Abstract:In this paper, there are three specimens of head shields possessing the external skeleton, collected from the purple red muddy limestone of the Qiaerbake Formation, early Late Ordovician, from the Yijianfang section of Bachu County, Xinjiang Autonomous Region. Among these specimens, the external morphological characteristics of the orbits (orb), pineal body (pi) are preserved on the one of the head shields (no.7 19 8), but the armour plates are absent on another two head shields. There are oral (Or) and the six pairs of the external branchial openings (bro2~7) outward independently opening on ventral shield of the fish bodies. In addition, the differences and similarities between the Ordovician and the Silurian—Devonian agathans possessing the external skeleton are discussed. Since there is no the naso hypophysial openings (nhypo) on the fossils, which possess six pairs of external branchial openings on the branchial region of the ventral aspect on the head shield. Therefore the Ordovician vertebrates of Bachu County should be a special and independent palaeotological vertebrate fauna. The paper is for the first time reporting the early vertebrate of the Ordovician possessing external skeleton, since Cambrian vertebrates fossils have no external skeleton in China up to now. This study is of great implication for understanding the early vertebrate's developing and evolution, and for establishing phylogenetic analysis on the basis of vertebrate biology.

Abstract:For a long time a lot of the models about the tectonic evolution and the orogenic architecture of the Paleo Asian tectonic domain are suggested by many famous geologists. However, there are large divergence of the views, especially about both the space distribution and the closing time of the Paleo Asian Ocean. Based on the intrusive tectonic map of China with the scale of 1:2500, 000, by this paper we would like to join the discussion. (1) The formation of the intrusive arc, and the collisional as well as the postorogenic igneous petrotectonic assemblages is occurred progressively younger from west to east with time, and the trend lines of the main tectonic zones is developed from near east—west in the west to near north—south directions in the east, both of which is suggested the transition of the Paleo Asian Ocean closing to development of the Pacific tectonic domain. (2) The broad trench—arc—basin system developed at the southern margin of the Siberia craton situated in the north of the main oceanic basin; the passive continental margin at the west, and the narrow trench—arc—basin system in the middle, as well as the active continental margin at the east, respectively, developed at the northern margin of the Tarim—North China craton. (3) Both the remnant arc and the oφ since Pt3 is scattered within the main arc, and is regarded as the basement beneath the main arc. (4) The classical “massif” in the orogenic zone is considered to be the remnant arc by this paper, because they are intrusive arc formed in the early stage during the oceanic subduction. (5) The main oceanic basin is recognized from three signs by this paper, （a) The closing of the ocean is latest, （b) The oceanic subduction is bidirectional when the active arc at both the sides, or is developed at one side when one side is active continental margin, and the other side is passive continental margin, （c) The long live and the residue ocean of the Mediterranean sea type are developed as the early stage of the continent—continent collision. (6) A lot of both the intrusive arcs and the oφ during Pt3—T support the formation of the large amount of the juvenile continental crust by Sngor et al., as well as is corresponded to the positive value of the εNd(t) for the granites, which, in turn, is suggested to be formation of the large amount of the oceanic subduction resulted in the cooling of the mantle, and the adding eclogites into the mantle, finally, the high density mantle flow is formed as the dynamic source for the closing of the Paleo Asian Ocean and then the collision between the Siberia and the Tarim—North—China cratons.

Abstract:Tarim basin rifted from the northwest margin of East Gondwana supercontinent and drifted to Laurentia supercontinent during the period from Cambrian to Triassic. While its north margin is passive continental environment and south mainly is back arc foreland basin or uplift as a result of different blocks or terranes accretion. First order sequences, regional uncomformity events and tectonic evolution of secondary tectonic units in Tarim basin all related to tectonic activity in plate boundary and change of plate motion track. Compressional orogeny along plate boundary caused uplifts in the basin and significant change of lithofacies paleogeography framework. Carboniferous strata were erosioned in dome shape and uplifted by vertical activity of mantle plume, which led to the large igneous provinces in the early Permian. Tarim superimposed basin, product of multi prototype bains in small blocks composited in the different periods, differed from that in the other plates with no vertical composite influenced by variations in the lateral migration. Tarim block is smaller than other global typical craton basins, underwent tectonic reworking intensely because of the collision with adjacent blocks ,such as Kazakhstan/Altyn-Qilian and Qiangtang block, with strong tectonic deformation extending from magin to the inside.

