Welcome to Journal of Palaeogeography

	· 《Petroleum Science》
	· Periodical Press of CUP
	· China University of Petroleum (Beijing)
	· 《Journal of China University of Petroleum(Edition of Natural Science)》
	· 《ACTA PETROLOGICA SINICA》
	· 《Geology in China》
	· 《China Geology》
	· 《ACTA GEOCHIMICA》
	· 《geochimica》
	· 《GEOTECTONICA ET METALLOGENIA》
	· China Geoscience Journal Portal
	· 《Bulletin of Mineralogy, Petrology and Geochemistry》

	JOPC 2020 Vol.22 Number 6
	2020, Vol.22 Num.6
	Online: 2020-12-01

	PALAEOGEOGRAPHY AND MINERAL RESOURCES LITHOFACIES PALAEOGEOGRAPHY AND SEDIMENTOLOGY BIOPALAEOGEOGRAPHY AND PALAEOECOLOGY GEOCHEMISTRY AND SEDIMENTARY ENVIRONMENTS PAST AND PRESENT GEOGRAPHIC ENVIRONMENTS AND HUMAN CIVILIZATION

PALAEOGEOGRAPHY AND MINERAL RESOURCES

	1021	Luo Jing-Lan, Li Chi, Lei Chuan, Cao Jiang-Jun, Song Kun-Peng

		Discussion on research advances and hot issues in diagenesis of clastic-rock reservoirs
		The research on diagenesis of clastic-rock reservoir is developing rapidly in recent ten years. Thus, it is of great significance in academic and scientific exploration to summarize the domestic and international research progress and the key issues of frontier research on diagenesis. The research progress, main achievement and recognition in diagenesis of clastic-rock reservoirs in recent years is discussed, and the hot issues or developing trend of diagenesis in the future is probed in this paper, on the basis of summarizing the previous research results and understanding, combined with the typical research examples at home and abroad. It is believed that great progress was obtained in provenance and parent rock constraints on sandstone types and their diagenetic evolution pathways, impact of fluid-rock interaction and its product on diagenesis, influence of thermodynamics and overpressure background on diagenesis and pore development, the timing sequence between hydrocarbon accumulation and filling process and the sandstone reservoir becoming low permeability-densification. At present, diagenetic research is developing in direction of the spatial and temporal dynamics and quantitative evolution mechanistic and diagenetic system controlled by the basin fluid dynamics, thermal dynamic processes, combining the micro-scale diagenesis research with the basin macroscopic background such as sedimentation from the source to the basin, burial history, hydrocarbon maturity and charge into reservoirs, tectonic evolution and fluid activity, and fluid and rock interaction.The aim of this paper is to induce the academic peers and experts in diagenesis and the related research fields to come forward with their valuable contributions, to cooperate and work together and joint efforts on the research exquisite, profundity and breadth of diagenesis, and application of the most advanced analytical measurement techniques and methods, as well as integration and infiltration of multidisciplinary, in order to promote the course of the clastic-rock reservoir diagenetic research in China.
		2020 Vol. 22 (6): 1021-1040 [Abstract] ( 700 ) [HTML 1KB] [PDF 7892KB] ( 421 )

