authors emphasize the study of nonplate tectonics, and the determination of the far field effect in continental interior. Finally, for the purpose of pushing the theory of plate tectonics forward, deeply understanding continent, exploring the continental dynamics and establishing a new global tectonic view including the plate tectonics on the planet earth, the paper calls on to draw attention to the importance of the interaction between continental blocks in continent which leads to the real and pure intracontinental tectonics under the conditions of the nonequilibrium of deep dynamics and different blocks. Related Articles | Metrics

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High Poisson’s ratio anomalies in the crust of the eastern part of North China and its origin. 2011, 18(3): 13-21.  Abstract ( 1862 )   PDF (2731KB) ( 3616 )   The seismic tomography can provide both fine Pwave and Swave velocity structures of the crust and upper mantle, and also a Poisson’s ratio image from the seismic velocities via proper computation. However, it is unsure that Poisson’s ratio images have any advantages comparing with the Pwave and Swave velocity images. In this study, the high resolution seismic tomography is applied to the determination of detailed 3D crustal P and Swave seismic velocities structure as well as Poisson’s ratio images under the eastern part of North China region. Results of Poisson’s ratio imaging show a high Poisson’s ratio(highPR)anomalies located in HengshanNorth TaihangZhangjiakou(HNTZ)region, showing Poisson’s ratio imaging can provide new geophysical constraints for the regional tectonic evolution. HNTZ region shows prominent and continuous highPR anomalies in upper crust, extending down to the middle crust with thickness up to about 26 km. According to petrophysical property measurements and other geological data, this crustal Poisson’s ratio anomaly may be explained by the upper mantle partial melting and basaltic magma underplating during the Mesozoic era，related to the lithospheric thinning in North China craton. Related Articles | Metrics

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Viscous characteristics of the present Tibetan lower crust： From the constraint of the GPS velocity field. 2011, 18(3): 22-33.  Abstract ( 1873 )   PDF (1643KB) ( 845 )   Assuming that the GPS velocity field is greatly affected by the interseismic elastic deformation of the upper crust, under the constraints of the existing GPS data, and referring to the elevation data and the NUVEL1A model of global plate movement, we have constructed the viscoelastic mechanical models to analyze the rationality of the explanation to the Tibetan presentday crustal movement by two different deformation mechanisms in the deep continental lithosphere, including the viscous flow in the lower crust and the ductile strain localization in the deep fault zones. Numerical experiments show that the presentday crustal movement in different regions of the Tibet may be attributed to different geodynamic mechanisms. In the Tibetan southeast area, although the lower crustal ductile strain localization could not be excluded, the viscosity of the lower crust should be much lower in order to reduce the model’s prediction error. In the middlenorth and northeast areas of the Tibet, the GPS velocity field is interpreted much better by the ductile strain localization in the deep fault zones, implying that the actual active faults may incise down deeply in these areas. Ignoring the lateral change of the viscosity in the lower crust, the model whose prediction of the movement has a firstorder similarity with the GPS data yields an estimate of (15)×1022 Pa·s for the average viscosity of the Tibetan lower crust, and about 1021 Pa·s for that of the deep fault zones. Due to the high elevation and the lower viscosity of the lower crust, the gravity plays an important role in the presentday movement of the Tibetan plateau. Related Articles | Metrics

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The tectonicthermal evolution history in the Kuruketage uplift, Xinjiang Province, China. 2011, 18(3): 33-41.  Abstract ( 2633 )   PDF (1890KB) ( 1028 )   Based on the apatite fission track thermochronology, organic matter maturity index, apatite fission track thermal modeling and wellEASY%Ro inversion data, tectonicthermal evolution history in the Kuruketage areas were investigated. The apatite fission track thermochronology shows that Kuruketage uplift underwent three periods of tectonic movements, the Early Cretaceous (991244 Ma), the Late Cretaceous (6687 Ma) and  the Early Tertiary（28463）. Organic matter maturity data and apatite fission track thermal modeling reflect a Hercynian tectonic movement. Wellmodeling demonstrates that Palaeozoic source rocks in the Kongquehe slope reached maximum thermal evolution from the Late Silurian to the Early Devonian with maximum paleogeothermal gradient of 356 ℃/100 m. Paleogeothermal gradient was 31 ℃/100 m in  the  Late Jurassic and 415 ℃/100 m in the south depression of the Yanqi Basin in   the Late Jurassic. The Kongquehe slope was transferred from deposition to erosion owing to the strong Hercynian tectonic movements, which is important to oilgas accumulation. Thermal evolution of the Jurassic source rocks in the Kongquehe slope and Yanqi Basin stopped because of the Late Cretaceous uplift. Related Articles | Metrics

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The seismic reflection characteristics of deep structure in CCSD well district. 2011, 18(3): 42-47.  Abstract ( 1602 )   PDF (2826KB) ( 954 )   Chinese continental scientific drilling (CCSD) well is located in Donghai County which lies in the southern part of Sulu ultrahigh pressure metamorphic zone. The seismic survey is one of the multiscientific integrated research projects. The well has been surveyed by world advanced digital seismic instrument (HF300) and three component digital geophone (geochain). Combining the achievement of seismic survey and the information of rock core 5 000 mCCSD, and through detailed analyses of deep structure reflection characteristics of seismic profile, we found that there is a threeunitlayer structure in the deep area. Six strong reflection bands appeared within 11 km in the firstunitlayer with the basically consistent attitudes, the trend is SE and the dip angle is 28 degree. The rock core sample and the VSP exploration data confirmed that the front four reflection bands are mainly the reflections from the eclogite and the ductile shear zone. The eclogite zone and the gneiss are distributed as irregularly alternative layers. Four quite clear reflection bands appeared between approximate 11 km to 30 km in the secondunitlayer, whose energy is weak, and the reflection continuity is poor. There are some weak anomalous reflections among the four bands. Their attitudes are also consistent basically, however, the dip angle is very small and the trend changes gradually to NW from shallow area to deep area. The interaction relation between the firstunitlayer and the secondunitelayer is angular unconformity. Only one quite strong reflection band appeared below approximate 30 km in the thirdunitlayer, whose continuity is good; the attitude is gentle and the trend is still NW. However, the reflections are even and there isnt any anomalous reflection below the reflection band. According to the reflection characteristics and the geologic background mentioned above, we speculate that the firstunitlayer is the turned back terrane from the subduction zone of the Yangzi and SinoKorean plate; the secondunit layer is the Yangzi Craton; the thirdunitlayer is the upper mantle, and the reflection of its top is from the Moho interface. Related Articles | Metrics