Abstract:The Datong basin is a Cenozoic rift located in the central part of North China Craton. It has experienced intensive and persistent rifting since late Miocene. Based on the analysis on the kinematics and dynamics of the marginal faults, the summary on the Cenozoic sedimentary and basaltic strata and the discussion on regional dynamic background, writers proposed the formation mechanism of the Datong basin. Since 10~8 Ma, the NW extending tectonic stress field formed on the northeastern margin of the Ordos block and acted on the marginal faults resulting in the Datong basin’s forming. The formation of the Datong basin corresponds to the lithosphere thinning process and may be related to the far field effect of India—Eurasia collision and Pacific—Eurasia collision. What’s more, the article shows some new facts. The normal fault stress field of the Datong basin is that σ1 is vertical, σ2 and σ3 is horizontal, the strike of σ3 is about 150°, which differs from the strike slip fault stress field of North China. The K Ar age of Dayukou basalt in Datong volcanic field related to mantle activity is 0.68±0.13Ma. The Datong basin has characteristics of intraplate narrow rifts. All these research provide a new basis for building the Cenozoic kinematics and dynamatics model of the Shanxi Rift system.

Abstract:Foreland thrust belts have shown great hydrocarbon potential and their oil and gas occurrences are controlled by the structural segmentations. Longmen Mountains thrust belt is characterized by the structural segmentation, but there is rarely research on the segmentation mechanism. The results of sandbox experiments have identified the basement difference and indenters in the thrust belt as the main controlling factors over the structural segmentation of foreland thrust belts. Recently research has presented the existence of Western Sichuan palaeo aulacogen in Sinian strata, associated with two large scale palaeo uplifts, including Dayi palaeo uplift and Jiangyou—Laoguanmiao palaeo uplift, which lead to basement difference in the basin. Combining with the geological condition of Longmen Mountains thrust belt, the structural segmentation mechanism of Longmen Mountains thrust belt can be concluded as follows：the northern segment formed firstly when the Bikou block transmitted power and was blocked by the margin palaeo uplift of Longmen Mountains initial rift inside the basin. Central segment corresponds to Western Sichuan palaeo aulacogen, where Pengxian—Guanxian（Dujiangyan）complex squashed into the basin and inheritably formed Western Sichuan foreland basin during Yanshanian—Himalayan Periods. Southern segment formed thrust belt above Dayi palaeo uplift when Baoxing complex transmitted power.

Abstract:Manchuria region is located in the southern section of the Ergun block,which was heavily influenced by Pal Asia and Pacific tectonic domain causing large scale of magmation and tectonic activities in Mesozoic．An ancient crater with geographical coordinates of longitude 116° 20.6096′ and latitude 48° 51.4327′ is first discovered at about 42km northwest of New Barg Right Flag in Inner Mongolia during the national geological survey project in 2011．This ancient crater is covered by the Quaternary sediments and named as Balegenhade ancient crater．Circular structures and radial drainage in images of remote sensing very clearly show the cyclic volcanic necks．The lithology is mainly composed of rhyolitic volcanic breccia lava, volcanic agglomerate lava, volcanic agglomerate breccia lava and rhyolite forming several cyclothems．Three complete eruption circulations starting from explosive facies ending with overflow facies can be observed except that the top and bottom are incomplete．The explosive index is from 0.72 to 0.92 experiencing a gradual weakening process from below to above．Zircon U Pb age in rhyolite ranges between 167.8 Ma ± 3.3 ~ 162.2 ± 2.1 Ma that indicates the eruptive activities took place in Middle Jurassic．The analysis of stress field shows that the direction of σ1 converted from NWW to NNW since early mesozoic to later，which reveals a tectonic transformation from ancient Asia to Pacific．The Buergan fault zone reactivated under the compressive force of NWW—SEE direction, then formed the NNE trending Eerguna fault zone with the property of sinistral shearing and corresponding NWW trending tensile fractures,so the conjunctions of those two sorts of faults would be the ideal space for rising magma．Therefore, those many centric craters including Balegenhade and Jiawula craters distributed like beads on NNE direction are results of the joint effect of ancient Asia tectonic and Pacific tectonic．

