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The Nanhua Basin of South China recorded complete Cryogenian stratigraphic sequence from the Sturtian Glaciation (~717-660 Ma) to the Marinoan Glaciation (~654-635 Ma). The interglacial Datangpo Fm in the Nanhua Basin is divided into two members, and the first member consists of the Mn-carbonate unit and the overlying black shale unit, containing a series of large and superlarge manganese deposits. The metallogenic process of manganese deposits is not clear, and the Mn-carbonates formed through the precursor of Mn-oxide/oxyhydroxide reduction or directly precipitated from an anoxic water column. Moreover, the redox conditions in the deep Nanhua Basin during the precipitation of manganese deposits are also controversial. In this study, the high-resolution nitrogen contents (TN), isotope compositions, carbon isotope compositions of organic and inorganic matter from the first member of the Datangpo Fm are analyzed. The d15N values of the Mn-carbonate unit (+1.53‰ to +5.26‰, mean +3.36‰) are higher than those of the overlying black shale unit (-3.74‰ to +3.54‰, mean +0.89‰). The Mn contents show a negative relationship with TN but a positive relationship with δ15N in the Mn-carbonate unit, implying that the formation of Mn-carbonates is related to redox variations. The relatively higher δ15N values in the Mn-carbonate unit indicated oxic conditions, and NH4+can be released and partially oxidized during the mineralization of organic matter, resulting in the residual 15N-enriched NH4+ being transferred into clay minerals. Meanwhile, the lower d15N values in the black shale unit indicated anoxic conditions, which recorded primary N isotope signals. The Mncarbonate unit is characterized by negative d13Ccarb values (-11.17‰ to -5.22‰, mean -8.30‰), which show a positive relationship with d13Corg, but a negative relationship with Mn contents, implying that the negative d13Ccarb excursions were related to the organic matter degradation during Mn-carbonate formation. The findings of this study indicated that the metallogenesis of manganese deposits in the Cryogenian Nanhua Basin was constrained mainly by the oxic interval in the deep basin. The nitrogen and carbon cycling process can provide new insights into geochemical cycling after the Sturtian Glaciation. [ABSTRACT FROM AUTHOR]

In 1989, the first prolific hydrocarbon reservoirs were discovered by Saudi Aramco in the highly porous and permeable friable continental sandstones (Unayzah reservoirs) and shallow marine carbonates (Khuff reservoirs) of the Paleozoic successions in the south of Riyadh, central Arabia. Since 1989, Saudi Aramco has discovered new oil and gas fields in various stratigraphically and genetically different units of the Permo-Carboniferous and Permian successions. These successions were strongly affected by tectonic movements (Caledonian and Hercynian orogenesis) and Early and Late Paleozoic Gondwana glaciations. Therefore, the thickness of some sections was fully eroded or significantly reduced. The sequence stratigraphic interpretation of the Paleozoic successions allowed us to understand the depositional environments and regional distribution of the source, reservoir, and cap rock facies in improved palynologic studies. Hydrocarbons were discovered with the Late Permian continental sandstones of the Unayzah Formation, the glaciogenic sandstones of the Late Ordovician Sarah Formation in Saudi Arabia, Late Silurian Hazro reservoir in southeast Türkiye, and the cold desert eolian sandstones of the Permo-Carboniferous Haradh Formation. Potential source rock facies of the Qusaiba Shale Member in Saudi Arabia and the hot shale facies of the Dadaş Formation in southeast Türkiye were deposited at the base of the Early Silurian regional transgression (444 Ma) during the melting phase of the huge Gondwana ice mass. The hydrocarbons migrated downward into the glaciogenic reservoir sandstones due to the hydrostatic pressure provided a useful depositional environment model. The hydrocarbon discoveries have provided core and well log data for regional correlations. Every aspect of the sequence stratigraphy was investigated and various types of unconformities, sequence boundaries, glaciation periods, and maximum flooding surfaces were recognized and correlated between Middle East countries. The relationship between the sea-level fluctuations and sediment supply into the basin was established by the regressive (progradational) and transgressive parasequences and parasequence sets. This genetic sequence stratigraphic approach has significantly increased the hydrocarbon explorations and production in the entire Arabian Platform. [ABSTRACT FROM AUTHOR]

The document is an index of editorial contents for Volume 47 of the Journal of Petroleum Geology, published in 2024. It includes articles on various topics such as the structural style and timing of folds in Iran, lacustrine source rocks in Argentina, the modern oil industry in Iran, the Arabia-Eurasia collision zone in Iran, and the influence of Pleistocene glaciation on petroleum systems in the Barents Sea. The document also lists the authors and referees who contributed to the journal. [Extracted from the article]

We review published studies characterizing the Thamama‐B reservoir zone in the upper Kharaib Formation (late Barremian) in Abu Dhabi oilfields and at outcrops in Oman. Available data for oxygen and carbon isotope compositions, fluid inclusion measurements, cement abundance and formation water composition are interpreted in terms of a paragenetic model for the Thamama‐B in field F in Abu Dhabi where the interval is deeply buried. The present synthesis provides a useful basis for understanding and predicting reservoir quality in static models and undrilled prospects, as well as for planning promising directions for further research. The goals of this study were to summarize the geologic setting and petrology of the Thamama‐B reservoir and its surrounding dense zones, and to examine how sedimentology, stratigraphy and diagenesis have interacted to control porosity and permeability. Results that may have useful applications for similar microporous limestone reservoirs in general include: the depositional environments and stratigraphy of the subject strata;a model for how porosity variations result mainly from calcite cementation sourced from stylolites, with little dependence on lithofacies other than the localization of chemical compaction by depositional clay linked to sequence stratigraphy;the use of solidity (rock thickness with porosity removed) as a check on porosity creation by burial dissolution;observations linking high‐permeability streaks with storm lag beds and fractures;the concept of strata being gradually buried through a relatively static salinity‐stratified water column;integration of conventional and clumped stable‐isotope data with petrologic observations to constrain the timing of porosity evolution. [ABSTRACT FROM AUTHOR]

The process by which Palaeolithic Europe was transformed from a Neanderthal-dominated region to one occupied exclusively by Homo sapiens has proven challenging to diagnose. A blurred chronology has made it difficult to determine when Neanderthals disappeared and whether modern humans overlapped with them. Italy is a crucial region because here we can identify not only Late Mousterian industries, assumed to be associated with Neanderthals, but also early Upper Palaeolithic industries linked with the appearance of early H. sapiens, such as the Uluzzian and the Aurignacian. Here, we present a chronometric dataset of 105 new determinations (74 radiocarbon and 31 luminescence ages) from four key southern Italian sites: Cavallo, Castelcivita, Cala, and Oscurusciuto. We built Bayesian-based chronometric models incorporating these results alongside the relative stratigraphic sequences at each site. The results suggest; 1) that the disappearance of Neanderthals probably pre-dated the appearance of early modern humans in the region and; 2) that there was a partial overlap in the chronology of the Uluzzian and Protoaurignacian, suggesting that these industries may have been produced by different human groups in Europe. Here, the authors present 74 radiocarbon and 31 luminescence age determinations from four sites in southern Italy. They use these data to suggest that Neanderthal disappearance in the region predated the appearance of early modern humans, a previously unclear chronology [ABSTRACT FROM AUTHOR]

ABSTRACT The mechanisms for the deposition of the Cambrian carbonate sedimentary successions remain controversial. The carbonate‐dominated successions (Stage 3 to Stage 10) are well developed in the North China Craton and they are commonly thought to represent a platform setting because of the flat top. In this study, we propose a new scenarioi, that the Cambrian successions in North China are more likely a carbonate ramp rather than a platform. Detailed sedimentological investigation for the Cambrian rocks in the Yanshan area (Stage 4 to Stage 10) reveals a total of 21 lithofacies which can be grouped into 7 facies associations, including sabkha and mixed tidal flat, shoal, carbonate tidal flat, tidal flat on shoal, protected lagoon, mid‐ramp and outer ramp to shelf basin. Sequence stratigraphy analysis of the Cambrian in the Yanshan area reveals nine third‐order depositional sequences, which shows an overall second‐order transgression. A number of sedimentary characteristics, including the gentle depositional slope, abundant open marine deposits, scattered shoals and microbial mounds, absence of slump or gravity flow sediment, domination of subtidal facies cycles and widespread deposits that formed below the storm wave‐base, indicate that the Cambrian sediments in the Yanshan area were deposited in an intracratonic carbonate ramp depositional system. This intracratonic carbonate ramp includes inner ramp, mid‐ramp, outer ramp and shelf basin facies belts, with the inner ramp exhibiting sub‐facies corresponding to tidal flat, protected lagoon and shoal sub‐facies. Sequence stratigraphy analysis indicates that relative sea‐level changes, corresponding to these nine third‐order sequences, show synchronous with the global sea‐level change across the studied sections. This consistency implies that eustatic sea‐level changes could have been a major factor for the sequence stacking patterns in the Yanshan Area. [ABSTRACT FROM AUTHOR]

