Lakes serve as one of the significant sinks for organic carbon. For lake deposits, it is generally accepted that water depth is a primary control on the spatial distribution of total organic carbon (TOC) accumulation because the deeper part of a lake potentially has a higher organic population to be settled. However, lake TOC distribution is often spatially variable regardless of water depth, and an exact mechanistic explanation of TOC hotspots that do not align with the deepest water depth remaines unsolved. We suggest that flocculation significantly influences the lake TOC distribution pattern. The flocculation of fine sediment is possibly a major contributor to the occurrence of high TOC in deposits, as organic material aggregates with flocculated sediment during settling. The process of flocculation positively correlates with water salinity and thus potentially enriches TOC in deposits under a high saline condition. Furthermore, depending on the extent of flocculation, a lake entering plume type is different, leading to different run-out distances. Therefore, to investigate the role of flocculation associated with the TOC pattern in a lake, we design settling and gravity flow experiments with varying salinity and sediment concentration. Considering the flocculated grain size is seldom recorded in deposits, the current study provides a possible mechanism for why sediments with similar grain size deposited at similar water depths could have varying TOC content. This leads to a better understanding of the spatial distribution of carbon storage and the formation of source rocks associated with hydrocarbon reservoirs.

SignificaneThe analysis of source-to-sink system is a comprehensive study of tectonic geology, sedimentology, and sequence stratigraphy. Because of its integral, dynamic, and semiquantitative-quantitative characteristics, it has attracted widespread attention.ProgressThis review first introduces the key issues of the deep-time source-to-sink systems (pre-Quaternary systems), which include the quantitative characterization of sediment mass balance and the control of the transport process on the sediment. Due to the lack of stratigraphic records and the difficulty in obtaining parameters, the research is still challenging.Second, it reviews the quantitation methods of deep-time source-to-sink systems that can be classified into three categories, namely, geochronology, uniformitarianism, and sedimentology. By obtaining information such as geomorphological parameters, hydraulic parameters, erosion rates, and sediment flux, various methods establish the quantitative relationships between "sources" and "sinks" and then rebuild the sedimentary basin infilling history. This article introduces the principles and related parameters of different methods and then compares the advantages and limitations to provide a reference for future research. It is believed that geochronology is widely used, and the core lies in provenance analysis. The key to uniformitarianism is the analogy of geological background and the selection of geological parameters. The sedimentology is controlled by multiple variables, and the tectonic-climate background and research scale need to be considered comprehensively.Conclusions and ProspectsFinally, this review states the development of quantitative analysis of deep-time source-to-sink systems. Under the guidance of the important idea of "the present is the key to the past", the research needs to focus on the provenance systems, sediment routing systems, sediment dispersal, and redistributive process, and coupling relationship between various parameters. Research also needs to pay attention to quantitative analysis at multiple timescales and multidisciplinary dynamic analysis. Compared with continental margin source-to-sink systems, continental lacustrine source-to-sink system patterns and prediction models need to be further improved.

源-汇系统是目前国内外地球科学领域的研究热点,对于含油气盆地古地理重建以及源储预测评价有着重要的指导作用.本文以准噶尔盆地二叠系为研究对象,通过基于盆地地质大剖面的构造-层序特征分析、定年数据的物源体系演化分析和沉积过程约束的正演模拟等方法,深化了对准噶尔盆地二叠纪古地理格局的认识,探讨了二叠纪源-汇系统演化特征与二叠系源储分布规律.早二叠世为盆地断陷发育期,以石炭系为主物源,除东南部发育海相-海陆过渡相沉积外,总体以近物源扇三角洲-湖相沉积体系为主,多断陷的沉积格局控制了玛湖等凹陷优质烃源岩的分布,与火山岩相关的扇三角洲前缘砂体与混积云质岩构成有利储集体;中二叠世为盆地断-拗转换期,物源年龄开始趋于复杂,沉积中心、沉降中心较早二叠世明显向盆内迁移,早期断陷趋于连通,盆地西部仍以近物源的扇三角洲群-湖相沉积体系为主,东南部则转换为远物源三角洲群-湖盆沉积体系,在盆地中部发育连片分布的规模烃源岩,可与同期(扇)三角洲前缘形成良好的源储组合;晚二叠世进入盆地拗陷发育期,物源供给范围更广,物源年龄进一步复杂化,大型浅水湖盆发育远物源为主的退覆型河流-三角洲沉积体系,为盆地规模油气成藏奠定了储层基础.