	1041	Lei Han, Huang Wen-Hui, Yi Shuo, Wang Ya-Ting

		Dissolution characteristics of deep?buried dolostone in the Member 5 of Ordovician Majiagou Formation in southern Ordos Basin
		The different types of deep-buried dissolution process in the Member 5 of Ordovician Majiagou Formation in the southern Ordos Basin and its influence on the reservoir properties are studied in this paper. It shows that three types of mechanisms include organic acid fluid, hydrothermal fluid and TSR are identified through studies of core observation, thin section analysis, inclusion temperature, trace elements and rare earth elements. It is found that the dissolution of organic acid fluid causes the stratified dissolution pores, film-like asphaltene and ring-like asphaltene, while hydrothermal fluid causes the non-selective dissolution pores without petrofabric, veins of pyrites, massive pyrites and the association of hypothermal minerals. Four occurrence models of dissolution include, (1) the deep-buried dissolution of low-temperature hydrothermal fluid occurs in Zhiluo Period of Middle Jurassic; (2) the deep-buried dissolution of organic acid fluid started from the late Middle Jurassic followed by the first hydrocarbon injection; (3) the deep-buried dissolution of middle-high temperature hydrothermal fluid occurred in the Dongsheng Period of Early Cretaceous; (4) TSR occurred at the end of Early Cretaceous with the second larger hydrocarbon injection. Both organic acid fluid and hydrothermal fluid can improve the porosity and permeability of reservoir, but the hydrothermal fluid is more effective than that of organic acid fluid.
		2020 Vol. 22 (6): 1041-1054 [Abstract] ( 551 ) [HTML 1KB] [PDF 3058KB] ( 286 )

	1053	Sang Lin?Xiang, Liu Jun, Wang Gui?Wen, Wang Su?Tian, Li Quan, Zhang Yun?Long

		High￣quality reservoirs prediction of fan delta in the Triassic Baikouquan Formation in west slope of Mahu sag,Junggar Basin
		High?quality reservoirs prediction of fan delta in the Triassic Baikouquan Formation in west slope of Mahu sag,Junggar Basin. Because of the physical properties of fan delta sandstone of Baikouquan Formation in Fengnan area of west slope of Mahu sag vary greatly in space,it is difficult to predict high?quality reservoirs. In this study,under the guidance of sedimentary petrology,seismic inversion and interpretation theory,high?resolution sequence stratigraphy,sedimentary microfacies description and high?quality reservoir seismic inversion are carried out by comprehensive utilization of well logging,core and 3D seismic data. The fourth?order sequence stratigraphic framework of Fengnan area was established,and the filling process of multi?stage transgression and regression in fan delta was identified. The result indicates that the SSQ3 and SSQ5 are the favorable sequences for high?quality reservoirs development. Sedimentary microfacies including distributary channel and inter?channel bay in fan delta plain,subaqueous distributary channel,mouth bar and sheet sand in fan delta front were identified. It was pointed out that fan delta plain is an optimum reservoir facies belt.The reservoir facies?controlled impedance inversion of separated layers in PSTM was carried out by applying the constraints of vertical boundary of high?resolution sequence stratigraphy and lateral boundary of sedimentary facies to improve reservoir prediction accuracy. Five high?quality reservoir development areas are predicted in the sequence of SSQ3 and SSQ5,and three wells were proposed for drill,which was later proven to have industrial oil flow during drilling.
		2020 Vol. 22 (6): 1053-1064 [Abstract] ( 603 ) [HTML 1KB] [PDF 12636KB] ( 268 )

LITHOFACIES PALAEOGEOGRAPHY AND SEDIMENTOLOGY

	1065	Li Xiang-Dong

		Advances in genetic mechanism research on hummocky and hummocky-like cross-stratifications
		Hummocky and hummocky-like cross-stratification(HCS and HCS-like)as the identification criteria for sedimentary environments have recently become confused because of the little knowledge on their genetic mechanism based on the following facts: HCS and HCS-like are often associated with storm deposits and turbidity current deposits,respectively; the views on HCS produced in shallow water environments and HCS-like produced in deep-water environments have been abandoned recently. According to the detail reviews on structural and morphologic characteristics and vertical sequence of HCS and HCS-like from literatures,here we found that: (1) the special features of HCS include the sharp or erosional basal contact,the internal truncation surface,close relationship with swaley cross-stratification,and the missing zone or amalgamation of HCS in vertical sequence;(2) the special features of HCS-like often include various thickness of individual lamina,hummocky layer interbedded with parallel bedding or small-scale cross-bedding under continuous deposition,and alternating sedimentary structures of upper and lower flow regime in vertical sequence. According to hydrodynamic theory and flume experiment achievements,these results show that the genetic mechanism of HCS and HCS-like could be divided into two parts,hydrodynamic mechanism and depositional mechanism. The hydrodynamic mechanism of HCS and HCS-like is same and could be interpreted by vertical vortex generated by baroclinic wave in nature. However,depositional mechanism of HCS and HCS-like is very different: HCS and HCS-like could be interpreted by erosion suspending sand mechanism and suspending sand settling mechanism,respectively,and the special features in HCS and HCS-like are due to the different sediment suspension concentration and depositional flow energy. The division for hydrodynamic and depositional mechanism of HCS and HCS-like is very significant in determining sedimentary environments from depositional flow evolution perspective.
		2020 Vol. 22 (6): 1065-1080 [Abstract] ( 582 ) [HTML 1KB] [PDF 1349KB] ( 534 )