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A discussion on the collision time. 2011, 18(3): 48-56.  Abstract ( 2368 )   PDF (1282KB) ( 2174 )   Based on the isotopic ages collected in some collision zones of China and Europe continents, the process from subduction to collision between plates is discussed; in this process the following events occurred in sequence: the decrease in the moving velocity of plates, the disappearance of the oceanic crust on the surface, the beginning of the collision, the formation of the strong deformation and dynamic metamorphism, the occurrence of a series of magmatism and, at last, the uplifting of mountains. Above events have extremely different isotopic ages. The initial collision age is younger than that of the oceanic crust disappearing on the surface, and older than that of the formation of strong deformation and dynamic metamorphism. Obviously, it is very difficult to determine the initial age of subduction by using the isotopic age of only one geological event. The first decrease in moving velocity of subduction plate may have occurred because of the transformation from the subduction lithosphere plate with oceanic type to that with oceaniccontinental transition type. For the smaller plates with less strength, for example, the Chinese continental blocks, after the collision and amalgamation between two plates, the continental plate may subsequently rotate and migrate rather widely. The stitching pluton, intruded into main fault plane of collision zone, could be formed in syntectonic period and also in the period of subsequent collision, i.e. post collision. Related Articles | Metrics

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Songnen Massif and its research significance. 2011, 18(3): 57-65.  Abstract ( 1570 )   PDF (1601KB) ( 1523 )   Matching of massifs is one of the basic characteristics of Northeast China geotectonic framework. Upon such a background, the Songnen Massif, which has been relatively poorly researched, is studied in the present work in terms of its regional geology. The history of Songnen Massif matching with adjacent massifs has been explored through stratigraphy, palaeobiogeographic zoning, tectonomagmatic assemblage and isotopic chronology. It is found that the Songnen Massif is connected with Higgan foldbelt through the MiddlePaleozoic Nenjiang orogenic belt on the west, with the EarlyPaleozoic XarMoren foldbelt in the northern margin of North China Craton through the LatePaleozoic CentralJilin orogenic belt on the south, with Jiamusi Massif through the Mesozoic Zhangguangcai Range orogenic belt on the east, and with the Mesozoic MongolianOkhotsk orogenic belt on the north. Furthermore, the origins of the massifs in Northeast China are studied in connection with the previous results of the global tectonic evolution history studies, and it is concluded that it is the Zhangguangcai Range that marks the transformation of PaleoAsian Ocean domain into CircumPacific domain. Key words: Songnen Massif； matching history of massif； orogenic belt； origin of massif Related Articles | Metrics

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Syncollisional exhumation of Sumdo eclogite in the Lhasa Terrane, Tibet: Evidences from structural deformation and 40Ar39Ar geochronology. 2011, 18(3): 66-78.  Abstract ( 1860 )   PDF (7726KB) ( 997 )   The structural deformation and muscovite and amphibole 40Ar39Ar dating of muscovite quartz schist, eclogite and retrograde eclogite indicate that an Indosinian orogenesis occurred in 220240 Ma in the Lhasa Terrane, which caused the closure of PaleoTethys ocean basin and the collision between the northern Lhasa Terrane and southern Gondwana. The accordance of muscovite and amphibole 40Ar39Ar dating among eclogite, retrograde eclogite and muscovite quartz schist shows that the eclogite exhumation and Indosinian collisional orogenesis occurred simultaneously, which suggests that the regional ductile extrusion should be the main mechanism for the exhumation of Sumdo eclogite. The existence of large scale granite belt of late Indochina EPoch in the Lhasa Terrane, with the high precision single zircon UPb ages of 210190 Ma, confirms the syncollisional exhumation of eclogite from the another side, indicating that the eclogite exhumation had no relation to the postorogenic extension and granite activities. Related Articles | Metrics

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The opposite MesoCenozoic intracontinental deformations under the superconvergence: Rifting and extension in the North China Craton and shortening and thrusting in the South China Craton. 2011, 18(3): 79-107.  Abstract ( 2366 )   PDF (8450KB) ( 1720 )   During the Mesozoic and the Cenozoic, two important blocks in East China, the North China and South China blocks, were exactly a center surrounded by westward subduction of the Pacific Plate, northward subduction of the India Plate beneath the Eurasian Plate and southward subduction of the Central Asian Orogen due to Mesozoic Okhotsk Sea. It was a convergent center of the three global tectonic domains. Under the same setting of the superconvergence, two distinct structures are the extensional structures in the MesoCenozoic Bohai Bay Basin in the Eastern Block of the North China Craton and the compressional structures in the center of the South China Block characterized by shortening, thrusting and decollement. On the basis of our 10year research on the formation of the Bohai Bay Basin and the post2006 research on the intracontinental tectonic system of the South China Block, we focus on the continental dynamics of distinct Mesozoic to Cenozoic deformations in North and South China. It is revealed that the deep structures between North and South China are distinctly different according to the tomographic images although they have the same shallow setting of super convergence.  Therefore, they possibly have different deformation mechanism. It is suggested that the continental dynamics should focus on the structures of deep Earth to reveal the relationship between deep and shallow structures. Related Articles | Metrics

