The Chuanlinggou Formation(ca 17 Ga)is characterized by dark shale and is widespread in the North China Platform， with a thickness up to 900 m. In this formation abundant centimeterscaled pygmatic sandveins are well developed. They have been interpreted as deriving from the sand filled fissures created by biogenic gas release. In the sandveins minor amounts of authigenic carbonate precipitation(ACP)and pyrites have been identified . The ACP is mainly of crypto-to microcrystalline dolomites， occurring either as horizontally continuous seams or as discrete spots， often accompanied with organicrich lamina. The ACP seams generally occur at the places where biofilms densely concentrated， and tend to extend along the biofilms. In contrast, the ACP spots prefer to exist in intergrain pores as cryptocrystalline cements or along the outer margins of sandveins as microcrystalline dolomites. These two types of ACP have been recognized both in the sandveins and host sediments. The associated  framboidal pyrites are more abundant in mud sediments. while rimmed pyrite crystals in the sandveins. Siderite crystals also exist in the sandveins. These minerals are often associated with ACP forming characteristic fabrics， along with the organicrich shale and well developed microbially induced sedimentary structures(MISS)， suggesting an anoxic environment for the Chuanlinggou deposition. Analyses of the morphology and rheology of the sandveins and their distribution in relation to the dark shale suggest that they were derived from the fissures created by gas release as passages and subsequently filled by stormtransported sands. The gas release origin is also supported by the existence of gas blisters(MISS)on sedimentary surfaces. The coexistence of ACP and authigenic pyrites and their preferential occurrence in the sandveins indicate that they resulted from the anaerobic oxidation of methane(AOM)and bacterial sulfate reduction(BSR)happened in a sulfatemethane transition zone(SMTZ)few centimeters below the sedimentary surface. The recognition of putative microbial fossils in the sandveins and the biomarkers indicative of archaea and sulfur bacteria from the dark shale may also provide evidence for AOM. Methane might derive from anaerobic degradation of buried organic matter， with part from the possible methanogenesis as well. The recognition of ACP and AOM in the Chuanlinggou Formation is of significant implications for the Mesoproterozoic plaeoclimate and paleoceanographic analyses. With a low seawater sulfate concentration and therefore a shallow SMTZ during the Mesoproterozoic ocean， the consumption of methane by AOM would be proportionally lower than that in the modern marine environments. As a result， the methane fluxed into the atmosphere would inevitably increase the relative importance of methane in maintaining the Mesoproterozoic greenhouse climate.

 A set of darkgray， grayishblack or black calcareous shale(bearing shell sometimes)occurred at the Upper Triassic Carnian—Norian Maantang Formation in the Longmen Mountains region， Sichuan Province. Numerous bivalves， primary divalent metal sulfides(pyrite)， thinintermediate layers and horizontal bedding observed in the shale indicated an anoxic lowenergy environment. The Late Carnian sediments mainly mudstone，shale  or silty slate， calcareous slate which are timeequvalent to this black shale，can be found in the east Paleotethys including Songpan—Ganzi Area， Changdu Area，and Hoh Xil Area. We considered that they reflected a black shale event which strongly influenced the marine sediments in the eastern Paleotethys of west China. The global correlation indicated that the dark color mudstone（shale）were widely distributed in western China， Indian Himalayas， Eastern Alps， and overlied on the Early Carnian carbonate rocks. Thus we proposed a Tethyswide black shale event， which caused the late Early Carnian global carbonate production crisis occurred， while the dark color mudstone(shale)developed in the middle part of the Maantang Formation is a reflection of this event along the western margin of the Yangtze Platform. Based on investigation and studies of the Upper Triassic sections in Hanwang， Jushui， and Maantang areas in northwestern Sichuan， it is concluded that the Carnian limestone(ie. oolid limestone， sponge reef limestone in the middlelower Maantang Formation)was deposited before the anoxic event， and the Norian gray siltstone and fine sandstone was laid down after the event. The black mudstone(shale)triggered by the event not only indicated the significant lithological change， but also was the turning point of sudden paleontological and paleoecological changes. Marine fossils such as hexactinellida， crinoid， bryozoa，and coral were abundant in the limestones of the lower Maantang Formation， but they suddenly disappeared in the black shales in the Maantang Formation. Shell fauna fossils such as rich bivalves， ammonoids，and brachiopods occurred in the middleupper Maantang Formation.