Abstract:This study apply LA-ICP-MS to date the U-Pb age of detrital zircons from the Chentangwu Formation, Pingshui Group in Pujiang County, Zhejiang Province, and obtained the youngest peak age at (828±3.8 Ma), represent the lower limit of the ages of deposition of this suite of rocks. Based on this age, coupled with the SHRIMP U-Pb age (825.3±8.1 Ma) and (830±6 Ma) of the tuff from the Chentangwu Formation, the age of Pingshui Group in Pujiang County is limited to middle neoproterozoic, and just above the Shuangxiwu Group in Fuyang area and the Pingshui Formation in Shaoxing area. The Pingshui Group in Pujiang County is a sequence of weakly deformed, low grade metamorphic marine volcanic lava, volcaniclastic rock and sedimentary pyroclastic rocks, Skeleton particle statistical results of the Chentangwu Formation show that volcanic fragments adds up to 60%~80%, sedimentary lithic fragment adds up to 10%~30%, feldspar adds up to 15%~20%, and that quartz is rare, the average content is 5%, it is subangular, and with poor sorting and rounding, these features all show the characteristics of proximal volcanic eruption, the source is from volcanic arc, and its sedimentary rock has abundant 850~800Ma detritus zircons without ~1000Ma or older ones, show that the volcanic fragment of the Chentangwu Formation derived from the volcanic rocks that almost the same period of sedimentation, this also suggests the Pingshui Group form in an area which near the new magmatic arc. Both the time and space and structural properties, the Pingshui Group in Pujiang County and the Shuangqiaoshan Group show the corresponding arc—basin system, suggest that they have some causal association.

Abstract:While high density turbidity current and sandy debris flow are two significant geological agents in deep water environment, a dispute always exists in how to distinguish between the two kinds of fluids and their deposits. By discussing the relationship between the fluids, it is of help to clarifying deep water sedimentary process, to properly distinguishing between their deposits and to predicting reservoir. On the basis of reviewing concept, characteristics and concrete examples, fluid properties and sedimentary characteristics are compared. Combined with triggering mechanism, forming process and influencing factors, the relationship between high density turbidity and sandy debris flow is discussed from the two aspects of basic theory and practical application. High density turbidity current deposits can be divided into bottom part, middle part and upper part vertically, in coarsing upwards then fining. Abundant in sand, sandy debris flow deposits are characterized by massive bedding and can be formed by vertically superimposed massive sandstones. Triggering mechanisms of debris flow are various. Besides, in comparison with moderate to weak viscous ones, strong viscous debris flow is not likely to convert in turbidity. In the use of terms, high density turbity is more suitable. If fluid conversion occurs in debries flow, so does high density turbidity current deposits. If it does not happen and source is rich in sand, sandy debris flow deposits can be formed. Sandy debris flow can be used to explain abrupt contact between massive sandstone and overlying muddy sediments, while high density turbidity current can explain gradual contact.