ABSTRACT Since diagnostic primary depositional sedimentary structures and depth‐dependent grain‐size trends are rarely preserved, building a comprehensive sequence stratigraphic framework for the vast majority of the Phanerozoic carbonate platform sequences is pending. Among the two most important sequence stratigraphic surfaces, while the subaerial unconformity can be reliably identified by either karst development or the appearance of siliciclastic materials, the demarcation of the maximum flooding surface remains difficult in lithologically uniform shallow marine carbonate sequences. The present study attempts to identify the globally documented maximum flooding surface within the body of the negative carbon isotope excursion of the Palaeocene–Eocene Thermal Maximum recorded in the shallow marine carbonate platform sequences. The results show that, along with the carbonate microfacies, the yttrium to holmium ratio (Y/Ho ratio) of the carbonate fraction reliably records the sea‐level changes. A Y/Ho ratio between 70 and 80 demarcates the stratigraphic position of the maximum sea‐level state (the most open marine condition in the studied interval) and maximum flooding surface in the studied sections. Since the Y/Ho ratios remain relatively stable throughout diagenesis, they can be used for maximum flooding surface identification in shallow marine carbonate platform sequences. The possibility exists that the same method can also be applied to the mixed siliciclastic–carbonate systems. [ABSTRACT FROM AUTHOR]

Anticosti Island (Québec, Canada) contains one of the thickest Ordovician/Silurian boundary sections in the world, providing a fossiliferous and well-preserved record of the Late Ordovician mass extinction; however, the absence of a comprehensive correlation framework for the island prevents the full incorporation of data from across Anticosti into a global understanding of the extinction event. Here, we combine sedimentological, stratigraphic, and chemostratigraphic data to develop a sequence stratigraphic framework for the Ellis Bay and lowermost Becscie formations along the northeastern shore of Anticosti Island. These formations record six fourth-order (∼100–400 k.y.) depositional sequences bounded by regionally traceable unconformities. Evidence of subaerial weathering and exposure at many of these unconformities is subtle and has long gone unrecognized, which highlights the complexity of correlation in this and other stratigraphically thin icehouse records. Quartz pebble lags that mantle these surfaces punctuate the otherwise fine-grained, mixed carbonate–siliciclastic strata of the Ellis Bay Formation and provide the means to trace unconformities across localities; these surfaces are also marked by depleted carbon isotopic values, meteoric cement, microkarst, and incised valleys. This sequence stratigraphic framework provides the first correlation framework for exposures from the eastern end of this classic Ordovician/Silurian boundary section, and thus enables the integration of paleobiological, stratigraphic, and geochemical data into a basin-wide perspective of the Late Ordovician mass extinction. Critically, comparison to sequence stratigraphic frameworks from coeval sections suggests that other regions may be incomplete at the level of the fourthorder cycles recorded on Anticosti Island and may contain similarly cryptic unconformities. [ABSTRACT FROM AUTHOR]

The lower Triassic Kangan Formation is one of the most important carbonate reservoir rocks in southern Iran and the Persian Gulf. This formation is part of the Dehram Group and consists of a carbonate-evaporite sequence, including limestone, dolomite and anhydrite. This carbonate sequence has been deposited on a gently-sloping homoclinal carbonate ramp in a warm and dry climate conditions. In this study, by carefully examining geological reservoir zones (GRZs) in three wells in the central (wells A and B) and northern (well C) Persian Gulf, in terms of facies changes, sedimentary environment, diagenesis and sequence stratigraphy, it is possible to determine the reservoir quality by considering the reservoir heterogeneity. Petrographic observations show that the Kangan Formation consists of fifteen microfacies related to four facies belts, including sabkha, lagoon, tidal flat and shoal environments. Facies and environmental changes in the Kangan Formation indicate three third—order and seven fourth-order sequences in the central and northern Persian Gulf. Each sequence includes TST (Transgressive System Tract) and HST (Highstand System Tract) related to sabkha, intertidal, lagoon and shoal environments. The main diagenetic processes in the reservoir are dolomitization, dissolution and cementation. The connection between the depositional facies, sedimentary environment and diagenetic processes (dolomitization, anhydrite and calcite cementation and dissolution), allowed for the identification of seven geological reservoir zones (GRZs) related to the fourth-order sequences. These sequences and GRZs demonstrate vertical and lateral heterogeneity of the reservoir, observed as variation in GR log changes, lithology, facies frequency, diagenetic features and reservoir properties among the studied wells. GRZ-1 to GRZ-3 in the northern Persian Gulf and GRZ-4 to GRZ-7 in the central Persian Gulf show better reservoir quality. Facies analysis of the Kangan Formation indicates higher energy conditions for the central parts than the northern parts. [ABSTRACT FROM AUTHOR]

Zealandia has very few biostratigraphic markers to help elucidate the often complex and discontinuously cored stratigraphy of Quaternary sequences on the margins and submarine plateaux of the subcontinent. In this study, a detailed biostratigraphic framework has been developed to help unravel the complex stratigraphy of tectonically deformed Quaternary sediments on the Hikurangi margin of north-eastern Zealandia. The framework is based on well documented and dated 0–1.2 Ma planktic foraminiferal records from Ocean Drilling Project (ODP) Site 181–1123 on the Chatham Rise, just north of the Subtropical Frontal Zone. The framework has 104 biostratigraphic markers and is subdivided using the Sinistral Truncorotalia truncatulinoides Zone (STZ) 0–533 ka, the Dextral Tr. truncatulinoides Zone (DTZ) 533–2440 ka, the lowest common occurrence (LCO) Tr. truncatulinoides (621 ka), the highest common occurrence (HCO) Neogloboquadrina pachyderma (624 ka), and the HCO Tr. crassacarina (1101 ka). Further subdivision is then based on the tops and bases of short-lived climatically-tempered influxes of Globigerinoides ruber, Hirsutella hirsuta, Hr. praehirsuta, Tr. truncatulinoides, Tr. crassacarina, and Nq. pachyderma. Most of these biostratigraphic markers are not unique, but sequences of markers that are unique to each marine isotope stage provide an unprecedented level of biostratigraphic detail and chronological dating when they are used within the contextual chronological framework of keystone biostratigraphic markers. [ABSTRACT FROM AUTHOR]

The construction of an accurate and high‐resolution reservoir parameter model is crucial for reservoir characterization. However, due to the band‐limited characteristics of seismic data, the inversion results heavily rely on the accuracy of the initial model. Most existing techniques for constructing an initial model interpolate well logging data within the stratigraphic framework, neglecting the effect of the stratigraphic sequence, which compromises the reliability of the initial model. The stratigraphic sequence is essential for dividing stratigraphic evolution stages and defining a geological relationship between reservoirs within the stratigraphic framework. Therefore, an initial model construction method constrained by stratigraphic sequence representation is proposed for pre‐stack seismic inversion. The process begins with establishing the stratigraphic framework using horizon and fault data. Subsequently, the collaborative sparse representation algorithm is used to learn a joint dictionary that captures the relationship of structural features between seismic data and stratigraphic sequence from the well logging data. In the process of seismic data representation, the stratigraphic sequence is accurately represented in three‐dimensional space by sharing sparse coefficients in the joint dictionary. Finally, the elastic parameter model is constructed by integrating the stratigraphic framework, stratigraphic sequence and well logging data, providing a reliable initial model for pre‐stack seismic inversion. The main innovation of the proposed method is the three‐dimensional representation of the stratigraphic sequence. A synthetic example demonstrates that the proposed method produces a more accurate initial model than conventional interpolation methods. Additionally, when applied to field data, it yields satisfactory results even without complete S‐wave velocity well logging data. [ABSTRACT FROM AUTHOR]

The Mount Grace metamorphosed carbonatites (Late Devonian) outcrop as thin (0.5–4 m), laterally discontinuous, strata-bound mappable lenses within the Monashee complex of the southeastern Canadian Cordillera. The host stratigraphic sequence (Monashee cover gneiss) was metamorphosed and deformed in the Late Cretaceous to early Eocene followed immediately by exhumation of the Frenchman Cap and Thor Odin domes. We present seven stratigraphic logs for Mount Grace carbonatites including new and previously described outcroppings spanning ∼30 km. The Mount Grace carbonatite units were deposited regionally within or near the top of a shallow marine sedimentary sequence within miogeoclinal strata of the western margin of paleo-North America (Laurentia). The distribution of the Mount Grace carbonatite lithofacies and the preserved depositional structures and textures suggest that these are pyroclastic deposits resulting from phreatomagmatic eruptions. Our new data enhance the volcanological story with an eruption scenario involving phreatomagmatic reactions and deposition from pyroclastic density currents, sourced from multiple centers within a field of monogenetic maar volcanoes. The distribution of the Mount Grace carbonatites parallel to the western margin of the paleo-North American continent correlates well with regional Late Devonian alkaline magmatism associated with development of an extensional back-arc basin. [ABSTRACT FROM AUTHOR]