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The base age of the Changchengian System at the northern North China Craton should be younger than 1670 Ma: Constraints from zircon UPb LAMCICPMS dating of a graniteporphyry dike in Miyun County, Beijing. 2011, 18(3): 108-120.  Abstract ( 2261 )   PDF (6505KB) ( 1230 )   Recently a graniteporphyry dike has been recognized near the Dalongmen Village in the north of the Shachang Town, Miyun County, Beijing. The dike emplaced into the Neoarchean Miyun Group amphiboleplagiogneiss. Both the dike and the wall rock gneiss were unconformably overlain by the conglomerate and sandstone of the Changzhougou Formation. By means of LAMCICPMS zircon UPb dating, the emplacement age 1673±10 Ma of the graniteporphyry dike has been obtained. This dating result indicates that the base age of the Changzhougou Formation, i.e. the base age of the Changchengian System at the northern North China Craton (NCC) should be younger than 1670 Ma, probably close to 1650 Ma, at least ~150 Ma younger than the conventionally adopted age 1800 Ma. This is the most direct and precise age constraint for the base of the Changchengian System at the northern NCC to date. Combining with the available age results of the overlying Dahongyu and Gaoyuzhuang formations, the duration of the newlyrevised Changchengian System can be limited in the time interval from 1650 Ma to 1600 Ma, comparable with the latest of the Statherian Period (18001600 Ma). Moreover, this new achievement suggests that the base age of the Meso and Neoproterozoic succession at the northern NCC is almost identical with that of the Riphean at the Siberia and the Vindhyan at the northern India, which probably implies that the NCC and the abovementioned paleocontinents have close affinity relationships during the assemblage and breakup of the Columbia Supercontinent. Related Articles | Metrics

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What  resulted in new tectonic activities in the eastern North China Craton in the Neogene？ 2011, 18(3): 121-140.  Abstract ( 1835 )   PDF (5713KB) ( 2662 )   In spite of tectonicplate environments surrounding the Chinese continent having no obvious variation in the recent about 40 Ma, the tectonic activities in the eastern North China Craton in the Neogene showed obvious difference with those in the Paleogene. For example, regional lithosphere seems to be thickened, TangshanXingtai faults became active, but the activities of the Taihangshan Piedmont faults reduced. Some evidences showed that the dynamical effects caused by the uplift and extending of the Tibetan plateau which is often attributed to the IndoEuarasin collision controlled the dynamics of North China in horizontal direction in the Paleogene, and in the time after about 8 Ma, however, the influences and reformations caused by the extending are weaker than the vertical reformation of eastern North China attributed to the Pacific plate subduction beneath the Asian continent; the former was less important even in the period of 823 Ma in the horizontal direction than the latter. Previous studies showed that the Pacific plate movement underwent some obvious changes at  about 47 Ma. If we only consider the Pacific plate subduction just since this time, we could find that the subduction slab can reach eastern North China after about 20 Ma (at about 27 Ma ago), and the slab may have been destructed completely at this position. In the 20Mamovement processes, the evolution of the cold slab could be divided into several stages with the slab being heated and destructed. In different evolution stages, the slab also could result in different effects on the overlying asthenosphere and lithosphere. The slab evolution showed some temporal consistence with the tectonic activities in eastern North China, and also with the Japan Sea opening. Furthermore, the possible effects acted on the overlying lithosphere by the slab in different stages could interpret the tectonic events mentioned above. Thus, the bottomup effects  attributed to the Pacific subduction mainly controlled the evolution of eastern North China in the Cenozoic, and they are also the dominant factors controlling the dynamics of North China even in the horizontal during about 823 Ma. Related Articles | Metrics

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Cenozoic uplift of the Tibetan Plateau: Evidence from tectonicsedimentary evolution of the Western Qaidam Basin. 2011, 18(3): 141-150.  Abstract ( 2042 )   PDF (3040KB) ( 1149 )   on the basis of the analysis of structure and sedimentary evolution of the seismic section in Western Qaidam Basin and combining the  basement lithology, faults distribution and history of tectonic movement, we reconstructed the dynamical evolution framework of structure and sedimentation of Western Qaidam Basin during the Cenozoic. Our results suggested that Western Qaidam Basin was under the compression tectonic background of the Tibetan Plateau uplift caused by the collision of India and Eurasia in the Cenozoic and underwent two violent periods of tectonic deformation. The Western Qaidam Basin had undergone two periods of tectonic deformation. The first ocurred in the Paleocene, and reached the peak at the E23; the second was in the NeoceneQuaternary, and the deformation intensified rapidly. The forces transmitted from the south to the north, while the tectonic deformation spread from the west to the east, which indicated that the thrust of the Kunlun fault and the slip of the Altyn Tagh fault were controlled by the collision of the IndiaAsia Plate and the northward uplift of the Tibetan Plateau. Changes of the sedimentary facies indicatd that Western Qaidam Basin has undergone a process: Inflowsedimentationrecession  and the evolution of sedimentary facies were the result of tectonics. Separated by Youbei fault, in northern region of Western Qaidam Basin there existed thrust folders with the interphase upwarping and depression, generally with closed anticlines and relatively broad synclines, whose axial direction was consistent with the trend of Kunlun Mountains. Between Youbei fault and Ⅺ fault was the palingenetic Yingxiongling orogenic which made obvious elevation difference (about 800m) between the Yingxiongling region and the northern and southern Western Qaidam Basin. The characteristics of structuresedimentation evolution in Western Qaidam Basin was in response to Tibetan Plateau uplift, and was a good record of intermittent spread of the Tibetan Plateau northward as well. Related Articles | Metrics