Abstract:The Hongliugoubei simple mafic—ultramafic intrusion is located in the northeastern margin of Olongbuluck micro block, its wall rock is the Dakendaban Group (Pt1dk) of Palaeoproterozoic and the intrusion mainly composed of melaolivine—gabbro and gabbro. It’s a moderately enriched Fe—Ti—P ferruginous ultrabasic intrusion with m/f value being 2.66 to 3.04.The rocks from Hongliugoubei intrusion is well pervasive cumulatic texture, olivine poikilitic texture and plagioclase poikilitic texture. The crystallization sequence of minerals is olivine olivine + plagioclase + orthopyroxeneorthopyroxene + clinopyroxene + plagioclase. All kinds of the rocks from the intrusion are enriched in light rare earth elements （LREE） and large ion lithophile elements （LILE） and depleted in Nb, Ta. The Geochemistry information indicates that the magma has undergone some degree assimilation and contamination from upper crust. Partial melting process occurs in spinel stable field. SHRIMP zircon U Pb age is 418.3 2.8Ma belonging to late Silurian. The Geochemical characteristics of this intrusion , formation age and regional geological data show that it forms in the extensional (or rifting) environment of ancient continental margin. It also suggests northern margin of Qaidam Basin is extensional during late Silurian to late Devonian.

Abstract:Northwestern of Guizhou Province (it mainly includes Shuicheng area and Hezhang area), where plenty of middle—large scale magnesian siderite deposits and siderite deposits distributed, is located at the southwest margin of the Yangtze block. Hezhang area and Shuicheng area are the two largest iron ore clusters in Guizhou. The iron formation occurs in the carbonate of the Devonian and Carboniferous. The petrological, mineralogical, and geochemical characteristics of the Devonian magnesian siderite deposits in Shuitang, Xiongfei and Tiekuangshan at Hezhang county, Northwest Guizhou were reported in this paper. The ore bodies are mainly layered, stratoid or lode shaped in form and are hosted in the Devonian carbonate rocks. The major two types of ore, beige and gray magnesian siderite, usually have massive, banded or granular textures, and the paragenetic gangue minerals including dolomite, feldspar, pyrite and quartz. The feldspar that is associated closely with quartz shows the typical texture of saddle, which probably implies that hydrothermal superimposed transformation evolved in the process of iron mineralization. In addition, the higher Th (0.4×10-6~2.3×10-6, mean 1.1×10-6 and 0.2×10-6~3.2×10-6, mean 1.3×10-6, respectively), Zr (2.7×10-6~20.6×10-6, mean 8.1×10-6 and 1.3×10-6~17.8×10-6, mean 7.5×10-6, respectively), Sc (0.5×10-6~3.9×10-6, mean 1.3×10-6 and 0.1×10-6~3.6×10-6, mean 1.4×10-6, respectively) and Al2O3 (0.24%~1.78%, mean 0.85% and 0.06%~2.77%, mean 1.18%, respectively) content of Shuitang and Xiongfei magnesian siderite ores than Tiekuangshan magnesian siderite ores (Th: 0.2×10-6~0.8×10-6, mean 0.4×10-6, Zr: 0.6×10-6~9×10-6, mean 4×10-6, Sc: 0.1×10-6~1.7×10-6, mean 0.5×10-6 and Al2O3: 0.01%~1%, mean 0.38%) indicates that the weathering material from continental source evolved in the process of mineralization of former, while the high Eu/Eu* (6.73~8.94, mean 7.68) but low Y/Ho (26.67~33.33, mean 30.01) demonstrate that the hydrothermal activities played an more important role in the process of mineralization of later. Combing with the study of isotope sulfur and TOC, the sedimentation—transformation genesis for this deposit has been concluded.