0 INTRODUCTION The breakthroughs in unconventional petroleum have a great impact on world petroleum industry and innovation in petroleum geology（Dou et al, 2022; Jia, 2017; Zou et al., 2015b, 2014a; Yerkin, 2012; Pollastro, 2007; Schmoker, 1995）. The exploration and development evolution from conventional petroleum to unconventional petroleum and more and more frequent industrial activities of exploring petroleum inside sources kitchen have deepened theoretical understanding of unconventional petroleum geology and promoted technical research and development(Jia et al., 2021, 2017; Jin et al., 2021;

Through core observation, thin section identification, and logging and testing data analysis, the types and characteristics of event deposits in the ninth member of Yanchang Formation of Triassic (Chang 9 Member) in southwestern Ordos Basin, China, are examined. There are 4 types and 9 subtypes of event deposits, i.e. earthquake, gravity flow, volcanic and anoxic deposits, in the Chang 9 Member in the study area. Based on the analysis of the characteristics and distribution of such events deposits, it is proposed that the event deposits are generally symbiotic or associated, with intrinsic genetic relations and distribution laws. Five kinds of sedimentary microfacies with relatively developed event deposits are identified, and the genetic model of event deposits is discussed. Seismites are mainly developed in the lake transgression stage when the basin expands episodically, and commonly affected by liquefaction flow, gravity action and brittle shear deformation. Gravity flow, mainly distributed in the high water level period, sandwiched in the fine-grained sediments of prodelta or semi-deep lake, or creates banded or lobate slump turbidite fan. It is relatively developed above the seismites strata. The volcanic event deposits are only seen in the lower part of the Chang 9 Member, showing abrupt contact at the top and bottom, which reflects the volcanic activity at the same time. Anoxic deposits are mostly formed in the late stage of lake transgression to the highstand stage. Very thick organic-rich shales are developed in the highstand stage of Chang 9 Member, and the event deposits in the depositional period of these shales are conducive to potential reservoirs.

More and more attention has been paid to the sedimentary forward modeling (SFM) since the study on the sedimentology is targeted toward quantification, process orientation and systematization. This review first stated the main input and output data of the current sedimentary forward modeling and sorted out the determination methods of the input parameters. Then it reviewed the classification methods of the sedimentary forward modeling, and the classification principles included principle of simulation, number of simulation processes, types of simulation results, simulation dimension, simulation scale, data fidelity and source region covering source-sink system. Subsequently, it introduced the sedimentary forward modeling methods for the different sedimentary systems of clastic series, including hillside landform, river and deep-draft waterway, delta, lobe and landslide. It also described some classic simulation programs for the individual series, indicated the sedimentary characteristics of this series to be essentially simulated and their corresponding principles of simulation and covered multiple simulation methods as much as possible to expand the understanding of the sedimentary forward modeling. Finally, it looked into the development of the sedimentary forward modeling believed it would be targeted toward the three-dimension visualization, multi-process integration and multi-discipline integration, proposed to strengthen the training of compound talents in computer, mathematics, mechanics and geosciences; strengthened the experimental study on the sedimentary forward modeling hypothesis to study the sedimentation theory; tried multiple simulation methods and shifted the application foremost to the research and development foremost.

