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1
Abood, Mustafa, and Aiad Al-Zaidy. "Depositional Environment and Stratigraphic Sequence of the Oligocene Succession in Fallujah and Melh-Tharthar Oilfields, Central Iraq." Iraqi Geological Journal 57, no. 2F (2024): 168–83. https://doi.org/10.46717/igj.57.2f.11ms-2024-12-21.
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The current study dealt with the facies and stratigraphic sequence of the Oligocene succession in the Fallujah and Melh-Tharthar oilfields, which are located in the most part the northern of the Mesopotamian Zone at central Iraq. The studied Oligocene succession consists of Bajawan, Baba, Sheikh Alas and Plani formations in the Fallujah oil field, while in Melh-Tharthar oil field, consists of Anah, Azkand, Sheikh Alas and Palani formations. The facies analysis of the studied Oligocene sequence was described according to the carbonate fabric and the particle types in the Fallujah oil field that showed eleven micro-facies for seven facies associations (back-reef, shallow open, shoal, fore-reef, reef, slope and deep shelf), while in the Melh-Tharthar oil field, the Oligocene succession was characterized by thirteen micro-facies for six facies associations (back-reef, reef, fore-reef, shoal, slope and deep shelf). Four depositional cycles were diagnosed through facies analysis of the studied sequence, the first sedimentary cycle of Palani Formation represents a transgression stage (TST) of the deep-sea facies and ends with the slope facies during the highstand system tract stage (HST). The second depositional cycle of Sheikh Alas Formation represents by progressive stage (TST), which is characterized by deepening upward for fore-reef association facies in Fallujah oil field and reef/fore-reef facies associations in Melh-Tharthar oil field. The third depositional cycle represents Baba Formation which was deposited during three stages of the HST in a succession of fore reef/reef and shoal facies associations. While in Melh-Tharthar oil field represent by Azkand Formation which characterized by the similar facies associations of Fallujah succession, with exception of presence the fourth HST stage that represented by fore-reefs and coral reef facies associations. The high stand stage continued during the deposition of the Bajawan Formation, as a fourth depositional cycle, which showed the deposition in shallow open marine and back-reef associated facies, whereas in Melh-Tharthar oil field such cycle is characterized by alternative of reef and Backreef facies association which deposited during HST stage. The fourth cycle ended with a regional regression stage to form SB1 which marking the end of the Oligocene.
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Permana, Aang Panji, Subagyo Pramumijoyo, and Sunarty Suly Eraku. "MICROFACIES AND DEPOSITIONAL ENVIRONMENT OF TERTIARY LIMESTONE, GORONTALO PROVINCE, INDONESIA." Series of Geology and Technical Sciences 2, no. 446 (2021): 15–21. http://dx.doi.org/10.32014/2021.2518-170x.29.
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The research area is located in northern Limboto Lake in Gorontalo Province, which has complex geological characteristics. The geological complexities include stratigraphy and tectonics which influence the formation of the Limboto Basin. Limestone research in the Late Tertiary Limboto Basin is very intriguing to be done because of the lack of research in limestone. Gorontalo limestone outcrops, which become the focus of the research, have a total thickness of 30 meters. The research objective is to analyze facies, microfacies, and depositional environment of tertiary limestone. These two research objectives are attained by using two research methods, namely measurd section and petrography analysis. The research result exhibits that there are four Gorontalo limestones facies, including coralline rudstone intercalated with thin mudstone facies, sandy micrite intercession facies, coralline rudstone intercession facies and sandy allochem limestone intercession facies. According to the limestone micro- facies standard, the depositional environment of Gorontalo limestone is platform interior restricted (facies zone 8).
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Hou, Fang, Li Feng, Yue Wu, Zhe Zhang, Chenyang Wu, and Xuancheng Zhang. "Study on Sedimentary Facies and Reservoir in Taiyuan Formation in Qingshimao area." Academic Journal of Science and Technology 9, no. 2 (2024): 237–44. http://dx.doi.org/10.54097/kqrsm459.
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Recent exploration results show that there is an industrial airflow in Taiyuan Formation in Qingshimao area of Ordos Basin. The Marine quartz sandstone reservoir developed in Taiyuan Formation is the target reservoir after He 8 and Shan 1 Members in Qingshimao area. In order to study the sedimentary facies characteristics of Taiyuan Formation in Qingshimao area, this paper analyzed the well logging, single well facies and connected well facies on the basis of core observation. In addition, using the data of casting thin section, scanning electron microscope and cathode luminescence, the response relationship between sedimentary facies and well logging facies is established, thus the sedimentary facies in the study area is divided and the reservoir characteristic is studied. The results show that the Taiyuan Formation mainly developed barrier coastal sedimentary facies, which can be subdivided into four sub-facies: marsh, tidal flat, barrier island and lagoon. Lithic quartz sandstone is mainly developed in Taiyuan Formation, followed by quartz sandstone and lithic sandstone. The reservoir space types include intergranular pores, dissolved pores, intergranular pores and micro-fractures. Extra-ultra-low porosity and ultra-low permeability reservoir is developed in Taiyuan Formation in study area.
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Jia, WANG, and ZHOU Yue. "Study on volcanic reservoir characteristics of Yingcheng Formation in Xudong area of Xujiaweizi fault depression." E3S Web of Conferences 194 (2020): 01038. http://dx.doi.org/10.1051/e3sconf/202019401038.
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Types of deep reservoir rich in Yingcheng formation of Xudong area in Xujiaweizi fault depression, the study of volcanic rocks of Yingcheng formation in the main, using the date of core, logging, oil test, from lithology, lithofacies and physical properties to study volcanic reservoir characteristics. The main lithology of volcanic reservoir in Yingcheng formation of Xudong area include rhyolite, rhyolitic tuff, rhyolitic tuff fused, rhyolitic breccia and rhyolitic tuff breccia. In accordance with lithology combination of features, volcanic facies can be divided into volcanic explosive facies, volcanic effusive facies and volcanic sedimentary facies. The main types of porosity have air vent of primary pore, remnants pores of air vent filled after, cracks, micro-cracks and feldspar corrosion hole of secondary porosity, volcanic ash corrosion hole, micro-pore produced by rhyolitic glass from glass off in spherules rhyolite, quartz crystal chip corrosion hole, and so on. Through studying the ratio of reservoir and formation for a single well, the frequency distribution of reservoir thickness, production capacity situation and pool-forming regularity, Xudong area can be divided into three reservoir development zone, so we will find out the most favorable reservoir development zone, then it can play a guiding role for the next step of the exploration deployment.
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Liu, Cheng Zhi, Xue Du, Xiao Zhou, Bo Li, and Xi Liu. "The Types of Sedimentary Facies and Rock Characteristics of Xujiaweizi Fault Depression in Songliao Basin." Advanced Materials Research 787 (September 2013): 717–20. http://dx.doi.org/10.4028/www.scientific.net/amr.787.717.