Underground hydrogen storage (UHS) is considered to solve the intermittency problem of renewable energy. A geological assessment indicated that the B unit of the Salina Group in Southern Ontario, Canada, is the most promising for UHS because it is the thickest and most regionally extensive salt rock deposit. However, the comprehensive geological knowledge of potential sites and overall salt volume for UHS remains undiscovered. This paper collected 1112 wells' logging data to assess the geologic potential for UHS in Lambton County. The geological characteristic analysis of the B unit was conducted using high-frequency stratigraphic sequences and logging interpretation. The internal lithologies and thicknesses of the B unit were interpreted from 426 available wells. The storage capacity of the salt caverns was calculated from simplified cylinder models. The results indicate that the B unit can be subdivided into three high-frequency sequences, denoted as the SQ1, SQ2, and SQ3 subunits. SQ1 corresponds to salt–limestone, SQ2 corresponds to bedded salt rocks, and SQ3 corresponds to massive salt rocks. Well sections and thickness maps indicate that the study area can be divided into two sub-areas along the Wilikesport, Oil Spring, and Watford line. To the northwest, unit B was thicker and deeper in terms of paleo-water depth, and to the southeast, less of the B unit was deposited on the paleo-highs. The main thicknesses in SQ1, SQ2, and SQ3 range from 20 to 30 m, 25 to 35 m, and 30 to 40 m, respectively. In conclusion, the best subunit for UHS is SQ3, with a secondary target being SQ2. The main factor impacting cavern storage capacity for the SQ2 subunit is high mud content, while for SQ3, it is the meters-thick anhydrite developed towards the base of the unit. The available underground storage volume of the salt caverns in the B unit is 9.10 × 106 m3. At the standard state, the working gas volume is 557.80 × 106 m3. The favorable area for UHS is the western part surrounded by Wallaceburg, Oil Spring, and Watford. The thickness distribution of the B unit is the combined result of paleo-topography, sea-level changes, and tectonic movement in Lambton. The geological storage capacity of the salt caverns exhibits significant potential. [ABSTRACT FROM AUTHOR]

A stratigraphic sequence from Ghar-e Boof, a cave site in Iran, covering a period of c. 80,000–30,000 BP and containing more than 20,000 seed and chaff remains, allows a detailed study of the use of annual seed species of Palaeolithic hunter-gatherer groups and its evolution under the influence of changing environmental conditions. Taxonomic changes in the archaeobotanical assemblage and the stable carbon isotope data of pistachio support a considerable change in environmental conditions over the sequence from MIS 5a to MIS 3. The exceptional dominance of wild ancestors of modern crop species, including glume wheat and large-seeded legumes from Middle Palaeolithic layers AH VI (OSL ranges 72–81 ka BP), coincides broadly with the transition from MIS 5a to MIS 4. With the beginning of MIS 4 these taxa are strongly reduced, corresponding with a strong decrease in global CO2 concentrations and in the Δ13C values of Pistacia khinjuk/atlantica from the site. Wild glume wheat completely disappears after Middle Palaeolithic AH Vb and never reappears at the site. We hypothesize that the Middle Palaeolithic niche that allowed the harvesting and consumption of wild cereals and legumes ended with a destabilization of the vegetation in early MIS 4. [ABSTRACT FROM AUTHOR]

The Late Ediacaran Dengying Formation, located in the Sichuan Basin of the northwestern Yangtze Craton, is of significant interest in oil and gas exploration due to its abundant pores and vugs within microbial mound-shoal complexes. However, there is still uncertainty regarding the spatiotemporal distribution and controlling factors of the platform margin. This study comprehensively analyzes the retrogradation pattern of the Dengying Formation platform margin using seismic data, well logs, field outcrops, and petrological characteristics. Our findings reveal that the Dengying Formation strata surrounding the rift basin at the northwestern of the Yangtze Craton can be divided into three main depositional facies: basin facies, slope facies, and platform margin facies. Additionally, based on the integration of lithological, log, and seismic characteristics, the Dengying Formation is subdivided into four thirdorder sequences, with five sequence boundaries and three seismic facies identified. Supported by sequence stratigraphy and geophysical data, we have reconstructed the tectono-sedimentary evolution of the multiple platform margins on the eastern side of the Deyang-Anyue rift in the Sichuan Basin during the late Ediacaran. Our findings indicate that the platform underwent two phases of retrogradation. The second-stage platform margin underwent retrogradation towards the interior, spanning a distance between 10 and 80 km, based on the initial configuration established by the first-stage platform margin. The main controls for progradation and retrogradation of carbonate platforms are eustatic sea-level changes and tectonic activity. Eustatic sealevel changes can be divided into constructive and destructive phases. Constructive phases are commonly observed in highstand systems tracts, while destructive phases are often associated with transgressive systems tracts and are related to platform retrogradation processes. However, sea-level changes alone cannot fully control the process of platform retrogradation. The thermal subsidence following mantle plume events likely played a significant role in the retrogradation of the platform in the study area. During this period, tectonic processes controlled the geometry of the platform and the deposition of carbonates in the platform margin-slope-basin environment. Additionally, karst-related mound-shoal complexes developed extensively along the platform margin of the Dengying Formation in the northwestern Yangtze Craton. The Lower Cambrian dark shales represent high-quality hydrocarbon source rocks, while the Dengying Formation exhibits an optimal source-reservoir configuration. [ABSTRACT FROM AUTHOR]

In recent years, geoscientists have been employing machine learning techniques to automate lithological identification by integrating well logging data. However, in geologically complex regions, few have taken into consideration the differences between boreholes and the uneven distribution of lithology. Additionally, there has been limited effort to differentiate boreholes in the same region based on stratigraphic sequences when addressing these issues. We propose a workflow for machine learning-based automated lithological identification. Utilizing the Structural Deep Clustering Network (SDCN) algorithm for deep clustering, we differentiate logging sampling points with geological strata as the clustering scale, assigning each sampling point to its corresponding stratum. In order to obtain stratum information for each borehole, we have devised a Borehole Cluster Result Processing Layer. By segmenting logging data windows, we extract stratum information for each borehole, using the distinctiveness of borehole stratum information as the basis for borehole classification. Subsequently, we assess the impact of lithological classification on logging data for each borehole category using four machine learning methods: extreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), bidirectional long short-term memory (Bi-LSTM), and bidirectional gated recurrent unit (Bi-GRU). The experimental results indicate that, compared to the case where boreholes are not classified, the lithological classification performance for the majority of borehole categories has improved by 1% to 6%. However, there is also a category of boreholes where the classification performance is less than ideal due to the significant variability of diabase contained within the Paleogene strata in the electrical resistivity logging. [ABSTRACT FROM AUTHOR]

The Guadix-Baza Basin (southern Spain) displays one of the best continental records from the Late Miocene to the Middle Pleistocene in western Europe, with many localities of fossil small mammals in a quite complete and continuous stratigraphic sequence. The Late Miocene continentalization of the Guadix-Baza Basin was firstly mentioned in the 1980s based on the presumed presence of Hipparion gromovae granatensis at the site of Abla (Almería province). Subsequent discoveries of late Turolian deposits confirmed the Late Miocene continentalization of the basin. The interest in the Abla site led to a second sampling campaign to look for microvertebrate fossils, which proved successful. In this paper, a complete taxonomic study of the novel microvertebrate fauna from Abla is presented, providing updated information on the age of the locality. Representatives of the vertebrate families Cyprinidae, Alytidae, Anguidae, Soricidae, Cricetidae, and Muridae have been identified. The presence of Stephanomys specimens exceeding the size of latest Miocene-earliest Pliocene species allows us to correlate the Abla site with the Early Pliocene (Ruscinian), a younger age than initially stated. A qualitative paleoecological interpretation based on the herpetofauna suggests the dominance of open environments with presence of permanent water bodies during the deposition of the Abla site, under warmer and more humid climate conditions than today in the Guadix-Baza Basin. A revision of the Hipparion remains from this locality showed that the sample is closer to Hipparion fissurae than to the initially assigned species. [ABSTRACT FROM AUTHOR]

Global climatic and palaeogeographical changes generated a siliciclastic–carbonate system with high organic matter accumulations in a shallow sea during the lower Permian in Western Gondwana. The 60 m thick mixed siliciclastic–carbonate succession (Irati Formation and the base of the Serra Alta Formation) from the Paraná Basin represents a singular record of the interplay between carbonate production and siliciclastic input, providing a window of opportunity to integrate large‐scale depositional architecture with facies and geochemical analyses. The detailed study of cores supported by outcrop columnar sections revealed a siliciclastic‐dominated, retrogradational to aggradational facies, and a carbonate‐dominated, mixed aggradational to progradational facies composing three depositional sequences that record an outer‐ramp and mid to upper‐ramp. An integrated approach based on the description of facies and microfacies, organic geochemistry and mineralogical composition, indicated high‐frequency palaeoenvironmental changes during the evolution of this restricted basin. Climate changes, resulting in humid and dry phases, produced ideal conditions for high organic matter production and dolomite formation. The high organic matter production (humid phases) in addition to the restricted condition was responsible for the anoxic bottom waters that were widespread due to the low angle and homoclinal platform. Nutrient‐rich freshwater inflows in the anoxic and hypersaline restricted basin created a density‐stratified water column causing low‐salinity surface and anoxic bottom water, which allowed planktonic life, typical of lakes, such Botryococcus braunii, to flourish in the photic zone and sulphur bacteria to populate below the chemocline. Microbial activity induced primary dolomite precipitation (dry phases) and widespread formation of synsedimentary dolostone. Freshwater inflow and marine incursions are reflected in the organic matter accumulation (kerogen types I and II, respectively), generating bituminous shale with high total organic carbon (5 to 27 wt.%). [ABSTRACT FROM AUTHOR]

