The in-depth analysis of the development process of the delta front is of great significance for the judgment of the sedimentary environment,and it is necessary to deeply explore the formation characteristics and mechanism of the delta front from the perspective of hydrodynamics. In this study,the vertical distribution of the flow velocity in river water bodies and the development characteristics of delta front sedimentary bodies are investigated,from multiple perspectives of hydrodynamics,flume experiments,and underwater geomorphological observations. The results show that the phenomenon of river flow velocity,exhibiting a monotonic decrease with depth,has not been given sufficient attention. The terrain undulation of the middle and lower reaches of the riverbed increases with the flow direction,resulting in the underwater sand waves perpendicular to the flow direction,while the terrain undulation of the river section perpendicular to the flow direction becomes more and more gentle. During the process of rivers entering the sea,there will be a mainstream channel without branching channels underwater. Additionally,the originally undulating riverbed will gradually be filled up,changing from a sharp V-shaped or W-shaped to a U-shaped. It can be concluded that most of the front edge of the delta are sheet-like or fan-shaped,rather than a strip of erosion surface along the flow direction. Microfacies such as underwater distributary channels and bays do not develop in the delta front subfacies,which cannot be found in the modern delta front subfacies and are not supported by flume experiments. Furthermore,a water depth velocity interaction model for river channel and delta sedimentation is proposed.

The upper Oligocene Huagang Formation is crucial for oil and gas exploration in the central and southern Xihu sag of the East China Sea Shelf Basin. However,there has been ongoing debate on the sedimentary system,and limited research has been conducted on the characteristics of sand body architecture and the controlling factors. This paper studied the sedimentary environment,microfacies types,sand body architecture,and controlling factors of the upper Oligocene Huagang Formation through a comprehensive analysis of core,logging,and seismic data. The upper Huagang Formation in the central-south part of Xihu sag shows shallow-water delta plain sedimentation,with distributary channels being the predominant type of sand body. These distributary channels are categorized into three types based on their curvature: braided(curvature=1~1.05),meandering(curvature>1.15),and braided-meander transition(curvature=1.05~1.15). The sand bodies found in braided distributary channels are wide and thick,with intertwined wide bands. Channel bars in these channels are arranged in a speckled pattern. The sand body’s vertical stacking style is mainly characterized as incised stacking. In contrast,the sand bodies in meandering channels are narrow and thin,appearing as either single strip type or bifurcation-merging type in the planar direction. Thick sand layers are distributed as point bars in the channel margin,and the vertical stacking style is mostly isolated. The braided-meandering type of diversion channel is a transitional type between braided and meandering channels. It is characterized by moderate-sized channel sand bodies containing inner channel bars and point bars. The thickness and width of these distributary channels are positively correlated in a logarithmic manner. The ratio of width to thickness follows the pattern of braided type>transitional type>meandering type. The architecture characteristics of distributary channels are primarily influenced by paleogeomorphology and changes in base levels. Paleogeomorphology controls changes in channel types within shallow water delta plain,and low curvature braided distributary channels are more likely to develop in steep terrain. As the long-term base level increases,the size of distributary channels decreases,while a rise in mid-term base level has resulted in the transition of distributary channel sand bodies from incised to superimposed and isolated stacking types. This research enhances our understanding of the sedimentary structure of shallow water deltas and provides valuable guidance for predicting and developing distributary channel reservoirs in underground shallow water deltas within oil and gas fields.

Silicate rocks are factors that influence the global carbon cycle as well as climate change by chemically reacting with carbon dioxide,removing atmospheric carbon dioxide and sequestering it in weathering products or ocean carbonate rocks. Quantifying the total amount of carbon dioxide consumed by weathering of global silicate rocks is key to understanding the Earth’s current and past climate change. This paper systematically investigates the data sources,research methods,calculation formulas,and main influencing factors of five quantitative models of chemical weathering-CO₂ consumption of silicate rocks. The CO₂ consumption calculated by the latest Celine model serves as a reference standard for comparing the advantages,disadvantages and scope of application of each model. The existing models estimate the global carbon dioxide consumption of chemical weathering of rock silicate rocks to be 69-169 Tg/yr,in which the main parameters of each model include climate(temperature,runoff)and lithology,and the secondary parameters include tectonic uplift,volcanism and plant interaction. Future exploration of the quantitative calculation of carbon dioxide consumed by the chemical weathering of silicate rocks should consider more control effects and the interconnections between factors. In addition,the use of big data analysis methods to generalize these quantitative models to the reconstruction of the palaeoclimate of the deep earth may be a future research trend.

As a key interface connecting the deep-time Earth's internal and external systems,paleo-landscape reconstruction provides an important way for studying deep Earth sciences. The development of computer simulation tools makes it possible to reconstruct deep-time dynamic paleo-landscape. Badlands(Basin and Landscape Dynamics)and goSPL(Global Scalable Paleo Landscape Evolution)software are designed to understand the evolution of surface Earth system and its interaction with the solid Earth system,by combining factors of different spheres such as deep tectonic process,precipitation and sea level change. Based on these new technical basis,some achievements have been made,e.g. regional models that reproduce the topographic inversion and drainage reorganization processes in East Asia and global models that couple the landscape dynamics with the Phanerozoic diversification of the biosphere. However,some differences among different paleo-landscape reconstruction models arise due to uncertainty in elevation proxy indicators. In addition,it is difficult to make the simulated results to be completely consistent with the high-precision geological observation records. It is urgent to carry out global paleo-landscape models of ultra-high resolution in time and space.

The Ghadames Basin has become one of the significant basins for overseas exploration and project investment in China. Accurate understanding of the early Paleozoic sedimentary system and lithofacies palaeogeographic characteristics is the basis for further exploration and the key to establish the early tectonic-sedimentary evolution history of the basin. Based on the comprehensive analysis of core,seismic and logging data in Ghadames Basin,combined with the restoration of palaeogeomorphology,the sedimentary system and lithofacies palaeogeographic characteristics are discussed. The results show four types of depositional systems in the early Paleozoic of Ghadames Basin: alluvial fan,braided river,braided river delta and shallow marine. In the early and middle Cambrian,the Avalon terrane drifted toward the Baltic plate,the Proto-Tethys Ocean initially expanded,and the active continental margin was formed. During this period,the whole basin was dominated by continental deposits. During the Cambrian-Ordovician,the platform uplift and depression pattern was initially formed owing to the Caledonian movement. Large-scale denudation occurred in the western and northern parts of the Ghadames Basin,and large-scale glacier deposits were developed to form glacial moraine reservoirs. In the Early and Middle Silurian,the Palaeo-Tethys Ocean continued to expand,the sea level rose,and a extensive transgression occurred in the northern part. Shallow marine sedimentary environment predominated in the area during this time,and hot shale and mudstone were widely developed which are important source rocks and cap rocks in the region. In the Devonian period,the Hercynian movement uplifted the region as a whole,and the sea area in the basin was reduced and replaced mainly by continental sediments. On this basis,the establishment of the marine-continental transition sedimentary model under the early Paleozoic Tethys Ocean evolution background in the Ghadames Basin is established,which can provide a reference for the next exploration work in the study area.