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In the Shahezi Formation of Xujiaweizi fault depression in the Songliao Basin mainly tow sedimentary system is developed: the Xudong gentle slope belt and Xuxi fault zone systems. However, this area is little studied as there have been only limited efforts in exploration. Based on the latest drilling, outcrop data, description of core observation and laboratory microscope identification, it has been concluded that four mainly sedimentary facies are developed in this area: braided river delta, fan delta, lacustrine facies and sublacustrine fan. The subaqueous distribute channel is the main type of the fan delta front while the braided channel is the main type of the braided river delta. A number of clastic, sandstone and mudstone are developed in these two types of sedimentary facies. We can use it to make further study of dividing into micro-facies.
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Saha, Bikas, Pradip Samanta, Soumik Mukhopadhyay, and Patrick G. Eriksson. "Effects of transgression on sedimentation system vis-à-vis coastal erosion on the Chandipur coast, Odisha, India." Indian Association of Sedimentologists 40, no. I (2023): 5–19. http://dx.doi.org/10.51710/jias.v40ii.276.
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There has been a decade-long debate about global warming and its far-reaching effect on sea level rise. However, little attention has so far been given to the effects of transgression in sedimentation systems. The present paper deals with the effects of transgression on sedimentation dynamics of a meso - to micro -tidal coastal environment. The sediment characteristics, flow dynamics, current flow patterns giving rise to facies of the individual environments have been analysed in detail. Shallow vertical trenches excavated in different parts of the coastal area elucidated facies characteristics and shifting of facies in response to transgression. The temporal variation in facies gave rise to a facies model that can be used as an authenticated tool for interpreting similar ancient environments. The coastal erosion resulting from on-going transgression and other short-term causes has also been evaluated with the help of facies mapping for last ~15 years and modifications in geomorphic features along and across the coastline. The coastal erosion concomitant with anthropogenic interventions cause serious stress on biological inhabitants of coastal areas. Coastal conservation and management studies will help in protecting further degradation of coastal areas and also help to maintain the biodiversity and ecosystem.
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Li, Donghui, Shouhua Dong, Cong Zhang, Shuaiqi Deng, and Shujie Li. "Application of micro-seismic facies to coal bed methane exploration." Mining Science and Technology (China) 21, no. 5 (2011): 743–47. http://dx.doi.org/10.1016/j.mstc.2011.04.001.
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Homonnay, Emmanuelle, Jean-Marc Lardeaux, Michel Corsini, et al. "Arc-related high-K magmatism in the Ceuta Peninsula (Internal Rif, Spain): discovery and consequences." Geological Magazine 156, no. 08 (2018): 1385–99. http://dx.doi.org/10.1017/s0016756818000717.
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AbstractWe document the occurrence of micro-diorite magmatic sills, with magmatic enclaves, in the Ceuta Peninsula within metapelites from the Lower Sebtides units (Internal Rif). All magmatic rocks show a primary magmatic mineralogy and geochemical signature diagnostic for high-K calc-alkaline to shoshonitic island arc magmatism. Moreover, these rocks are significantly affected by secondary metamorphic transformations under greenschist- to amphibolite-facies conditions, regionally dated atc. 21 Ma. Geometric relationships between the sills and the main regional foliation, developed under intermediate-pressure granulite-facies conditions atc. 28 Ma, demonstrate that the sills emplaced during the late stage of this main tectonic event. New U–Pbin situanalyses of monazite performed on the micro-diorite sills provide an age of 20.64 ± 0.19 Ma, coherent with this chronological framework and interpreted as the age of greenschist-facies re-equilibration. The discovery of pre-Miocene high-K calc-alkaline to shoshonitic arc-related magmatism is clearly consistent with the subduction context proposed for the Alboran Basin evolution, according to geophysical investigations. In this framework, the Lower Sebtides units could be considered as part of the upper plate of the subduction system, while the Upper Sebtides must be regarded as the lower subducted plate.
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Fadhil, Doaa T., Mustafa A. Theyab, and Aboosh Al-Hadidy. "Petrographical and microfacies study of Sinjar formation in Bazyan anticline, Sulaimaniyah region (Northern Iraq)." Naukovyi Visnyk Natsionalnoho Hirnychoho Universytetu, no. 6 (2021): 11–15. http://dx.doi.org/10.33271/nvngu/2021-6/011.
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Purpose. The work studies Sinjar formation (upper Paleocene lower Eocene) within the Bazyan anticline in the Sulaimaniyah region (northeastern Iraq). The facies analysis is based on the petrographic study of limestone deposits and is essential to identify their nature. The sediments that formed Sinjar formation have a high content of skeletal granules which include a small amount of red algae and residues of unicellular organisms-foraminifera. Methodology. The method of work included two main aspects: field study and laboratory work. The first part included the field description of the rocky excavation and modeling of 10 rocks samples from it within the Bazyan section. As for the second main aspect, it included the preparation of 10 slides for petrographic study of Sinjar Formation rocks followed by a facial analysis of these deposits. Findings. Micro facial analysis showed that the sequences of Sinjar formation consist of three main facies. The wacky limestone facies bears benthic foraminifera. The facies of compact limestone bears the benthic foraminifera and red algae while the compact wacky limestone facies bears the fossils. Originality. Wacky limestone facies bearing benthic foraminifera, compacted limestone facies bearing benthic foraminifera and red algae, and wacky limestone facies bearing benthic foraminifera were selected and studied. Thus, according to the facial analysis, Sinjar formation was deposited within the open shelf before the formation of the main deposit. Practical value. Samples of rocks were obtained from the Bazyan anticline for further production of slides in order to study the facies of this anticline, which allowed showing its lithostratigraphic column.
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Qiang, Kun Sheng, Jian Min Wang, Xin Wen Tian, Xiu Xiang Lü, and Lei Tian. "Research on Three-Dimension Sedimentary Facies Model Building of the Reservoir Chang2 Member, Yanchang Formation in Zhifang Area, Erdos Basin." Advanced Materials Research 466-467 (February 2012): 303–7. http://dx.doi.org/10.4028/www.scientific.net/amr.466-467.303.
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Through the Ordos basin sample with Triassic Yanchang formation Chang 2 member sedimentary facies research and analysis, the use of deterministic modeling and the theory of stochastic modeling, using PETREL software, the establishment of a three-dimensional visualization of the study area Chang 2 member geological reservoir facies model, the model and geological interpretation in the whole match, a true reflection of the sedimentary characteristics of the study area, the numerical simulation for the latter part of remaining oil and provide a geological basis. Sand distribution model based on a clear understanding of sand microfacies characteristics distribution in the plane and space, the combination of relations, proved in the study area is mainly sand flat on the NE - SW band distribution, the distributary channel facies under control the trend of the sand body, in the same succession of small rivers within the good level, migration is not swinging, with micro-facies stability.Chang2 member channel development , is the favorable oil and gas accumulation zones.
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Djakovic, Martin, Hans-Jürgen Gawlick, and Milan Sudar. "Early-Middle Jurassic stepwise deepening in the transitional facies belt between the Adriatic Carbonte Platform Basement and Neo-Tethys open shelf in northeastern Montenegro evidenced by new ammonoid data from the early Late Pliensbachian (Lavinianum Zone)." Annales g?ologiques de la Peninsule balkanique 82, no. 1 (2021): 1–25. http://dx.doi.org/10.2298/gabp201230001d.