Near the Cenomanian–Turonian boundary, the filament event has been identified worldwide. In Tunisia, filaments are well represented in the laminated black shales of the Bahloul Formation. These black shales were deposited under anoxic conditions in an outer ramp environment. Filaments are particularly abundant in the upper part of the Bahloul Formation, and within the W. archaeocretacea Zone; these correspond to the massive occurrence of fragments of thin-shelled bivalves, whether planktic or nektonic. In terms of sequence stratigraphy, two sampled sections in Central and Central-West Tunisia have led to the interpretation of these deposits as a transgressive interval (TST). In the Oued Ettalla area, the organic-rich laminated limestone and the interbedded dark grey marly claystone constitute the Bahloul Member. The transgressive interval ends with a maximum flooding surface (MFS) included within the lower part of the Kef Formation (Annaba Member) which consists of yellowish-grey marly claystone and marly limestone intercalations, rich in filaments. Whilst in the Oued Sfala section the maximum flooding surface (MFS) is characterised by a thin layer of pebbles (approximate centimetric scale) occurring between Unit 4 and Unit 5. Through the analysis of both oxic and anoxic facies from the Cenomanian–Turonian transition, five bioevent markers have been identified in our sections and in other regions within the Tethyan domain: the extinction of the genus Rotalipora , the Heterohelix shift, the proliferation of globular planktic foraminifera, the filament event, and the first occurrence of Helvetoglobotruncana helvetica. These bioevents are important for establishing high-resolution correlations both regionally and worldwide. [ABSTRACT FROM AUTHOR]

A sequence-stratigraphic model of the Tanopchinskaya Suite of coastal continental genesis was constructed in order to establish the distribution patterns of reservoir properties, clarify the geometry of sand bodies, and identify the main hydrocarbon concentration zones within the studied sediments. The system approach to well correlation was substantiated, which formed the basis for creating a model of Cretaceous sediments with high predictive ability. Regional peculiarities of the structure of the Tanopchinskaya Suite of a large field in the Yamalo-Nenets Autonomous District of the Russian Federation were analysed; core and GIS data from 64 exploration wells and 224 production wells in TP1–TP26 formations were analysed; an algorithm for building a sequence-stratigraphic model that takes into account sedimentation peculiarities was formulated; peculiarities of sand bodies formation were revealed for the whole Cretaceous section. As a result of the analysis, all wells in the Tanopchinskaya Suite interval (TP1–TP26 formations) were correlated with the definition of facies environment and the main surfaces of sedimentation regime change (flooding surfaces, erosion incisions, transgressive surfaces). Taking into account the correlation of formations for the entire well stock, a geostatistical section was constructed and sequence-stratigraphic subdivisions characterising the Tanopchinskaya Suite formations were identified. The 1D sequence-stratigraphic model of wells was analysed for the main hydrocarbon accumulation zones, taking into account open deposits, and the regularities of their location in the section were formulated.

Abstract The Offshore Niger Delta, Nigeria, stands as a dynamic geological marvel, known for its intricate processes and extensive hydrocarbon reservoirs. This study employed an integrated approach, utilizing 3D seismic data and well logs, to conduct a thorough analysis of sequence stratigraphy and reservoir characterization in the pursuit of optimizing hydrocarbon exploration in the region. The study focused on the NW–SE trending Miocene depocenters, which predominantly comprises alternating sandstone and thick shale layers within the Agbada Formation. These reservoir units showcased stacked shallow marine fluvial–deltaic sediments, separated by significant marine shale units. Within the study area, two hydrocarbon-bearing reservoirs were identified and named: R1 and R2. Petrophysical analysis identified R2 as the most promising reservoir, with a permeability of 1184 × 10− 3 µm2, 85% hydrocarbon saturation, porosity of 0.30, and effective porosity of 0.27. Fault structural analysis uncovered that hydrocarbons are trapped within a network of growth faults within the wave-dominated Niger Delta depositional system. From the sequence stratigraphic interpretation, four depositional sequences were delineated between the depths of 2030–3417 m, and are bounded by five sequence boundaries. Integrated seismic facies analysis revealed high-energy feeder systems likely supplying sediments from river sources to offshore locations. These integrated findings provide essential insights to inform resource management, exploration strategies, understanding of reservoir distribution, and structural intricacies within the complex offshore Niger Delta, Nigeria, providing valuable information. The depositional environment helped in the understanding of the stratigraphic traps which are prospects in the study area. This together with the associated reservoir quality allowed accurate prediction for potential reservoir facies and will further improve the field development plans.

Carbonate rocks are the most important sedimentary rocks since they hold almost 60% of the world’s oil reserves. Therefore, it is very important to evaluate the factors that control the formation and deposition of these rocks. The current study aimed to better understand the depositional facies and sequence stratigraphy of Eocene Chorgali Formation from Barian and Nathia Gali Sections of Hazara Basin, NW Himalayas, Pakistan. The field observation shows that the formation comprises of grey to pale grey compacted limestone, argillaceous limestone, and greenish grey shale. From microscopic observations, eight and nine microfacies were constructed form both Barian and Nathia Gali section respectively. The formation is also rich from benthic foraminifera. The constructed microfacies and foraminiferal assemblage shows that the carbonates of Chorgali Formation were most likely deposited in the inner ramp to proximal middle ramp setting. Frequent variations in the microfacies reveals that the Eocene Chorgali Formation was deposited in a 3rd order cycle representing several second order system tracts. Transgressive Systems Tracts (TSTs) and High Stand System Tracts (HSTs) based on sea level variations derived from microfacies in the vertical section. The sea-level curve of the present study deviates from the established global scheme, indicating the influence of intense local tectonics. The carbonate unit of the Chorgali Formation also represents various diagenetic alteration like micritization, bioturbation, dissolution, cementation, compaction and dolomitization. Overall, processes like fracturing, dissolution, and dolomitization enhanced the reservoir quality while cementation infills the available pore spaces and significantly reducing the reservoir quality. [ABSTRACT FROM AUTHOR]

Abstract Identifying and characterizing sedimentary evolution patterns are crucial for assessing the distributions of source and reservoir rocks, which are fundamental to hydrocarbon exploration. This study analyzed the stratigraphic sequence, lithological characteristics, sedimentary lithofacies, individual well sedimentary sequences, and seismic reflection properties. The analysis revealed six fourth-order sequences, including progradational and regressive sequences, indicative of water level changes. The sediment sources for the second and third sub-members of the Eocene Shahejie Formation's third member (Es3 2+3) in the Nanpu Sag were identified as the Baigezhuang and Xinanzhuang Uplifts. Predominantly, the sandstones are lithic arkose and feldspathic litharenite, both of which exhibit low compositional and structural maturity. Notably, 22 lithofacies and 8 lithofacies associations suggest fan delta processes. This study identified three fundamental seismic reflection package reflection types. These lithofacies associations, sedimentary sequences, and seismic reflections serve as critical indicators for determining sedimentary environments. The results from the sedimentary facies analysis indicate that the Es3 2+3 Formation developed fan delta deposits, controlled by the sequence of the sedimentary evolution pattern. The potential of these fan delta sediments to form oil and gas reservoirs is significant. Therefore, precise characterization of the sedimentary evolution pattern is essential for a comprehensive understanding of basin dynamics and hydrocarbon potential.

Thick coal seams are widely distributed in the world, which contain rich geological information and play an important role in the global carbon cycle. The genetic mechanism of thick coal seams has recently gained attention in coal geology research. In order to reveal the composition characteristics and genetic mechanism of ultra thick coal seams in the isochronous sequence stratigraphic framework, the ultra thick coal seam M7, developed in lacustrine transgressive system tract of Middle Jurassic sequence S1 in the northern Qaidam Basin, was continuously sampled at equal intervals, and then the macerals and minerals were identified. A comprehensive analysis was conducted based on the recognition principle of key surface in coal seam, and the paleo-environmental indication of maceral and mineral. The results showed that the content of vitrinite is the highest (48.5%), followed by inertinite (37.22%), and liptinite is fairly low (3.32%). The content of minerals is relatively stable, with an average value of 10.96%. Based on the alternated development of coal seams-detrital deposits, and the content variation of macerals and minerals in vertical direction, five key surfaces were identified, including terrestrialization surface, erosional subaerial exposure surface, paludification surface, give-up transgressive surface, and accommodation reversal surface. The vertical evolution of swamp was analyzed by selecting boreholes at the landward and basinward locality along the sedimentary trend compared to the Yuqia coal mine. Four sedimentary cycles were identified in the ultra thick coal seam M7 of Yuqia coal mine. In landward YQ6–22 and basinward YQ6–12, three sedimentary cycles were identified due to the separation of M7–1 to M7–3 by terrigenous detrital and lacustrine deposits. High resolution sequences were found in ultra thick coal seams, which were divided into four fourth-order sequences. Combined with the sequence boundary corresponding to the key surface in coal seam, the genetic mechanism of ultra thick coal seams was revealed. A multi-peat superposition genetic model in the sequence stratigraphic framework was established, which can be further applied to the research of thick coal seams in more geological times around the world.