In recent years,oil and gas exploration in the Junggar Basin has gradually shifted from conventional traps outside the source to lithological traps within the source. The Upper Urho Formation is currently the main exploration target for boosting reserves and production in the basin. The distribution of sedimentary system has a controlling effect on the distribution of lithological reservoirs in the Upper Urho Formation. Using drilling cores,thin sections,combined with seismic data and drill cuttings and wireline logs,this study identified and characterized the sedimentary facies and depositional systems of the Upper Urho Formation in the Junggar Basin,and summarized the large-scale transgression. The sedimentary model of fan(braided river)delta-beach bar composite sandy conglomerate body was analyzed,and its controlling factors were analyzed. The results show that: (1)The study area is characterized by various sedimentary facies,including fan delta,braided river delta,and shallow lake beach bar. Among them,fan-delta plain and fan-delta front are mainly developed in the west of the basin,while braided river-delta plain and braided river delta front mainly developed in the east and north of the basin,and beach-bar is mainly superimposed on fan-delta and braided river-delta fronts or occurs independently at their front ends. (2)The depositional system of each member of the Upper Urho Formation developed under the background of overall lacustrine transgression. During the first member of Urho Formation,the basin was relatively small,and the deposited sand bodies were thick and of limited lateral extent,located in proximity to the depression center;during the second member of Upper Urho Formation,with continuous sediment supply and increased water depth the area of the lacustrine basin increased,with thinner but more extensive sand bodies deposited;during the third member of Upper Urho Formation,lacustrine transgression was enhanced,basin area was thus further expanded,and lacustrine mudstone was widely developed in the basinal area. (3)The fan(braided river)delta front-beach-bar composite gravel body was formed under continuous change of lake level and transformation of lake waves in the fan delta state and braided river delta front. (4)During the depositional period of the Upper Urho Formation in the Junggar Basin,the main controlling factors of the depositional system were climate,source supply,lake-level changes,and palaeotopographic slope and palaeogeomorphology at the time of deposition. This study provides a geological basis for oil and gas exploration in the Upper Urho Formation.

North Africa,located on the northern margin of the Gondwana continent in Paleozoic era,is one of the important oil and gas enrichment areas worldwide,experiencing two rift-sag-foreland basin evolution cycles,namely the Paleozoic Gondwana and the Mesozoic Cenozoic Tethys. Based on a comprehensive analysis of publicly available geological data and oil and gas exploration data,this article identified three types of petroliferous basins in the North African region: cratonic superimposed sags,rifts,and passive margin related basins;summarized two basin evolution cycles: Gondwana and Tethyan basin-forming cycle;clarified the controlling role of tectonic evolution on basin types,basin structures,and the development of source,reservoir,and cap rocks. Under the influence of the global plate tectonic evolution,different regions in North Africa have gone through five stages of tectonic evolution: (1)late Proterozoic-early Cambrian basement assembly and rift stage;(2)Cambrian-Early Carboniferous intra-cratonic sag stage;(3)Late Carboniferous-Early Permian Hercynian orogenic stage;(4)Late Permian-Early Cretaceous rift stage; and (5)Late Cretaceous-Present Alpine orogenic stage. Marked by the Hercynian orogeny,the basin features cycles that consist of the Paleozoic Gondwana Cycle and the Mesozoic-Cenozoic Tethyan Cycle. The evolution of the basins in western North Africa are dominated both by the Gondwana and Tethyan cycles,forming superimposed sag basins, while the evolution of the eastern basins are dominated by the Mesozoic and Cenozoic Tethyan cycle,forming the Mesozoic and Cenozoic rift basins and passive continental margin basins. Controlled by the development differences of basins,the source rocks of the western superimposed sag basins are developed mainly in Silurian and Devonian,with including the Paleozoic and Triassic reservoirs. The regional cap rocks are Silurian shale and Upper Triassic-Lower Jurassic evaporate. In comparison the source rocks of the eastern rift basins developed in Cretaceous,Paleogene,and Neogene,with pre-rift Paleozoic and syn-rift Mesozoic and Cenozoic reservoirs. The regional caprocks include the Late Mesozoic and Cenozoic evaporites rocks deposited in the rifting stages. Overall,the differential tectonic evolution in the North African controls the formation mechanism of petroliferous basins and the distribution of source,reservoir,and cap rocks.

The Yangtze River,Asia's largest river,represents a significant geomorphological event within the integrated tectonics-climate-landscape system of the Cenozoic era in China. A key point of debate in understanding its formation is the timing of the incision of the Three Gorges,situated between the Sichuan and Jianghan basins,which marked the emergence of the modern Yangtze River. Despite abundant geological data,there remains controversy over when exactly the Three Gorges were formed or incised. Previous studies usually focused on isolated factor affecting the river development,e.g., tectonic movements,sedimentology,paleo-climate and sea level changes,to resolve this key issue. In contrast,our study utilizes Badlands,a software for simulating paleo-landscape,to integrate these key factors quantitatively. Focusing on the area east of the “first bend”(Shigu Town in Yunnan Province)of the Yangtze River,we used Badlands to reconstruct the paleo-landscape and river system evolution process since the Late Cretaceous(80 Ma). We further validated our model results using seismic data from the Sichuan and Jianghan basins. The results revealed that the river flow direction in the Sichuan Basin was reversed to drain northwards due to the Late Eocene-Oligocene uplift in the eastern Tibet and the southwestern Upper Yangtze Plate. The Jianghan Basin maintained a consistently low base level during the early Paleogene,influenced by the continental rifting environment in eastern China. The reversal of the drainage direction in the Sichuan Basin and the long-lasting low base level in the Jianghan Basin eventually made the Three Gorges to be incised at the latest Oligocene. We propose that the reversal and subsequent capture of the Upper Yangtze River's flow by the middle Yangtze River played a crucial role in the incision mechanism of the Three Gorges.

This paper briefly describes the new achievements of oil and gas exploration in carbonates,deeply buried carbonate rocks,especially the genetic theory of dolomites at the 17th National Congress of Palaeogeography and Sedimentology. The relevant theme includes 55 oral presentations and 15 panels,which are related to(1)the genesis and reservoir of dolomite in Tarim,Sichuan,Ordos,Qaidam,Tuha and Bohai Bay basins,(2)formation,characteristics and preservation mechanism of deep and ultra-deep dolomite reservoirs,and(3)quantitative evaluation of bioliths and carbonate formation processes. It is worth recommending the study on the characteristics and genetic mechanism of high-quality,ultra-deep(10 km)dolomite reservoir,Exploration of the ultra-deep dolomite has become a representative result of the genetic theory of dolomite,guiding production practice. It is a supplement to the weak link in the application of basic research of dolomite genesis in the 21st International Sedimentology Congress(2022,Beijing)and in recent years. The summary of the characteristics and genetic mechanism of deep dolomite reservoirs in various parts of the Sichuan Basin comes from graduate students’ summary of the results of different university projects,which is very valuable. The theory of formation of deep dolomite reservoir,evaluation and exploration of high-quality ultra-deep dolomite reservoir is put forward. In particular,the laser ablation plasma mass spectrometry U-Pb dating technique has been widely used,which has realized the qualitative and quantitative analysis of the characteristics and genetic mechanism of dolomitization in geological time. The discussion of biolith is characteristic. They represent the close integration of sedimentology,lithofacies and paleogeography,mineralogy and petrology,new technology and dolomite genetic theory and practical application. The overall innovation depth,research means,system theory and application characteristics in oil and gas exploration deployment are significant,which is the highlight of this conference. Shortcomings are represented by the only one poster on marine reef dolomite. It is expected that the 18th Karamay Conference will further deepen the research in the above fields,and the topic of marine island dolomite research will be paid more attention.

