China University of Petroleum（Beijing），Beijing100083
Palaeogeography is a science to study the physical geographical characteristics and their evolution in the geological history and human history. Palaeogeography of China mainly originates from the stratigraphy， historical geology， tectonics， palaeontology， sedimentary petrology， physical geography， Quaternary geology， human historical geography， etc〖DK〗. As a result， some branch subjects， such as stratigraphic palaeogeography， tectonopalaeogeography， biopalaeogeography， lithofacies palaeogeography or sedimentary palaeogeography， physical geographic palaeogeography， Quaternary palaeogeography， human historical palaeogeography,etc〖DK〗.〖KG-*5〗， have all come into being. There are three main characteristics about palaeogeography of China. Firstly， all the branch subjects have been developing， ie〖DK〗.〖KG-*5〗， all the branch subjects have come to a mature period， and shown a good situation of a hundred flowers blossom. Secondly， one of these branch subjects is very distinguished from other branch subjects for its significant achievements， ie〖DK〗.〖KG-*5〗， lithofacies palaeogeography has reached a quantitative stage， and has developed into the quantitative palaeogeography， and has already been in the leading position among all the branch subjects. Thirdly， palaeogeography is a guide to mineral resources exploration， ie〖DK〗.〖KG-*5〗， palaeogeography of China， especially the lithofacies palaeogeography and quantitative lithofacies palaeogeography have actively and effectively worked for the prediction and exploration of all kinds of mineral resources， especially for the petroleum resources， and have made great contribution to them. This is the important reason why palaeogeography of China has grown and flourished. Palaeogeography of China has two bright spots， namely as the academic conference of palaeogeography and the Journal of Palaeogeography. The academic conference of palaeogeography has been held for ten times， and is more and more successful than ever. The Journal of Palaeogeography has been started publication for ten years， and have been one of the advanced journals of science and technology in China. This coexistance of  “one conference and one journal”  has greatly improved the development and innovation of palaeogeography of China.  
 palaeogeography， branch subjects of palaeogeography， quantitative lithofacies palaeogeography， guide to mineral resources exploration， academic conference of palaeogeography， Journal of Palaeogeography

The Lower Silurian is divided into the Longmaxi， Dazhongba and Ziyang Stages. The sedimentation is continuous within these stages in northern Guizhou Province. The central and southeastern Guizhou Province， however， was uplifted and became a land during the Longmaxi Age and early Dazhongba Age in Early Silurian， which resulted in a stratigraphic gap. The fall of sea level made the LowerMiddle Ordovician experienced exposure and a karst landform was formed. With the line from Yuqing to Huangping， the uplifting area is divided into two parts: northern area and southern area. In the southern area， the Wengxiang Formation(or the Gaozhaitian Formation)of the Ziyang Stage unconformably overlaps on the exposed surface from south to north. Bay and lagoon calcareous sandmudstone deposits were dominant in the KailiDuyun region， while in the Guiyang region open shoreshallow marine deposits were developed. During this transgression in the Early Silurian， the underlying karst and weathered crust were reworked. The wavereworked calcirudite and transgressionfilled limestonebearing gravely clastics were deposited， neither of which belonged to the basal conglomerate.
 

Analyses of the carbonate platform have been carried out based on the achievements of previous researchers， combining with the authors studies of the carbonate platforms in the Tarim Basin and Sichuan Basin. The carbonate platform is divided into the following types according to geographical position， slope gradient， sealability of platform margin and rimming feature of platform， namely as: the gentle slope and open platform without rims， the gentle slope and restricted platform without rims， the steep slope and open platform without rims， the steep slope and restricted platform without rims， the gentle slope and open platform with rims， the gentle slope and restricted platform with rims， the steep slope and open platform with rims， the steep slope and restricted platform with rims， the reefbank isolated platform and the buildup isolated platform. The sedimentary characteristics of different types of platforms were investigated and their sedimentary models were established which can guide the hydrocarbon exploration of carbonate rocks. Finally， the main factors controlling the formation and development of carbonate platforms are discussed. The reseaarch indicates that paleotopography formed by tectonic movement and the water flow energy control the types of the platform and sediments and the sea level changes control the types of platform and the changes of sediments.