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New ammonoid data prove an early Late Pliensbachian deepening event above the ?Late Hettangian-Sinemurian shallow-subtidal gray-reddish micro-oncoidal-foraminifera grainstone facies and the ?early Pliensbachian deeper-marine micro-oncoidal-crinoidal-ammonoid wacke- to packstone facies. Based on the presence of Fuciniceras lavinianum (Fucini), Lytoceras ovimontanum Geyer and Arieticeratinae gen. indet. from a hardground above the deeper-water micro-oncoidal limestones in the Mihajlovici section (north - eastern Montenegro) a Late Pliensbachian to early Toarcian condensation horizon is proven. The Middle Toarcian ammonoid-bearing horizon also yielded species not known from previous studies: Calliphylloceras capitanii (cATuLLo), Harpoceras subplanatum (oPPeL) and Furloceras aff. chelussii (PAriScH & ViALe), also described in the present paper. These new data prove a stepwise deepening of the depositional area during the early and the Middle Jurassic reflected in detail in four sedimentary members: 1) ?Late Hettangian to Sine - murian/?earliest Pliensbachian open-marine shallow subtital micro-oncoidal limestones; 2) ?early to Late Pliensbachian open-marine condensed limestones with few micro-oncoids and more open-marine influence; 3) Toarcian open-marine condensed red limestones with hardgrounds; and 4) condensed red nodular Bositra Limestone. These four members are separated by hard - rounds representing stratigraphic gaps in deposition. The stepwise deepening during the early-Middle Jurassic follows the general trend of deposition as known in the whole Western Tethys realm above the Late Triassic Dachstein carbonate Platform.
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McElhinney, Tara R., Tim J. Dempster, and Peter Chung. "The influence of microscale lithological layering and fluid availability on the metamorphic development of garnet and zircon: insights into dissolution–reprecipitation processes." Mineralogical Magazine 86, no. 1 (2021): 9–26. http://dx.doi.org/10.1180/mgm.2021.97.
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AbstractThe response of garnet and zircon to prograde amphibolite-facies metamorphism in late Proterozoic mica schists from the Scottish Highlands has been investigated. Spatial analysis of zircon populations using scanning electron microscopy was undertaken in Dalradian Schists that have undergone a sequence of prograde garnet growth and localised breakdown reactions involving coupled dissolution–reprecipitation. Fluid availability and matrix permeability strongly control this metamorphic response and different generations of garnet contain radically different populations of metamorphic micro-zircon and associated changes in the detrital zircon population. Micro-zircon abundance increases during garnet growth, whereas that of detrital zircon decreases. The mineralogy of the matrix influences zircon abundance in porphyroblast phases, where garnet overgrows a micaceous matrix zircon-rich garnet forms and where it overgrows a quartzofeldspathic matrix the result is zircon-poor garnet. Following garnet growth, micro-zircon abundance decreases at each stage of the prograde reaction history, with sillimanite-zone schists containing the lowest abundance, suggesting micro-zircons are texturally less stable at staurolite- and sillimanite-grade metamorphism. Micro-zircons are distributed evenly across host minerals in the matrix, with the exception of retrograde chlorite where micro-zircons are absent due to fluids removing Zr before new zircon can precipitate. There is an overall decrease in the mode of zircon at each stage of the reaction history, indicating that zircon is a highly reactive phase during amphibolite-facies metamorphism and is very sensitive to individual prograde and retrograde reactions.
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Liu, Tao, Zongbao Liu, Kejia Zhang, et al. "Intelligent Identification Method for the Diagenetic Facies of Tight Oil Reservoirs Based on Hybrid Intelligence—A Case Study of Fuyu Reservoir in Sanzhao Sag of Songliao Basin." Energies 17, no. 7 (2024): 1708. http://dx.doi.org/10.3390/en17071708.
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The diagenetic facies of tight oil reservoirs reflect the diagenetic characteristics and micro-pore structure of reservoirs, determining the formation and distribution of sweet spot zones. By establishing the correlation between diagenetic facies and logging curves, we can effectively identify the vertical variation of diagenetic facies types and predict the spatial variation of reservoir quality. However, it is still challenging work to establish the correlation between logging and diagenetic facies, and there are some problems such as low accuracy, high time consumption and high cost. To this end, we propose a lithofacies identification method for tight oil reservoirs based on hybrid intelligence using the Fuyu oil layer of the Sanzhao depression in Songliao Basin as the target area. Firstly, the geological characteristics of the selected area were analyzed, the definition and classification scheme of diagenetic facies and the dominant diagenetic facies were discussed, and the logging response characteristics of various diagenetic facies were summarized. Secondly, based on the standardization of logging curves, the logging image data set of various diagenetic facies was built, and the imbalanced data set processing was performed. Thirdly, by integrating CNN (Convolutional Neural Networks) and ViT (Visual Transformer), the C-ViTM hybrid intelligent model was constructed to identify the diagenetic facies of tight oil reservoirs. Finally, the effectiveness of the method is demonstrated through experiments with different thicknesses, accuracy and single-well identification. The experimental results show that the C-ViTM method has the best identification effect at the sample thickness of 0.5 m, with Precision of above 86%, Recall of above 90% and F1 score of above 89%. The calculation result of the Jaccard index in the identification of a single well was 0.79, and the diagenetic facies of tight reservoirs can be identified efficiently and accurately. At the same time, it also provides a new idea for the identification of the diagenetic facies of old oilfields with only logging image data sets.
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Shelekhova, T. S., N. B. Lavrova, and Yu S. Tikhonova. "Relative sea-level variations indicated by micropaleontological data from small lake bottom sediments (Kandalaksha Bay, NW Russia)." Limnology and Freshwater Biology, no. 4 (2022): 1580–82. http://dx.doi.org/10.31951/2658-3518-2022-a-4-1580.
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Abstract. The results of the micro-paleontological study of bottom sediments from a small lake on the Kandalaksha Bay shore of the White Sea are reported. Three stages in the evolution of the lake basin: marine, transitional and lacustrine were recognized. The characteristics of their diatom complexes and palynological spectra were revealed. Marine-facies sediments were shown to be dominated by poly- and mesohalobes, their share in the transition facies is twice as small, and freshwater diatom complexes contain up to 10% halophiles. Facies were shown to be reliably identified, using the pollen and spores of distinctive species indicative of certain ecological conditions. Non-pollen palynomorphs (algae Pediastrum, Botryococcus and sponge spicules) can be used for identifying various facies. These data will be used later to more reliably and objectively reconstruct variations in relative sea level and the sea shoreline migration in the Holocene. A decrease in sea level was established at the turn of 7200 cal. years and the isolation of the lake from the sea occurred about 6700 cal. years ago.