It is of great significance for understanding the initiation and evolution of sandstone-type uranium deposits from the perspective of tectono-sedimentary evolution. In this study,based on a literature review,fieldwork,logging and seismic data,the tectono-sedimentary evolution of the Shizigou and Qigequan Formations in Qigequan Anticline in the Qaidam Basin and its links to the mineralization of sandstone-type uranium deposits are revealed. Our findings indicate that: (1)The Shizigou Formation is characterized by argillaceous-sandstone-rich stratum associated with retrogradation,while the Qigequan Formation is characterized by conglomerate-rich stratum associated with progradation. The Neogene-Quaternary angular unconformity developed between the Shizigou and Qigequan Formations and the Intra-Quaternary angular unconformity developed inside the Qigequan Formation. Large-scale alluvial fans,composed of debris flow,incised-valley-fill,and sheet flow deposits,were developed in the Shizigou and Qigequan Formations,and the sandy earthquake-induced soft-sediment deformation layers were frequently developed in the Shizigou and Qigequan Formations. (2)The most intensive uplift and denudation events occurred between the Neogene and the Quaternary,resulting in the initiation of the Neogene-Quaternary angular unconformity and the tectonic setting of the Qigequan Anticline. (3)It can be inferred that these potential uranium mineralization columns of the Shizigou Formation in the Qigequan Anticline developed in the uplift and denudation events between the Neogene and the Quaternary. The uplift and denudation events led to the initiation and evolution of the uranium-bearing structure,and increased the uranium flux from the source area and dominated the spatial distribution of the potential uranium mineralization columns ultimately. The Neogene-Quaternary angular unconformity can be used for the spatial distribution predicting of the potential uranium mineralization columns as a key tectonic identification mark. In addition,the thin interbeds of sandstone(including the conglomerate)and mudstone in the middle and distal parts of alluvial fans,with sand(including the conglomerate)percentage ranging from 20% to 50%,can be used for the spatial distribution predicting of the potential uranium mineralization columns as a key sedimentary identification mark. This research provides sedimentary and stratigraphic evidence for the basin analysis of the northeastern Tibetan Plateau and is of great reference value for the exploration of sandstone-type uranium deposits in other anticlines in the Qaidam Basin.

Quartz is an important part of shale,making it crucial to clarify its genetic mechanism for the reconstruction of shale diagenetic process and the formation of shale oil and gas reservoir. The genesis of quartz in shale is complex,with the main types, including terrigenous detrital quartz,biogenic quartz and diagenetic authigenic quartz, identifiable through ordinary thin section observation,scanning electron microscopy,energy spectrum analysis and cathodoluminescence. The main sources of diagenetic authigenic quartz silica are clay mineral transformation,felsic dissolution and biosilicon dissolution,and volcano-hydrothermal activity. Terrigenous detrital quartz is mostly silt-grade and strongly emits light under cathodoluminescence,typically displaying a two-peak spectrum. Micron-sized biogenic quartz does not emit light,and clay mineral-derived quartz is predoninantly found around or embedded within clay minerals, such as illite. In addition to the morphology and occurrence characteristics of different types of quartz,there are also differences in geochemical elements. Quartz affected by hydrothermal activities is rich in Fe and Mn,while terrigenous detrital quartz is rich in Ti and Al elements. Detrital SiO₂ and Zr are positive correlation,as does biogenic quartz with TOC content. The biogenic quartz Fe/Ti ranges between 0.4 and 20. Diagenetic authigenic quartz is formed in multiple stages,which is closely related to the burial diagenesis process of shale and affects the properties of shale reservoirs. Diagenetic authigenic quartz is mainly formed in early and middle diagenetic stages. Terrigenous detrital quartz and biogenic quartz are conducive to inhibiting compaction and protecting primary pores. Processes involving diagenetic authigenic quartz, like clay mineral transformation and felsic dissolution create dissolution pores and organic pores,with quartz filling some pores,thereby reducing porosity. Identifying the origin of quartz in shale is of great significance to the analysis of shale sedimentary environment and the prediction of favorable reservoir distribution.

洪水类型与流量变化是影响扇三角洲地貌形态与沉积特征的主要因素，但不同类型洪水作用下扇三角洲沉积单元发育规律研究薄弱。论文以滦平盆地桑园剖面下白垩统西瓜园组为例，通过剖面测量和岩相划分，恢复了沉积流体类型、沉积过程及其沉积响应单元，建立了不同洪水作用下扇三角洲沉积模式。根据岩相组合将该剖面的主控沉积过程解释为碎屑流、洪流与片流3种洪水，分别对应于碎屑流建造期、洪流建造期与片流建造期。结合沉积过程与砂砾岩沉积形态特征，将目的层解释为8种沉积单元，具体包括扇三角洲平原环境的陆上碎屑流舌状体、洪流主控辫状河道和扇三角洲前缘的水下碎屑流舌状体、高密度浊流水道、牵引流水下分流河道、高密度浊流朵体、水下片流朵体及滑塌体。在扇三角洲碎屑流建造期，发育多期垂向上叠置的、向湖盆进积的碎屑流舌状体；在洪流建造期，平原中形成洪流主控辫状河道，而进入湖盆后洪流转化为高密度浊流，发育高密度浊流水道与朵体；在片流建造期，则以水下快速沉积形成的水下片流朵体为特征。洪水期扇三角洲前缘沉积物快速沉积和沉积物坡失稳易于形成滑塌体，而间洪期则以平原上辫状河道和前缘中低流态水下分流河道的发育为特征。基于洪水类型及其沉积过程的扇三角洲沉积规律的研究，深化了对其砂体形态与结构规律的认识。

This study assesses the historical lakes in the lower reaches of the Yellow River using ancient documents,estimating the general shape and approximate area of over 130 ancient lakes during historical times. We have meticulously analyzed the extinction process of these ancient lakes and discussed the factors contributing to their demise. Our findings reveal that during the historical period,there were at least 135 lakes in the lower reaches of the Yellow River,covering a total area of 16195.64 km². These lakes were primarily situated along the ancient channel of the Yellow River,with small and medium-sized lakes(areas under 100 km²)constituting the majority. These smaller lakes accounted for 74.81% of the total number of lakes and 30.23% of the total area. Since the Song Dynasty,there has been a noticeable shrinkage in these ancient lakes. Among the smaller and medium-sized paleolakes,60.34% of 135 lakes have disappeared. Only 28 ancient lakes remain today,marking a decline of 79.26% in their number,and their total area has reduced to 4910.66 km²,a decrease of 69.68%. The study suggests climate change is the background for the extinction of ancient lakes. The sediment accumulation caused by the Yellow River avulsion and flooding is the direct reason for the disappearance of these ancient lakes. Meanwhile,human activities such as land reclamation around the lakes have accelerated this process.

A shallow water delta was developed in the Lower Jurassic period in the Dongdaohaizi sag,Junggar Basin,but its sedimentary evolution and main controlling factors were not fully understood. Through the analysis of well logging,core and geochemical data from the Dongdaohaizi sag and its surrounding areas,the sedimentary facies,paleogeomorphology and paleoclimate of this region were analyzed. The study identified three subfacies within the shallow water delta: delta plain,inner front,and outer front. The delta plain subfacies consisted mainly of distributary channels,forming glutenite layers over a hundred meters thick. The inner front featured medium-fine sandstone with argillaceous interlayers,while the outer front was mainly composed of sheet sandstone microfacies interbedded with mudstone and argillaceous siltstone. The paleogeomorphology of the area was higher in the east and lower in the west,categorized into paleo-highland,paleo-slope and paleo-depression based on relative positions and slopes. Analysis of geochemical indicators and sedimentary characteristics suggested fluctuations between humid and arid conditions during the Early Jurassic,with the lake level experiencing three progression-regression cycles. The progradation and regradation of the delta extended over tens of kilometers with the sedimentary distribution and evolution influenced by both paleogeomorphology and paleoclimate. The gentle overall paleogeomorphology provided a foundation for shallow water delta development,while regional paleogeomorphology height and evolution affected sedimentary system distribution and transition. Alternating dry and wet paleoclimate conditions affected lake level fluctuations,thereby controlling delta progradation and regradation. Through a comprehensive analysis,the progradational and regradational depositional models were established for shallow water delta sedimentary patterns,offering valuable insights into the impact of paleogeomorphology and paleoclimate on shallow water delta,and serving as a reference for future exploration in the area.

