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Sequential Analysis in the Identification of 3rd Order System Tract in the Abidjan Margin

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Open Journal of Applied Sciences 2024年第6期14卷 1474-1489页

作者： Blandine Akissi Egoran N’guessan Donald Ahoure Fori Yao Paul Assalé Sylvain Mondé Loukou Victor N’da UFR Marine Sciences San Pedro University San Pedro Cte dIvoire UFR of Sciences and Technologies Alassane Ouattara Bouak Laboratory of Plant Biology and Earth Sciences Bouak Cte dIvoire UFR/STRM Flix Houphout Boigny de Cocody Abidjan Cte dIvoire PETROCI Consultant at the Center for Analysis and Research Department of Sequential Stratigraphy Abidjan Cte dIvoire

The use of sequential stratigraphy.concept, based on well logs, sedimentology, and biostratigraphy. has shed light on the complex mechanisms controlling sedimentary accumulations. Consequently, identifying these mechanisms allows us to predict the hydrocarbon generation potential of source rocks. In the Ivorian offshore sedimentary basin, certain studies have contributed to understanding and characterizing the petroleum system. However, these previous works did not integrate biostratigraphic data to highlight sedimentary facies. This study, conducted on two wells in the Abidjan margin, is crucial as it helps us comprehend the geometry of fossil sediments in relation to sea level variations. It will also aid in reconstructing the basin-filling history and predicting the distribution of rocks capable of trapping oil, determining lowstand systems tracts (reservoir rocks), transgressive systems tracts, and highstand systems tracts (cap rocks). Lithological analysis revealed predominantly clayey sedimentation with sandy layers. Well log data facilitated the delineation of formation boundaries and highlighted reservoirs consisting of sands, sandstones, limestones, and occasionally intercalated shales. Integrating these analysis results with biostratigraphic interpretations based on foraminifera and palynomorphs revealed that the traversed formations were deposited in a transitional environment ranging from Coniacian to Maastrichtian ages. Applying sequential stratigraphy.concept from well logging resolved dating issues encountered in microfossil-poor or microfossil-free zones. The results of the Coniacian-Maastrichtian age sequential subdivision were aligned with the chart.

关键词： sequence stratigraphy Systems Tracts Senonian Côte d’Ivoire

Facies, Sedimentary Environment and sequence stratigraphy.of Dalan Formation in South Fars, Iran —(Qatar-South Fars Arch) Well ASL-A

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Open Journal of Geology 2016年第8期6卷 944-962页

作者： Nasser Rezavand Davood Jahani Hossein Asilian Department of Geology North Tehran Branch Islamic Azad University Tehran Iran Department of stratigraphy.and sedimentology NIOC Exploration Tehran Iran

Dalan Formation is one of the most important gas reservoirs of south and southwest Iran which it belongs to Dehram Group and its age is Middle to Late Permian. The Dalan formation is interpreted as reflecting a major tectono-eustatic event related to the onset of rapid thermal subsidence of the early Neo-Tethys passive margin in Arabia and Iran, and the drowning of its rift shoulders. The Dalan formation consists mainly of medium to thick-bedded oolitic to micritic shallow-marine carbonate, with intercalations of evaporates. This formation overlies the Faraghan formation and extends up into the Lower Triassic kangan formation. The current paper is focused on the facies, sedimentary environment and sequence stratigraphy.study of the Middle to Upper Permian Dalan formation in the West Assaluyeh gas field the subsurface section of well ASL-A. Based on microfacies analysis and significant founa and flora, nineteen major facies in five facies associations including Tidal flat (A), Lagoon (B), Shoal (C), Open marine (D) and Mid ramp (E) were recognized in the Dalan formation. Facies analysis and those comparisons with modern and ancient environments indicated that the Dalan formation was deposited inner to mid parts of a homoclinal ramp. The sequence stratigraphy.studies on the Dalan formation in this gas field led to assessment of seven main sedimentary sequences of the third-order in the Assaluyeh field, well ASL-A. The boundary between the third-order sequences with the Faraghan formation and between the Nar and Upper Dalan members are Subaerial Unconformity (SU) and the boundaries between the third-order sequences with each other and also with the Kangan formation are Correlative Conformity (CC). The main diagenetic processes in this formation are dolomitization, dissolution, anhydritization, cementation and compaction which played a significant role in improving reservoir quality. The shoal ooid grainstone facies with intergranular and oomoldic porosity comprise the