Abstract:Dongpu sag is a typical hydrocarbon rich sag in Bohai Bay Basin. Based on the methods of generation and expulsion stages of major hydrocarbon source rocks and fluid inclusion analysis, the oil and gas accumulation periods of Paleogene in Dongpu sag were studied. The results showed that the hydrocarbon accumulation period was divided into two stages. The first stage was from late Dongying deposition period to the early uplift stages, and the second was from the late Minghuazhen deposition period to the Quaternary. The first stage was the main accumulation stage. The accumulation periods of different parts and different layers was studied and compared. The main controlling factors of the differences were analyzed. The oil and gas reservoirs generated in the first phase were extensively distributed and covering all the area; By contrast the oil and gas reservoirs generated in the second stage were mainly distributed in the area near the hydrocarbon generation sags. Reservoirs formed in the fist period were extensively distributed and covering all the area. By contrast, reservoirs generated in the second period were mainly distributed near the hydrocarbon generation sags. Reservoirs formed in the second period were mainly concentrated in the sourse rock layers. The differences were mainly controlled by fault activity and the distribution of high mature source rocks.

Abstract:The purpose of this article is to study the evolution of Xujiaweizi rift depression in Songliao Basin and then anylysis its control on the accumulation of natural gas，so it is necessary to know how active faults controlled sedimentary, reservoir reconstruction and caprock preservation.We take geological period first into consideration to classify function of fault controlling reservoir,and use the maximum throw subtracting method to research Xuxi fault.Xuxi fault was composed of several single faults and not the whole fault in Huoshiling Stage,and connected the whole fault in Shahezi Stage.The east branch fault of Xudong strike slip fault belt was active in Huoshiling Stage and Shahezi Stage,playing similar role in rift controlling as Xuxi fault,and involved in strike slip in Yingcheng Stage.Because fault dense zones on T2 reflecting layer were controlled by pre existing faults in rift stage, reactivation of pre existing faults can be recognized by the relationship between pre existing faults and fault dense zones,so we can find out which faults are gas source faults and which faults destroyed gas reservoirs.According to the stages of structure evolution,functions of fault controlling reservoir in Xujiaweizi fault depression can be divided into several categories: faulting in the rift stage controlled sedimentary of reservoir rock and source rock,which deposit in hangingwall of strongly active faults that had relative large peleo displacement;volcanic rock of Yingcheng Formation erupted along Xuzhong fault and Xudong Fault belt in order to form dominant volcanic facies;faults on T41 reflecting layer partly reactived,forming a lot of fractures to improve property of volcanic reservoir and being gas source faults,and it has feature like simultaneous reservoir formation and gas migration,and neighbourhood between advantageous reservoir and gas source faults,that benefited gas formation;most reserviors wasn`t destroyed in later stage because of weak faulting in northern and middle part of Xujiaweizi fault depression.So we present combined reservior pattern of “gas source faults and volcanic vents”.The several large scale faults including Xuxi fault,Xuzhong fault and Xudong,had multiple functions of reservoir controlling,and even the same fault has different function in every stage.

Abstract:In this paper, we studied the enrichment characteristics of lead in soil within Xinqiao sulfide mining area, Anhui province. The sources of the metal Pb in the soils were traced using Pb isotopic compositions . The results showed that Pb was enriched in most of the topsoil (0～20cm) moderately, and not enriched in the deep soil (below 20cm) obviously. Pb isotopic compositions of the soil suggested that Pb of the soil was a binary mixture and was contributed from both natural and anthropogenic processes. The naturally sourced Pb might be contributed from both weathering of the quartz monzonite and granodiorite, and most of the anthropogenic Pb came from pyrite, chalcopyrite and galena ores in the mining area. In topsoil, the anthropogenic Pb varied from 73.6% to 98.7%, and in the deep soil there were 61.4%～76.1% naturally sourced Pb.

Abstract:In Songshan Mountain area, Precambrian geological heritages are conserved, these strata are complete, and tectonic movements develop well. Tectonically speaking, it is one of the typical areas record the Precambrian geology in China. This paper analyzes and concludes the features, genesis and scientific value of its geological heritages in Songshan World Geopark；and designs the geological tourism route through researching on these factors, providing scientific guidance for geological internship and survey and reduce their blindness, making Songshan an ideal place for researching Precambrian geology.