The study of incidence and attributes of regional extreme climatic events under the background of global change is a frontier of climate change research. This paper reconstructs the extreme flooding events with a probability of 10% in the Northeast China in 1750-2020 using historical documentary records and precipitation data,and then analyzes its incidence characteristics and driving mechanism. The main conclusions include: (1)In 1750-2020,29 extreme flooding events were identified in the Northeast China,exhibiting fluctuating patterns,with 1871 to 1930 marking the period of highest frequency over the past 270 years;(2)The global and regional warming significantly enhanced the frequency of extreme flooding events in the Northeast China;(3)The anomaly of the monsoon rain belt caused by the change of the East Asian summer monsoon is the direct cause of the occurrence of extreme flooding events in the Northeast China. Particularly,periods with a stronger monsoon and a northward shift in the rain belt significantly raise the likelihood of such events;(4)The Indo-Pacific warm pool and the sea surface temperature anomalies in the tropical central and eastern Pacific caused the incidence of extreme floods events in northeast China by affecting the location of the East Asian summer monsoon and the water vapor transport. The positive anomaly of water vapor transport at the time of La Niña years is crucial for the occurrence of extreme flooding,and is a reliable predictor of extreme flooding events in the Northeast China.

Historically,two kinds of storm surge disasters occurred frequently along the coast of Jiangsu Province,which brought huge losses to this region. Establishing a long-term sequence of these disasters is crucial for understanding historical patterns and forecasting future events. Based on the records of storm surges in historical documents,local chronicles,marine disaster bulletins,etc.,a storm surge disaster identification system has been established,and the storm surge disaster sequence along the coast of Jiangsu Province from 1300 to 2019 has been reconstructed. Then,the temporal and spatial variation characteristics of the storm surge disaster along Jiangsu coast have been analyzed. Finally,the relationship between the storm surge disaster and climate anomalies,the evolution of the estuaries of the Yellow River and the Changjiang River have been explored. Our analysis of the temporal and spatial variations reveals that Jiangsu's coast experienced 246 storm surge disasters from 1300 to 2019,averaging one every 2.9 years,with a notable increase in frequency over the past century. There are 17,61 and 115 year time scale cycles in the interannual variation by wavelet analysis,of which the 115 year cycle is most pronounced. We observed that typhoon storm surges tend to decrease during active El Niño years,possibly due to air-sea interactions. Additionally,our study indicates a positive correlation between temperature rise and the frequency of typhoon storm surges,although the underlying mechanisms remain unclear. Geographically,Yancheng,Nantong,and Suzhou are the regions with high incidence of storm surge disasters,while Changzhou and Wuxi are less affected. Since 1855,climate warming and coastal erosion and siltation changes in Jiangsu Province,result in an increase in storm surge disasters in Yancheng and Nantong,and a significant rise in the Lianyungang region. Following the migration of coastline and the evolution of the Changjiang River estuary,the impact of storm surge disasters in Zhenjiang,Yangzhou,Taizhou,and Suzhou,Wuxi,and Changzhou regions has decreased.

Despite significant breakthroughs in oil and gas exploration in the glutenite section of the Qingshuihe Formation in the southern Junggar Basin,the sedimentary characteristics,genetic mechanism and controlling factors of the glutenite remain unclear,which has become a key restricting factor for hydrocarbon exploration. As such,we investigated the lower Qingshuihe Formation glutenite body in the western section of the southern Junggar Basin based on wireline logs,cores,outcrops and experimental data,with a focus on the lithofacies,lithofacies assemblage and distribution of the glutenite body,as well as their main controlling factors and genetic mechanism. Six types of lithofacies and lithofacies assemblages and genetically different glutenites are identified in the lowstand and transgression systems tracts of the Qingshuihe Formation in the western section of the southern Junggar Basin. The lowstand and transgression systems tracts of the Qingshuihe Formation in the southern Gaoquan area of the western section are dominated by alluvial fan and fan delta depositional systems,and braided river delta depositional system predominates the northern Caindic area. During the depositional period of the Qingshuihe Formation,glutenite sedimentation in the south western section of the Junggar Basin was affected by the nature of the parent rock in the provenance area,sediment supply and paleoclimate. Among them,nature of the parent rock in the provenance area and sediment supply control the sedimentary type and scale of the glutenite body. While paleoclimate affects the weathering and denudation degrees of the parent rock area and the sedimentary transport environment. Based on the controlling factors and sedimentary characteristics,a sedimentary model for the southern alluvial fan-fan delta and the northern braided river delta front of the Qingshuihe Formation lowstand and transgression systems tract in the western section of the southern Junggar Basin has been established,which can provide a geological basis to aid discrimination between different glutenite bodies and hydrocarbon exploration in similar settings.

The Huaiyuan Movement is an important tectonic event in the early Paleozoic of the North China Platform,resulting in a regional unconformity. Based on outcrop data,geological maps,drilling data and new seismic data,the identification marks,types and distributions of unconformities formed during the Huaiyuan movement in the Ordos Basin were analyzed. The results show that(1)sandy conglomerate and weathered crust developed near the unconformity surface;additionally,high acoustic time,high gamma values,high content of trace elements(U,Th and K),high thorium-uranium ratios,low resistivity,and low density of logging curves occurred near the unconformity surface. The seismic response of the unconformity is characterized by a strong phase,and there are obvious differences in amplitude intensity,frequency and continuity in the wave groups on both sides of the unconformity. In addition,the truncation point reflections can be observed in local domain. (2)The Huaiyuan movement caused both parallel-unconformity and low-angle cutting unconformity in the basin. The former was widely distributed in the basin and its periphery areas,and the latter was distributed near the paleo-uplift in the basin. (3)The Ordos Basin and its periphery areas were affected by three stages of the Huaiyuan tectonic movement: during the depositional period of the Zhangxia Formation in the Middle Cambrian,uplift first occurred in the southeast region of the basin and then moved to the northwest direction;at the end of the Sanshanzi Formation deposition period in the late Cambrian,paleo-uplifts developed in the basin,and they were subjected to erosion; at the end of the late Cambrian, before the Ordovician Majiagou Formation was deposited,the negative drift of carbon isotopes first occurred in the bottom layer of Majiagou Formation due to the influence of global sea level decline. These results provides a reference for the research of new fields of oil and gas exploration in Lower Paleozoic in the Ordos Basin.

Given China's oil and gas demand and the endowment of domestic and foreign oil and gas resources,it is the era's responsibility and duty for various oil companies to use foreign oil and gas resources effectively to alleviate domestic energy demand pressure,in line with the trend of energy transformation and green energy development. Geological research serves as a fundamental aspect of oil and gas exploration and development. Accordingly,a special issue dedicated to foreign oil and gas geological research has been issued. To help readers better understand the five overseas regional research papers published in this issue,editors have written this article to introduce the overall research background,individual achievements,features,and the innovative understanding of these five overseas papers.

Since the Mesozoic,North China experienced an abrupt landscape transition from the collapse of the paleo-plateau to the formation of the Bohai Bay Basin. The distribution of the Mesozoic North China Paleo-plateau and the Paleogene rifting in the Bohai Bay Basin have been well known. However,factors driving the Late Cenozoic landscape evolution of the region remain a subject of debate,due to major geological events,such as the uplift of the Taihang Mountain,the sediment transport and the evolution of the Yellow River and marine transgression. In this study,we used Badlands software to quantitatively analyze the contributions of mantle convection,tectonic events,paleoclimate change,erosion and deposition to landscape,respectively. We then reconstructed the paleo-landscape evolution of eastern North China since the Late Cenozoic(25 Ma). The credibility of the modeled results was validated by comparing with existing geological data on tectonic frameworks and sedimentary facies patterns. We suggested that the landscape configuration in eastern North China was primarily established during the Miocene,controlled by the subsidence of continental shelf sea. Notably,our model identified an ancient river,termed'the East China River' near the Shandong Peninsula,which formed no later than the Early Neogene and disappeared by the Holocene. Our results are of great scientific significance to the systematic study on the multiple-sphere coupling in the eastern North China Ocean-Continent Connection Zone.