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Rao, Rameshwar, and Hakim Rai. "Mineral chemistry of eclogites to investigate the evolutionary metamorphic history of UHP rocks from Tso-Morari region, Ladakh, India." Journal of Nepal Geological Society 40 (December 1, 2010): 13–20. http://dx.doi.org/10.3126/jngs.v40i0.23592.
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Micro textures of metabasics from the Tso-Morari region, Ladakh were studied in order to understand the evolutionary metamorphic history of eclogites. The mineral chemistry, paragenesis of mineral inclusions in garnet, and zoning in omphacite, garnet and amphibole suggest three main metamorphic stages: (i) an eclogite stage with late blueschist facies metamorphism, (ii) a medium-pressure amphibolite facies stage, and (iii) a low-pressure amphibolite to greenschist facies stage. The high Si content in phengite, presence of rutile besides almandine-rich garnet and omphacite in eclogites indicate the attainment of high pressures. Also, the textural features and composition of amphiboles indicate that blueschist facies conditions represented by growth of glaucophane at high pressure and low temperature were followed by a lower-pressure stage of metamorphism represented by partial and in some cases complete reaction of glaucophane to calcic green amphibole such as magnesio-hornblende. The relationships define a clock-wise P-T path with the involvement of an isothermal uplift path for the eclogites and associated garnet-amphibolites of Tso-Morari region.
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Shiggins, Connor J., Matthew R. P. Harris, Peter G. Knight, and Christopher J. Fogwill. "Micro-Scale isotopic analysis of ice facies frozen from supercooled water." Geografiska Annaler: Series A, Physical Geography 102, no. 2 (2020): 104–17. http://dx.doi.org/10.1080/04353676.2020.1762364.
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Zhou, Xiaogang, Kai Wang, Baozhen Yan, et al. "Methane Adsorption Energy Variation Affected by Industrial Components in Deep and Thick Coal Reservoirs." Processes 12, no. 12 (2024): 2780. https://doi.org/10.3390/pr12122780.
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The relevant literature indicates that coal facies have a significant impact on the pore structure and adsorption properties of deep coal reservoirs. The content of submicroscopic components is used to calculate the parameters of coal facies. Based on traditional coal phase parameters and ash content, the coal phases of the coal samples in the study area were divided. Based on the adsorption potential theory, the differences in methane adsorption energy changes between different coal phases were compared. The results are as follows. The wet herbaceous swamp facies (type A) could be divided into two subtypes by using the ash yield: subtype A-1 (with an ash yield lower than 20% and a gel index (GI) lower than 5), and subtype A-2 (with an ash yield larger than 20% and a GI lower than 5). With the increase in micro-pore volume shown in A-1 samples, cumulative surface free energy increases linearly and the maximum rate of decline decreases linearly. Coal facies have an important effect on adsorption parameters: VL increases and PL decreases with higher structural preservation index (TPI). The effect of a low ash yield and different Ro,max on methane adsorption energy parameters is stronger.
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STONE, TRAVIS, ROWAN MARTINDALE, TANNER FONVILLE, et al. "ASSESSMENT OF A REEF COMMUNITY FROM LOWER JURASSIC (PLIENSBACHIAN) STRATA IN THE CENTRAL HIGH ATLAS MOUNTAINS OF MOROCCO." PALAIOS 37, no. 11 (2022): 633–49. http://dx.doi.org/10.2110/palo.2022.010.
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Abstract During the Early Jurassic, reefs in the shallow seas of the Atlas Rift experienced substantial changes as they recovered from the end-Triassic mass extinction. Excellent Lower Jurassic reef deposits documenting this change occur in the Central High Atlas region of Morocco, and herein we describe Owl Olistolith, a micro-olistolith found in lower Pliensbachian-aged (∼ 188.7 million years ago) Moroccan strata. The olistolith records the composition of a reef that grew within the Atlas rift zone and represents a snapshot of reef recovery ∼ 10 million years after the end-Triassic mass extinction. Owl Olistolith is derived from a reef that was originally situated on an outer platform within fair weather wave base; it broke loose and was transported to deeper water and deposited amongst marls. Corals and microbialites formed the primary framework of the reef; microproblematica, foraminifera, and other minor components were also present. The reef can be divided into two dominant facies: a microbialite facies that contains no corals (54%–94% microbialites), and a coral-microbialite facies with substantial proportions of both microbialite (23%–50%) and corals (14%–72%). The micro-olistolith contains at least 15 distinct coral types. In this study, seven coral genera were identified, three of which represent taxa that span the Triassic/Jurassic boundary, including Coryphyllia, Stylophyllopsis, and Margarosmilia. These results indicate that, although surviving taxa played a significant role, newly evolved corals were the most important taxa in the reestablishment of reef ecosystems in the Early Jurassic of Morocco.
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Brenner, Wolfram W. "Micro-Absorptionsphotometry: new possibilities of facies analysis in fossil and recent pollen." Neues Jahrbuch für Geologie und Paläontologie - Monatshefte 1996, no. 5 (1996): 257–78. http://dx.doi.org/10.1127/njgpm/1996/1996/257.
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da Silva, Maurício Dias, Márcia Elisa Boscato Gomes, André Sampaio Mexias, et al. "Geochemical Variations of Kerolite, Stevensite, and Saponite from the Pre-Salt Sag Interval of the Santos Basin: An Approach Using Electron Probe Microanalysis." Minerals 15, no. 3 (2025): 285. https://doi.org/10.3390/min15030285.
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This study investigates the mineralogy and chemical characteristics of pre-salt clay minerals, classifies them, and defines assemblages in reactive microsites. Using Electron Probe Micro-Analysis (EPMA), the chemical formulas of Mg-rich clays were determined. Stevensite exhibited low interlayer charge and aluminum content, while kerolite was characterized by a minimal charge. K/S (kerolite/stevensite) mixed layer showed intermediate compositions and charges between these endmembers. Saponite was distinguished by higher levels of Al, K, and Fe, along with a higher interlayer charge. The proposed assemblages are as follows: saponite in mudstone facies (without spherulites/shrubs), with a hybrid matrix; pure kerolite in spherulstone and shrubstone facies, marked by the absence of significant reactions and high preservation of matrix and textures; stevensite in facies with extensive matrix replacement by dolomitization/silicification; and K/S and kerolite in similar facies with intermediate matrix replacement levels and the coexistence of two intimately related clay mineral compositions. This study enables reliable differentiation of these species based on point mineral chemistry and mapping, combined with a microsite approach and conventional techniques. Additionally, it discusses the formation of pre-salt clays, influenced by significant kinetic and chemical interactions during their genesis and burial to depths of approximately 5 km.
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Geng, Xiao Jie, Chang Song Lin, Xiao Min Zhu, Yan Lei Dong, and Qi Luo. "Facies Evolution and Distribution of Subaqueous Fans Complex in Biyang Sag, Eastern China." Advanced Materials Research 868 (December 2013): 168–71. http://dx.doi.org/10.4028/www.scientific.net/amr.868.168.