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Discovery of Tuerkubantao ophiolitic mélange in Xinjiang and its significance. 2011, 18(3): 151-165.  Abstract ( 2371 )   PDF (5816KB) ( 1137 )   蛇绿岩作为残留洋壳的良好记录，对于研究古板块构造及其演化具有重要意义。新发现的吐尔库班套蛇绿混杂岩位于新疆阿尔泰布尔津南部，主要由超镁铁岩、辉长岩、辉绿岩、玄武岩、复理石建造等构成。其中辉长岩和片麻状花岗岩的锆石UPb年龄在363～355 Ma，指示蛇绿岩的形成、洋壳俯冲时代在晚泥盆世晚期。岩石地球化学特征表明，该蛇绿岩套的镁铁超镁铁岩和玄武岩属低碱、低钛、富镁的拉斑玄武岩系列，具有较典型的幔源岩石特征，玄武岩形成于类似洋中脊的构造环境。混杂岩带中的片麻状花岗岩属于钠质的低钾岩石系列，形成于火山弧或同碰撞构造环境，亦为洋壳俯冲的结果。吐尔库班套蛇绿岩与科克森套、乔夏哈拉、布尔根蛇绿岩一起构成了沿额尔齐斯分布的蛇绿混杂岩带，构成了分割西伯利亚板块和哈萨克斯坦—准噶尔板块的斋桑—科克森套—南蒙古缝合带。 Related Articles | Metrics

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A preliminary frame of magmatectonicMo metallogenic events of Mesozoic Era in Da Hinggan Mountains and Xiao Hinggan Mountains areas. 2011, 18(3): 166-178.  Abstract ( 1711 )   PDF (2750KB) ( 1391 )   MongoliaHinggan Orogen is an important metallogenic belt of China; many Modeposits were discovered in this belt recently owing to the great deal of input by government and companies. But the regional geological background of Modeposits remains unknown. Based on the study of igneous rocks, the regional geological maps and Modeposits, this paper reaches the following conclusions: (1) The Indosinian orogeny and Yanshanian orogeny are independent orogenic cycles; the Indosinian orogeny was ended at about 220200 Ma, which is marked by a suit of alkaline, peralkaline and miarolitic granites in the area; furthermore, the Yanshanian orogeny was started from the earlyJurraic and went into postorogeny at the late of earlyCretaceous, which is marked by another suit of alkaline, peralkaline and miarolitic granites in the area, as Baerzhe pluton, Alongshan pluton, etc..  (2) There are mainly two Mo metallogenic epochs in Yanshanian era: about 180 Ma and about 130 Ma; 180 Ma is the early time of Yanshanian orogeny, the deposits of this time were mainly CuMo deposits and the correlated igneous petrotectonic assemblage is  Tonalitegranodioritegranitegranodiorite porphyrygranite porphyry etc.; 130 Ma is the late time of Yanshanian orogeny, the deposits were mainly Mo（W/U）deposits and the correlated igneous petrotectonic assemblage is finegrained granitegranite porphyryquartz porphyryfelstone etc.. (3) About four regional compressionthrust events can be recognized: after J1, after J2, after J3 and after K1; the unconformity sediments of K2 had covered all of above thrust tectonics and the compressionthrust events were over. So, the formation of Modeposits of the Yanshanian was under the background of compressionthrust, rather than the background of continental rift by extension of lithosphere.   Related Articles | Metrics

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A discussion on the manifestation of Jixian movement and early Yanshanian movement in the study area based on the new dating information： Taking the Western Shenzhen and  National Geopark in Eastern Shenzhen Dapeng Peninsula as  examples. 2011, 18(3): 179-188.  Abstract ( 1782 )   PDF (6644KB) ( 1104 )   The authors attended geological line survey and collected 20 rock samples for dating in the Western Shenzhen and National Geopark  in Eastern Shenzhen Dapeng Peninsula and other places in last 3 years. Using the new laser testing method of zircon UPb dating，  we obtained seven data sets focused on the range of 1007897 Ma，  and for the first time we found out the Neoproterozoic Jixian “Period”Qingbaikouan “Period”， and basically can confirm the existence of Jixian movement （14001000 Ma）； The ages of the Mesozoic volcanic rocks can be further divided into the Middle Jurassic and MiddleLate Jurassic volcanic rocks （1569±2 Ma， 1658±29 Ma）， the Late Jurassic volcanic rocks （14191456 Ma），  and the late Late Jurassicearly Early Cretaceous volcanic rocks （131±2 Ma1462±29 Ma）。Among the 13 data in the range of 16581391 Ma，  there are 11 data focused on the range of 14631391 Ma，  which shows the intense early Yanshanian movement （205135 Ma）in the area Shenzhen Jixian movement （14001000 Ma）mainly occurred as strong tectonic movement between the Mesoproterozoic and the Neoproterozoic； the metamorphic rocks underwent strong compression，  and close linear folds，  regional metamorphism and migmatization occurred. Yanshanian movement in the local district can be distinguished two stages，  the early and the late，  and the early movement was dominant. Meanwhile the early movement can be further divided into 14 screens and the late movement was the 5th screen. The intensely tectonic movement was related to the subduction of the Pacific plate into the Eurasian plate. The Yanshanian movement was mainly the folding and faulting，  volcanic eruptions，  magma intrusion and some areas’ metamorphism. According to new data measured in the study area we carried out the analyses of the main tectonic movements； for the southern tectonic belt of the east Guangdong Lotus Hill area，  we have studied its isotopic geochronology，  the time of its formation，  its evolutionary history，  and its structural mechanisms and kinetics； these studies are of important practical significance. Related Articles | Metrics