xygendeficient environment is an important condition for formation and preservation of marine source rocks. The study of paleoxygenation facies is significant for tracing spatialtemporal distribution of highquality marine source rocks and interpreting the evolution of depositional environments. During the Devonian， carbonate platform(nearshore and isolated platforms)and inner platform taphrogenic trough resulting from intracontinental rifting were simultaneously developed in the southern South China Sea. The Devonian paleoxygenation facies types are controlled by seawater layering in platform troughs and the QinzhouFangcheng taphrogenic trough， where quasianaerobic and anaerobic facies were dominant. The paleoxygenation facies is controlled by sealevel changes in platform in which developed aerobic and dysaerobic facies. Siliceous， phosphorus and organic carbonrich deposits of the Devonian indicate the upwelling flows influence. The southern South China Sea was located in the tradewind zone near the equator in the Devonian. Westward surface ocean current passed over the southern South China Sea and formed offshore currents. Eastward bottom current compensated toward shore and formed the upwelling flow. The Devonian upwelling flow led to the formation of an oxygendeficient environment in the southern South China Sea.

here are many silty dykes in peritidal silty muddy shales of the lower part of the Paleoproterozoic Chuanlinggou Formation at Jixian section in Tianjin. Particular configurations on bedding planes and on the surface perpendicular to the bedding planes lead to different explanations for the genesis of these silty dykes:(1)they are considered as the oldest trace fossils of metazoan according to the spindlecrack of siltstones on the bedding plane and the sandfilling tube configurations on the surface perpendicular to the bedding plane;(2)they are considered as the liquefied sandveins induced by earthquake according to the sinuous configuration of siltstone dykes on the surface perpendicular to the bedding plane and the obvious liquation feature. Several features indicate that these silty dykes were generated by the degassing and dewatering processes in the early diagenesis under the condition that the sedimentary surface was sealed by microbial mats， and can further be grouped into the microbial induced sedimentary structure(MISS). These features include:(1)the clear boundary being enriched with residue organic substance and the obvious fluidization feature shown by the relative accumulation of silty grains under the petrographic microscope;(2)the accompanied wrinkle structure and the palimpsest ripples which indicate the development of microbial mats on the sedimentary surface. 

A great quantity of stormrelated sedimentary structures， such as gutter cast， storm domal bodies， wavy erosion surface， lumachelle， graded bedding and wave ripple， were discovered in the Silurian Xiaoheba Formation in Jiangping area， northwestern Hunan Province. Three sequences with different vertical stacking patterns were deposited in the formation， whose vertical thickness is less than 5〖CS％0，0，0，0〗〖CS〗m. Sequence Ⅰ is the storm domal bodies with wavy erosion surfaces. Sequence Ⅱ is the graded bedding and massive bedding interval with gutter cast. Sequence Ⅲ is the graded bedding and horizontal bedding interval with wavy erosion surfaces. All the storm deposits are in situ or of proximal deposition. The occurrence of storm deposits indicates  that during deposition of the Early Silurian Xiaoheba Formation， the palaeogeographic environment of northwestern Hunan Province was characterized by  a shoreface setting with a relatively lower water depth.

Analyses have been carried out on the lacustrine setting of the Wudaoliang Formation in the Tuotuohe Basin of QinghaiTibet Plateau. The study focuses on information of  climate changes reflected by the sedimentary stratigraphic records and investigates the palaeoenvironmemt changes in the plateau in the Miocene. Rock types and sedimentary characteristics of the Wudaoliang Formation were analyzed and flood plain， shallow lacustrine， shore lacustrine and salt lake sedimentary facies were recognized. With reference to the present lacustrine features and the study examples of ancient lakes， the sedimentary origins of the lacustrine carbonates in the study area were discussed. The facies markers in the section and the stratigraphic stacking patterns indicate that the palaeolake experienced three cycles of low lake level to high lake level changes during the deposition of the Wudaoliang Formation. The minimum lake level is marked by the occurrence of the gypsum interval， while the high lake level period is characterized by the deposition of flooding mudstones. The results indicate that the depositional setting of the Wudaoliang Formation was dominated by a drywet climate alternation， lake level change and the fluctuation is mainly influenced by climate with structural subsidence and fault block uplifting as the secondary controlling factors.
 QinghaiTibet Plateau， Wudaoliang Formation， sedimentary facies， palaeoevironment