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Hetaoyuan formation of Palaeogene in Biyang sag experienced the process of sedimentation during the main depressing period. Lithological traps were formed by the Sandstone-conglomerate bodies as favorite targets for oil and gas exploration in the southeast of Biyang sag. In this study, seismic profile, cores and well loggings as main data are used to analyze the micro-facies of subaqueous fan complex system. Methods such as Phasing concertion, spectrum decomposition, and strata slice play important roles in the study of facies evolution and distribution in high-resolution sequence framework of the upper member of the third Hetaoyuan formation. Subsequently, All of the coarse-grained turbid sandstone and the distributary channels sediments are potential reservoirs for oil and gas storage.
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Erragragui, Mohamed, Aïssa Masrour, Hicham Benbaqqal, and Mostafa Gretaa. "Le Domérien-Toarcien Inférieur De La Ride De Fert Elbir (Rides Sud-Rifaines, Maroc)." European Scientific Journal, ESJ 13, no. 36 (2017): 132. http://dx.doi.org/10.19044/esj.2017.v13n36p132.
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The South-Rifain ridges are located at 30 Km in the North of Meknes City, they constitute the extreme southern limit of the Rifaine chain. Globally, these ridges integrate into the history of African northwestern margin evolution. Mainly, the frame of this ridge is composed of the Jurassic sedimentation. The Fert Elbir ridge, subject of this study, is among the leading reliefs in the South-Rifain ridges. Generally, in this ridge, two geological sections have been studied, in the objective to determine and to understand the history of sedimentological, bio-stratigraphical and paleoenvironmental evolution of the Jurassic sedimentary series. Essentially, it includes the carbonates and marls deposits, composed mainly by several facies and micro-facies, grouped in eight facies associations. They contain a very important biological diversity especially at the level of the middleDomerian. Paleo-environmentally, this sedimentation series was deposited in the many diversified environments, having the areas of deposit essentially very close to the coast (proximal), or located in distal position with several hundred meters from the shore.
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Li, Jian-ping, Zi-ying Qiu, and Hong-yi Li. "Lithology and Lithofacies Characteristics of Deeply Buried Clastic Reservoirs in Alternating Wet-arid Climate and its Hydrocarbon Significance." Journal of Physics: Conference Series 2594, no. 1 (2023): 012039. http://dx.doi.org/10.1088/1742-6596/2594/1/012039.
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Abstract There have been series of HPHT (high temperature and high pressure) reservoirs with good quality and high productivity discovered in the Triassic Skagerrak Formation in the Central Graben of the UK North Sea. The bottlenecks for further E&P activity are the complicated depositional facies and high reservoir heterogeneity. The main reservoir space is a mixed porosity network composed of primary pores, micro-pores, secondary pores, secondary micro-pores and micro-fractures. Reservoirs of the Skagerrak Formation have greatly varied lateral connectivity as well as poor vertical connectivity. In the case of sufficiently high pressure differentials, hydrocarbon can be fed from high-potential area to low-potential area. There is no simple linear relationship between depth and reservoir quality. The primary depositional texture (grain size/sorting/clay content, etc.) linked to facies has a fundamental control on reservoir quality. Clean and well sorted cross laminated sandstone has the best reservoir quality, while the reservoir quality of planar laminated sandstone decreased due to increased degree of compaction caused by mica drapes. The reservoir quality of the fine-grained ripple cross laminated sandstone is even poorer than that of the planar laminated sandstone, due to abundant mica and clay drapes. Mottled bioturbated sandstone is fine grained with high clay content, which is more muddy because of containing burrows and insect larva. Pedoturbated sandstone has the poorest reservoir quality due to severe dolomite cementation. The dominant detrital material of the Skagerrak Formation is feldspar that provides abundant secondary porosity by alteration and dissolution. Chlorite coats are commonly developed and stained with residual oil or bitumen, which clearly inhibits quartz cementation and feldspar overgrowth. The presence of these clay coats contributes to the preservation of anomalously high porosity at depth in the cleaner and coarser grained fluvial channel facies. The Skagerrak formation facies is a dryland fluvial-lacustrine depositional system which is controlled by fluctuations of depositional base level due to salt mobilisation. The Skagerrak formation consists of several cycles that are vertically separated by lacustrine mudstone. The reservoir permeability system is composed of active fluvial channel sandstones, terminal splay sandstones, abandoned fluvial channel sandstones, minor channel sandstones connecting fluvial channel and terminal splay, as well as low-permeability faults, while the active fluvial channel sandstone is the “sweet spot”. The analysis of controls on deeply buried reservoir quality is significant to precisely predict “sweet spot” in the Skagerrak Formation.
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Bankole, Shereef, Jim Buckman, and Dorrik Stow. "Unusual Components Within a Fine-Grained Contourite Deposit: Significance for Interpretation of Provenance and the Contourite Budget." Minerals 10, no. 6 (2020): 488. http://dx.doi.org/10.3390/min10060488.
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Deep-water contourite muds are an important component of many continental margin systems and are currently the focus of much interest amongst deep-water researchers. One outstanding gap in our knowledge of these systems is to understand and quantify a contourite budget, both at the small (facies) scale and at the larger drift scale. A second problem concerns the establishing of robust criteria for discriminating between contourites and associated deepwater facies—turbidites and hemipelagites. This paper contributes to these topics by detailed examination of sediment composition, with a particular focus on potentially diagnostic components, within contourites and hemipelagites from the same depositional basin. Samples were selected from Pliocene to Quaternary muddy contourites from the Gulf of Cadiz (IODP 339) and examined by scanning electron microscopy. The presence of tunicate spicules, micro-bored shell fragments, and a particular species of coccolithophore, Braarudosphaera biglowii, all indicate derivation from shallow waters and hence lateral off-shelf supply. In contrast, micro-mudclasts and fragmented bioclasts are indicative of alongslope transport in bottom currents. A normal planktic component of the contourite muds shows a significant vertical input from pelagic settling. Such diagnostic components can also help in the discrimination between contourites, turbidites and hemipelagites.
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Smodej, Jörg, Laurent Lemmens, Lars Reuning, et al. "Nano- to Millimeter Scale Morphology of Connected and Isolated Porosity in the Permo-Triassic Khuff Formation of Oman." Geosciences 10, no. 1 (2019): 7. http://dx.doi.org/10.3390/geosciences10010007.
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Carbonate reservoirs form important exploration targets for the oil and gas industry in many parts of the world. This study aims to differentiate and quantify pore types and their relation to petrophysical properties in the Permo-Triassic Khuff Formation, a major carbonate reservoir in Oman. For that purpose, we have employed a number of laboratory techniques to test their applicability for the characterization of respective rock types. Consequently, a workflow has been established utilizing a combined analysis of petrographic and petrophysical methods which provide the best results for pore-system characterization. Micro-computed tomography (µCT) analysis allows a representative 3D assessment of total porosity, pore connectivity, and effective porosity of the ooid-shoal facies but it cannot resolve the full pore-size spectrum of the highly microporous mud-/wackestone facies. In order to resolve the smallest pores, combined mercury injection capillary pressure (MICP), nuclear magnetic resonance (NMR), and BIB (broad ion beam)-SEM analyses allow covering a large pore size range from millimeter to nanometer scale. Combining these techniques, three different rock types with clearly discernible pore networks can be defined. Moldic porosity in combination with intercrystalline porosity results in the highest effective porosities and permeabilities in shoal facies. In back-shoal facies, dolomitization leads to low total porosity but well-connected and heterogeneously distributed vuggy and intercrystalline pores which improves permeability. Micro- and nanopores are present in all analyzed samples but their contribution to effective porosity depends on the textural context. Our results confirm that each individual rock type requires the application of appropriate laboratory techniques. Additionally, we observe a strong correlation between the inverse formation resistivity factor and permeability suggesting that pore connectivity is the dominating factor for permeability but not pore size. In the future, this relationship should be further investigated as it could potentially be used to predict permeability from wireline resistivity measured in the flushed zone close to the borehole wall.