	1081	Zhu Yi-Jie, Xia Rui, Zheng Yun-Ke, Liu Chen-Hu, Yu Bin, Lü Jun-Ling, Feng Wen-Jie

		Architectures and evolution of arid alluvial fans: Insights from a flume experiment
		Using time-lapse cameras and a 3D laser scanner,74 groups of geomorphic data of alluvial fans were obtained through flume experiments. Then a detailed sedimentary analysis based on these data was performed by using a quantitative software to reveal the sedimentary evolution process of the arid alluvial fan and its depositional architecture. Results suggest that there are obvious differences in hydrodynamics,water flow patterns and growth pattern during the evolution of arid alluvial fans. Based on these differences,the experiment is divided into three stages,including an early,middle,and late stage. In the early stage,the fan surface hydrodynamics was relatively strong,and the sheet flow dominated the deposition. According to the distribution of sheet flow deposits,it can be divided into wide-spread sheet flow deposition and local sheet flow deposition. In the middle period of the experiment,the hydrodynamic strength and expansion rate at the middle-distal part of the fan body reduced. The non-confined channel which is close to the source dominated the deposition,and terminal lobe was mainly deposited on the edge of the river channel. In the late stage of the experiment,the hydrodynamic further reduced causing by the large fan surface and confined channels were the main deposits. Through the flume experiment,an arid alluvial fan depositional architecture model with a three-layer structure has been established. The bottom layer is of a sheet flow lobe complex,the middle layer is characterized by unconfined channels and terminal lobes,and the top layer is constituted by stacked confined channels and small terminal lobes.
		2020 Vol. 22 (6): 1081-1094 [Abstract] ( 590 ) [HTML 1KB] [PDF 5709KB] ( 341 )

	1095	Wei Si-Yuan, Liu Zhong-Bao, Wu Sheng-He, Wang Xi-Tong

		Simulation experiment of sedimentary process and sedimentary architecture of alluvial fan under the control of normal faults
		Normal fault structures are widely developed in basins and orogenic belts,which control the accommodation space and the distribution of sediments and thus affecting the morphology of alluvial fans. A flume tank experiment was carried to simulate and clarify the control of normal faults on the sedimentary process and internal architecture of alluvial fans.The results show that the large amount of sediments carried by debris flow tend to be unloaded near the hanging wall of faults and are subsequently reworked by traction current,which result in a triangular distributary gravel bar grows vertically on fault plane with the tip pointing to the source area. When the hydrodynamic force is strong,debris flow goes across distributary gravel bar and forms over-bar lobe at the tail of the distributary gravel bar. When the hydrodynamic force is weak,debris flow forms fault plane-dominated lobe along fault plane and is located on both sides of the distributary gravel bar. Under the control of normal faults and the barrier of distributary gravel bar,the unloading process of sediments varies greatly at different positions on the surface of alluvial fan. The particle size varies greatly among different facies,with coarsest grains developed on the fans of hanging wall,finer grained on over-bar lobe and finest sediments on fault plane-dominated lobe. The development process of alluvial fan can be divided into three stages,according to the sandbody thickness and fault throw of distributary gravel bar. The fault throw also affects the sedimentary architecture of alluvial fan,with larger the fault throw generating larger the accommodation space of hanging wall,longer development time of distributary gravel bar and more complex of the superposition pattern of the sand bodies inside the fan. The internal architecture of alluvial fan that is controlled by normal faults includes longitudinal sandbar,distributary gravel bar and debris flow lobe in the profile vertical perpendicular to the sediment source direction from the proximal to the distal end. Along sediment longitudinal section,composite channel,superimposed distributary gravel bar complex and superimposed bodies of multi-phased lobes are dominant facies.
		2020 Vol. 22 (6): 1095-1108 [Abstract] ( 559 ) [HTML 1KB] [PDF 8801KB] ( 490 )