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Features of the mantle source and tectonic setting of the Poshi NiCu sulfidebearing intrusion， Xinjiang, China. 2011, 18(3): 189-200.  Abstract ( 1855 )   PDF (2378KB) ( 1030 )   The Pobei gabbroic intrusion is located in the Beishan rift zone of the northeastern margin of Tarim cratonThe Poyi and Poshi NiCu bearing ultramafic bodies are situated in the western portion of the Pobei intrusionIt is sharp contact between the Poshi ultramafic body and the Pobei gabbroHowever，both the Poshi ultramafic rocks and the Pobei gabbros have similar trace element and isotope compositions，indicating that they are comagmaticThe triangle plots of MnOTiO2P2O5 and ThHfTa show that the parental magmas of the Pobei and Poshi intrusions have features of island arc magmaIn contrast，the layered intrusions and maficultramafic dykes in the Bachu area of the Tarim large igneous province (TLIP) show that the intraplate volcanic featuresIn the trace element spider diagram，the Pobei gabbros and Poshi wehrlites are relatively  enriched in large ion lithophile elements (such as Rb，Sr，Ba) and depleted in high field strength element (such as Nb，Ta，Zr，Hf，HREEs)，and show extensive negative NbTa anomaliesThese geochemical features are similar to the typical island arc volcanics and Alaskantype intrusionsHowever，the layered intrusions and maficultramafic dykes in the Bachu area are similar to the ocean island basalt (OIB)These geochemical features indicate that the parental magmas of the Pobei gabbros and Poshi ultramafic rocks were derived from a metasomatized mantle modified by subduction events，rather than the Tarim mantleData of SrNd isotopes show that the magmas of the Pobei and Poshi intrusion underwent 3% to 10% contamination of the Proterozoic metamorphic rocks of the Tarim craton Related Articles | Metrics

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The sedimentarytectonic evolution and sedimentary response of mantle plume in Emeishan. 2011, 18(3): 201-210.  Abstract ( 2062 )   PDF (4715KB) ( 1396 )   In the MiddleLate Permian, a large scale of mantle plume event in Emeishan took place in the UpperYangtze region and the volcanic product of the event was Emeishan Basalt. The sedimentarytectonic evolution of mantle plume in Emeishan, and sedimentary characteristics and sedimentary responses of volcanic activity were studied. Mantle plume in Emeishan is considered to have undergone the stages of deep magmatic activity, volcanic dome, volcanic eruption, crustal subsidence, etc. Mantle plume also caused other correlative important events such as volcanic dome, earthquake, tsunami and hydrothermal activity, and  its sedimentary responses included syngenetic deposit sliding, hydrothermal deposit and storm deposit. Therefore, the lump limestones of Maokou Formation and their characteristics are the results of syngenetic deposit sliding, the flints of Maokou FormationChangxing Formation are hydrothermal deposits of magmatic differentiation, and the mud and megaclast in the Maokou Formation is the result of storm deposit. Disorderly deposits of Maokou Formation and Wujiaping Formation are related to earthquake activities, which may be called  seismite. Key words: mantle plume in Emeishan; basalt; volcanic activity; sedimentary response Related Articles | Metrics

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Analysis of the sedimentary setting of the Paleoproterozoic Hutuo Group in the Wutaishan area: Foreland basin or intracontinental rift basin? 2011, 18(3): 211-220.  Abstract ( 2130 )   PDF (2580KB) ( 1036 )   The tectonic setting and geological evolution of the Paleoproterozoic Hutuo Group distributed in the Wutaishan area are crucial constraints on the formation time and evolution of the TransNorth China Orogenic Belt between the Western and Eastern Blocks of the North China Craton. Through integrated analyses of the contact relation between the Hutuo Group and underlying geological bodies, the assemblage of the sedimentary sequence, the structural patterns and recent geochronological data of the Group, the following results were obtained: (1) the Hutuo Group unconformably overlies the three geological units of varying metamorphic degrees of the Neoarchean Wutai Group (the Shizui, Taihuai and Gaofan subgroups) and TTG, suggesting that the Neoarchean subductioncollision orogenic belt recorded by the Wutai Group and TTG had completed its collision and orogenic process and then underwent longterm uplift and erosion before depositing the Hutuo Group; (2) both the assemblage of the sedimentary sequence and the tectonic feature of the volcanic rocks of the Group demonstrate the depositional setting of intracontinental rift basins rather than foreland basins; (3) the formation time of the Hutuo Group was 2.141.83 Ga and that of the Wutai Group and TTG ca.2.5 Ga, with a gap of 0.30.35 Ga from the beginning of the Hutuo sedimentation, and thus it is inappropriate to place the two groups into one structure system; (4) the Hutuo Group predominantly underwent a crustal shortening process through regional NWSE structural compression and the structural pattern was an upside down fan in shape and the deformation direction was fixed, which was quite different from that of the Wutai Group of complex deformation history and the fanshaped structural pattern of the general collision orogenic belt. So the Hutuo Group can not be interpreted as forming in foreland basins or backarc (forearc) basins, but forming in the intracontinental rift basins after the ca.2.5 Ga cratonization of the North China Craton. Therefore, the various geological evolution models of assembling the western and eastern blocks of the NCC along the 1.85 Ga TransNorth China orogenic belt through the way of integrating the geochronological, geochemical and metamorphism data need further examination. The research of the field relations between geological units in the Central Orogenic Belt should be enhanced in order that the proposed plate tectonic model of the Belt accords with the geological facts and the misinterpretation is reduced to the least. Key words: Hutuo Group; sedimentary assemblage; structural pattern; unconformity; foreland basin; intracontinental rift basin 摘要：分布于五台山地区的古元古界滹沱群形成的大地构造环境和地质演化过程，对华北克拉通东、西部陆块之间的华北中部碰撞造山带的形成时代和演化具有关键性的地质约束。通过对滹沱群与下伏地质体之间的接触关系、滹沱群沉积岩石序列组合特征、构造变形样式和已有同位素年代学资料的综合分析，认为（1）滹沱群呈区域性角度不整合覆盖于新太古代五台群变质程度不同的3个地质单元（石咀亚群、台怀亚群和高凡亚群）和TTG之上，说明了滹沱群沉积之前，以五台群和TTG为地质记录的新太古代俯冲碰撞造山带已经完成了其碰撞造山过程，并且之后还经历了漫长的抬升剥蚀作用；（2）滹沱群的沉积岩石序列组合和火山岩构造属性指示了其具有克拉通内裂谷盆地基本特征，而不具备前陆盆地沉积序列组合的特征；（3）滹沱群形成时代为214~183 Ga，而五台群及其TTG等形成于25 Ga左右，与滹沱群开始接受沉积的时间相差03~035 Ga时间跨度，因此，把两者置于同一个构造演化系统在时间上也是不恰当；（4）滹沱群主要经历了一次区域性北西南东向构造挤压作用下的地壳缩短过程，构造样式呈倒扇形构造，并且变形方位稳定，与五台群经历了复杂的多期变形的构造样式显著不同，也与碰撞造山带一般具有的正扇形构造样式不同。因此，滹沱群不能被解释为华北克拉通中部碰撞造山带的前陆盆地或弧后（前）盆地，而是25 Ga华北克拉通化后的陆内裂谷盆地。那么，目前主要依据地质年代学、地球化学和变质地质学的资料而提出的华北克拉通东、西部陆块是通过华北中部185 Ga碰撞造山带碰撞拼合而克拉通化的各种构造演化模式值得进一步商榷，特别是应加强华北中部造山带内不同地质体构造单元之间的野外地质关系研究，使得华北中部板块构造演化模式更与地质事实相吻合，避免引起可能的误解。 Related Articles | Metrics