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Qinghai Province is located in the northern QinghaiTibet Plateau. Due to its special tectonic location， the geological structure and lithofacies palaeogeography are rather complicated. Its lithofacies palaeogeography has been studied for less than in other provinces. To some extent， this became a restricting factor of the exploration work. Based on the new data and research results of the coalbearing strata sections including regional geology， coal exploration and petroleum geology， the authors compiled the lithofacies palaeogeographic maps of Qinghai Province including the Carboniferous， Permian， and Triassic; and discussed the depositional environments. During the Carboniferous， the Qaidam and Qilian palaeolands existed in northern Qinghai Province. From north to south， the Jun UL， Qimantag， Anyemagen and Jinshajing troughs were developed. The Jun UL and Qimantag troughs expanded. The Anyemagen restricted ocean basin， Xijir Ulan restricted ocean basin and Jinshajiang restricted basin were formed. This study provided a foundation for further compilation of lithofacies palaeogeographic maps of the main coal formation periods in Qinghai Province， and has an important practical significance in predicting the areas favorable for coal formation.

The Permian of Daxiakou section at Xingshan County， Hubei Province is composed of the Qixia， Maokou， Wujiaping and Changxing Formations， with a thickness of 43372 m. The rock types of this section are rather simple. There are limestones， dolostones， siliceous rocks and shales. Limestones can be further divided into bioclastic limestones， bioclasticsbearing limestones， microcrystallinefine crystalline limestones and eyeball shaped limestones. The eyeball shaped limestones were mainly developed in the lower part of the Qixia Formation and the middle to lower parts of Maokou Formation. They were formed by the interaction of sedimentation and diagenesis. The dolostones are dominated by calcitic dolostones that are distributed in patches . They were mainly developed in the upper part of Changxing Formation， and probably formed by burial dolomitization. Siliceous rocks are of nodule， lump and bandlike types， which were formed by metasomatism. According to the comprehensive analyses of lithology， palaeontology and sedimentary structures， four kinds of sedimentary environments were identified.They include shore zone， carbonate platform， basin margin and basin， and locally there was bank in the platform. Then the sedimentary environment evolution has been analyzed and the sedimentary model has been built. The sedimentary evolution indicates that two sedimentary cycles of transgression and regression occurred in the Permian. The first transgression began in the Early Qiaxia Age， ended in the Late Maokou Age. In the Early Wujiaping Age， the second transgression began  and lasted until the Late Changxing Age. The preliminary analyses show that the conditions of hydrocarbon source rocks and reservoir rocks of the Permian in the study area are rather favorable.

The Banghu SubSag is the depositional and subsidence center of the Qianjiang Formation in Qianjiang Sag. Origins of sandbodies along its two sides and their distribution have been a controversial topic. Their origins have been distinguished by core observation， hydrodynamic analyses and clastic zircon dating analysis. Further more， the relationship between palaeogeomorphology and sandbody distribution was identified. The research indicates that during the deposition of the Member 3 of the Qianjiang Formation,  two provenances—Jingmen and Hanshui were developed in the north，the BanghuWangchang SubSag was developed in the central area，a “Y” shaped low uplift and a slope was present in the west，a slope belt was developed in the east and expansive gypsumbearing mudstones of shoreshallow lacustrine origin were deposited in the south slope belt. New research results show that during the deposition of the Member 3 of Qianjiang Formation，the sandbodies along the south side of the Banghu SubSag were neither deposits of salt density fluid flowing through the Banghu SubSag， nor transported by traction， but transported and deposited along the ditchtrough or west slope by traction.