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El Kadiri, Khalil. "Description de nouvelles espècies deradiolaires jurassiques de la dorsales calcaire externe (Rif, Maroc)." Spanish Journal of Palaeontology 7, no. 3 (2022): 37. http://dx.doi.org/10.7203/sjp.25013.
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The study of radiolaria obtained from the botton of the Jurassic radiolarian beds in the Rif "Dorsale calcaire externe" display the study of some new species. Sorne one and two new genres are described here. The presence of ammonites in the botton of that facies and the inmediately in the lower beds attribute an Upper Lias or Lower Dogger age to the siliceous micro-faune recolted.
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Kathleen, Staffier, Goodwin Laurel, and Tikoff Basil. "Micro- to macroscale strain partitioning in granulite facies rocks: Mt.Hay block, central Australia." ASEG Extended Abstracts 2006, no. 1 (2006): 1–3. http://dx.doi.org/10.1071/aseg2006ab168.
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Shehab, Mayssa, Fahad Al-Najm, and Mohammed Al-Kaabi. "Image Log Facies and Lost Circulation of the Dammam Formation in Rumaila Oil Field, Southern Iraq." Iraqi Geological Journal 56, no. 1C (2023): 150–68. http://dx.doi.org/10.46717/igj.56.1c.10ms-2023-3-21.
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One of the most useful logging tools for identifying losses and fractures is Formation Micro Imager. Drilling through the Dammam Formation is typically associated with substantial nonproductive time due to severe and often entire drilling fluid losses. The majority of remedy this problem require time for preparation, placement or setting. Combining between conventional well log and FMI log associated with drilling data, a special study of the shallow Dammam carbonate formation penetrate by wells is accomplished. For a better understanding of the loss mechanism, Image log study was highlighted to imagine the loss zones and as such adapt data to advance loss prevention or cure future scenario. Five images and conventional logs available data associated with drilling operation documents were applied to suggest best subsurface stratigraphic facies in order to knowledge sediment environment of Dammam Formation. Five image log facies were identified as representing the different environments within the different depths, large, fine vugs, carbonate layers, laminate interrupt and laminate. The stratigraphy succession reveals shallowing upward from deep water represented by laminate facies to more disturbed water signified by vuggy large facies. There are six internal picks zone according to GR log sign D90 at the top of Rus Formation, D80, D70, D65, D60, D50 and D40. It has been clear that nearly severe or complete losses events limit intensively in D60 and D65 based on logs interpretation analysis associated with drilling data.
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Neugebauer, I., M. J. Schwab, N. D. Waldmann, et al. "Hydroclimatic variability in the Levant during the early last glacial (∼ 117–75 ka) derived from micro-facies analyses of deep Dead Sea sediments." Climate of the Past 12, no. 1 (2016): 75–90. http://dx.doi.org/10.5194/cp-12-75-2016.
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Abstract. The new sediment record from the deep Dead Sea basin (ICDP core 5017-1) provides a unique archive for hydroclimatic variability in the Levant. Here, we present high-resolution sediment facies analysis and elemental composition by micro-X-ray fluorescence (µXRF) scanning of core 5017-1 to trace lake levels and responses of the regional hydroclimatology during the time interval from ca. 117 to 75 ka, i.e. the transition between the last interglacial and the onset of the last glaciation. We distinguished six major micro-facies types and interpreted these and their alterations in the core in terms of relative lake level changes. The two end-member facies for highest and lowest lake levels are (a) up to several metres thick, greenish sediments of alternating aragonite and detrital marl laminae (aad) and (b) thick halite facies, respectively. Intermediate lake levels are characterised by detrital marls with varying amounts of aragonite, gypsum or halite, reflecting lower-amplitude, shorter-term variability. Two intervals of pronounced lake level drops occurred at ∼ 110–108 ± 5 and ∼ 93–87 ± 7 ka. They likely coincide with stadial conditions in the central Mediterranean (Melisey I and II pollen zones in Monticchio) and low global sea levels during Marine Isotope Stage (MIS) 5d and 5b. However, our data do not support the current hypothesis of an almost complete desiccation of the Dead Sea during the earlier of these lake level low stands based on a recovered gravel layer. Based on new petrographic analyses, we propose that, although it was a low stand, this well-sorted gravel layer may be a vestige of a thick turbidite that has been washed out during drilling rather than an in situ beach deposit. Two intervals of higher lake stands at ∼ 108–93 ± 6 and ∼ 87–75 ± 7 ka correspond to interstadial conditions in the central Mediterranean, i.e. pollen zones St. Germain I and II in Monticchio, and Greenland interstadials (GI) 24+23 and 21 in Greenland, as well as to sapropels S4 and S3 in the Mediterranean Sea. These apparent correlations suggest a close link of the climate in the Levant to North Atlantic and Mediterranean climates during the time of the build-up of Northern Hemisphere ice shields in the early last glacial period.
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Phillips, R. Ikhane, F. Folorunso Adetayo, E. Nton Matthew, A. Oluwalaanu Josiah, and O. Oyebolu Olalekan. "FACIES EVALUATIONS AND PALEOENVIRONMENTAL RECONSTRUCTION OF THE TURONIAN NKALAGU FORMATION, SOUTH EASTERN NIGERIA." International Journal of Sciences Volume 1, no. 2012-12 (2012): 107–20. https://doi.org/10.5281/zenodo.3348117.
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The Turonian Nkalagu Formation exposed at NIGERCEM (Nigerian Cement Company) within the Lower Benue Trough was studied in this work in order to determine and establish the lithostratigraphic successions and reconstruct the paleoenvironment of the deposition. Two major litho-facies were delineated. The first is matrix-supported bioclastic shell lag wackestone facies which account for about 70% of the carbonates. The second is a massive fossil-poor micritic limestone. However, using the fossil contents, five distinct micro-biofacies were recognized namely: massive lithoclastic floatstone, bioclastic wakestone, siliceous fossil-poor limestone, bioclastic (bivalve debris) wackestone and bioclastic packstone. The litho-clast consists of probably shallow water transported materials while still in various degrees of lithification from shelf into deeper basin. Many of the lithoclasts are sub-angular whereas others have rounded shape. Textural gradient was upward fining and algae were completely absent which is typical of shallow calcareous marine sediments of the photic zone. The trends of the textural characteristics fall in pattern correlatable with the different facies outlined in the study. Thus, the evidence from this study has put Nkalagu Formation as a deposition in shallow marine environment but later displaced into relatively deeper water, probably that of the off-shelf zone, by some sedimentary flow mechanisms.Read Complete Article at ijSciences: V120121186
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Wu, Xiuling, Dawei Meng, Xiaoyu Fan, Xin Meng, Jianping Zheng, and Roger Mason. "Defect microstructures in garnet, omphacite and symplectite from UHP eclogites, eastern Dabieshan, China: a TEM and FTIR study." Mineralogical Magazine 72, no. 5 (2008): 1057–69. http://dx.doi.org/10.1180/minmag.2008.072.5.1057.