A series of tectonic movements during the Late Mesozoic greatly changed the topography and landform in eastern China,forming a geomorphic pattern of “high in the east and low in the west”. There is still a controversial issue on the existence of plateaus or mountains in eastern China during the Cretaceous,and thus the evolutionary processes,paleoaltitude and the extensional range of plateaus or mountains need further studies. In this paper,we collected the palynological data of xerophyte and disaccate pollen from vorious localities of China during the Cretaceous,and further discussed the paleovegetation succession and palaeoclimate evolution,which provides paleontological evidence for the interpretation of the geomorphology in eastern China at that time. The result shows that there were three climate zones in China during the Cretaceous: (i)the northeastern region was a warm and humid subtropical-warm climate zone;(ii)the northern region was a semi-arid tropical-subtropical transitional climate zone;(iii)the Tibet,Xinjiang and southern China were a hot and tropical-subtropical climate zone. The interpretation of the geomorphology shows that there was a high-altitude landform in northeast China during the early Early Cretaceous. Additionally,it is likely that coastal mountains existed in the Fujian and Zhejiang regions during the Early Cretaceous. In early Late Cretaceous,the range of coastal mountains in eastern China reached its maximum. From the late Late Cretaceous to Early Paleocene,the mountains in eastern China gradually collapsed,and by the Early Paleocene,the mountains were probably disappeared.

陆相优质烃源岩发育大多与湖泊咸化相关，但湖泊咸化对页岩发育的影响仍不清晰。以东营凹陷古近系页岩重点取心井樊42井为例，通过岩石薄片观察、XRD、岩石热解测试、XRF二维元素扫描、微量元素测试等分析，结合有机地球化学测试数据、微量元素含量的垂向变化等，分析不同盐度演化阶段页岩成分、纹层结构、有机质丰度的变化。结果表明，研究区目的层段页岩可划分为5种岩相类型。目的层段环境演化可以划分为5个阶段，受控于气候、陆源输入等因素。古气候在沙三下亚段沉积时期呈现暖湿—相对湿冷—暖湿—相对干冷—相对暖湿的变化特征。陆源输入量呈多期旋回变化。不同类型岩石的沉积环境特征各异，高盐度的湖泊水体营养盐浓度高，具有较高的初级生产力，水体分层强烈，水体循环较弱。氧/盐度跃层位置相对较高，富氧带水深较浅，使得有机质更快脱离氧化环境沉降进入还原性水体，有利于有机质的保存。碳酸盐矿物含量高，且呈纹层状发育于滞水层中。

Carboniferous-Permian period was the key tectonic transition period in the ocean-continental transition in the eastern Xinjiang region,during which multiple oceanic crust closure and continental collision occurred. Due to the complexities of ocean basin properties,trench-arc-basin subduction events and land-land collisions in the eastern Xinjiang region,there is insufficient understanding of the late Paleozoic stratigraphic framework comparison and sedimentary filling characteristics in the basin. The theory of active tectonic palaeogeography was used to restore the tectonic-sedimentary features of basin-mountain tectonic belt in the eastern Xinjiang region,and the tectonic-sedimentary environment of each tectonic stratigraphic unit was determined. The prototype basin restoration was carried out comprehensively and dynamically from the perspectives of sedimentary filling,tectonic evolution restoration and the peripheral tectonic environment. The results show that the eastern Xinjiang region experienced five stages of extension and convergence cycles: Early Carboniferous extension,late Early Carboniferous-early Late Carboniferous weak extension,late Late Carboniferous compression,early Early Permian extension,and late Early Permian compression. Subsequently,5 tectonic transformation processes occurred: Late Permian,Late Triassic,Late Jurassic,Late Cretaceous-Paleogene and Late Cenozoic. The reconstruction of the basin-mountain tectonic pattern reveals that the southern boundary of the Tuha Basin in the Carboniferous period is approximately 46-70 km south of the present basin-mountain boundary. The Kelameili Mountains in the northern part of the eastern Junggar Basin during the Carboniferous period were approximately 30 km north of the current boundary. The northern orogenic belt of the Santanghu Basin in the Carboniferous period has a boundary of about 55 km south of the current boundary. The sedimentary environment experienced a transition from the Carboniferous marine to the Early Permian marine-continental transitional phase,and then to Middle-Late Permian continental facies. During the Carboniferous period,the marine arc-related rift basins,rift marginal basins and rift basins were developed. During the early Permian,marine and continental rift basins were mainly developed. During the middle Permian period,continental depression basins were mainly developed. During the late Permian period,compressional depression basins developed. The analysis of basin-mountain tectonic patterns and tectonic palaeogeographic evolution of the Carboniferous-Permian strata in the eastern Xinjiang region lays a good foundation for exploring the reservoir formation conditions and source-reservoir combination distribution of the Carboniferous-Permian period in the main sedimentary basins of the eastern Xinjiang region.

塔里木盆地塔河油田西北部中下奥陶统发育深切的地表水系结构，对水系两侧岩溶缝洞的发育影响显著，因此，对水系结构的定量描述及其演化模式的研究至关重要。基于三维地震资料，通过地震属性提取技术，对古岩溶台面和古岩溶地表水系进行了识别。同时，对水系的平面和垂向形态学结构参数进行了量化表征，据此探讨了古岩溶地表水系的形成与演化模式，剖析了水系演化与古岩溶缝洞发育的关系。研究结果表明：(1)塔河油田西北部自东向西发育3个岩溶台面和一个深切曲峡型地表流域结构。该流域的主干水系南北向汇流、分支水系东西向汇流，呈不对称分布。(2)水系单河曲弯曲率均大于1.5,超过了定义蛇曲的弯曲率临界值，具有典型的蛇曲特征。东西向河曲带弯曲率为2.42,南北向河曲带弯曲率为1.78。(3)东西向水系形态以单一“V”字形为主，南北向水系具有复合“V”字形，水系下切深度可达100～200 m。自东向西3个岩溶台面中水系的下切深度逐渐加大，水系宽深比平均值分别为4.06、3.52、3.03。(4)研究区古岩溶地表水系经历了自由曲流和深切曲流2个阶段，分别反映了水系的侧向侵蚀和垂向侵蚀作用过程。其中，水系的垂向侵蚀是逐步发生的，与3个岩溶台面的逐级抬升相适应。(5)深切曲流是区域性的最低排泄基准面，控制了河流两侧大型岩溶暗河的发育。每个岩溶台面具备独立的水循环结构，岩溶台面的逐级抬升促进了水系的差异演化，进而控制了岩溶暗河的规模和类型的差异性。对研究区古水系结构及其演化的认识对于古岩溶缝洞储集空间发育特征与分布规律的研究提供了重要的参考依据。