	1109	Hu Sheng, Tan Xiu-Cheng, Luo Bing, Zhang Ben-Jian, Zhang Ya, Su Cheng-Peng, Lu Fei-Fan, Li Ming-Long

		Sequence stratigraphic characteristics and geological significance of the Permian Qixia Stage in northwestern Sichuan Basin
		Based on outcrops, drilling, cores, and logging data, the Liangshan Formation and Qixia Formation in the northwestern Sichuan region are analyzed using the theory and method of sequence stratigraphy. Three third-order sequence boundaries are identified, including the basal boundary of Liangshan Formation (type Ⅰ), the boundary between Qi 1 Member and Qi 2 Member (type Ⅱ), and the boundary between the Qixia Formation and the Maokou Formation (type Ⅰ). The Middle Permian Qixia Stage can be subdivided into two third-order sequences (from base to top: SQ1 and SQ2). The SQ1 sequence corresponds to the Liangshan Formation and the Qi 1 Member, and the SQ2 sequence corresponds to the Qi 2 Member. Based on the sequence stratigraphic framework reconstruction of the Qixia Stage, the sedimentary filling pattern of the “onlapping at the base and truncation at the top” is discovered. The contour maps of SQ1 and SQ2 sequence stratigraphic thickness are calculated and plotted. Combined with the stratigraphic filling pattern, the tectonic-palaeogeographical framework of the early SQ1 and SQ2 phases of the Qixia Stage, their geological significance is discussed. At the Qixia Stage, the differentiation between uplift and depression occurs in the northwest and northeast trends. The Hannan uplift, the northern Sichuan uplift, the northern margin uplift and the Guangyuan-Wangcang sag have controlled the sedimentary pattern in the study area. It is indicated that prototype of the Guangyuan-Wangcang Trough began in the Middle Permian Qixia Stage. In the study area, the karst cave-type dolostone reservoir and the karst-type limestone reservoir around the Guangyuan-Wangcang sag rim are favorable exploration areas.
		2020 Vol. 22 (6): 1109-1126 [Abstract] ( 577 ) [HTML 1KB] [PDF 8228KB] ( 538 )