溶蚀作用是玛湖凹陷黄羊泉地区百口泉组储层孔隙形成的重要成岩事件.砾岩储层泥砂砾混杂,孔隙结构复杂,成岩流体运移模式不明确,溶蚀作用是否提高储层物性取决于溶蚀副产物是否被有效带出.因此,溶蚀作用对砾岩储层物性的影响值得进一步研究.在砾岩储层岩相分类基础上,通过铸体薄片中矿物溶蚀量的精确统计,结合物性、扫描电镜、Quemscan矿物分析、X射线衍射和包裹体等分析测试,系统研究了砾岩储层中溶蚀作用对储层物性的影响.研究表明:溶蚀作用副产物主要为自生石英和自生黏土矿物.第一期石英次生加大主要来源于蒙皂石向伊利石转化,第二期石英次生加大主要来源于石英颗粒的压溶作用;伊利石主要来源于凝灰质溶蚀、高岭石和蒙脱石的转化;促进形成绿泥石所需的Fe2+主要来源于研究区内大量火山岩碎屑.溶蚀作用对不同类型岩相储层物性影响不同.以岩相类型Ⅰ为主的储层含少量矿物溶蚀孔和贴粒缝,溶蚀作用较弱,储层物性低;以岩相类型Ⅱ为主的储层多见凝灰质溶蚀形成的溶蚀孔,孔隙内沉淀大量伊/蒙混层和伊利石,孔隙度分布范围较大,渗透率低,溶蚀作用对此类储层仅进行物质再分配;以岩相类型Ⅲ为主的储层,含大量长石和岩屑溶蚀孔,溶蚀作用对储层物性有一定的提升.

AbstractDuring late Carboniferous time, the residual ocean basin gradually closed in West Junggar and only a small amount of seawater remained in the Hala’alat Mountain area, where discussions of provenance and tectonics are limited. In this study, LA-ICP-MS U–Pb dating and heavy mineral identification are conducted on the upper Carboniferous tuffaceous sandstones from the Hala’alat and Aladeyikesai formations in the Hala’alat Mountain area. The results reveal the low maturity of the clastic sediments, indicating proximal deposition. The Hala’alat Formation detrital zircons present a single peak (c. 330 Ma). Speculatively, the primary provenance is the Boshchekul–Chingiz Arc, and the secondary sources are the Darbut Tectono-Magmatic Belt and island arcs in the basin. The main peak and provenance of the Aladeyikesai Formation are similar to those of the Hala’alat Formation. Moreover, several age groups, namely, 370–344 Ma, 427–404 Ma and 478–476 Ma, potentially correspond to provenances of the Darbut Tectono-Magmatic Belt, the Boshchekul–Chingiz Arc and the Kujibai–Hongguleleng Ophiolitic Mélange Belt. In addition, the maximum depositional ages of the Hala’alat and Aladeyikesai formations calculated are 314.6 ± 1.54 Ma and 330.8 ± 0.61 Ma, respectively. Comprehensive analysis shows a relatively singular provenance of the Hala’alat Formation. While the provenance of the Aladeyikesai Formation shows inheritance, the provenance area extends northwards to the Kujibai–Hongguleleng Ophiolitic Mélange Belt. Furthermore, the closure of the Junggar Ocean during Carboniferous time caused the potential source region of the Hala’alat Mountain area to migrate northeastwards from Barleik Mountain to Xiemisitai Mountain. This study provides a basis for the analysis of regional geological evolution.