关键词： Facies Sedimentary Environment Homoclinal Ramp sequence stratigraphy Dalan Formation

Analysis of Sedimentary Environment and sequence stratigraphy.of Middle-Late Permian Sediments in Coastal Fars, Iran (Zireh Gas Field, Well ZH-A)

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Open Journal of Geology 2016年第12期6卷 1539-1552页

The current paper is focused on the facies, sedimentary environment and depositional cycles study of the Middle-Late Permian sediments in the South Fars Zireh Gas Field, the subsurface section of well ZH-A. Four hundred thin-sections obtained from cores and cuttings were examined under standard petrographic microscope. For this study research, Corel Draw X6, Corel Photo-Paint, DN2 Microscopy Image Processing System, Scope Photo, Autodesk Map, Geocalc and Auto Cad 2014 were utilized. Based on microfacies analysis and significant founa and flora, fourteen major facies in four facies associations comprising tidal flat (A), lagoon (B), shoal (C) and open marine (D) identified in the well ZH-A. This formation was deposited in inner part of a homoclinal ramp. Based on depositional cycles, seven main 3rd order sequences were revealed in the Well ZH-A. The ooid grainstone facies with interparticle and oomoldic porosity has high reservoir potential. The diagenetic processes like dolomitization and dissolution have significant effect in the reservoir quality. Based on research results, a major framework can be weaved and used to correlate reservoir layering.

关键词： Middle-Late Permian Sediments Depositional Cycles Homoclinal Ramp

CpG Island Definition and Methylation Mapping of the T2T-YAO Genome

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Genomics, Proteomics & Bioinformatics 2024年第2期22卷 69-79页

作者： Ming Xiao Rui Wei Jun Yu Chujie Gao Fengyi Yang Le Zhang College of Computer Science Sichuan UniversityChengdu 610065China Key Laboratory of Systems Health Science of Zhejiang Province School of Life ScienceHangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China CAS Key Laboratory of Genome Sciences and Information Beijing Institute of GenomicsChinese Academy of Sciences and China National Center for BioinformationBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Precisely defining and mapping all cytosine(C)positions and their clusters,known as CpG islands(CGIs),as well as their methylation status,are pivotal for genome-wide epigenetic studies,especially when population-centric reference genomes are ready for timely ***,we first align the two high-quality reference genomes,T2T-YAO and T2T-CHM13,from different ethnic backgrounds in a base-by-base fashion and compute their genome-wide density-defined and position-defined ***,by mapping some representative genome-wide methylation data from selected organs onto the two genomes,we find that there are about 4.7%–5.8%sequence divergency of variable categories depending on quality *** among the divergent sequences are mostly associated with neurological ***,CGIs associated with the divergent sequences are significantly different with respect to CpG density and observed CpG/expected CpG(O/E)ratio between the two ***,we find that the T2T-YAO genome not only has a greater CpG coverage than that of the T2T-CHM13 genome when whole-genome bisulfite sequencing(WGBS)data from the European and American populations are mapped to each reference,but also shows more hyper-methylated CpG sites as compared to the T2T-CHM13 *** study suggests that future genome-wide epigenetic studies of the Chinese populations rely on both acquisition of high-quality methylation data and subsequent precision CGI mapping based on the Chinese T2T reference.

关键词： T2T-YAO Position-defined CpG island Density-defined CpG island DNA methylation Genome analysis

A Novel Approach for Inferring the Proportion of Terrestrial Organic Matter Input to Marine Sediments on the Basis of TOC:TN and δ<sup>13</sup>C<sub>org</sub>Signatures

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Open Journal of Marine Science 2013年第2期3卷 74-92页

作者： Antonio Fernando Menezes Freire Marcelo Costa Monteiro Department of Geochemistry Petrobras Research Center Rio de Janeiro Brazil Department of sedimentology and stratigraphy Petrobras Research Center Rio de Janeiro Brazil