Abstract:Fe isotope geochemistry has been attracted more and more attentions recent years. Understanding the supergene processes occurred in the Earth surface system, which includes atmosphere, hydrosphere, biosphere, and the surface of lithosphere, are essential for geoscience. Here the Fe isotope compositions for soil, river, ocean and other main reservoirs of the Earth surface system and basic processes in Earth surface system leading Fe isotope fractionation were summarized. Fe isotope behavior during supergene processes including weathering, river transferring, sedimentation, diagenesis, and Fe cycling in ocean was also presented. The basic theory of Fe isotope geochemistry of Earth surface system have been constructed, and it shows that Fe isotope geochemistry is a powerful tracer for supergene geochemistry.

Abstract:The Xiamaling Formation study has progressed much since it was firstly named as Xiamaling Shale in Western Hills, Beijing, in 1920. The Formation is reviewed here from different perspectives after nearly one hundred years, including its lithology, stratigraphic succesion, sedimentary environment, regional differences, chronostratigraphy, palaeontology, oil/gas possibility, diabase sills in it, its significance for paleoceanic evolution, basin type and also evolution. Thus we could have a more comprehensive, detailed and profound understanding of the formation and its significance for the evolution of both North China and the Earth in the Proterozoic. The Zhaojiashan section, together with the suggested Xiahuayuan standard section, are described carefully for its lithological variation and sedimentary environment evolution. The boundary of each member are also further modified and defined. Contrasting of the 4 important sections, toghther with the other 10 sections and the marginal deposition in the North China Craton, outline the remaining basin and their vertical similarities and also differences for the formation. The 4 memmbers of the formation are comparable, although the upper part may be eroded after deposition and the thickness of the succesion can be variable because of possible lateral facies change. The biotic found and its chronological study advancement are also summarized. The study focuses concerning the formation are reviewed, including: (1) their organic content and corresponding hydrocarbon generating potential, (2) evidence for the ocean redox structure in the Mesoproterozoic, (3) the extensive basic sills and their tectonic significance, and (4) indication for the basin type and evolution of the so called Yanliao aulacogen. We conclude the formation should be further studied for its basic geological aspects firstly. Its high resolution stratigraphic correlation, chronostratigraphic framework improvement, origin of the rhythm and provenance analyses can also be done in the future. Other stratigraphic segments and later deformational—tectonic events in the Norch China, the corresponding Mesoproterozoic geologic recoreds in the word should also be concerned for a fully understanding of the formation.

Abstract:For the first time this paper studies the sedimentary environment and sequence stratigraphy of Jiyang depression by means of observation and statistics of ostracods occurrence in thin sections.According to the characteristics of ostracods distribution on the level, the distribution patterns of fossil are classified into uniform distribution, dispersed distribution and banded distribution. Based on the ostracods preservation condition, the fossil is classified into double valve, single valve, fracture and flattening deformation. The fossil abundance is sorted into rich (>100 flap/4cm2), medium(30~100flap/4cm2) and rare ( <30 flap/4cm2) . Ostracods occurrence is closely related to the palaeosalinity, lithofacies, sequence stratigraphy and carbonate content of shale . Research shows that: ①The watery environment of Es4cx —Es3x Jiyang depression has undergone an evolution of water body from salty to fresh, where the salinity change is agreement with fossil abundance change. ② The carbonate content in the range of 50%~60% is most conducive to the preservation of ostracods fossil. ③ The fossil abundance of laminated tuffaceous shale facies and laminated argillaceous limestone facies are very high, however, the slow deposition rate during the period of laminated structure formation and firm deposition basement are not favorable to the burial and preservation of ostracods fossil, thus the majority of fossil presence is in form of fracture. ④ The vicissitude of ostracods abundance has a close relationship with stratigraphic sequence. The ostracods abundance sequentially presents three stages：appearance — prosperity — recession，corresponding to the low stand system tract, lake expansion system tract and high stand system tract respectively.This method solving the problem that the primary preservation and the distribution patterns of fossil are difficult to observe using the routine analysis, is able to be used to maximize the fossil information acquisition.