ABSTRACT Lake systems are among the largest integrated depositional complexes in the continental realm. Their interplay with tectonics and climate often complicates the interpretation of depositional processes, usually resulting in a complex facies architecture that is challenging to correlate regionally. The Lower to Middle Permian Roseneath–Epsilon–Murteree strata of the Cooper Basin in Australia represent a glacially influenced fluvial–deltaic lake system, which hosts substantial petroleum resources. Despite their potential, the Roseneath–Epsilon–Murteree strata are inadequately understood in terms of regional facies architecture and their palaeogeographical implications. Using a multidisciplinary approach with robust data, including cores, petrology, wireline logs and geochemistry, the sedimentary evolution of the Roseneath–Epsilon–Murteree strata is described within a new basin‐wide sequence stratigraphic framework defined by key surfaces identified from cores and wireline logs. Detailed facies analysis of over 1400 m of cores and wireline logs from nine wells identified twelve lithofacies and eight facies associations, revealing various depositional processes and environments. The Roseneath–Epsilon–Murteree strata are interpreted as having formed in a fluvial–deltaic–lacustrine system influenced by a cold climate. First‐order and second‐order maximum flooding surfaces define a regional sequence stratigraphic framework, subdividing the Roseneath–Epsilon–Murteree strata into four sequence units (SU1, SU2, SU3 and SU4), deposited during four phases (I, II, III and IV). Cyclic stacking patterns observed in both cores and wireline logs reveal two transgressive–regressive cycles. Palaeogeographical maps of the four depositional phases suggest that the Roseneath–Epsilon–Murteree strata were dominated by a lacustrine system with some delta and mire deposits. Rivers primarily drained towards the south/south‐west from the Gidgealpa, Merrimelia, Packsaddle and Innamincka ridges (‘GMI Trend’) as indicated by decreasing sandstone percentages and increasing gross unit isopach maps. The deposition of the Roseneath–Epsilon–Murteree strata was primarily controlled by basin subsidence. Additionally, palaeoclimate trends and extensive glaciation in the Permian played important roles in providing sediments and affecting lake level changes. The lake system recorded by the Roseneath–Epsilon–Murteree strata serves as an analogue for other fluvial–deltaic–lacustrine systems in basins worldwide. A multidisciplinary approach, similar to the one utilized in this study, can help to elucidate their evolution and aid in resource prediction. [ABSTRACT FROM AUTHOR]

Recognizing stratigraphically important bounding surfaces relies on assessing the facies that juxtapose these surfaces as well as the trace fossil omission suite associated with the surface. The ability to differentiate between purely transgressive surfaces and those that conceal earlier stratigraphic surfaces that allude to a more complex history of development regarding the identification of allogenic surfaces of sequence stratigraphic significance that might have otherwise been overlooked. This study analyzes four examples of transgressive surfaces of erosion from Cretaceous-aged strata, with three of the examples representing a TSE/SB (amalgamated transgressive surface of erosion with a sequence boundary) that mask earlier base level falls. Consideration of variable omission suites along depositional strike and dip highlights the influence of substrate rheology on the nature of omission suites. In this study we demonstrate marked changes in the omission suite along bounding surfaces along proximal to distal trends that arise due to changes in underlying rheology. Finally, detailed core analysis is shown to be an imperative asset to subsurface investigation to address the limitations of using wireline well data alone in identifying stratigraphically important surfaces for more accurate regional mapping and characterization of transgressive surfaces. This study highlights that many stratigraphically important surfaces such as those that correspond to a TSE/SB may go unnoticed if utilizing wireline data alone. Overall, this study provides a comprehensive approach to further understanding and identifying transgressive surfaces in the rock record, especially those that demarcate a more complex history other than simple transgressive ravinement. [ABSTRACT FROM AUTHOR]

The transition from syn‐rift to post‐rift sedimentation in rift basins is difficult to characterize in terms of stratigraphic architecture and dominating control on sedimentation, due to decreasing tectonic activity interplaying with regional subsidence, eustatic sea level changes, and differential compaction of underlying syn‐rift sediments. Our case study of the Late Palaeozoic Inner Hornsund Fault Zone targets late syn‐rift strata recorded in the (?Pennsylvanian – ?lower Permian) Treskelodden Formation in Hornsund, southern Spitsbergen, representing a mixed siliciclastic‐carbonate succession, with siliciclastics primarily sourced from the adjacent Sørkapp‐Hornsund High. We document local scale (<10 km) facies variability, sequence stratigraphy, and evolution of a succession deposited along a flank of the structural high during the late syn‐rift stage. We observe that during the transition towards rift termination (glacio‐)eustatic sea level changes and overall regional flooding became a more prominent forcing factor controlling sedimentation. Our dataset includes sedimentary logs, microfacies analysis, and high‐resolution digital outcrop models. We identify four progressively backstepping stratigraphic sequences, reflecting an evolution from (1) terrestrial siliciclastics through (2–3) nearshore mixed siliciclastic–carbonates, to (4) carbonate ramp deposits. On the small scale (<5 m) the internal sediment cyclicity of the succession was formed by autogenic processes, particularly the changing rate of sediment input from the southwestern source area (the uplifted Sørkapp‐Hornsund basement high). On the larger scale (10s of m), the importance of glacio‐eustatic sea‐level changes, driven by waxing and waning of ice caps in the southern hemisphere (Gondwana), increased as the rift‐related tectonics decreased. The interdisciplinary methods used in this study provide new knowledge of the Middle Pennsylvanian to Permian depositional evolution in southern Spitsbergen, besides a novel framework for comparison to adjacent basins in the region and similar basins elsewhere. [ABSTRACT FROM AUTHOR]

The Stuart Shelf is part of the Adelaide Superbasin overlying the Gawler Craton and Cariewerloo Basin in South Australia. The basin is of interest for sediment-hosted copper mineralisation known to be hosted in numerous stratigraphic intervals across the region. Therefore, facies analysis and understanding of spatial distribution of host units are essential for exploration targeting and mineral systems research. Our study presents improved and new definitions of Cryogenian and Ediacaran Stuart Shelf stratigraphy, and a detailed, regional-scale sequence stratigraphic analysis. The Cryogenian non-glacial interlude was of particular interest, as it includes the Tapley Hill Formation, a known host for copper mineralisation. The succession of Tapley Hill Formation (including Sturtian cap carbonates), Brighton Limestone and Angepena Formation represents a third-order depositional cycle, an equivalent to the lowermost cycle of the Cryogenian non-glacial interlude in the adjacent Adelaide Rift Complex. The Ediacaran post-glacial succession includes the Nuccaleena Formation and Tent Hill Formation and is interpreted as a second-order depositional cycle. The Sturtian and Marinoan cap carbonates form regional stratigraphic marker horizons and were deposited in a transgressive systems tract. Variations in facies and thickness can be linked to development of localised depocentres and topographic highs, such as the Pernatty High. Modelling of 3D surfaces reveals a shift in the basin orientation between the Cryogenian and Ediacaran sedimentation from an NNW–SSE axis towards a N–S axis. The Stuart Shelf sequence stratigraphic framework provides new insights in the basin sedimentology and evolution, which aids sediment-hosted mineral systems analysis and improves the understanding of Cryogenian and Ediacaran basin evolution in Australia. The Cryogenian non-glacial interlude on the Stuart Shelf represents a third-order depositional cycle. The Pernatty High develops during deposition of the Cryogenian successions. The Stuart Shelf basin orientation shifts from NNW–SSE during the Cryogenian towards N–S in the Ediacaran. 3D stratigraphic surfaces aids copper exploration targeting in sediment-hosted mineral systems. [ABSTRACT FROM AUTHOR]

The Cenozoic stratigraphy of the Zagros records the ongoing collision between the Arabian and Eurasian Plates and the closure of NeoTethys. A Paleogene NW‐SE trending foreland basin was inherited from a Late Cretaceous precursor. Widespread progradation into the foredeep was a feature of both margins which, allied to ongoing tectonism, had by the late Eocene led to the narrowing and subsequent division of the foredeep into the Lurestan – Khuzestan and Lengeh Troughs, separated by the northward continuation of the rejuvenated Qatar‐Fars Arch. This sub‐division strongly influenced subsequent deposition and the petroleum geology of the area. In addition, the diachronous nature of the Arabian – Eurasian collision led to strong diachroneity in lithostratigraphic units along the length of the Zagros. Hence its petroleum geology is best understood within a regional sequence stratigraphic framework. This study identifies three tectono‐megasequences (TMS 10, TMS 11a, TMS 11b) and multiple depositional sequences. The Cenozoic contains a world class hydrocarbon province with prolific oil reservoirs in the Oligo‐Miocene Asmari Formation sealed by the evaporite‐dominated Gachsaran Formation, mostly contained within giant NW‐SE trending "whaleback" anticlines concentrated in the Dezful Embayment. Reservoirs in the SW are dominantly siliciclastic or comprise mixed siliciclastics and carbonates, whereas those to the east and NE are dominated by fractured carbonates. There remains untested potential in stratigraphic traps, especially in deeperwater sandstone reservoirs deposited along the SW margin of the foredeep. Late Miocene to Pliocene charge to the Asmari reservoirs was mostly from Aptian – Albian Kazhdumi Formation source rocks. In some fields, an additional component was from organic‐rich late Eocene to earliest Oligocene Pabdeh Formation source rocks confined to the narrowing Lurestan – Khuzestan Trough. Where mature, the latter source rock is also a potential unconventional reservoir target, although the prospective area is limited due to recent uplift and erosion. Deeper Jurassic source rocks contributed to the Cheshmeh Khush field in Dezful North. Silurian source rocks charged gas‐bearing structures in the Bandar Abbas region. [ABSTRACT FROM AUTHOR]