Based on the data of outcrops, seismic sections, thin sections, heavy mineral assemblages and detrital zircon U-Pb dating, the sedimentary characteristics, lake level fluctuation and provenance characteristics of the Middle Jurassic Lianggaoshan Formation (J2l) in eastern Sichuan Basin, SW China, were investigated to reveal the control of tectonic movements of the surrounding orogenic belts on the sedimentary systems. The J2l mainly developed a delta—lake sedimentary system, which contained a complete third-order sequence that was subdivided into four lake level up-down cycles (fourth-order sequence). The lake basins of cycles I and II were mainly distributed in eastern Sichuan Basin, while the lake basins of cycles III and IV migrated to central Sichuan Basin, resulting in the significant difference in sedimentary characteristics between the north and the south of eastern Sichuan Basin. The provenance analysis shows that there were three types of provenances for J2l. Specifically, the parent rocks of Type I were mainly acidic igneous rocks and from the proximal northern margin of the Yangtze Plate; the parent rocks of Type II were intermediate-acid igneous rocks and metamorphic rocks and from the central parts of the southern and northern Qinling orogenic belts; the parent rocks of Type III were mainly metamorphic rocks followed by intermediate—acid igneous rocks, and from the North Daba Mountain area. It is recognized from the changes of sedimentary system and provenance characteristics that the sedimentary evolution of J2l in eastern Sichuan Basin was controlled by the tectonic compression of the Qinling orogenic belt. In the early stage, the lake basin was restricted to the east of the study area, and Type I provenance was dominant. With the intensifying north-south compression of the Qinling orogenic belt, the lake basin expanded rapidly and migrated northward, and the supply of Type II provenance increased. In the middle and late stages, the uplift of the North Daba Mountain led to the lake basin migration and the gradual increase in the supply of Type III provenance.

被动大陆边缘依据地貌可分为平直型与S型,前人对其控制作用的研究多集中在三角洲发育与深水沉积物输入量2个方面,而对于峡谷和海底扇的影响以及坡折的作用仍然缺乏定量化的系统研究.采用沉积正演方法,研究S型与平直型被动大陆边缘上的沉积体系特征的异同点,系统对比了沉积体系分布、沉积物配置关系、层序格架发育、演化特征,以及河流和浊积水道特征.研究表明,S型边缘三角洲欠发育,进积为主,加积为辅,峡谷内可见明显凹岸侵蚀,海底扇为沉积物主要卸载区域,总体受海平面升降影响小;而平直型边缘三角洲高度发育,加积为主,进积为辅,峡谷中上部被三角洲沉积覆盖,海底扇几乎不发育,总体受海平面升降影响大.进一步研究表明,陆架坡折导致沉积物在陆架之上贮存少,向深水区搬运多,而陆坡坡折导致沉积物在陆坡上贮存少,在峡谷口大量卸载.

The debate on the submarine canyon origin between the upslope erosion model dominated by retrogressive mass failures and the downslope erosion model controlled by gravity flows has not been fully settled. However, this debate is critical for explaining submarine canyon evolution. This study combines susceptibility mapping and stratigraphic forward modeling (SFM) to examine the origin and evolution of submarine canyons under various fluvial discharge and morphologies. The SFM work consists of dozens of hypothetical numerical experiments based on typical passive margin bathymetry with half bathymetry occupied by an incipient canyon and associated river mouth topography, and another half bathymetry by steep slopes without canyons. Evolution characteristics in both plan and cross-section views are analyzed, and the impacts of fluvial and morphological features on canyon evolution are tested.The results indicate that the submarine canyons retreat landward, tributaries develop on the canyon outer banks, and blind canyons grow landward to capture small gullies and form shelf-incising canyons. The upslope pattern is dominant regardless of changes in fluvial discharge and morphologies. The locations of tiny gullies on steep slopes determine the distribution and growth direction of submarine canyons, whereas fluvial conditions and morphology parameters affect the canyon dimensions. High fluvial discharge and high canyon sidewall slope angle promote tributary development and canyon erosion. High canyon sinuosity leads to an asymmetrical distribution of tributaries on canyon outer banks whereas high regional slope angle increases the canyon length and decreases the canyon spacing.This study settles the debate between the upslope and downslope erosion models. In addition, it refines the up slope model by highlighting the importance of small-scale gullies and testing the influence of fluvial and morphological conditions on canyon evolution. The conclusions could promote the understanding of submarine canyons and assist in reservoir exploration and hazards prevention.(c) 2021 Elsevier B.V. All rights reserved.