Central Laboratory of Geological Sciences，Research Institute of Petroleum Exploration and Development，PetroChina，Beijing100083
Five types of marine sandbodies were identified in the marine sandy mudstone deposits of the Tierekeawati Formation in northwestern Manjiaer Sag based on detailed analyses of 5 wells including Yangwu 2， Yuenan 2 and Jinan 1， combined with microfacies analyses of single well and interpretation of over 350 km seismic profiles. They are shoreline， inner shelf ridge， inner shelf ditchtrough， storm and tidal channel sandbodies. Ditchtrough sandbodies with transgressive conglomerate and flooding surface at the basal part were developed at the bottom part in Yangwu and Hade areas in the west of the study area which was characterized by normal rhythm. Above it， the inner shelf ridge sandbodies with normal and reverse rhythms and no development of flooding surface. The top part is dominated by shoreline sandbodies with development of paralleling bedding and cross bedding and a reverse rhythm. The storm sandbodies with a strong heterogeneity were developed on the uppermost. In Jinan well area in the east of the study area， inner shelf ridge sandbodies were developed in the lower part， tidal channel sandbodies and tidal deposits were developed in the upper part. The distribution range of sandbodies gradually expanded with the influence of global sea level falling during the Late Ordovician. The marine sandstone reservoir in the Tierekeawati Formation is dominated by secondary pores with a high heterogeneity due to the inhomogeneous cementation， dissolution， and locally developed fissures. Reservoirs are ranked by their properties from good to poor ones as: inner shelf ridge， shoreline， inner shelf ditchtrough， tidal channel and storm sandbodies.
Tarim Basin|Upper Ordovician|Tierekeawati Formation|marine sandbody|reservoir property
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Gao Zhiyong was born in 1974. Now he is an engineer of Research Institute of  Petroleum Exploration and Development，PetroChina and is mainly engaged in researches of sequence stratigraphy and sedimentology. E-mail:gzybox@163.com.

Based on the petrologic data of over 40 wells， the characteristics and main controlling factors of the Permian reservoirs in Wuxia area were systematically described. The Permian reservoir in this area is diverse， which mainly includes terrestrial clastic rocks， dolomite or dolomitic rocks， volcanic clastic rocks and volcanic rocks. The reservoir pore space is dominated by secondary pore， and the pore spaces of the clastic reservoir are mainly intergranular solution pore， dissolved pore of interstitial materials，and microfracture. The dolomite reservoir is dominated by fractures; volcanic clastic rock and volcanic reservoirs are dominated by gasreleasing pore. The reservoir  is characterized by  lowmedium porosity and permeability. Its pore texture types include small pore and fine throat， micro pore and tiny throat， and micro pore and mini throat. The reservoir is classified as poor to moderate categories of reservoirs and possess the lowmoderate porosity and permeability. The comprehensive evaluation showed that lithology and grain size， diagenesis and compaction， dissolution and fracturing are the main controlling factors of reservoir quality in this area. Of them， lithology and grain size are the main influencing factors for reservoir property， mechanical compaction is the main controlling factor of porosity reduction which may have caused 2365 percentage points of porosity loss. Dissolution， fracturing and faulting improved the reservoir property effectively. Comprehensively considering the reservoir property and the controlling factors， the reservoirs are divided into five categories， of which， type Ⅲ， Ⅳ， Ⅴare the main types in Wuxia area.