This research uses both three-dimensional (3D) modeling and geologic well control to piece back together the architectural parts of the Late Cretaceous formations. The goal is to figure out the sizes, directions, locations, and controls of the layers of the fluvial sandstone reservoirs. Sequence stratigraphy is essential for 3D reservoir modeling and petroleum geology understanding in the Bahga oilfield. The purpose of this work is to create a static model that shows the layers and facies distribution in the reservoir interval. We will use data from nine well logs and 22 seismic lines calibrated by the Abu Roash G Member reservoir core intervals to accomplish this. The petrophysical study discovered three parts in the Abu Roash G Member reservoir rock: channel fill that is affected by tides, channel fill that is dominated by tides (intertidal sands), and channel top with lenticular bedded sandstone. The model's findings point to the existence of an NNW-oriented sand body, which could be a prime location to produce hydrocarbons. The original oil in place (OOIP) is about 3,438,279 Stock Tank Barrels (STB), and the oil reserve reaches up to 1,031,484 (STB). Sequence stratigraphic analysis using seismic and well log information (SB) reveals that the Upper Cretaceous AR/G reservoir of the Bahga field is characterized by third- and fourth-order stratigraphic sequences, which are constrained by three Maximum Flooding Surfaces (MFS) and two Sequence Boundaries. The integration of the derived geological model and sequence stratigraphic results can lower future extraction risk by identifying the locations and trends of the geologic facies with the necessary petrophysical properties for the hydrocarbon accumulations. [ABSTRACT FROM AUTHOR]

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The Plomosas deposit is the product of a sequence of overlapping events of Pb–Zn, Ag, and Au low sulfidation mineralization that occurred in Mexico’s southwestern Sierra Madre Occidental (SMO). Field observations, detailed petrography, and U–Pb age dating of the entire stratigraphic sequence were used to characterize the magmatic evolution of the district and to obtain new insights into the evolution of the SMO. The stratigraphy at Plomosas is distinct from other areas to the north as it lacks Jurassic marine units, Cretaceous continental volcanic successions as well as Cretaceous and Palaeocene batholiths. The local basement is composed of undeformed Late Jurassic volcaniclastic units and coeval felsic intrusions. Early to late Oligocene silicic ignimbrites, intermediate lava flows, and occasional basaltic flows unconformably overlie the Jurassic basement. Several Oligocene intermediate to felsic porphyry bodies and rhyolitic domes crosscut the stratigraphy. The upper volcanic sequence is separated into two packages by an angular unconformity. Mineralization produced an early Pb–Zn-mineralized hydrothermal fault breccia, followed by Cu–Ag veins and late Au veins. The Pb–Zn mineralized breccia is hosted by ~30 Ma Oligocene volcanic units that form the basal sequence. The Cu–Ag and Au-rich veins overlap and crosscut the early hydrothermal features and cut the late Oligocene volcanic cover that unconformably overlie the basal sequence. Our results highlight the importance of episodes of Oligocene magmatism to the genesis of mineralization in the southwestern SMO specifically through a genetic link between Pb–Zn veins and intermediate Oligocene intrusive bodies, and of Ag and Au veins with late Oligocene volcanism. [ABSTRACT FROM AUTHOR]

Identifying and characterizing sedimentary evolution patterns are crucial for assessing the distributions of source and reservoir rocks, which are fundamental to hydrocarbon exploration. This study analyzed the stratigraphic sequence, lithological characteristics, sedimentary lithofacies, individual well sedimentary sequences, and seismic reflection properties. The analysis revealed six fourth-order sequences, including progradational and regressive sequences, indicative of water level changes. The sediment sources for the second and third sub-members of the Eocene Shahejie Formation's third member (Es32+3) in the Nanpu Sag were identified as the Baigezhuang and Xinanzhuang Uplifts. Predominantly, the sandstones are lithic arkose and feldspathic litharenite, both of which exhibit low compositional and structural maturity. Notably, 22 lithofacies and 8 lithofacies associations suggest fan delta processes. This study identified three fundamental seismic reflection package reflection types. These lithofacies associations, sedimentary sequences, and seismic reflections serve as critical indicators for determining sedimentary environments. The results from the sedimentary facies analysis indicate that the Es32+3 Formation developed fan delta deposits, controlled by the sequence of the sedimentary evolution pattern. The potential of these fan delta sediments to form oil and gas reservoirs is significant. Therefore, precise characterization of the sedimentary evolution pattern is essential for a comprehensive understanding of basin dynamics and hydrocarbon potential. [ABSTRACT FROM AUTHOR]

The Aurignacian is the first European technocomplex assigned to Homo sapiens recognized across a wide geographic extent. Although archaeologists have identified marked chrono-cultural shifts within the Aurignacian mostly by examining the techno-typological variations of stone and osseous tools, unraveling the underlying processes driving these changes remains a significant scientific challenge. Scholars have, for instance, hypothesized that the Campanian Ignimbrite (CI) super-eruption and the climatic deterioration associated with the onset of Heinrich Event 4 had a substantial impact on European foraging groups. The technological shift from the Protoaurignacian to the Early Aurignacian is regarded as an archaeological manifestation of adaptation to changing environments. However, some of the most crucial regions and stratigraphic sequences for testing these scenarios have been overlooked. In this study, we delve into the high-resolution stratigraphic sequence of Grotta di Castelcivita in southern Italy. Here, the Uluzzian is followed by three Aurignacian layers, sealed by the eruptive units of the CI. Employing a comprehensive range of quantitative methods—encompassing attribute analysis, 3D model analysis, and geometric morphometrics—we demonstrate that the key technological feature commonly associated with the Early Aurignacian developed well before the deposition of the CI tephra. Our study provides thus the first direct evidence that the volcanic super-eruption played no role in this cultural process. Furthermore, we show that local paleo-environmental proxies do not correlate with the identified patterns of cultural continuity and discontinuity. Consequently, we propose alternative research paths to explore the role of demography and regional trajectories in the development of the Upper Paleolithic. [ABSTRACT FROM AUTHOR]

The region surrounding Zermatt (SW Switzerland and NW Italy) displays some classic examples of imbrications between continental and oceanic units. In particular, the studied units, called Cimes Blanches and Frilihorn or Faisceau Vermiculaire, consist of a set of thin bands of continent-derived metasediments intercalated at different levels within the ocean-derived units. These bands are locally reduced to only one meter thick but can be traced for several tens to more than one hundred kilometers across the Pennine Alps. The mechanisms leading to such imbrications are a long-standing and still-debated question. Based on detailed mapping and structural analysis of key areas, we present new data on the structure and stratigraphy of the Faisceau Vermiculaire in the area surrounding Zermatt, with particular focus on the Täschalpen sector, where the Faisceau Vermiculaire is locally in contact with basement units. Our observations allow: (i) to confirm the presence of widespread breccias of probable Jurassic age in the Faisceau Vermiculaire; (ii) to interpret the contacts between the Faisceau Vermiculaire and the overlying non-ophiolitic Schistes Lustrés (Série Rousse) as stratigraphic; (iii) to show that the stratigraphy of the Faisceau Vermiculaire and associated Série Rousse contrasts strongly with the cover of the Siviez-Mischabel nappe and that these sequences originate from different paleogeographic domains (Prepiemont basin and Briançonnais platform respectively); (iv) to interpret as stratigraphic the contact of the Faisceau Vermiculaire and the Série Rousse with the basement forming the Alphubel anticline; the local unconformity is interpreted as the result of the activity of synsedimentary Jurassic normal paleofaults; (v) to highlight the trace of a major Jurassic normal fault, that should have marked an abrupt thinning of the paleomargin; it corresponds now to the contact between the Faisceau Vermiculaire (and associated Série Rousse) and the Siviez-Mischabel basement in the hinge of the Mischabel backfold. We propose a new tectonic scheme for the structure of the Faisceau Vermiculaire and adjacent units involving an early northward folding of the Faisceau Vermiculaire with the Série Rousse and the ophiolitic Schistes Lustrés of the Tsaté nappe, followed by major backfolding responsible for the southward emplacement of these units above the HP Zermatt-Saas and Monte Rosa nappes. Our study at regional scale shows that the group formed by the Alphubel basement, the Faisceau Vermiculaire and the Série Rousse share a tectonic position and stratigraphic sequences identical to those of the Mont Fort nappe, which outcrops on the other side of the Dent Blanche klippe. It leads to the proposition that this group constitutes the eastern extension of the Mont Fort nappe. [ABSTRACT FROM AUTHOR]

Lithostratigraphy of the Yongtan Group is newly established based on detailed sedimentologic and stratigraphic studies on recently exposed, less deformed, relatively continuous outcrops and comprehensive review of previous studies, mainly focusing on the Jeongseon Formation which occupies most of the group spatially and stratigraphically. The Yongtan Group is divided into the Jeongseon, Haengmae, and Hoedongri formations in ascending order, and all the units are assigned to the Ordovician. The Jeongseon Formation is divided into three members based on lithology. Eleven sedimentary facies are recognized in the Jeongseon Formation and organized into five facies associations (FAs), FA1 (tidal flat), FA2 (inner-ramp), FA3 (shoal), FA4 (mid-ramp), and FA5 (ramp-slope to outer-ramp). The formation is interpreted to have been deposited on a homoclinal ramp. The Yongtan Group is divided into two supersequences separated by type 1 sequence boundary and the lower and middle members of the Jeongseon Formation belong to Supersequence I and the Upper Member to Supersequence II which includes the Haengmae and Hoedongri formations. The relative sea-level curve inferred from sequence stratigraphic analysis suggests that the formation evolved through two depositional stages in accordance with second-order sea-level changes separated by the boundary between the Sauk and Tippecanoe sequence, and the curve is greatly similar to that of the Taebaek and Yeongwol groups. The southeastward thickening of FA3 and northwestward prevalence of shale-rich facies suggest that topographic highs and lows were present in the Taebaeksan Basin and a slope might have developed along the carbonate platform during the early stage of deposition. The correlation and lateral thickness variation of the facies associations additionally suggest that the basin was deeper toward the northwestern part of the Jeongseon area. The deepening is likely attributed to the weakening of the productivity of the carbonate factory during the early Ordovician. [ABSTRACT FROM AUTHOR]