大陆风化是地球表层系统中的关键过程，涉及多种能量形式(太阳能、风能、化学能和重力势能)和物理化学过程，是地球化学元素在地球不同层面(如岩石圈、水圈、生物圈和大气圈)之间迁移和重新分配的基础。在此过程中，异常的元素富集可形成工业级的风化淋滤矿床。风化淋滤矿床可进一步区分出风化矿床和沉积—淋滤型矿床2种类型。传统的矿床学和沉积学研究方法在理解风化淋滤矿床形成过程中存在局限性，特别是在解析成矿阶段和动态成矿过程方面仍不甚明晰，导致该类型矿床在基础研究和勘查方面长期存在亟待解决的一批问题。本研究在厘清大陆风化作用、风化壳(古风化壳)、土壤(古土壤)等概念的基础之上，对现代风化淋滤剖面(如广西贵港三水铝石矿床)和古老风化淋滤型矿床(如中国华南地区早石炭世—晚二叠世铝土矿床及沉积淋滤型稀土矿床)开展了系统的沉积学分析与对比工作。研究发现，风化淋滤矿床的结构组分主要包括碎屑、团粒与包粒、块状黏土等结构类型，分别对应碎屑状、包粒状、致密状矿石的形成。成岩过程主要依赖于氧化物矿物及黏土质的胶结与填隙作用。基于上述认识，提出了风化淋滤矿床的淋滤序列和剖面结构划分方案。该方案以风化剖面中渗流带与潜流带作为基本的划分依据，进一步区分出风化矿床序列与沉积—淋滤型矿床序列，两者主要以是否出现沉积单位作为主要识别标志。以古气候为主线分析了风化淋滤矿床的成因机理，并结合近年来质量平衡计算相关成果，总结了淋滤过程中元素迁移规律，将风化淋滤型矿床的成矿过程概括为成矿母质形成、成矿物质风化和后期改造3个阶段。

江苏徐州地区寒武系馒头组发育极具特色的陆源碎屑组分与碳酸盐组分混合沉积现象。本研究以寒武系馒头组一套典型的混合沉积序列为例，依据剖面实测与镜下特征，对该序列中的混合沉积组合类型开展了系统的岩石学研究；通过分析不同沉积环境中的混合沉积特征，建立了陆表海近岸背景下陆源碎屑组分与碳酸盐组分混合沉积模式，探讨了各种混合沉积组合类型的混积成因类型、混积过程及主控因素等。结果表明：徐州地区寒武系馒头组混合沉积序列中主要发育含砂鲕粒灰岩、含内碎屑砂质灰岩、灰质细砂岩、含灰粉砂岩等11种混合沉积组合类型；混合沉积序列整体为陆表海海侵背景下次级海平面频繁波动且伴随多期次风暴作用的产物，主要表现为海侵作用下由近岸的混积潮坪逐渐演化为混积局限台地；混合沉积主要为相混合与间断混合，局部发育原地混合与母源混合。气候、陆源输入程度、海平面变化、碳酸盐产率是形成相混合的主控因素，同时也受到生物活动、水动力条件的调控；多期次风暴作用在主导间断混合形成的同时，一定程度上会促进相混合与母源混合的发育；在各因素叠加影响下，研究区具有多种混积成因类型组合发育的特征。厘清各种混积成因类型的分布与混积过程可为华北板块寒武纪古环境恢复与沉积演化提供参考，并为“深时”陆表海台地混合沉积相关研究提供典型范例。

目前对于被动大陆边缘沉积古环境演化的研究相对较少，特别是对上升洋流活动变化规律认识不足，导致对有机质富集主控因素认识不清。据此，以渝北地区下志留统龙马溪组为例，基于岩心/露头、矿物岩石学、有机地球化学和元素分析等资料，探讨被动大陆边缘页岩沉积古环境及其对有机质富集的控制。研究表明，区内有机质富集受保存条件、陆源输入和古生产力水平等因素控制，但不同时期主控因素存在差异：鲁丹期(LM1-LM5沉积期),保存条件、陆源输入和古生产力水平共同控制有机质富集，TOC含量最高；埃隆早期(LM6沉积期),盆地进入挠曲—迁移期，构造活动增强，渝北地区障壁开口打开，上升洋流活动增强，保存条件变差是造成TOC含量降低的主因；埃隆中期(LM7沉积期),迁移作用增强，障壁开口进一步打开，上升洋流活动达到最强，保存条件变差和古生产力水平急剧升高是导致TOC含量与LM6沉积期差异不大的主因；埃隆晚期(LM8沉积期),障壁开口向西北方向迁移，TOC含量降低，有机质富集主控因素与LM1-LM5一致；特列奇早期(LM9沉积期),海平面降至最低，以富氧环境为主，TOC含量降至最低，保存条件是控制有机质富集的主要因素。总体而言，研究区不同时期有机质富集主控因素变化与构造活动和海平面变化引起的沉积古环境变化密切相关。

The Jurassic Qigu Formation in the Yongjin area is a set of important oil-bearing strata in the central Junggar Basin. It is a typical deep-buried sandstone reservoir with a burial depth of 5400~6100 m,and its reservoir quality controls oil and gas reserves and production. In this paper,the diagenetic evolution process of deep-buried sandstone reservoirs in the Qigu Formation is studied by using the data of cast thin section,cathodoluminescence,scanning electron microscopy,XRD whole rock and clay mineral analysis. A diagenetic sequence is established,and the impacts of various diagenetic processes on reservoir quality are quantitatively assessed,integrating regional burial and hydrocarbon charge histories to delineate the reservoir’s diagenetic evolution. The lithology of the Qigu Formation reservoir in the Yongjin area is mainly composed of feldspathic lithic sandstone and lithic sandstone. The cement includes mainly carbonate minerals,siliceous minerals and clay minerals with low composition maturity and high texture maturity. The reservoir space types are mainly the remaining primary intergranular pores and secondary intergranular dissolved pores. Overall,the reservoir porosity changes are mainly controlled by compaction,cementation and dissolution,which are the main diagenetic factors reducing reservoir porosity,resulting in primary pore loss rates of 65.98% and 21.80% respectively. Dissolution increases the porosity by 5.13%,which effectively improves the physical properties of the reservoir. The comprehensive study shows that the diagenetic evolution of the Qigu Formation reservoir in the Yongjin area is mainly controlled by four factors: sedimentary environment,diagenesis,burial history and oil and gas charging. Diagenesis plays a role in the transformation of reservoir physical properties and is the critical determinant of the observed reservoir heterogeneity.

Uplift processes of the southern margin of the North China Block are of great significance for understanding interactions between the Qinling Orogenic Belt and the North China Basin. Based on sedimentary facies analysis,this paper studies the detrital zircon U-Pb geochronology and fission track chronology of the Permian Shihezi Formation in Luonan area,and discusses the source characteristics and uplift processes of the southern margin of the North China Block. It is expected to provide a sedimentary constraint for the subduction time of the Mianlue Ocean Basin and provide a possible source area for the Triassic recycled sediments in the southern North China Basin. The results show that the Permian Shihezi Formation in Luonan area experienced an upward change in sedimentary facies from alluvial fan to braided river,and then to delta. The sample from the lower part of the strata contains three groups of U-Pb ages,i.e.,353-280 Ma,1139-400 Ma,and 2620-1306 Ma. The fission track ages are decomposed into three peaks of 199 Ma,255 Ma,and 408 Ma. The sample from the upper part of the strata contains two U-Pb age groups,i.e.,339-259 Ma and 2655-1700 Ma,and the fission track ages were decomposed into three peaks of 205 Ma,268 Ma and 656 Ma. The results show that the southern margin of the North China Block received sediment from the Qinling Orogenic Belt during the early sedimentary period of the Shihezi Formation,but the sediments mainly came from the northern margin of the North China Block in the late depositional stage. The tectonic pattern had been transformed from high in the south to high in the north in this time. The initial uplift of the southern margin of the North China Block occurred during the Middle-Late Permian,which was related to the initial subduction of the Mianlue Ocean Basin,and became a potential provenance area to the Triassic strata in the south of the North China Basin.