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AbstractGarnets, omphacite and the minerals of a clinopyroxene/amphibole/plagioclase symplectite in UHP eclogites from Yingshan, Dabieshan have been investigated by TEM and Micro-FTIR. TEM reveals that the predominant microstructures in eclogites and symplectite-forming minerals are chain multiplicity faults (CMFs), dislocation substructures, clusters of water molecules up to ∼50 nm in diameter and recrystallized grains ∼1.75 μm in diameter. This indicates dynamic recrystallization of omphacite, probably during an eclogite-facies metamorphic episode. The deformation structures in symplectite-forming minerals were produced by plastic deformation related to an amphibolite-facies retrograde metamorphic event. CMFs described in the present work demonstrate the existence of an infrequent ½<011> (010) slip system for P2/n omphacite from an UHP eclogite sample from Dabieshan. The frequent occurrence of CMFs in omphacite suggests that they indicate an important deformation mechanism in omphacite and shows that this slip system plays a significant role in the deformation and recovery of eclogite. The hydrous components of deformed minerals may cause plastic deformation of the rocks by dislocation movement and accelerate retrograde metamorphism. Micro-FTIR results show that all the garnets and omphacites contain structural water occurring as hydroxyl groups (OH) or water (H2O). The structural water contents in omphacite range from 110—710 ppm and in garnet from 0—180 ppm. Water released during decompression might supply an early-stage retrograde metamorphic fluid.
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You, Xue Lian, Jing Quan Zhu, Qing Li, Ling Liu, Kai He, and Shi Qiang Wu. "Microbialites from the Upper Cambrian in the Tarim Basin, Northwest China: Implication for Depositional Environments." Advanced Materials Research 734-737 (August 2013): 388–92. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.388.
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Microbialites from Penglaiba section, a well-exposed stratigraphic section in the northwestern area of the Tarim Basin are widely distributed throughout the Lower Qiulitage Formation of the Upper Cambrian. Stromatolites and thrombolites are recognized as the two major components. Thrombolites have two kinds of fabrics under the microscopy based on varying arrangements macroscopically, which are microbial reefs and clotted laminations. The microbial reefs are kind of round and irregular buildups with branched shapes and interconnection as frame, which played the major roles in protecting the other microbial structures against the tides and waves. Based on petrology, stratigraphy and micro-facies combination, depositional environments are indicated for varying water depths and energy. In addition, a model of peleaoenvironments is established in the Lower Qiulitage Formation. Both of thrombolites and stromatolites are associated in the subtidal zone, but in this sedimentary model, thrombolites deposited in the deeper water, in which this facies association is similar to what has happened in Bahamas.
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Moitra, A. K. "Depositional Environmental History of the Chhattisgarh Basin, M.P., Based On Stromatolites and Microbiota." Journal Geological Society of India 46, no. 4 (1995): 359–68. http://dx.doi.org/10.17491/jgsi/1995/460406.
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Abstract The Proterozoic Chhattisgarh basin, comprising 2000m thick sediments mainly limestonel/dolomite, sandstone and shale, shows prolific growth of stromatolites and presence of micro biota dominantly cyanobacteria. Added to these there are many sedimentary features and structures found in the rocks throughoutthe sequence. Depositional environment is thus well doculnented by physicochemical factors in general and biological features in particular. Based on all these biogeological features, it has been deduced that the deposition is largely marine under tidal flat conditions, sources of sediments being both precipitation as well as terrigenous material. Sedimentation shows a distinct cyclic pattern commencing with arenaceous facies culminating into argillaceous facies with intervening calcareous facies. During the waning stage of sedimentary history of the Chhattisgarh basin, the cycles repeated rapidly, interpreted from the intercalatory sedimentation of the upper horizon, namely Raipur Limestone. Disposition of stromatolites ancLtheir morphologies reveal low as well as high-energy conditions of deposition, levels of deposition being both intertidal and subtidal ones. The sedimentological, mineralogical and petrological evidences point towards an alternating oxidising and reducing environments throughout the sequence irrespective of cycles or lithologies. Overwhelming dominance of procaryotic algae and absence (7 or near absence) of eucaryotic algae have possibly the following implications, namely the temperature during deposition was raised above 40°C at least for major part during deposition and also the pH of the environment. was 7 or more.
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GUPTA, SHEKHAR, R. V. Singh, Rahul Banerjee, and M. B. Verma. "Facies Architecture and Sedimentary Structures in the drill cores of Uranium Bearing Sediments of Banganapalle Formation of Palnad Sub-basin, Guntur District, Andhra Pradesh." Journal of The Indian Association of Sedimentologists 38, no. 1 (2021): 109–18. http://dx.doi.org/10.51710/jias.v38i1.128.
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The Banganapalle Formation, the lowest member of the Neoproterozoic Kurnool Group of rocks, resting over the basement granites, has been identified as the host rock for uranium in Koppunuru area in the western part of Palnad sub-basin. The uppermost arenite facies of the Banganapalle Formation is exposed on surface and shows only few bedform indicators like ripple marks, planer laminations etc. Down-hole lithological examinations on course of core drilling in Koppunuru and adjoining areas identified five recognizable lithofacies of Banganapalle Formation, viz. basal conglomerate unit, quartzite-shale intercalated facies, and two quartz arenite facies separated by a grey shale dominated argillaceous facies.
 The polymictic conglomerate, with unsorted grit to pebble size clasts of granite, shale, quartzite, vein quartz and dolerite indicate short distance transportation and derivation from nearby granitoids traversed by quartz reef/dolerite dykes. Cyclic repetitions of arenaceous and argillaceous sediments in Banganapalle lithocolumn above the basal conglomerates point to alternate rhythmic marine transgression and regression regimes. These units can also be discriminated based on their sedimentary texture, bedforms and several soft-sedimentary penecontemporaneous deformational structures (PCD) like load structure, convolute bedding/laminations, and slump structures such as micro-slips, gravity faults and folds. These syn-sedimentary structures clearly indicate perturbation and submergence of the basin contemporaneous to deposition. Cross-beds suggests change in current direction/intensity while bi-directional symmetrical ripples in outcrops of upper arenite facies suggests that the Banganapalle sediments are derived from the basement granitoids exposed to the north as well as upper Cuddapah sediments to its west. Overall, the sedimentary structures, textural and composition variation of the lithounits suggest deposition of these sediments in marginal marine, inter- to supra-tidal flat environment. The porous and permeable nature of the quartz arenite and the basal conglomerates and the presence of available reductants in the form of sulphides and carbonaceous matter make them the best suited loci for fluid movement and precipitation of uranium.