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Sedimentary response to geodynamic reversion in Tarim Basin during Cambrian and Ordovician and its significance to reservoir development. 2011, 18(3): 221-232.  Abstract ( 2188 )   PDF (4042KB) ( 1005 )   In order to search after the control of tectonic evolution over depositional facies and reservoir development in Tarim Basin, the geodynamic reversion from pullapart to convergence surrounding the Tarim Plate and its sedimentary response in the Basin have been discussed in detail on the basis of the knowledge of the  tectonic evolution of Tarim Basin. It has been considered that the formation of paleouplifts, migration of facies, distribution of reef and bank zones with high energy condition, reversion of base level from fall to rise, lithological change from dolomite to limestone and occurrence of unconformable surfaces in different orders are closely related to the geodynamic environment surrounding the Basin. These sedimentary responses to the geodynamic reversion, on  one hand, control the distribution of reef and bank reservoirs and, on the other, restrict the development and distribution of karst reservoir under the unconformable surfaces, which provides us with geological basis for predicting and evaluating favorite reservoirs. Related Articles | Metrics

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The Early Cretaceous volcanic rocks in Suhongtu Depression in Yingen  Ejina Qi Basin: Its scientific significance to the research of Altun Fault. 2011, 18(3): 233-240.  Abstract ( 1963 )   PDF (1413KB) ( 1573 )   In the study, the 39Ar40Ar dating of volcanic rocks of Suhongtu Depression in YingenEjina Qi Basin yielded an age of (10555±403)(11271±206) Ma, indicating the rocks being the Early Cretaceous eruption products. The volcanic rocks in Suhongtu Depression and in Hongliuxia of Jiuxi Basin are the eruption products of the same period caused by the reactivation of the AltunEngeerwusu Fault in the Early Cretaceous (106113 Ma) according to the geochronology, but they might come from different mantle source regions according to their geochemical characteristics. More important, the study suggested that from the beginning of the activation of the Altun Fault to the volcanic eruptions in Suhongtu and Hongliuxia, the Altun Fault had at least extended northeastward to the Suhongtu area. Related Articles | Metrics

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New consideration on the genesis of suture. 2011, 18(3): 241-249.  Abstract ( 3643 )   PDF (12893KB) ( 6984 )   It is traditionally considered that sutures in the carbonates were formed under the pressure solution caused by rock load or tectonic stress, which is a result of chemical compaction. Here we demonstrate that sutures are characterized by integrality, hydrophilicity, antihole， and burst and concourse. Sutures are a kind of sawtooth cracks caused by the rock bursting due to hydrocarbons (or mud) under the rock load or tectonic stress, which are hydrocarbon (mud)expulsion passages. The contribution of pressure solution is not clear. Compared with carbonates, mudstone has few sutures. This is because the mudstones have relatively larger pore radius, and hydrocarbons can be expelled through micropore permeation. on the basis of  the studies of formation mechanism of sutures, we investigated the difference of hydrocarbon expulsion between carbonates and mudstones, and compared their sealing capabilities. Related Articles | Metrics

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Compositional migration of sodium enriched metavolcanic rocks and its relationship with mineralization in Longbohe Copper Deposit, Jinping, Yunnan Province. 2011, 18(3): 250-260.  Abstract ( 2025 )   PDF (1697KB) ( 859 )   Longbohe copper deposit, a structure fractured alteredrock type of copper deposit, is located in the southeast end of AilaoshanRed River tectonic zone, Jinping,Yunnan. The wallrock is sodiumenriched metavolcanic rock, and the alteration consists of chloritization, silicification, pyritization, and sericitization. The voluminal change and compositional migration between metavolcanic rock and mineralizational metavolcanic rocks are calculated based on the geochemical compositions. The results show that, from weakly mineralized metavolcanic rocks to strong mineralized metavolcanic rocks, the volumes increase by about 14% and 12%, respectively, and the contents of SiO2, HREE, metallogenic elements (Cu and S), and proiron elements such as Cr and Ni increase gradually, but the contents of CaO, MnO， LREE, etc., decrease gradually. It suggests that the SiO2, HREE and metallogenic materials, such as Cu， S, etc., are moved into the wallrock by the orebearing fluid, and the CaO, MnO， LREE, etc. are moved out from the wallrock, and the metallogenic materials come mainly from the magmatic hydrothermal. Related Articles | Metrics

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ReOs dating of molybdenites from Getingkeng molybdenum deposit of Southern Jiangxi Province and its geological significance. 2011, 18(3): 261-267.  Abstract ( 1541 )   PDF (1281KB) ( 926 )   Located in the inside and outside contact zone of granite porphyry, the Getingkeng molybdenum deposit is a mediumsized porphyry deposit in southern Jiangxi Province. ReOs isotopic dating of 7 molybdenite samples from the mineralized quartz veins of Getingkeng deposit has yielded a precise isochron age of (1594±16) Ma and a weighted average model age of (1588±13) Ma. The intercept of isochron is (0001±0055)ng/g, and the MSWD is 17. Getingkeng molybdenum deposit formed in the MidLate Middle Jurassic, the mineralization age corresponds to the second mineralization stage (170150 Ma) in the Late Jurassic of South China, consistent with the tungstentin mineralization around 160 Ma within the region. South molybdenum mineralization occurred in a row of 16590 Ma. Related Articles | Metrics