	1127	Cheng Yi-Fan, Dong Yan-Lei, Zhu Xiao-Min, Yang Dao-Qing, Wu Wei, Yang Ke, Su Bin, Zhao Rui-Xing, Qiao Chen-Kai

		Cretaceous paleogeomorphology restoration and its controlling mechanism on sand-bodies in Chunguang exploration area, Junggar Basin
		Paleogeomorphology restoration is one of the significant methods of sedimentary study. The distribution of drilling wells in the Chunguang exploration area,Junggar Basin is uneven,which make it hard to evaluate the reservoir potential of the Cretaceous strata effectively in depression zone. Based on 3D seismic data,well logs and core observation,this paper restores the paleogeomorphology precisely by establishing sequence stratigraphy in study area,strata decompaction correction and restoration of denudation and paleo-water depth. The paleogeomorphology restoration of each Cretaceous sand group has recognized several kinds of geomorphologic cells,such as incised valleys,slope break belt and bulges. The restored results show that the sedimentary basin in the Cretaceous experienced the process of expansion,shrink and filled up,and the sedimentary system has great inheritance. Accurate paleogeomorphology restoration can reveal the sedimentary process of basin,which can improve the prediction of reservoir and the division of microfacies and has great significances for the study of sedimentary characteristics of the Cretaceous strata. Then we analyze the geomorphologic cells, control on sand-body distribution and sedimentary facies,and we think that the features of paleogeomorphology have obviously controlled the sand-bodies,e.g., the bulge can separate sand-bodies,the slope break belt has controls on sand-bodies, thickness variations and origin types and the incised valley serves as transport conduits for sand. Finally,we make detail descriptions of valley systems,summarize the patterns of valley systems(V-U-W)and analyze the sediment transport ability of each type of valley system.
		2020 Vol. 22 (6): 1127-1142 [Abstract] ( 498 ) [HTML 1KB] [PDF 17984KB] ( 433 )

	1143	Xing Zuo-Chang, Zhang Zhong-Tao, Lin Chang-Song, Zhang Bo, Hong Fang-Hao, Gong Yue

		Sedimentary types and features of gravity flow depositional systems from Late Oligocene to Early Miocene in Liwan sag, Pearl River Mouth Basin
		The sedimentary characteristics of gravity flow depositional systems(GFDS)in Liwan sag,Pearl River Mouth Basin,has not been clear. Based on a large number of high-revolution seismic data and a small amount of borehole data,the sedimentary types,spatial-temporal evolution,and controlling factors of the gravity flow depositional systems in Zhuhai Formation and the basal Zhujiang Formation in the Liwan sag are summarized. Four sedimentary types of the GFDS,can be identified according to the different seismic facies associations. Pordelta turbidite fan,the first type,is relatively small-scale compared with other type,but formed at the same time with the shelf edge delta,which is likely to be sand rich. Mass transport complex deposition,the second type,is featured by fault scarps,multiple small detachment faults,internal deformation structures such as sliding and compression,and overall southeast movement. The channelized slope fan,the third type,with lots of small channels on the head,contains microfacies such as turbidite channel,channel-levee complex and crevasse splay. The basin floor fan,the fourth type,is a bidirectionally down-lapped,mound-shaped and strong amplitude continuous intermediate-frequency reflection seismic facie association,and its microfacies such as incised valley,channel filling,front crevasse fan and sheet like lobe can be recognized. It is believed that the coupling of tectonics,climate,sea level change and sediment supply results in the GFDS in the study area and different types of GFDS are formed at different period during the base level cycle change. This research can provide a reference for the summary of gravity flow depositional law and hydrocarbon exploration in the ultra-deep water area.
		2020 Vol. 22 (6): 1143-1156 [Abstract] ( 665 ) [HTML 1KB] [PDF 7910KB] ( 237 )