The Middle Permian Lucaogou Formation is the source rock and the main oil shale pro-ducing formation in the southeastern Junggar Basin. This study focused on the Lucaogou Formation exposed in two outcrop sections on the northern flank of the Bogda Mountain, namely the Jingjingzi-gou and Dalongkou sections. Here, we present integrated analysis of the sedimentology, major and trace elements, mineral components and total organic carbon contents. The paleo-environment was re-constructed including provenance, redox conditions, paleo-salinity, chemical weathering intensity and primary organic matter productivity. The results showed that the upper and lower units were deposited in distinct depositional environments with different organic matter accumulation mechanisms. The low- er unit was characterized by low lake level, dry climate, fresh-brackish and well-oxygenated water. While during the deposition of the upper unit the lake level rose, climate turned wetter and the bottom water became less oxidized and much saltier. The mechanism of the organic matter accumulation is dif- ferent for these two units. The preserved organic matters were mainly controlled by the primary pro- ductivity in the lower unit and by the redox conditions in the upper unit.

The basin type of the Junggar Basin changed during the Permian, but the time constraint of the tectonic evolution remains unclear. Besides, the fan deltas developed in the Permian in the Mahu Sag in the northwestern of the oil-rich basin. However, the provenances of the sedimentary systems remain unclear. Based on petrology and detrital zircon U-Pb ages, this study investigates the source-to-sink systems evolution and tectonics implications. Abundant lithic clasts in sandstones with low compositional and textural maturity imply proximal sources. The dating results showed a dominant peak (310–330 Ma) and a secondary peak (400–440 Ma) in the northern Mahu Sag, only one peak at 295–325 Ma in the central Mahu Sag, several peaks at 270–350 Ma in the southern Mahu Sag, and multiple peaks at 370–450 Ma in the Zhongguai Uplift. Thus, the north-western Junggar Basin was divided into four major source-to-sink systems, with adjacent central West Junggar as the main provenance and northern and southern West Junggar as the secondary provenance. The proportion of sediment supply from the southern and northern West Junggar is higher during the Middle-Late Permian. It suggests that the source-to-sink systems show inheritance and evolve from a single provenance into a complex provenance, indicating the uplift of West Junggar. The tectonic inversion may occur early in the Middle Permian and the response to tectonic activity is stronger in the southern West Junggar than in the northern West Junggar.

Morphology is one of the principal driving forces governing the sedimentology and evolution of delta‐canyon‐fan systems. However, quantified and systematic studies of morphological controls are still very limited. This study applied hydraulic‐based stratigraphic forward modelling to investigate the impacts of morphological parameters on sediment budget partitioning and channel network of delta‐canyon‐fan systems on passive margins. A total of six sets of stratigraphic forward models are built using 47 initial bathymetries with six varying morphological parameters: shelf gradient; shelf width; slope gradient; canyon sinuosity; canyon depth; and basin gradient. The quantified relationships between morphological parameters and sedimentological parameters (dimensions, deposition/erosion volume/area, number of tributaries and slope channels) are investigated. The causes behind the relationships are explored by analyzing the response of qualified sedimentary features to morphological controls, such as grain‐size distribution, channel migration and sequence stratigraphic frame. The results suggest that low shelf gradient, low shelf width, high canyon gradient and low canyon sinuosity are beneficial for sediment budget partitioning into deep basins and turbidity currents to flow inside canyons. Low canyon depth also promotes sediment delivery but results in more channels on canyon flanks. For the delta, channel lateral migration increases then decreases with increasing shelf gradient due to the gradient threshold in determining channel sinuosity; delta size increases then stops increasing with increasing shelf width due to the shelf width threshold in determining the balance between accommodation and sediment supply. For the canyon, low canyon gradient, high canyon sinuosity and low canyon depth have similar effects on canyons, all resulting in significant channel translation and canyon widening but less canyon head retrogradation. This study improves the knowledge of controlling factors and sediment transport regime of a delta–canyon–fan system. Moreover, the observed relationships could provide semi‐quantitative guidelines to predict the dimensions of delta–canyon–fan systems and the distribution of hydrocarbon reservoirs.