Abstract:LA-ICP-MS Zircon U-Pb Ages, Geochemical Characteristics of the Silurian Basic Dykes in the Hengshi Area, Southern Jiangxi, and Their Geological Significances, and the diagenetic models and source characteristics are preliminarily discussed. The geochemical Characteristics indicate that the mafic dykes are pertain to the tholeiite series and calc alkaline series, and also belong to the sodium rich rock type. Especialy the TiO2 values are in the average of 1%, attributes to the basic rocks enrich of titanium . A/CNK values are less than 1%, shows that it belongs to the meta aluminous basic rocks, and displaying it s mantle derived magmatic characteristic. LA-ICP-MS U-Pb isotopic dating of zircons separated from the mafic dykes yields average 206Pb/238U ages of (422.8±1.8) Ma and (421.7±2.2) Ma, respectively, indicate that the mafic dykes belong to the Late Silurian, suggesting that the mafic dykes are later Caledonian orogenesis period in the tension (stretch) settings. At the same time, exposing two kind of acidic granite of the Caledonian orogenic and post orogenic period in this area， Which generally reflects this area has experienced the construction process from the extrusion type acidic magmatic emplacement gradually converted to tension mafic magma emplacement.

Abstract:Celaomiao Depression, east margin of Bayingebi Basins, is situated to the north of Mount Langshan, in Urad Rear Banner（Wulate Houqi), west of Inner Mongolia, China. The Depression is filled with Cretaceous clastic rocks and covers 850km2. The authors of this article have found a small volcanic vent filled with alkli syenites and basalts enclosed with hornfels outcropped in the southern margin. The outcrop is 185m long in the NEE trending and 55m wide in the NNW direction and extruded for 20m more than the surrounding sedimentary rocks. The igneous rocks of different types inside the vent show clear zonations. The center is a lenticular intrusive body (1m wide) of light colored syenite trending in NEE; a zone of 10m wide encircling the central syenite is composed of dark colored syenite, and the outmost zone of more than 10m wide is black basalt with horizontal columnar jointing structures perpendicular to the vertical wall of baked clastic rocks outside of the igneous rocks. There is a diabase dike of 2m wide across the vent in the W—E orientation. Obviously, the light color syenite—dark color syenite—basalt filled in the volcanic vent and the diabase dike across the vent are originated from the same mafic magma and separated through crystal fractionation during cooling process in the crust. The tectonic setting of this magmatism is still unclear. However, the outcrop is a typical example of volcanic conduit for geologists to investigate in detail and a nice site for geological field training.

Abstract:There are amphibole xenocrysts in Cenozoic basalts from the South China Sea. We have investigated the geochemical characteristics of the kaersutites in these alkali basalts from the South China Sea in this study, and calculated their crystallization pressure and temperature. Results show that the kaersutites crystallized from the magmas of a mantle source. They are rich in Ti and Al with average Mg# at 0.68. The abundances of major elements, trace elements as well as REE and multi trace element patterns of kaersutites are all similar to that of amphibole megacrysts in alkali basalts and amphibole veins in mantle xenolithos. The crystallization pressure and temperature of kaersutite have been calculated by using geothermobarometer, and the depth they crystallized is estimated. The kaersutites could be divided into two groups by depths. One group crystallized at depth ~35.09~43.74km，which formed at the bottom of the lithosphere and has pressure ~1019MPa~1305MPa and temperature ~1049~1066℃. Another group crystallized at shallow depth ~27.20~27.29km and formed at lower part of the lithosphere ~759~771Mpa and ~1031~1078℃. The kaersutites in this study are possible the products of fractional crystallization of alkali magmas at different depths, recording the progressive lithosphere thickening of the South China Sea which leads to the tholeiites transforming to alkali basalts.