BIOPALAEOGEOGRAPHY AND PALAEOECOLOGY

	1157	Zhang Hong-An, Wang Chang-Zheng, Jiang Fei-Hu, Jin Ya-Qin, Hu Bin

		Gravity flow deposits associating with ichnoassemblages within the middle Member 3 of Paleogene Shahejie Formation in Dongpu sag, Henan Province
		Based on the observation and analyses of 97 exploratory well cores in Dongpu sag,four types of gravity flow(including sliding,slumping,debris flow and turbidity current)deposits in lacustrine facies have been recognized within the middle Member 3 of the Paleogene Shahejie Formation. Their main identification marks are outlined as follows: (1)the sliding deposits are characterized by the partial preservation of primary sedimentary structures,the development of small penecontemporaneous fracture or fault in sandstone beds,and steep dip of strata,with Skolithos-Palaeophycus ichnoassemblage and/or Planolites-Taenidium ichnoassemblage,which commonly occurred in the shore and shallow lake environments. (2)General characteristics of slumping deposits mainly are the abrupt contact between sandstone beds(top and bottom)and dark mudstone beds,and development of all kinds of penecontemporaneous soft-sediment deformation structures such as convolution bedding,flame structure,water-escape structure,liquefied vein and tearing debris. (3)The sandy debris flow deposits are mainly marked by the massive sandstone,abrupt contact between sandstone beds(top and bottom)and dark mudstone beds,as well as developing floating gravels near the top of sandstone beds and tearing mudstone debris in the bottom of sandstone beds,sometimes with occurring the mud-coated intraclasts. Meanwhile,slumping and sandy debris flow deposits commonly associated with the Mermoides-Parapaleodictyon ichnoassemblage produced in semi-deep water lake environment. (4)The turbidity deposit is mainly indicated by the complete or incomplete Bouma sequences,normal-graded bedding,and all kinds of sole marks such as scour marks,irregular flute casts and load casts,and the Semirotundichnus-Puyangichnus ichnoassemblage frequently occurred in the middle to upper parts of the turbidite beds that formed in deep-water lake environment. After comprehensive analyses of above four types of gravity flow deposits and water-depth variation reflected by different ichnoassemblages,it can be considered that ichnoassemblage changes appear a zonation with the depth of the lake,which is consistent with variations in gravity flow deposits from sliding-slumping-debris flows to turbidity currents,and the bioturbation generated with gravity flow deposits is enhanced. Therefore,the research of bioturbation structures(ichnofossils)is not only of great significance to study the physical property of sandstone reservoir in lacustrine deposits,but also to provide important ichnological information for discerning various types of gravity flow deposits.
		2020 Vol. 22 (6): 1157-1170 [Abstract] ( 560 ) [HTML 1KB] [PDF 8416KB] ( 224 )

	1171	Dang Zhi-Ying, Zhang Li-Jun

		Palaeoenvironmental evolution of the Upper Permian Maomaolong Formation in Gannan area of the West Qinling: Based on ichnonetwork analysis
		The continuous Permian-Triassic strata in West Qinling represent deep-marine deposits. In this paper,abundant trace fossils(seventeen ichnospecies,twelve ichnogenera)have been identified in the Upper Permian Maomaolong Formation in the Gannan area of the western Qinling orogen. As a new ichnologic method,ichnonetwork analysis focuses on the reconstruction of the community system composed of interconnected ichnotaxa,which provides useful means for studying the behavior and ecology of ichnocoenosis. In this study,an ichnonetwork analysis is conducted with trace fossils data obtained from the first hand filed trip. The results show that ichnocoenosisis structured in the Maomaolong Formaiton,and three ichnoassociations were controlled by palaeoenvironments: Palaeophycus-Lockeia-Arenicolites-Dictyodora-Planolites-Protovirgularia-Chondrites (C1,proximal turbidite zone),Palaeophycus-Lockeia-Arenicolites-Dictyodora-Protovirgularia-Phycodes-Chondrites-Helminthopsis (C2,turbidite transition zone-distal turbidite zone),and Palaeophycus-Nereites-Scolicia-Protovirgularia-Helminthopsis (C3,distal turbidite zone). The evolution from C1 to C3 in the Upper Permian Maomaolong Formation from the Gannan area of the West Qinling reveals the palaeoenvironmental changes from proximal turbidite zone to distal turbidite zone.
		2020 Vol. 22 (6): 1171-1180 [Abstract] ( 479 ) [HTML 1KB] [PDF 8327KB] ( 230 )

GEOCHEMISTRY AND SEDIMENTARY ENVIRONMENTS

	1181	Sun Long-Fei, Tang Dong-Jie, Zhou Li-Min, Fang Hao, Wu Meng-Ting, Guo Hua, Zhou Xi-Qiang, Zou Jia-Nan, Shi Xiao-Ying