坳陷湖盆大型浅水三角洲是目前中国陆上岩性油气藏规模储量增长的主体.通过对松辽盆地南部上白垩统保乾三角洲和现代鄱阳湖赣江三角洲解剖,重点探讨湖盆浅水三角洲形成的地质背景、沉积特征与生长模式.结果表面:①坳陷湖盆具有形成大型浅水三角洲的沉积背景,敞流型湖盆导致的湖平面频繁升降控制了浅水三角洲的纵横向发育规模.②松辽盆地南部上白垩统发育2种不同类型的三角洲,深湖型三角洲一般呈朵叶状,沉积亚相展布清晰,沉积微相以分流河道、河口坝和分流河道间为主;浅湖型三角洲一般呈鸟足状或树枝状,沉积亚相分异不明显,沉积微相以分流河道和分流河道间为主,河口坝不发育;③通过现代沉积遥感定量分析,刻画了鄱阳湖赣江中支三角洲近50年的发育特征和演化规律,揭示了分流河道从分散树枝状到闭合结网状的生长过程.④坳陷湖盆大型浅水三角洲是不断发育的多期朵叶体在平面上拼接而成的复合体,其中分流河道是最重要的储集砂体类型,在平面上呈结网状分布,控制了大面积岩性油气藏的分布与富集.

This study examines the characteristics and pore evolution of the Baikouquan conglomerate reservoir in the Mahu sag of the Junggar Basin from original sedimentation and diagenesis. Analysis is based on core observation, thin section, X-ray diffraction, cathodoluminescence and image analysis, and combined with physical property and well log data. The results show that conglomerate reservoir in the Baikouquan Formation can be divided into three lithofacies types: Type I is argillaceous filling conglomerate facies, in which cementation and dissolution are not developed, and the interstitial material is mainly argillaceous; Type II is tuffaceous filling in fine conglomerate facies, in which volcanic rock debris, illite and dissolution are developed; Type III is sandstone filling conglomerate facies, in which cementation and dissolution are developed. The reservoir undergoes complex diagenesis, and the diagenetic sequence is: compaction→early chlorite film→early calcite cementation→detritus, feldspar and tuffaceous dissolution→quartz secondary enlargement→late calcite cementation→oil invasion→forming illite. Quantitative study of pore evolution shows that dissolution and calcite cementation are relatively developed in lithofacies Type III, and that compaction has a great influence on lithofacies Type I and II. According to comprehensive evaluation of lithofacies, diagenesis and pore structure characteristics, the reservoir space type is mainly the dissolution pore. It is mainly primarily mainly composed of lithofacies Type III, thickness of the gravel body is more than 25 m, porosity is generally more than 12%, which represents favorable conditions for the distribution of favorable reservoir.

A laboratory experiment on sedimentation is an experiment conducted under highly controlled conditions to simulate the sedimentary processes in a wide variety of sedimentary environments. It is a useful method which has been widely used in many scientific disciplines and sub-disciplines including hydraulics engineering， environmental science， environmental engineering， oceanography， sedimentology， as well as petroleum geology. The recent drastic increase in unconventional oil and gas production requires new insights into fine-grained sediment， such as processes of organic-sediment accumulation. Many equations or theories have been proposed for uncohesive sediments including physical properties of sand/clay particle， sedimentary bedforms， sedimentary landscapes， sediment gravity flows. However， because of their small grain size， and their cohesive properties， cohesive sediments present more of a challenge in the experiment and have been relatively understudied. A review is given of laboratory experiments on sedimentation of fine-grained cohesive sediments， with emphasis on the aspect of physical properties of particles， processes of erosion and deposition， sedimentary bedforms， transport mechanics and facies models， as well as organic matter accumulation and preservation. This article also discusses the organic matter transportation and accumulation in recent Qinghai Lake and proposes a hypothesis of accumulation of organic-rich fine-grained sediments. Laboratory experiments on sedimentation of fine-grained sediment are useful for both paleoenvironment reconstruction and lithofacies prediction， which can be applied to genetic analyses and prediction of sweet spots/areas in unconventional shale plays. A successful research of fine-grained sediment requires the application of methodologies and results of a broad range of scientific disciplines， a combination of physical and computational simulations， and some large-scale and long-term flume experiments.