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Diamond and deep carbon cycle. 2011, 18(3): 268-283.  Abstract ( 1806 )   PDF (2116KB) ( 3479 )   Deep carbon cycle is an indispensable part of global carbon cycle. While extensive research has been done on surface carbon cycle, there is still little understanding of the carbon in deep earth. We do not know how much carbon is stored in deep repository, nor do we quantify the migration of carbon between different repositories and its exchange with earths surface. As a simple substance mineral of carbon from deep earth, diamond is a wonderful window of glimpsing deep carbon cycle. Recent rapid development of insitu microanalysis techniques provides strong support for diamond and deep carbon cycle research. This article makes a brief introduction on carbon exchange between surface and deep earth, deep carbon repositories and mineral characteristics of diamond. Subsequently, a discussion is made for mechanism of diamond formation, characteristics and sources of deep earths carboncontaining fluid/melt through stable isotopes compositions of diamond and its inclusion. Related Articles | Metrics

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Geophysicalgeological prospecting models  for positioning prognosis of hidden metal deposits. 2011, 18(3): 284-292.  Abstract ( 1592 )   PDF (3468KB) ( 1185 )   The paper introduces a kind of new idea and method: “geophysicalgeological models of ore deposits” which is based on the geologic prospecting experience of thirty eight different kinds of metal deposits. Geophysicalgeological model of ore deposit is a visible prospecting model. As a combined concept of geological models and geophysical models of ore deposits, the model summarizes the orecontrol structures and the geophysical anomalies from which the spatial allocation pattern of ore bodies is abstracted. Thirty eight different kinds of metal deposits have been carried out the positioning prognosis of concealed ore deposits more effectively by integrated geological and EH4 HybridSource Magnetotelluric geophysical investigations. Based on the twelve types of geological models and eight types of geophysical models of ore deposits, eight types of geophysicalgeological models of ore deposits have been established in order to change positioning prognosis of hidden deposits from qualitative conceptual prognosis to quantitative positioning prognosis. Related Articles | Metrics

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The fractal dimension characteristics of element abundance of the granitoid in China. 2011, 18(3): 293-301.  Abstract ( 1775 )   PDF (1377KB) ( 1098 )   将各种化学元素的丰度集合视为一组丰度序列，首次将分维数(盒维数)应用于研究中国花岗岩类的化学元素组成及演化特征。原理上，分形的遍在性源于随机性的遍在性，分维数的取值可表征丰度序列的内部结构性及演化的方向性，为矿产资源勘查提供重要信息；实践上，以观测元素相容性序列为基础分析其地球化学行为，采用盒维数以不失观测变量的整体性。详细探讨了分维数与成岩序列上的演化趋势或分异程度与研究对象地球化学特征间的相互关系及作用机制，据以解释为何在组分、时间与空间上同属花岗岩类却呈现出截然相异的成矿专属性与含矿性；确立了从频数特征角度探讨化学元素组成研究的新思路。研究结果表明：中国花岗岩类化学元素在丰度序列演化中均存有某种形式的结构性演化，即在组成、时间及空间上的有序结构，传统的(对数)正态分布模型难以描述其频数规律。然而，累加(差)的频数却是服从分形分布的，分维数与聚类分析的结果十分接近，且其递减序列可作为研究体系演化程度的判据，具有相当重要的地球化学意义。 Related Articles | Metrics

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The method of seismic random noise blind separation based on JADE. 2011, 18(3): 302-309.  Abstract ( 1494 )   PDF (2099KB) ( 833 )   Seismic data usually contains random noise generated from a wide variety of unpredictable irregular factors. Independent Component Analysis (ICA) is a new multidimensional signal processing method based on high level statistics able to achieve separation of source signals in the absence of priori information. This article attempts to apply ICA to removing random noise from seismic exploration data and analyzes the assumptions and inherent uncertainties of the technique. We use an improved preprocessing algorithm to remove additive white Gaussian noise (AWGN) first, and then, by joint approximate diagonalization of eigenmatrices (JADE algorithm), further process the data to blindly separate the effective signal from the nonGaussian distributed random noise. Furthermore, the article establishes the normative similarity coefficient criteria to identify effective signal to resolve the order uncertainty problem in ICA and achieve an effective signal extraction. Simulation experiments and the actual seismic data processing experiments show that the algorithm proposed in this paper effectively removed the random noise. Related Articles | Metrics

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Remote sensing interpretation on June 28, 2010 Guanling landslide, Guizhou Province, China. 2011, 18(3): 310-316.  Abstract ( 1546 )   PDF (2701KB) ( 879 )   On June 28, 2010, a largescale landslide occurred in the county of Guanling, Guizhou Province. On June 30, China Aero Geophysical Survey & Remote Sensing Center for Land and Resources (AGRS) carried out the urgent remote sensing flight disposed by China Geological Survey Administration, and highresolution aerial image data of three days after landslide was captured. Then, orthorectification was completed for disaster interpretation and analysis. QuickBird data, aerial photo, 1∶50 000 digital topographic data and DEM were taken as preand post628 landslide remote sensing data and geographical control data respectively. Disaster loss assessment and landslide morphological structure and movement properties were interpreted by using digital landslide technology. Landslide volume was estimated by using the DEM calculation of preand postlandslide. Based on the analysis of formation factors of 6.28 landslide and hidden geohazard interpretation, suggestions are proposed for disaster prevention and mitigation. Related Articles | Metrics