Abstract:With the enhancement of exploration extent, deep oil—gas exploration is inevitable . It's imperative to figure out the law of porosity evolution of deep reservoirs as well as to raise forecast accuracy,which is the basis of deep exploration . Through systematic collection of cuttings and core samples from Well kun 2, Qaidam Basin and using casting thin sections, scanning electron microscope and logging data interpretion, the characters of petrology, mineralogy and physical properties of reservoirs in both Paleogene and Neogene stratums are systematically analysed .As a result, the content of argillaceous matrix and the porosity evolution of sandstones are closely related . In order to complete the forward modeling of the process of porosity evolution, well sorted aeolian quartz sands and the fine grained red clay are chosen as materials, and four kinds of quartz sands are made respectively containing clay matrix of 5%, 10%, 15%, 20% to carry out the simulation . Unconsolidated sediments compaction simulation was carried out from 1.4 MPa to 210.4 MPa, containing 21 cycle experiments respectively . The results of stimulant experiment against the core data of Well kun 2 under a comparative analysis shows that the much higher the content of argillaceous matrix in clastic rocks was, the smaller the primary porosity would be and the faster the porosity would decay ; for arenite with low argillaceous content, when the overburden pressure reached 76.5MPa, a large number of particles were broken and rearranged, which led to intergranular volume reduction and occurrence of few linear intragranular fractures,meanwhile the reservoir physical properties significantly worsen . The experimental data of compaction simulation can provide a basis for the reservoirs quality prediction of the sandstones in rapid subsidence area .

Abstract:Take S Ⅱ layer group in north development area of Daqing oil field as an example,it's studied that what is Stochastic inversion technique and its application to describe channel sandbody subtly.The study has shown that:In the vertical,there are large differences between the stochastic inversion results coincidence rate of sandbody of different thickness:The sandbody of over 3 metres,its coincidence rate is 98.6%,;The sandbody of 2~3 m, its coincidence rate is 79.1%;less than 2 metres,its coincidence rate is 71.5%;in the plane,the average coincidence rate of all sedimentary units can reach more than 75%,and the coincidence rate of delta distributary plain subfacies is higher than that of inner front subfacies.With the logging curve and inversion results,combinating well and seismic the channel trend,the single channel sandbody boundary in compound channel sandbody and the superimposed relationship between interwell sandbody ,can be described subtly.

Abstract:Based on geological and archaeological studies, including palaeoreconstruction of the sedimentary environment and AMS 14C dating, a new fishing camp in Chuanganglu Pit, located ~5 km west to the present shoreline on the west coast of Bohai Bay, left by the West Han people was found recently from a buried shelly beach and it was overlayed by 1.6 m thick marine layer which lasted for 700~800 years. Until now, this West Han people ruin which was overlayed by marine layer is the nearest one to the modern shoreline on the west coast of Bohai Bay. Following the mid Holocene marine regression, at least five chenier—linear earthy mound palaeoshorelines existed on the west coast of Bohai Bay. Their forming ages were 6.6~6.2 ka cal BP, 5.5 ka cal BP, 3.3 ka cal BP, 2.4~2 ka cal BP and 0.9 ka cal BP (4650~4250BC, 3350BC, 1350BC, 450~50BC and 1050AD), respectively. Each chenier—linear earthy mound shoreline was a boundary between land and sea in a certain time period, during which its seaward area was ancient sea while its landward depression area was frequently inundated by high waters (both storm surges and spring tides). Of them, the Shanggulin—Qijiafu chenier—linear earthy mound shoreline emerged during the Warring States to West Han Dynasty and dead a thousand years later in the East Jin—North Wei Dynasties. During this period, seaward area was occupied by sea water and landward depressions were frequently influenced by high waters. On the other hand, the West Han ruin at the Chuanganglu site was directly buried by the marine layer. Both of them provided plausible geological evidence for the West Han Transgression existence on the west coast of Bohai Bay.