		A pulsed oxygenation in shallow seawater recorded by the Mesoproterozoic Wumishan Formation,North China Platform
		Oxygen is crucial for the origin and early evolution of eukaryotes. However,the oxygen levels in the atmosphere and shallow ocean of Mesoproterozoic have been poorly constrained,with varying viewpoints including persistent low(equals to <0.1%~1% of the present atmosphere level,PAL),relatively high(>4%~8% of PAL),and dynamic variation. In order to further constrain the redox conditions in shallow waters where eukaryotes inhabited,the Ce anomaly of the peritidal carbonates from lower Member 4 of the Mesoproterozoic Wumishan Formation in North China was investigated. The results show that the significant negative Ce anomalies(Ce/Ce^*=0.82±0.11,n=10)occurs in the carbonate of the lower Member 4 of the Wumishan Formation with the thickness of about 150 m. The carbonate formation with the significant negative Ce anomaly is interlayered between the carbonates with inconspicuous positive Ce anomalies,which may represent a pulsed oxygenation in shallow seawater with a duration of ~5 Ma(~1480-1475 Ma). It reflects that the redox conditions of Mesoproterozoic shallow seawater fluctuated greatly rather than stable at low or relatively high level of oxygen. The results are helpful to determine the evolution of redox state of the Mesoproterozoic shallow sea,and it provides important information for studying the influence of redox state of seawater on the evolution of early eukaryotes.
		2020 Vol. 22 (6): 1181-1196 [Abstract] ( 597 ) [HTML 1KB] [PDF 4569KB] ( 263 )

	1197	Lu Yi, Cui Yu-Chi, Liu Xin-Yu, Shao Lei, Qiao Pei-Jun

		Sedimentary types and features of gravity flow depositional systems from Late Oligocene to Early Miocene in Liwan sag, Pearl River Mouth Basin
		Based on combination features of lithology,element geochemistry,TEX86 and many other indicators of Well Xike-1,Shidao Island,Xisha area,South China Sea,we aim to reconstruct the regional sea-level changes in Xisha area since the Early Miocene,and discuss the dominant factors of the carbonate platforms formation and development. Under the impacts of both the regional tectonic events in the South China Sea and the global sea level changes,it is found that the sea level in Xisha area shows a high-low-high-low variation trend during the Early Miocene,Middle Miocene,Late Miocene and Pliocene,and Quaternary. The sea surface temperature shows an overall downward trend from the Early Miocene to Pliocene. The combination features of lithology indicate that the Xisha carbonate platform initially formed in the Early Miocene,and it gradually flourished and developed in the Middle Miocene,then reached up to the peak in the Middle Miocene characterized as the formation of large reefs with lagoon facies. During the Late Miocene-Pliocene,the rapid increase of sea level and water temperature decrease led to the gradual shrinking and submergence of the carbonate platform which further shrinked in the Quaternary.It is found that two intense dolomitization events occurred in Xisha area during the Early Miocene and Late Miocene-Pliocene,respectively. These events are closely related to the exposure and erosion of carbonate platforms caused by regional sea-level drop. The carbonate platform evolution of Xike-1 is there presentation of the prosperity and extinction of the Cenozoic carbonate platform in the South China Sea. It was the comprehensive result of the Cenozoic tectonic evolution and global climate changes in the South China Sea.
		2020 Vol. 22 (6): 1197-1208 [Abstract] ( 604 ) [HTML 1KB] [PDF 2020KB] ( 371 )