The mineral composition and particle size of heavy minerals in sediment are important indicator for revealing sediment sources and hydrodynamic sorting processes. However,due to the limitations of research methods,there is still no research on the relationship between the heavy mineral composition, provenance and hydrodynamic sorting of fine-grained sediments in the Yangtze River. In this study,the TESCAN Integrated Mineral Analyzer(TIMA)was used to study the composition and particle size of heavy minerals in different water layers of the Yangtze River Estuary and East China Sea inner continental shelf. In parallel, the automatic identification results of fine-grained heavy minerals were verified by electronic probe analysis. The study shows that the characteristic heavy mineral assemblages in the suspended solids in the Yangtze River Estuary is hornblende,epidote and ferruginous metal minerals,which is consistent with the characteristic heavy mineral assemblages in the sediments of the lower reaches of the Yangtze River. There is an excellent correlation between the heavy mineral composition of suspended matter in the Yangtze River estuary and sediment in the lower reaches of the Yangtze River,indicating that its source is related to the Yangtze River. However,hematite/magnetite is relatively enriched in the suspended matter outside the Yangtze River estuary,which may be the result of the reworking and diffusion of medium density heavy minerals caused by strong tide. It is worth noting that abnormal enrichment of chromite appears in suspended matter samples at stations near Zhoushan Islands,which may be related to human production activities in the sea area. The vast majority of suspended heavy mineral particles in the Yangtze River Estuary are coarse silt to extremely fine sand,enriched in the coarser fractions(Ф<D_0.5)of suspended solids,which are mainly carried and transported by runoff. There is no significant difference in the particle size between different types of heavy minerals in suspended solids in different water layers, indicating that they are less affected by sedimentation differences.

The boundary belt of the eastern margin of Ordos Basin is believed to be composed of the Jinxi flexural fold belt and Lishi fault,but this boundary is a residual boundary and not the original sedimentary boundary. Taking the northern region of Shillou as an example,a regional geological profile was constructed at the basin-mountain scale in the eastern part of the Ordos Basin. The 2D-Move software was used for inversion and forward simulation of tectonic evolution,and quantitative analysis of structural deformation was conducted. Based on theseresults,the eastern boundary of the Ordos Basin was redefined. (1)In the late Caledonian period,the northern part of the Shiliouarea was affected by deep basement fault activity,and salt detachment folds were formed in the Ordovician gypsum salt rock layers,followed by the deposition of the Carboniferous,Permian,Triassic,Jurassic and Cretaceous systems. During the Yanshanian,the strata were subjected to E-W compressive stress,causing the overall strata to tilt. In the Cenozoic Lvliang uplift,they accelerated and underwent differential weathering and erosion,forming the present tectonic pattern. (2)The present length of the regional geological profile is 263.76 km,with an altitude of up to 2000 m. The shortening of strata from the late Caledonian to the Cretaceous sedimentary period is 3.14 km,with a shortening rate of 1.18%. The elevation of the formation uplift is 3.82 km. (3)Based on the characteristics of stratigraphy,structure,and evolution,the eastern boundary of the Ordos Basin during the Yanshan Movement is redefined,and it is believed that the eastern boundary should extend easternward to the east side of Lvliang Uplift. This paper can provide a reference and new ideas for studying the eastern margin of the Ordos Basin,structural deformation,and coalbed methane exploration and development in the western Shanxi flexural fold belt.

The carbonate-evaporite symbiotic system is a rock symbiotic association formed by chemical depositional differentiation. Microfacies analysis and sedimentary model construction of such a system are conducive to revealing the sedimentary information that have guiding significance for oil and gas exploration in evaporatic environments. Based on a large number of borehole data of the Majiagou Formation in Ordos Basin,macro-and microscopic observation of the rocks was carried out to identify sedimentary microfacies,analyze sedimentary sequence,and construct sedimentary model.The results show that there are ten types of sedimentary microfacies(MFT1-MFT10)in the carbonate-evaporite symbiotic system of the Majiagou Formation: halite,gypsum,gypsum-bearing dolomite,laminated dolomite,crystalline dolomitic grainstone,microcrystalline dolomite,microbial dolomite,bioturbated dolomite,laminated limestone,crystalline grainstone. four types of sedimentary sequence are developed in the symbiotic system: (1)upper intertidalto supratidal dolomite-gypsodolomite-argillaceous dolostone;(2)lower intertidal evaporite-algal dolomite-dolomite;(3)subtidal laminated limestone-churned limestone-bioturbation limestone;(4)lagoonal laminated evaporite-lumpy evaporite-salt rock. Evaporites of the Majiagou Formation were formed during the shallow basins period and low sea level period,while carbonates were formed during the high sea level period.The giant carbonate-evaporite symbiotic system formed through repeated fluctuations in sea level.

The deep-water area of the northern South China Sea experienced a transition from lacustrine to marine environments in the Paleogene,and has rich oil and gas resources and broad exploration prospects. Due to the limitation of water depth,the provenance of sediments and the palaeogeographic evolution of the basin are not clear. In this paper,the Paleogene of the Zhu-2 depression in the Pearl River Mouth Basin is systematically studied by means of detrital zircon U-Pb ages and source-sink correlation. The results show that in the Early and Middle Eocene,the sediments of the Zhu-2 depression were mainly from local uplift area around the depression. In the Late Eocene,the Kunyingqiong River originated from the western side of the depression provided a large amount of sediments for the basin,whereas the Paleo-Pearl River sediments had little influence on the deposition in the depression. In the Oligocene,the Paleo-Pearl River crossed the Panyu low uplift and entered the Baiyun sag,carrying sediments mixed with the Kunyingqiong River sediments in the form of delta deposition in the north and mid-west of the sag,forming a dual provenance river-delta system. The Paleogene provenance evolution of the deep-water area of the northern South China Sea was obviously controlled by regional tectonic palaeogeography of the Mesozoic. Identifying the provenance evolution during this period is of great significance for restoring the regional palaeogeography pattern.

The‘Taishan earthquake’ named after Mount Taishan,occurred in 1831 BC,which was the earliest historical earthquake recorded by writing-materials in China. Bamboo Annals recorded that the strong earthquake occurred,when the emperor named “Fa” was climbing the Mount Taishan in the seventh year of Xia Di Fa(i.e.1831 BC). The earthquake shocked the emperor at that time,so for the first time,it was written and named after Mount Taishan. Apparently,the geographical position that the emperor “Fa” was threatened by the earthquake was at the hillside of the Mount Taishan. However,seismic geologists have been unable to find any seismic-geological records or traces of the historical earthquake in the Taishan area and its surroundings. Therefore,the epicenter and magnitude of the “Taishan earthquake” have been a mystery. By reobserving the discovered seismo-geological remains,combined with a series of tests,experiments and analysis,the paper provides evidences that the “Taishan earthquake” was a strong and historical earthquake with its epicenter located in the Anqiu area within the Tanlu fault zone. First of all,in the Holocene soft soil layers of limnetic facies in the Anqiu-Xiazhuang Basin of the Tanlu fault zone about 200 km away from Mount Taishan,there are macroscopical seismic traces such as seismic-subsidence synclines and co-seismic micro-faults,which recorded epicenter-intensity for degree of IX ,seismic magnitude for M7.0. Second,by means of the results of dating¹⁴C isotope,combining with calculating the sedimention time of the related soil layer,the earthquake time(i.e.1827 BC)obtained is very close to 1831 BC. Third,based on seismic intensity attenuation model in North China,the attenuation intensity induced by the earthquake is calculated to the degree of VI near Taishan. The Chinese earthquake intensity table shows that the VI intensity completely makes people stand unstable or escape outdoors,which accords with the historical records that the mountaineering emperor was frightened by the earthquake.