The ratio of total organic carbon to total nitrogen (TOC:TN) and the stable carbon isotope ratio of organic matter (δ13Corg) are widely applied for inferring the origin of organic matter (OM) in Quaternary marine sediments. A plot of TOC:TN vs. δ13Corg is useful for such studies but is strongly based on qualitative constraints. This study is based on the qualitative characterization of the source of Quaternary OM via analysis of TOC:TN and δ13Corg signatures, but also proposes a probability parameter, which combines both signatures, to infer the amount of Terrestrial OM Input (TOMI). This index provides a method for quantifying the proportion of terrestrial OM vs. marine OMin a more comprehensive manner. The TOMI index concept was applied to a study area in theJoetsuBasin, eastern margin of theJapanSea, where previous studies have characterized theOMfrom the Last Glacial Maximum (LGM) to the present. The upwards increase in TOC indicates thatOMproduction during the Holocene was higher than during the LGM. The enriched δ13Corg signature upwards and decrease in TOC:TN suggest predominantly marine phytoplankton OM during the Holocene. Throughout the LGM, low OM production with depleted δ13Corg values and high TOC:TN values in the sediments suggest a predominantly C3 terrestrial plant source for the OM. Using these data, it was possible to calculate a proxy for a sea level variation curve during that period and to investigate the influence of the proximity of the coastal line to the continental slope on the input of terrestrial material to the basin. The proposal provides information for the application of sequence stratigraphic concepts. The TOMI index could confirm that the proximity to the shoreline and shelf break has a strong influence on the input of terrestrial material during lowstand periods.

关键词： δ13Corg Joetsu Basin Japan Sea Terrestrial Organic Matter Input TOMI Index TOC:TN

RECENT PROGRESS IN study OF THE QUATERNARY OF QAIDAM BASIN, QINGHAI

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Chinese Science Bulletin 1986年第4期31卷 252-256页

作者：王靖泰张勇 E.DERBYSHIRE J.SHAW Lanzhou Institute of Glaciology and Cryopedology Academia Sinica First Hydrological Team of Geological Bureau of Qinghai Province Department of Geography University of Keel UK Department of Geology University Gollege Cardiff UK series of mountain systems and intermountane basins extend across the northern and western China. The largest of the basins are those of Tarim Junggar and Qaidam. A thick sedimentary sequence has been deposited in these basins during the Cenozoic. Accordingly the region has great potential for the study of the Quaternary stratigraphy. However information on the Quaternary sedimentology and chronostratigraphy of this huge region is sparse.

A series of mountain systems and intermountane basins extend across the northern and western China. The largest of the basins are those of Tarim, Junggar and Qaidam. A thick sedimentary sequence has been deposited in these basins during the Cenozoic. Accordingly, the region has great potential for the study of the Quaternary stratigraphy. However, information on the Quaternary sedimentology and chronostratigraphy.of this huge region is sparse.

关键词： sedimentary Quaternary stratigraphy Cenozoic thick PROGRESS folding borehole sparse abundant

Cycle-sequences,Carbon Isotope Features and Glacio-Eustasy of the Triticites Zone in Southern Guizhou

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Acta Geologica Sinica(English Edition) 1997年第2期71卷 217-226页

作者： Li Rufeng Liu Benpei and Zhao Chenglin University of Petroleum, Beijing China University of Geosciences, Beijing University of Petroleum, Beijing University of Petroleum Beijing China University of Geosciences Beijing [?]Li Rufeng Born in 1962 got his doctor's degree in 1995 at China University of Geosciences (Beijing). He is now undertaking postdoctoral research work of carbonate sequence stratigraphy.and petroleum geology in Petroleum University (Beijing).

In light of the principle of sequence stratigraphy. detailed analysis of depositionalsequences and systematical carbon isotope measurements were done for the Triticites zone ofthe typical Late Carboniferous section in the Dushan area of southern Guizhou. Two sequencesand seventeen parasequences, which can be correlated with the two sequences and seventeensubsequences in the North American Midcontinent, are distinguished in the Gzhelian, whichprovides convincing evidence of the global synchroneity of the depositional records. The inter-nal relations between carbon isotope evolution and eustasy were studied and the evolutionarycharacteristics of carbon isotopes in depositional sequences have been summarized.