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The density and fractals of structural fractures in northern segment of Tazhong No.1 Fault, Xinjiang, China. 2011, 18(3): 317-323.  Abstract ( 1484 )   PDF (2103KB) ( 728 )   The development of fractures under the influence of faults is an important aspect of quantitative study of structural fractures in the carbonate rock area, which is important to reservoir prediction of fractured carbonate oil and gas reservoir. In order to know the development and distribution of structural fractures around the thrust faults, this paper studies the surface density and fractals with the example of Tazhong No.1 Fault. An exponential relationship between structural fracture surface density and its distance to the fault is discovered in this research, and the controlling width is about 3000 m; besides, in this paper we divide the development of structural fractures into three levels on the basis of fractals, with high fractals near the fault and low fractals far from the fault; making the description of fracture development quantitative. Related Articles | Metrics

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Cellular modelbased approach to selforganization channel formation in fluvialdeltaic systems. 2011, 18(3): 324-330.  Abstract ( 1665 )   PDF (1009KB) ( 734 )    Channel avulsion and evolution in deltaic plain tends to be complicated by a wide range of different types of nonlinear processes. Understanding the ways in which channel development after avulsion is critical to tackling many geomorphologic and river management problems. In the paper, a cellular framework was used to explore the dynamics of new channel development processes after avulsion in a fluvial deltaic system. An improved multiflow routing algorithm was integrated into the framework for modeling water and sediment across the landscape. Erosion and deposition caused by flowing water follow simple rules considering the slope between neighboring cells and other variables. Specifically, the algorithm allows for lateral transfer of water and sediment at angles of up to approximately 90° to the downstream direction. Modeling results appear able to reproduce many of the largerscale emergent and selforganizing features observed in natural environment. This study demonstrates the utility of relatively simple algorithms to simulate complex emergence features of channel processes in fluvialdeltaic system. Related Articles | Metrics

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The factors impacting on longterm performance of iron permeable reactive barriers for remediation of chlorinated hydrocarbons in groundwater: A review. 2011, 18(3): 331-338.  Abstract ( 1508 )   PDF (906KB) ( 753 )   Ironbased permeable reactive barriers (Fe0PRBs) for insitu groundwater remediation of chlorinated hydrocarbons such as perchloroethylene and trichloroethylene have become a mature technology. Results published recently focus on the evaluation of longterm performance of Fe0PRBs. This paper reviews the factors impacting on the longterm performance of Fe0PRBs in treating chlorinated solvents, including groundwater chemistry, mineral precipitates formed on iron surface, microbes within Fe0PRBs and other coexistent organic pollutants. It is mineral precipitates accumulating within Fe0PRBs that become the predominant factor to decrease barriers reactivity over time. Moreover, future research on multimedia permeable reactive barriers and sequential ones based on Fe0PRBs have been recommended. Related Articles | Metrics

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A comparative study of  sequence characteristics of intraplatform shoal reservoirs of Ordovician Yingshan Formation in Keping Area, Tarim Basin: Taking the Shihuiyao and Dawangou sections as  examples 2011, 18(3): 339-346.  Abstract ( 1761 )   PDF (2378KB) ( 960 )   Carbonate reefbank reservoirs have been the current hot spot of oil and gas exploration in Tarim Basin. Taking the Shihuiyao and Dawangou outcrop profiles in Keping Area of Tarim Basin as the examples, the intraplatform shoal petrographic constitute and sequence stratigraphic features in Ordovician Yingshan Formation are deeply compared, based on which, the controlling factors of intraplatform shoal strata development are analyzed. The results show that: (1)There are some differences on Yingshan Formation development in Shihuiyao and Dawangou Areas. Shihuiyao section mainly develops thin grain limestone and mudstone, while Dawangou section deposits thick layered grain limestone. (2)The sequence characteristics of retrogradation in Shihuiyao Area and aggradation in Dawangou Area reflect that the sealevel change has different control actions in different microtopography fields. The sealevel rising inhibited the limestone development of Shihuiyao Area in the lower topography field, but promoted the limestone development of Dawangou Area in the high topography field. (3) The two intraplatform shoal sedimentary styles of Yingshan Formation in Keping Area may become the favorable targets for oil and gas exploration. Related Articles | Metrics

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he relationship between environmental evolution and human activities in Liangzhu Sites Group, Zhejiang Province, China. 2011, 18(3): 347-357.  Abstract ( 1994 )   PDF (1938KB) ( 1010 )   The Liangzhu sites group is located in Yuhang division of Hangzhou city, Zhejiang Province. It is the most representative site of Liangzhu culture (5343 ka BP) by virtue of its site density, diversity and hierarchical differences. Synthetic analyses of grain size and pollen of sedimentary samples from North and West Liangzhu profiles near the Liangzhu citywalls revealed the relationship between the rise and fall of prehistoric cultural and four stages of Holocene sedimentary environment evolution in this area: (1) before 7 ka BP, sedimentary environment went into a relatively high water level stage with cyangray stillwater deposits and the finest grain size (665 Ф). The forest expanded and was characterized by dramatic rise of broadleaved evergreens under a warm and humid climate; (2) 751 ka BP, the regional water level declined and the overlying shallowwater deposits were thin with partial strong hydrodynamic. Human activities began to emerge and intensified in the late period of this stage evidenced by high proportions of Gramineae pollen (Pollen Zone 1); (3) 5143 ka BP, the water level continually declined and reached the lowest level. Liangzhu culture sites distributed all over the lowlying plains with thicker cultural layers. The evergreen broadleaved pollen were dominant taxa with Pinus pollen fluctuating (Pollen Zone 23); (4) 433 ka BP, the level of water increased, and the Liangzhu cultural layers were submerged by river floodplain facies which were mainly made up of brown yellow silt (555 Ф). Along with the impact of human activities, Gramineae pollen decreased clearly during 4336 ka BP (Pollen Zone 4), and then remains high (Pollen Zone 5). Hydrological changes might be the controlling factor of the collapse of the late Neolithic Culture in the Liangzhu sites group. Related Articles | Metrics