PAST AND PRESENT GEOGRAPHIC ENVIRONMENTS AND HUMAN CIVILIZATION

	1209	Zou Chun-Hui, Zhao Qiang, Mao Long-Jiang

		Holocene environmental evolution recorded by core sediments of Judian Lake in the east of Lubei Plain,Shandong Province
		Judian Lake in the east of Lubei Plain is located in the monsoon area of northern China,which is sensitive to global climate change and provides abundant lake sedimentary data for the study of the past climate and environment evolution in the land-sea interaction area. Based on the sporopollen identification,grain size analysis and AMS¹⁴C dating of core sediments from the drilling hole of the Judian Lake,the evolutional process of climate and environment since 8900 cal a BP in the northern Lubei Plain was discussed. The results show that: 8900-7625cal a BP,the temperature and precipitation increased and the climate changed from cold-dry to warm-wet;7625—6810 cal a BP,the overall climate was becoming cooler and drier;6810—4435cal a BP,the temperature rose and the precipitation increased,showing an overall warm and humid climate in the middle Holocene;4435—3150cal a BP,the climate was generally cold and humid with some low-amplitude fluctuations of cold and warm. During the middle Holocene,there were two obvious cold and dry events in 5450—5280cal a BP and 4160—4090cal a BP,which was consistent with the geological and climatic records in China and even in the world. It may be due to the southward movement of the equatorial convergence zone caused by the change of solar radiation,the change of ocean surface temperature and the feedback of surface vegetation.
		2020 Vol. 22 (6): 1209-1220 [Abstract] ( 593 ) [HTML 1KB] [PDF 1506KB] ( 238 )

	1221	Zhang Ren-Shun, Gao Chao, Wang Ya-Ping

		Reconstruction of the Changjiang River tidal-limit movement since the ninth century AD
		The tide can now propagate upstream for more than 600 km from the Changjiang River estuary to hinterland,which is rare in the world. In China,information and records reflecting tidal limit and its movement in the Changjiang River can be found from some ancient books,literary works and local chronicles. At the end of the 3rd and the beginning of the 4th century AD, the tide limit of the Changjiang River reached the upstream of Chaisang(now named Jiujiang in Jiangxi Province). At the early 9th century,the tide limit in the dry season retreated to the Penpukou in Jiujiang. In the last ten years of the 13th century,the tidal limit moved back to the Xiaogushan Mountain near the border between Anhui Province and Jiangxi Province. By the middle of the 20th century,the modern researchers generally agreed that the tidal limit retreated to Datong in Anhui Province. Before the main stream of the Changjiang River was cut off by large-scale water conservancy projects,the tide limit had retreated seaward continuously. From the 3rd decade of the 9th century to the last decade of the 13th century,the tide limit moved downstream 64 km during the 470 years,with an average annual rate of 0.136km/a. During the 670 years from the end of the 13th century to the middle of the 20th century,the tide limit had moved downstream 170 km,with an average annual rate of 0.254 km/a,almost twice as much as that of the previous period. We suggest the climate change accounted for the different retreat rate of the tidal limit between the two periods discussed. In addition,a recent study found that during the extremely dry periods,when the discharge of Jiujiang station was about 8440 m³/s,the tidal limit reached near Jiujiang. In the years when the water conservancy project on the main stream of the Changjiang River began to store water,the tide limit actually returned to the previous position of the middle Tang Dynasty,i.e. 1100 years ago.
		2020 Vol. 22 (6): 1221-1232 [Abstract] ( 501 ) [HTML 1KB] [PDF 5925KB] ( 297 )

	1233	Li Xin-Po, Zhang Xi-Juan, Zheng Xiu-Juan

		*Three-dimensional publication mode of Journal of Palaeogeography(Chinese Edition)*
		The network technology has provided impetus and channels for the development of sci-tech periodicals and promoted the transformation of the publication mode of Journal of Palaeogeography(Chinese Edition). Through the independent website construction,providing readers with diversified access to articles,diversified communication methods,personalized accurate article push,joining the OSID open science program,etc.,a three-dimensional publication mode adapted to the development of periodicals has been gradually formed.
		2020 Vol. 22 (6): 1233-1234 [Abstract] ( 501 ) [HTML 1KB] [PDF 295KB] ( 243 )

JOPC

Dynamic academic

Joint Special Issue of the 2nd Geo-Energy Frontier Forum：JOPC ：CCUS Geological Basis and Application

First notice of the 18th National Conference on Palaeogeography and Sedimentology

Together struggle for 20 years

The first 100 cited articles of 20th anniversary of founding of JOPC

more>>

Read Articles

Download Articles

Telephone：010 6239 6246　Email:Jpalaeo1999@163.com