Trilobite evidence indicates that all the plates and most of the terranes in China exhibit a close biogeographic link and may have formed part of the eastern PeriGondwana during the Ordovician， except for the Altay Terrane of the Northern Xinjiang Autonomous Region and the ErgenHinggan Terrane of the Hinggan Region， where trilobite faunas show a strong affinity with those of Siberia and Laurentia. Synthetic analyses based largely on the platform/inner shelf trilobite faunas suggest that the Chinese eastern PeriGondwanan plates and terranes may have belonged to a single biogeographic province during the Tremadocian(Tremadoc)and the late KatianHirnantian(Ashgill)， but may be divided into two subprovinces during the Floianearly Katian(ArenigCaradoc): One consists of South China， Tarim and Annamia， and the other may include North China， Sibumasu， southern Tibet， TianshanBeishan and possibly Hainan. However， the deepwater facies trilobites of the relevant Chinese biogeographic units had progressively become more unified from the middle Darriwilian to the early Katian(Llanvirn to Caradoc)before the subprovinces eventually broke down by the late Katian(Ashgill). Therefore，the exchange of genus and species between deepwater facies animal assemblages and the onset， development and complishment of the process were obviously prior to those of the trilobites in shallow water.

Correlation analyses have been conducted between pollen assemblages of Tauber traps and surface soil samples in the steppe area of northern China. The results indicate that the pollen assemblages from these two sampling methods have a good similarity， ie. arbors content is lower than 10％〖KG-*5〗， shrub content lower than 5％ and herbs content higher than 75％. The pollen types held by all assemblages constitute 743％ of the total amount. Artemisia and Chenopodiaceae are the main components of pollen assemblages. Ephedra and Nitraia usually occur in the desert steppe areas， while Stellera and Cyperaceae pollens dominate the typical steppe areas. The DCCA analyses show that pollen assemblages have the most obvious relationship with the severe cold month temperature and a more obvious relationship with the annual precipitation. The pollen components of Tauber traps are different from those of the surface soil samples. The former has more pollen types than the latter; the pollen content of Artemisia and Chenopodiaceae is lower than 70％〖KG-*5〗， while the latter higher than 70％. The pollen content of the desert steppe areas is lower than that of the typical steppe areas， which indicates vegetations are well developed in the typical steppe areas and their pollen production higher than the desert steppe areas， the pollen density of the surface soil samples in typical steppe area is obviously higher than in desert steppe areas which is due to the well developed vegetation and higher pollen production of the desert steppe area， and the poor preservation of the pollens in the desert steppe area. The Tauber traps samples and surface soil samples both can distinguish desert steppe area from typical steppe area， while cross experiment results of Tauber traps sample are better than surface soil samples.

With the knowledge of the Devonian sediment distribution and the Devonian plant localities in China， we compiled the palaeogeographic maps of the Early， Middle and Late Devonian plant distribution in China. According to these maps, we may find that the plants in the Early Devonian were distributed in Yunnan， Guangxi， and Hunan in southwest China and migrated to the middle reaches of the Yangtze River in the Middle Devonian and to the lower reaches of the Yangtze River in the Late Devonian. In North China， the Early Devonian plants were not recorded， but the Middle Devonian plants were found in northern Xinjinag. The plants migrated to the Qilian Moutains and some areas in Ningxia in the Late Devonian. The percentage of every kind of plants in the three ages of Devonian was calculated. The plants of zosterophyllophytes were the dominant types in the Early Devonian floras， associating with rhyniophytes and prelycopods. The lycopods became the dominant plants in the Middle Devonian floras. In the Late Devonian， lycopods still dominated， and sphenphytes， ferns and pteridosperms developed quickly. 