The Early Triassic Kangan Formation in southern Iran and Persian Gulf, equivalent to the Upper Khuff Formation in the neighboring Arab countries hosts vast natural gas resources in the Persian Gulf. The current study discusses sedimentary facies, diagenesis, depositional setting and reservoir characteristics of the Triassic Kangan Formation within a sequence stratigraphic framework across a section passing from the central to northern Persian Gulf. For this purpose, a comprehensive analysis was conducted using well logs, cores and thin sections from four wells. In this respect, fifteen microfacies representing four facies’ belts ranging from peritidal to lagoon and barrier (shoal) settings of a shallow marine carbonate ramp environment were identified. The Kangan Formation has undergone marine, meteoric and burial diagenesis severely impacting its reservoir quality through dolomitization, dissolution and cementation. Analysis of sedimentological and petrophysical characteristics enabled the recognition of three third-order and seven fourth-order depositional sequences. This unit’s persistent and complex diagenetic history, spanning since the Lower Triassic, has significantly altered reservoir quality by reshaping pore types, size and geometry. Dolomitization and dissolution have notably improved the reservoir quality of the Kangan Formation in the central Persian Gulf. However, towards the northern Persian Gulf, the presence of anhydrite in the form of cement, nodules and interbeds has adversely affected reservoir quality. Consequently, the Kangan Formation behaves as a tight gas carbonate reservoir in the Coastal Fars structural zone of Zagros. Therefore, the Coastal Fars and the northern Persian Gulf can be conceptualized as the inner part of a large-scale paleo-ramp environment (inner ramp), whereas the central Persian Gulf lies within its mid-ramp and basin environment. [ABSTRACT FROM AUTHOR]

This study focused on determining the stratigraphic phenomena of the sequences of the Kirkuk group, within the Tertiary age, in the study area at the Buzurgan oil field within the Maysan governorate. In addition to various seismic lines from the completed seismic survey of the study region, data from the Buzurgan oil field wells was utilized. The stratigraphic interpretation results showed that the seismic sections of the Kirkuk Group formations are deposited in the form of a sigmoid configuration through the continuous deposition of shallow-shelf carbonates. Periodic rises in sea level led to episodes of deeper-water sedimentation, including shelf and shelf margin facies. Clastic (sandstone) was deposited as the sea receded from the Ghar formation, which represents the alluvial fan in the outer-shelf basin (slop and basin fan), through periods of sea-level (LST) and in a shallow-marine environment, leading to an overlap between sediments and the presence of sand lenses, onlap, and down lap. The current study shows the phase change in reflectors and perfect hydrocarbon indexes. The study detected a stratigraphic trap in the formation's eastern part and a large lens in the Southeast parts of the study area. [ABSTRACT FROM AUTHOR]

A plethora of names has been applied to upper Cambrian and Lower Ordovician lithostratigraphic units distributed from western Utah to southeastern and central Nevada. We report comprehensive stratigraphic analysis utilizing lithologic, conodont, brachiopod, sequence stratigraphic, and carbon isotope data from several ranges in southeastern Nevada. Those data demonstrate that upper Cambrian to Lower Ordovician strata in that area belong to a variety of depositional systems that can be integrated into a comprehensive and functional depositional model that span carbonate tidal flat to shallow marine carbonate ramp to shelf to deep marine settings. Most of these strata should be placed within a single lithostratigraphic nomenclature based on the well-known Notch Peak Formation and House Limestone of western Utah. Strata of the Whipple Cave Formation in the South Egan Range, Nevada are reassigned to the three members of the Notch Peak Formation. Strata assigned to the Nopah Formation and Pogonip Group by geologic mappers who worked in the Delamar Mountains, Meadow Valley Mountains, Sheep Range, and Arrow Canyon Range in Nevada are reassigned to the Notch Peak Formation and overlying House Limestone. Coeval strata farther west record a deeper marine depositional setting and are appropriately assigned to the Windfall Formation and Goodwin Limestone. Conodonts and sequence stratigraphic packages identified from slope deposits of the Hales Limestone at Tybo Canyon in the Hot Creek Range allow correlation to the Notch Peak Formation and House Limestone in western Utah. [ABSTRACT FROM AUTHOR]

A combination of palynological and palynofacies data are used as lithological evidence to describe sequence stratigraphic framework. Hence, the objective of this paper as to deploy the palynological and sequence stratigraphy framework of Campanian-Maastrichtian deposit of Anambra Basin, Awgu Section, Southeast Nigeria using standard techniques. The sequence stratigraphic analysis of the various succession in the studied outcrop sections identified parasequences limited by flooding surfaces with no evidence of erosion. The Nkporo and Mamu Formations were dated using the associated palynomorphs. The Anambra Basin show some complexity in terms of depositional style, sequence stratigraphy and control during the early and post infill of the structurally control basin. The outcrop sections logged reveals the presence of key stratigraphic surfaces and system tracts. The results from this study provides useful information of reservoir and seal rocks that are essential for hydrocarbon accumulation and stratigraphic trapping on the bases of the alternating high stand, low stand and transgressive system tracts. [ABSTRACT FROM AUTHOR]

Field and petrographic studies of the Qishn Formation provide insights in to sequence stratigraphic and reservoir attributes of the formation. The reservoir properties are controlled by complex interaction between depositional textures and diagenetic products. The Barremian-Aptian Qishn Formation was deposited between Precambrian basement rocks and marl-dominated Albian Kharfort Formation. The Qishn Formation consists of lower sandstone (Shabon Member), middle unit dominated by lime mudstone (Hinna Member), and upper bioclastic limestone with dolostone interbeds (Hasheer Member). The formation defines a transgressive-regressive sequence with maximum flooding surface (MFS) at the top of the Hinna Member. The petrographic and diagenetic analyses indicate that Shabon and Hasheer members constitute good reservoirs. The Shabon Member is dominated by friable medium- to coarse-grained arkose to lithic arenite with porosity as high as 20%. Despite a burial depth of ~ 5 km, the sandstone maintains most of its intergranular pores. The diagenetic features include early calcite cement followed by burial compaction. However, since most of the pores were already filled by calcite cement, volumetric reduction due to compaction was minimal. Post-compaction dissolution of the early calcite cement resulted in restoration of the intergranular pores. The Hasheer Member consists of extensively cemented bioclastic packstone to rudstone with porosity < 6% and sucrosic dolomite with intercrystalline and vuggy pores reaching up to 15%. The mud-dominated Hinna Member can be considered as potential cap rock for any fluids within the Shabon Member, whereas the marls of the Kharfot Formation constitute potential caprock for the preservation of fluids in the Hasheer Member. [ABSTRACT FROM AUTHOR]

[Objective] The current focus of non-conventional petroleum theories is the accumulation mechanism of organic matter. One of the most commonly debated issues regards the main influences on organic matter enrichment previous studies lack analysis of the depositional process, which is the likely reason for the debate. [Methods] This study combines sedimentological and geochemical methods to conduct detailed sequence stratigraphy, and facies and elemental analyses, aiming to address the accumulation mechanism of sedimentary organic matter. [Results] The Late Permian Wuchiaping Formation and Dalong Formation in the northern Sichuan Basin and the West Hubei Basin are subdivided in ascending order into the First, Second and Third members of the Wuchiaping Formation, and the First and Second members of the Dalong Formation. The Late Permian is subdivided into five third-order stratigraphy sequences, SQ1 to SQ5. Analysis of the sequence stratigraphy revealed the four-stage developmental history of the rift basin in the northern Sichuan Basin and the West Hubei Basin: the initial stage followed by rapid rifting, rifting climax and a shrinking stage. The initial stage mainly coincided with the deposition of SQ2, and consists of dark cherty limestones of slope facies. The rapid rifting stage mainly occurred during SQ3, and comprises calcareous shales of deepwater shelf facies. The rifting climax stage mainly took place during SQ4, consisting of black bedded cherts of basin facies. The shrinking stage mainly occurred during SQ5, and consists of medium- or thin-bedded limestones. The sweet-spot interval developed mainly between the highstand system tract (HST) of SQ3 and the transgressive system tract (TST) of SQ5, during which the nutrient elements Fe, Cu, Ni, Zn and redox-sensitive elements Mo, V, Fe/Al and S were highly enriched. This sweet-spot interval is also associated with highly active hydrothermal activity indicated by Al/ (Al+Fe+Mn) ratios < 0.6 and the Al-Fe-Mn diagram. [Conclusions] The development of high primary productivity occurred prior to the strongly reducing conditions during the deposition of the sweet-spot interval. This suggests that the reducing conditions in the bottom water resulted from high consumption of oxygen during the decomposition of organic matter, and that organic matter enrichment was mainly the result of primary productivity. The nutrient material input was related to hydrothermal activity and volcanism during the formation of the rifting basins. Episodic tectonic activity brought abundant nutrient elements to the rifting sea, enhancing the primary productivity level; the primary productivity level was the onset and basic condition for the extraordinarily high organic matter accumulation in the sweet-spot interval, and the strongly reducing conditions in the bottom water was the key factor for organic matter preservation and burial. [ABSTRACT FROM AUTHOR]