为了深化对湖相细粒沉积岩储集层的认识，以渤海湾盆地济阳坳陷沾化凹陷渤南洼陷沙三下亚段（Es3L）为研究对象，利用岩心描述、薄片鉴定、扫描电镜观察、物性分析和测井曲线，揭示了储集层特征、分布规律及其主控因素。基于矿物组成、沉积构造和有机质含量，将渤南洼陷Es3L细粒沉积岩划分为6类岩相：富有机质纹层状灰质细粒混积岩（LF1）、富有机质纹层状长英质细粒碳酸盐岩（LF2）、富有机质层状灰质细粒混积岩（LF3）、富有机质层状/块状长英质细粒碳酸盐岩（LF4）、富有机质层状含长英细粒碳酸盐岩（LF5）、含有机质块状含长英细粒碳酸盐岩（LF6）。储集层的主要储集空间为粒间孔、晶间孔、溶蚀孔和层间微裂缝，储集层孔隙度主要介于0.67%～5.56%之间（平均值为4.93%）,渗透率主要介于（0.02～4.87）×10^-3μm²之间(平均值为0.59×10^-3μm²)。渤南洼陷Es3L细粒沉积岩储集层分布的主控因素包括岩相、沉积环境、成岩作用和有机质热演化。渤南洼陷Es3L的中下部的陆源输入水平低、水体盐度大、水体分层性强，主要发育岩相LF2和LF4,容易发育Ⅰ类和Ⅱ类优质储集层。渤南洼陷Es3L细粒沉积岩储集层处于中成岩A阶段，黏土矿物转化作用、溶蚀作用、重结晶和白云石化以及有机质热演化产生次生孔缝，改善了储集层物性。

During the Caledonian tectonic movement period,the Ordos Basin was uplifted as a whole in the Middle and Late Ordovician,and underwent deposition again in the Late Carboniferous. It has experienced nearly 150 million years of weathering and erosion,resulting in the development of an Ordovician carbonate weathering crust,which is highly important for natural gas accumulation. In this paper,a typical well was selected from the southern margin of the Ordos Basin. Based on the mineral composition,major and trace elements,and logging response characteristics,the vertical structure,degree of weathering and alteration,and paleoclimate environment of the weathering crust were analyzed,and the formation process and preservation mechanism were reconstructed. The results indicate that: (1)The weathered crust can be divided into a weathered residual layer,a strongly weathered layer,a weakly weathered layer,and a bedrock layer from top to bottom. The overall weathering degree is strong,and the logging response characteristics in each layer segment are very significant. (2)In this weathering crust profile,the main elements TiO₂,Al₂O₃,and Fe₂O₃ are enriched,with slight depletion of SiO₂ and strong depletion of Ca,Mg,and Na. (3)Based on paleolatitude data and relevant geochemical indicators,it is believed that the southern part of the Ordos Basin developed transitional sedimentary facies between sea and land during the late Paleozoic. The average annual temperature during the formation of weathered crust was 28.15 ℃,and it was in a humid-semi-arid environment,belonging to a tropical-subtropical climate. (4)The widespread development of cracks in each layer of the weathered crust indicates the existence of a karst fracture-cave system in the southern region of the Ordos Basin. Although the thickness of each structural layer of the weathered crust varies due to the influence of terrain elevation differences in the later stage,the probability of preserving the weathered crust structural layer is greater in areas with relatively flat terrain,suggesting that this location is favorable for later exploration of weathered crust gas reservoirs. These results can provide a reference for the exploration of oil and gas reservoirs in karst weathering crusts in the Majiagou Formation and aluminum-bearing rock series in the Benxi Formation in the Ordos Basin in the future.

It is suggested that the spatio-temporal evolution of the Jehol Biota in northeastern North China is driven by the North China Craton destruction during the Early Cretaceous,due to the abrupt changes in paleogeographic environment. However,little quantitative work on the dynamic paleo-landscape evolution in North China has been done. In this study,we employed paleosoil weathering indices(PWI and CFX_Na)and carbonate isotopes to reconstruct the paleo-elevation of North China around 145 ma. We then integrated factors such as tectonic movements,sedimentology,paleoclimate,and sea level changes using the Badlands software to model the Early Cretaceous paleo-landscape evolution of North China. Our findings reveal that the eastern North China experienced an abrupt geomorphological transition from the collapse of a paleo-plateau to the formation of the Bohai Bay Basin due to the subduction retreat of the paleo-Pacific Plate. The geomorphological transitions led to the formation of a series of eastward-migrating rifted basins,including several newly-formed isolated intermountain basins in the Yanshan area where the Jehol Biota first emerged. Frequent volcanic activity provides rich nutrients for the lakes,and the paleoclimate turns to warm and humid gradually,which provide favorable conditions for the prosperity of the Jehol Biota. The eastward migrating subsidence basin,eruption of volcanoes and suitable paleoclimate jointly controlled the eastward migration of the Jehol Biota.

中国北方烧变岩广泛发育，常见侏罗系煤层于中生代、新生代自燃形成的烧变岩。在烧变岩露头区，白色砂岩常与红色烘烤岩伴生，但国内外对其关注不够，成因不明。本次研究对伊犁、准噶尔、吐哈、鄂尔多斯等盆地周缘烧变岩区野外露头进行了观察，采集白色砂岩样品进行薄片鉴定、扫描电镜及能谱等测试与分析，对白色砂岩岩石学、矿物学特征进行观察和描述，认为中国北方侏罗系白色砂岩常分布在烧变岩的上覆、下伏或侧边位置，颜色多以灰白为主，结构疏松，孔隙发育，碎屑颗粒以石英、长石矿物为主，填隙物主要为高岭石，发育特殊的流体流动所致的孔洞构造；据其与烧变岩的空间相关性，推测白色砂岩的形成与煤层自燃有密切联系，煤层自燃导致高岭石大量生成、有色金属矿物或金属离子含量变化，这是砂岩呈现白色的主要诱因，因此烧变岩区所见白色砂岩为特殊类型的低温烘烤岩，其形成模式有3种：河谷下切型、裂隙下切型和山丘下渗型。

底流与重力流的交互作用是重要的深水沉积作用类型，对海底沉积物再分配及海底地貌改造具有重要控制作用。目前对底流与水道中重力流的交互作用研究较成熟，但对底流影响下朵体的沉积特征研究较少。本研究以东非鲁伍马盆地古近系中新统朵体为目标，综合利用三维地震和测井资料，通过地震相和地震属性分析，确定朵体分布及内部岩性特征。在定量恢复重力流流速基础上，结合区域洋流资料，揭示底流与重力流交互作用对朵体沉积的控制作用。结果表明受向北流动的底流影响，早期水道向南迁移，北侧天然堤发育，在水道南侧形成负向地形，导致后期朵体沉积于水道南侧。底流作用下的朵体沉积特征受底流和朵体内重力流流向的影响。当底流与朵体延伸方向相反且斜交时，由于重力流流速远大于底流，朵体在逆底流流向一翼(南侧),重力流与底流流向几乎相反，底流影响被抑制，朵体从轴部向末端逐渐变薄，泥质含量增加；在顺底流流向一翼(北侧),重力流方向与底流斜交，重力流顶部泥质被底流淘洗出去，朵体以砂质沉积为主。当底流与重力流流向接近正交时，朵体受底流影响整体上一致，重力流顶部泥质被淘洗，逆底流流向一翼朵体以厚层砂质沉积为主，向顺底流流向一翼砂体厚度减小、泥质含量增加。

随着气候模式在古气候研究中的应用越发广泛，更加准确的古地理边界条件重建成为研究深时气候变化机制的关键，而古地理边界条件重建过程中的不确定性却少有人关注。本研究基于古海陆分布、古海深、古地形重建方法及资料选择，研究古地理边界条件重建过程中的不确定性以及其对气候模式模拟结果的影响。结果显示，重建过程中板块运动模型的选择、海陆分布的修正、海洋洋壳年龄数据的更新、大洋深度—洋壳年龄关系模型选择、沉积物模型选择以及古地形高度代用指标的选择都会导致不同的古地理边界条件重建结果。更重要的是，这种古地理边界条件的差异会进一步影响模式模拟结果中的温度、盐度以及洋流等重要的气候环境变量。这表明重建气候模式中古地理边界条件时需根据具体需求合理选择重建资料，同时也需基于密集和可靠的代用指标进一步优化重建资料，从而减少古地理边界条件对古气候模式结果可靠性的影响。