关键词： Upper Carboniferous carbonate sequence stratigraphy eustasy Triticites zone carbon isotope

Distribution of major and trace elements in surface sediments of Hangzhou Bay in China

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Acta Oceanologica Sinica 2012年第4期31卷 89-100页

作者： LIU Shengfa LIU Yanguang YANG Gang QIAO Shuqing LI Chaoxin ZHU Zhiwei SHI Xuefa First Institute of Oceanography State Oceanic AdministrationQingdao 266061China Key Laboratory of Marine sedimentology and Environmental Geology State OceanicAdministrationQingdao 266061China

The Inductively Coupled Plasma Optical Emission Spectrometer was used to analyze sediment samples collected from the Hangzhou Bay to determine major and trace elemental concentrations. Based on these concentrations, the study area can be classified into three geochemical provinces. Province I covers the northern Hangzhou Bay area and contains high concentrations of A120~, Fe203, MgO, Na20, K20, MnO, Cr, Cu, Ni, Pb, V, Co and Zn. Province III is located in the western Hangzhou Bay, near the Qiantang River mouth, and contains high concentrations of SiO~, Na20, P205~ TiO2, Cr, Sr, Zr. Province II is located in the middle and eastern Hangzhou Bay, with the medium concentrations of major and trace elements. The results also demonstrate that the grain size is the dominating factor controlling the spatial variations of elemental concentrations, and the Changjiang River （Yangtze River） and Qiantang River sediments play an important role in the distribution of these elements. Anthropogenic impact on heavy metal concentrations （especially Cr, Sr and Zr） can be detected in the surface sediments near the Qiantang River mouth.

关键词： Hangzhou Bay Changjiang River sediments major and trace elements grain size,heavy metals

Using a modern analogue to interpret depositional position in ancient fluvial-tidal channels:Example from the McMurray Formation,Canada

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Geoscience Frontiers 2019年第6期10卷 2219-2238页

作者： Andrew D.La Croix Shahin E.Dashtgard James A.MacEachern Energy Initiative University of QueenslandBrisbaneQueensland4072Australia Applied Research in Ichnology and sedimentology(ARISE)Group Department of Earth SciencesSimon Fraser University8888 University DriveBurnabyBCV5A 1S6Canada

The fluvial-tidal transition(FTT)is a complex depositional zone,where fluvial flow is modified by tides as rivers approach a receiving marine *** in the relative importance of tidal versus fluvial processes lead to a distinctive distribution of sediments that accumulate on channel *** FTT generally consists of three broad zones:(1)a freshwater-tidal zone;(2)a tidally influenced freshwater to brackish-water transition:and(3)a zone of relatively sustained brackish-water conditions with stronger tides.A very common type of deposit through the fluvial-tidal transition,especially on the margins of migrating channels,is inclined heterolithic stratification(IHS).At present,a detailed account of changes in the character of IHS across the FIT of a paleo-channel system has not been reported,although a number of modern examples have been *** fill this gap,we quantitatively assess the sedimentology and ichnology of IHS from seven cored intervals in three geographic areas situated within the youngest paleovalley("A"Valley)in the Lower Cretaceous McMurray Formation of *** compare the data to trends defined along the FTT in the present-day Fraser River in British *** to interpret paleo-depositional position in the ancient fluvial-tidal *** determined that the mean mudstone thickness is 8.2 cm in the southern study area(SA).Mean thickness increases to 11 cm in the central study area(CA),and decreases again to 4.4 cm in the northern study area(NA).The proportion of mudstone is 31%in SA,44%in CA,and 27%in *** mean bioturbation intensity in sands varied from 0.29 in SA and *** 0.28 in *** the other hand,thickness-weighted mean bioturbation intensity(Bl)in mudstone increases from 1.46 in *** 1.77 in *** is 1.94 in *** ichnological diversity also increased from south to *** results show sinilar trends to those of the Fraser River,enabling the identification of a freshwater

关键词： Fluvial-tidal transition McMurray Formation Fraser river Inclined heterolithic stratification Modern analogue Quantirative sedimentology and ichnology