Extensional strike-slip basins have unique structural features that influence both sub-sags and traps. Despite previous investigations into the extension-strike-slip fault system, there remains a gap in the comprehensive analysis of its influence on sub-sag formation and trap development. The Huanghekoudong and Miaoxi'nan sub-sags within the Bohai Bay Basin, intersected by the Tan-Lu Fault Zone, offer exemplary cases for examining the interplay between strike-slip and extensional tectonic regimes. The neotectonic strike-slip movements along the Tan-Lu Fault Zone have given rise to various extensional strike-slip overlap zones in these sub-sags, rendering these locales ideal for investigating the dynamics of strike-slip and extensional tectonic processes. Employing three-dimensional seismic data, well logs, and a newly constructed sequence stratigraphic framework, our research delineates the geometric and kinematic phenomena characteristic of the extensional strike-slip fault system, including the dynamics of extensional fault deformation and interaction through time. By scrutinizing the fault system's vital role in shaping sub-sag evolution and trap genesis, we present a comprehensive model that significantly contributes to our understanding of structural trapping dynamics. This model not only fine-tunes existing trapping models but also offers invaluable insights for future exploration strategies within the Bohai Bay Basin and other similar extensional strike-slip basins worldwide. Our findings highlight the novel and significant implications of the extensional strike-slip fault system in controlling sub-sag and trap features, thus bridging a notable gap in existing geotechnical knowledge. [ABSTRACT FROM AUTHOR]

The sedimentary infill of the Quibas karstic site (Early Pleistocene, southern Spain) represents the only continuous succession with remains of continental vertebrates in Europe from pre-Jaramillo to post-Jaramillo age. The Quibas site, with a significant paleontological record, is dated between 1.1 and 0.9 Ma and offers a unique opportunity to carry out a paleoclimatic reconstruction of the time period immediately after the arrival of the first humans to western Europe. For this reason, defining the dominant sedimentary processes in the different stratigraphic units and the associated paleoenvironment is essential. The Quibas site is made up of two karstic features with two stratigraphic sequences: Quibas-Cueva, containing six lithostratigraphic units, and Quibas-Sima, which contains seven lithostratigraphic units. The detailed description and analyses of the stratigraphic sections have allowed the characterization of various autochthonous and allochthonous facies of cave deposits. Paleoclimatic proxies, inferred from sedimentological analyses, reveal a record of several alternating humid and arid phases resulting from the Early Pleistocene glacial-interglacial cycles, allowing correlation to the marine oxygen isotope record. The lowermost units (pre-Jaramillo) were deposited during a long-lasting interglacial, correlated to MIS 33–31. It was followed by an increase in aridity in the intermediate units of Quibas-Sima and uppermost unit of Quibas-Cueva (Jaramillo), revealing the beginning of a glacial period at the start of the Jaramillo subchron (1 Ma), which can be correlated to MIS 30. The upper Jaramillo and post-Jaramillo units suggest these were deposited in alternating periods of aridity and humid conditions, although less humid than the pre-Jaramillo period, probably representing the MIS 29 interglacial, the MIS 28 glacial and the MIS 27 interglacial. [ABSTRACT FROM AUTHOR]

Reconstructing the absolute chronology of Jerusalem during the time it served as the Judahite Kingdom's capital is challenging due to its dense, still inhabited urban nature and the plateau shape of the radiocarbon calibration curve during part of this period. We present 103 radiocarbon dates from reliable archaeological contexts in five excavation areas of Iron Age Jerusalem, which tie between archaeology and biblical history. We exploit Jerusalem's rich past, including textual evidence and vast archaeological remains, to overcome difficult problems in radiocarbon dating, including establishing a detailed chronology within the long-calibrated ranges of the Hallstatt Plateau and recognizing short-lived regional offsets in atmospheric 14C concentrations. The key to resolving these problems is to apply stringent field methodologies using microarchaeological methods, leading to densely radiocarbon-dated stratigraphic sequences. Using these sequences, we identify regional offsets in atmospheric 14C concentrations c. 720 BC, and in the historically secure stratigraphic horizon of the Babylonian destruction in 586 BC. The latter is verified by 100 single-ring measurements between 624 to 572 BC. This application of intense 14C dating sheds light on the reconstruction of Jerusalem in the Iron Age. It provides evidence for settlement in the 12th to 10th centuries BC and that westward expansion had already begun by the 9th century BC, with extensive architectural projects undertaken throughout the city in this period. This was followed by significant damage and rejuvenation of the city subsequent to the mid-eight century BC earthquake, after which the city was heavily fortified and continued to flourish until the Babylonian destruction. [ABSTRACT FROM AUTHOR]

Sequence architectures along the margins of rift basins are still poorly documented compared to passive continental margin settings. The Eocene Shahejie Formation on the rift margin of the Dongying Depression records a complex sequence stratigraphic distribution of conglomerate, sandy conglomerate, sandstone and mudstone. These facies have been mainly attributed to fan delta and marginal subaqueous fan depositional settings that developed during segmented fault activity along the rift margin. We utilize three‐dimensional (3D) seismic data, conventional cores, and wireline log data to dissect the overall wedge‐shaped upper sub‐member strata of the Shahejie Formation's fourth member. The study interval is a third‐order sequence formed between 45.4 and 42.5 Ma and contains a lowstand–transgressive systems tract (LST–TST) and a highstand systems tract–falling‐stage systems tract (HST–FSST). We found that the LST–TST developed several huge amalgamated depocenters along the Chennan border fault; whereas, these depocenters gradually diminished or even disappeared during the HST–FSST period, illustrating less significant control by the border fault. Through calculations of strata growth rates, we confirmed that the segmented activity of the border fault influences the stratigraphic distribution and facies evolution during these two periods. Specifically, deep‐water depositional systems, represented by marginal subaqueous fans were widely developed in the LST–TST period and were influenced by overall strong tectonic activity, including retrogradational (R) and aggradational (A) patterns. However, the aggradational to progradational (AP) deltas and progradational to degradational (PD) deltas dominated the generally muted tectonic activity setting during the HST–FSST. Additionally, influenced by localized segmented fault activity, these systems tracts exhibit incomplete vertical development, resulting in spatial variability in stratigraphic stacking patterns. [ABSTRACT FROM AUTHOR]

Large stratovolcanoes in the Cascade Range have high equilibrium-line altitudes that support glaciers whose Holocene and latest Pleistocene advances are amenable to dating. Glacier advances produced datable stratigraphic sequences in lateral moraines, which complement dating of end moraines. New mapping of glacial deposits on Mount Rainier using LIDAR and field observations supports a single latest Pleistocene or early Holocene advance. Rainier R tephra overlies deposits from this advance and could be as old as >11.6 ka; the advance could be of Younger Dryas age. Radiocarbon ages on wood interbedded between tills in the lateral moraines of Nisqually, Carbon, and Emmons glaciers and the South Tahoma glacier forefield suggest glacier advances between 200 and 550 CE, correlative with the First Millennium Advance in western Canada, and during the Little Ice Age (LIA) beginning as early as 1300 CE. These results resolve previous contradictory interpretations of Mount Rainier's glacial history and indicate that the original proposal of a single pre-Neoglacial cirque advance is correct, in contrast to a later interpretation of two advances of pre- and post-Younger Dryas age, respectively. Meanwhile, the occurrence of the pre-LIA Burroughs Mountain Advance, interpreted in previous work as occurring 3–2.5 ka, is questionable based on inherently ambiguous interpretations of tephra distribution. [ABSTRACT FROM AUTHOR]

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The Ordos Basin is a large cratonic basin with stable deposition in Northwest China. Given its mostly stable subsidence background and the urgent need for saline water disposal and carbon dioxide storage in the coal mining and coal chemical industries, the Ordos Basin has been chosen as a pilot demonstration site for carbon dioxide and saline water storage in China. However, few studies have been made to evaluate the sedimentary and sequence stratigraphy characteristics of this region, as well as their influence on carbon dioxide and saline water storage potential. To address this research gap, we conducted a sedimentary study of the Lower Triassic Liujiagou Formation in the northeastern Ordos Basin utilizing the stratigraphy theory, laboratory test analysis, and pilot project demonstration, to evaluate the area's viability for the deep geological storage of gas and liquid waste. We studied the tectonic setting, petrological features, and sedimentary characteristics of the favorable strata and predicted favorable areas based on sequence stratigraphy theory. The lithology predominantly consists of feldspathic graywacke, with a fine grain size and mostly fine-to-medium-grained sandstone. The distribution of thick-grained sandstone and fine-grained sediment was identified by dividing the sequence, and a favorable reservoir-cap assemblage configuration was formed. It's concluded that the Lower Triassic Liujiagou Formation exhibits suitable characteristics for the deep geological storage of carbon dioxide and saline water. This study demonstrates the importance of basic theory in guiding practical applications and provides a reference for the scientific selection of favorable areas for deep basin storage.