 In China， theories on secondary porosity of deep reservoirs need breakthrough urgently. The Qinan Sag， located in the Huanghua Depression， is an active hydrocarbon generation sag， and deve￣lops favorable reservoir sandbodies in the Paleogene Shahejie Formation， and has a significant exploration potential. Using thin sections，scanning electron microscope(SEM)，cathodoluminescence，Xdiffraction methods， integrated with measured reservoir properties and log interpretation, the authors summarized that distribution of secondary pores was different in different tectonic units. In the west slope， secondary pores were distributed in 3 belts: 1650～1800 m，2300～2600 m and 2880～2920 m. In the eastern Chengbei faulted belt， secondary pores were distributed in 2200～2800 m. In the central zone of the sag， secondary pores were distributed in 2900～3500 m. Lithic sandstone and arkosic arenite sandstone are the dominant rock types in the study area with low component and texture maturity which made the material basis for secondary pore development. Sedimentary environment also had some influence on reservoir quality. Lake shore zone and bar sandbodies possess thebest reservoir petrophysics. They are followed by main gravityflow channel sandbodies and channel of middle fan in subaqueous fan. The flankdistal sandbodies of gravityflow channel and middlebay in subaqueous fan constitute poor to fair reservoirs. The main mechanisms for secondary pore formation are as follows: ①The development of clay coating is favorable for development of secondary pore. ② The organic acid which formed during the process of organic material transforming into hydrocarbon and the acidic solution forned in resulting from the conversion of montmorillonite into illite could dissolve the feldspar and lithic grains. Asaresult, secondary pores could the develop. ③The activity of pore water entering into the sandbody reservoir influences the development of secondary pore. ④The dissolution dominated cementation during the hydrocarbon filling process and thus in the later period， secondary pores were developed. ⑤ Adjecent to fault and unconformity， a great deal of CO2 was dissolved in the atmospheric fresh water. Carbonate acids could be easily  to formed and they dissolved   feldspar grains when entering the reservoirs. As a result secondary pores were formed.

During the Phanerozoic， the mineralogies of nonskeletal marine cements and oolites oscillated between aragonite Mgrich calcite(aragonite sea)and Mgpoor calcite(calcite sea). Oscillations in the carbonate mineralogy of dominant reefbuilding and sediment producing organisms are in harmony with the oscillations for nonskeletal carbonates. These oscillations can be explained by secular variation in the Mg/Ca ratio of the seawater. Evidence from fluid inclusions， isotopes and trace elements also shows that very significant changes occurred in seawater chemistry. Though the relative importance of biologically induced biomineralization and biologically controlled biomineralization has been a topic of much controversy， evidence from the paleontological records and experiment shows that throughout the Phanerozoic the seawater chemical evolution  had significantly influenced biomineralization. Selection of aragonite versus calcite was largely dependent on seawater chemistry at the time of first appearance of carbonate skeletons in animals. Seawater Mg/Ca ratios controlled polymorph mineralogy of skeleton， which supplied a new proxy for calcitearagonite seas in the Precambrian， reconstruction of paleoclimate and paleoenvironment， isotope stratigraphy， carbonate sedimentation and diagenesis.
seawater chemistry|biomineralization|biomineral|aragonite sea|calcite sea
 Liu Xiting， born in 1983， is a master candidate of marine geology in China University of Geosciences(Wuhan)， and is engaged in carbonate sedimentology. E-mail:liu1999@126.com.

 The ancient civilization in different areas of the world has experienced decline in the course of their development， and the reasons have always been the focuses of attention. In recent decades， more attention has been paid to the influence of abrupt climate changes in ancient civilization declining due to the improvement of dating technology and the advances in researches of the Holocene climate change， the relatively more accurate declining time of ancient civilization. The current research progress of the relationships between climate change and ancient civilization declining， including the abrupt climate change， the Holocene climate change and the role of abrupt climate change in civilization declining，are introduced. The thorough understanding of such relationships will not only benefit to understanding of the reasons of ancient civilization declinig， but also provide useful references for humans adaptation to climate changes in the future.

 The Northern Five Lakes are a series of narrow lakes distributed along the Grand Canal west to the hilly area of central Shandong Province， from north to south namely as the Anshan， the Mata， the Nanwang， the Shushan and the Machang Lakes. In the past 100 years， the five lakes have become silted up gradually. Now the main bodies of all the five lakes have vanished， except the remains of the Anshan and Machang Lakes. The authors collected multisource geospatial data covering the study area， including the map made in 1907， the aerial photographs taken in 1954， MSS image acquired in 1975， TM images acquired in 1987 and 2001 respectively and the SPOT5 XS image acquired in 2005. After the preprocessing step was conducted such as the geometric and radiometric correction， image mosaicking， the spatial distribution of the Northern Five Lakes were extracted for each period by means of visual interpretation and classification of the multisource data. According to the spatial distribution feature of the Northern Five Lakes in each period， the dying out magnitude， dying out speed and the dying out timing of the lakes were analyzed.