The Junggar Basin is one of the very large, long-lived, Late Paleozoic lacustrine basins of China, developed by the closure of the early Paleozoic Junggar Ocean. The novelty of the reported research is outcrop measurements through the mid-Permian Jingzingzigou and Lucaogou formations, allowing reconstruction of interacting very coarse and very fine-grained alluvial-to-lacustrine depositional cycles within a km-thick succession of organic-rich mudstones. The deposits are interpreted as coarse grained fan deltas that extend subaqueously into Junggar lacustrine basin, depositing fine-grained muddy, sediment gravity flow deposits. The coarseness and frequency of both alluvial and subaqueous sediment gravity flows that thin and pinch out over short distances suggests that the margin of the basin was likely steep and fringed by relatively deep lake waters, but was not the main margin of sediment supply. The proposed depositional model highlights the process response to climate-driven lake-level changes around the steep lake margin. However, the coarse-grained alluvial to fan-delta cycles and the muddy lacustrine cycles occur at different thickness scales. The former (5-13 m thick) contain internal erosion surfaces and are dominated by river sheet flood and debris flow deposits and are likely incomplete due to frequent shifting, erosion and reworking of the sediments. The lacustrine cycles (few meters thick) are dominated by current-driven, very fine sandstone, siltstone and organic-rich mudstone beds with ripple lamination and graded beds, as well as dolomites during times or places where subaqueous currents were lacking. The age dating control is not detailed but we propose that depositional cycles were likely a response to Milankovitch orbital cyclicity, also suggested by previous Permian climate modeling, that cause alternating wet and dry periods and trigger tens of meters lake level changes with abrupt grainsize changes in the shallow proximal areas and more subtle changes in sediments of distal/deep lacustrine regions. The climate changes therefore cause both sediment supply changes subaerially and lake accommodation changes subaqueously, though these would also be modulated to a lesser extent in the resultant stratigraphy by autogenic responses and tectonic forcing of sediment yield.

鄂尔多斯盆地下三叠统刘家沟组与和尚沟组为一套规模巨大的红色砂泥岩沉积,其形成原因,仍存在疑问.以下三叠统刘家沟组与和尚沟组为研究对象,借助钻井岩心和野外剖面的观察描述、偏光显微镜、扫描电子显微镜、X射线衍射矿物成分分析以及主、微量元素分析等手段,结合红层上下其他颜色地层的对比,对这套红层的沉积特征和形成古气候背景进行研究,探讨其成因和成色机制.通过研究发现鄂尔多斯盆地的下三叠统刘家沟组与和尚沟组的红层是干旱炎热气候和强氧化环境的沉积产物,为原生成因,其红色主要来自作为染色剂的赤铁矿.通过上下不同颜色沉积岩对比研究发现,沉积岩出现不同的颜色主要是由于矿物组成不同,是盆地构造演化和气候环境变迁的结果.

This study presents a cyclostratigraphic investigation of the Mesoproterozoic Hongshuizhuang formation (about 1.45 Ga) in North China. High-resolution, continuous magnetic susceptibility and X-ray fluorescence elemental data were obtained from the YuanJi-2 drillcore. We tested the present astronomical age models using the multi-taper spectral analysis and correlation coefficient (COCO) methods from three paleoclimate proxies, i.e. magnetic susceptibility, Al and Ca elemental contents. The proxies record orbital forcing cyclicity with varying sensitivities which was attributed to their distinctive corresponded to depositional environments or diagenesis. The 405-kyr-calibrated ATS indicates the HSZ Formation has a similar to 3.1 Myr duration and an average sedimentation rate of similar to 3.94 cm/kyr. According to our results, the eccentricity at 1.45 Ga has cycle periods of similar to 405, similar to 125, similar to 115 and similar to 90 kyr. In addition, several significant cycle periods at similar to 28-20 kyr, similar to 18.2 kyr and similar to 16.3-14 kyr are regarded as the obliquity or precession cycles.