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Lu, Yuejian, Dameng Liu, Yidong Cai, Qian Li, and Qifeng Jia. "Pore-Fractures of Coalbed Methane Reservoir Restricted by Coal Facies in Sangjiang-Muling Coal-Bearing Basins, Northeast China." Energies 13, no. 5 (2020): 1196. http://dx.doi.org/10.3390/en13051196.
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The pore-fractures network plays a key role in coalbed methane (CBM) accumulation and production, while the impacts of coal facies on the pore-fractures network performance are still poorly understood. In this work, the research on the pore-fracture occurrence of 38 collected coals from Sangjiang-Muling coal-bearing basins with multiple techniques, including mercury intrusion porosimetry (MIP), micro-organic quantitative analysis, and optic microscopy, and its variation controlling of coal face were studied. The MIP curves of 38 selected coals, indicating pore structures, were subdivided into three typical types, including type I of predominant micropores, type Ⅱ of predominant micropores and macropores with good connectivity, and type Ⅲ of predominant micropores and macropores with poor connectivity. For coal facies, three various coal facies were distinguished, including lake shore coastal wet forest swamp, the upper delta plain wet forest swamp, tidal flat wet forest swamp using Q-cluster analysis and tissue preservation index–gelification index (TPI-GI), and wood index–groundwater influence index (WI-GWI). The results show a positive relationship between tissue preservation index (TPI), wood index (WI), and mesopores (102 nm–103 nm), and a negative relationship between TPI, WI, and macropores/fractures. In addition, groundwater level fluctuations can control the development of type C and D fractures, and the frequency of type C and D fractures show an ascending trend with increasing groundwater index (GWI), which may be caused by the mineral hydration of the coal. Finally, from the perspective of the pore-fractures occurrence in CBM reservoirs, the wet forest swamp of upper delta plain is considered to be the optimization areas for Sangjiang-Muling coal-bearing basins by a comparative study of various coal facies.
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Bellais, Kaylyn C., Samuel T. Barber, Donald A. Beebe, and Murlene W. Clark. "Lake or Estuary? Sedimentary and Benthic Foraminiferal Characterization of a Gulf of Mexico Coastal Dune Lake." Gulf and Caribbean Research 31 (2020): SC46—SC52. http://dx.doi.org/10.18785/gcr.3101.18.
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Coastal dune lakes are shallow estuaries located within dune environments that share a permanent or intermittent connection with the sea. Because coastal dune lakes are found in few locations worldwide (e.g. Australia, New Zealand, Florida, etc.) they represent unique environments worthy of protection. However; there is a distinct lack of scientific data related to the function and ecology of coastal dune lakes, especially in the Gulf of Mexico. Therefore, the purpose of this study was to characterize the sedimentology and foraminifera of a representative coastal dune lake in Walton County, FL (i.e. Eastern Lake) and determine whether it shares geologic similarities with nearby estuaries. Ten Ekman sediment grab samples were collected along a transect spanning the length of Eastern Lake. The samples were processed to determine sedimentary properties and foraminiferal assemblages. Results from the sedimentary and foraminiferal analyses reveal 3 distinct depositional environments including: (1) a coarse grained, moderately well sorted, organic poor, sandy beach facies with both agglutinated and calcareous foraminifera, (2) a fine grained, very poorly sorted, organic rich central mud basin facies with mostly calcareous foraminifera, and (3) a coarse grained, poorly sorted, organic rich sandy marsh delta facies dominated by agglutinated foraminifera. These environments and foraminiferal patterns are also found in much larger nearby estuaries including Choctawhatchee Bay, Pensacola Bay, and Mobile Bay. Our results therefore suggest that coastal dune lakes may serve as down-scaled micro-estuaries and are functionally related to larger estuaries of the Gulf Coast despite their size.
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Prayitno, Budi. "Limnic Condition In Rheotrhopic Peat Type As the Origin of Petai Coal, Central Sumatra Basin, Indonesia." Journal of Geoscience, Engineering, Environment, and Technology 1, no. 1 (2016): 63. http://dx.doi.org/10.24273/jgeet.2016.11.9.
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Petrographic coal is the study of organic and inorganic components of bearing coal formation. This study aims to determine the composition, depositional facies, type and stage of the genesis of coal in the area of research. This research method using a diagram approach Diessel, 1986, Calder et al., 1991 to determine the depositional facies and peat ecosystems formation of coal carrier. Microscopic observations using Carl Zeiss Microscope and Point Counter Model F was conducted to determine the micro-organic components of coal.
 Based on microscopic investigation of the overall sample average abundance maceral vitrinite reached 66.3%, 30.32% mineral matter, maceral liptinite 3:26%, and to absent maceral inertinit no indicates oxidation process that occurs during the decomposition of organic matter. Syngenetic depositional pyrite component type spread sporadically on the surface of the coal seam in the form frambiodal and particulates.
 Facies deposition of coal based on the calculation of tissue prevetion index versus gelification index show faises limnic while the calculation of ground water index versus vegetation index show atmosphere rheotropic mires (correlation +) supported the absence maceral inertinit and funginite, hypothesized water level in stable condition was high watertable during the decomposition process takes place in an atmosphere ph 6-8 and eh balanced. Average rate comparison gelifikasi the preserved tissues of plant cells (tellocolinite) is smaller than the 23.6% plant cell tissue is not preserved (desmocollinite) amounted to 52.6% indicated from plants of the type herbaceous plant.
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Neugebauer, I., M. J. Schwab, N. D. Waldmann, et al. "Hydroclimatic variability in the Levant during the early last glacial (∼ 117–75 ka) derived from micro-facies analyses of deep Dead Sea sediments." Climate of the Past Discussions 11, no. 4 (2015): 3625–63. http://dx.doi.org/10.5194/cpd-11-3625-2015.
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Abstract. The new sediment record from the deep Dead Sea basin (ICDP core 5017-1) provides a unique archive for hydroclimatic variability in the Levant. Here, we present high-resolution sediment facies analysis and elemental composition by μXRF scanning of core 5017-1 to trace lake levels and responses of the regional hydroclimatology during the time interval from ca 117–75 ka, i.e. the transition between the last interglacial and the onset of the last glaciation. We distinguished six major micro-facies types and interpreted these and their alterations in the core in terms of relative lake level changes. The two end-member facies for highest and lowest lake levels are (a) up to several meters thick, greenish sediments of alternating aragonite and detrital marl laminae (aad) and (b) thick halite facies, respectively. Intermediate lake levels are characterised by detrital marls with varying amounts of aragonite, gypsum or halite, reflecting lower-amplitude, shorter-term variability. Two intervals of pronounced lake level drops occurred at ∼110–108 ± 5 and ∼93–87 ± 7 ka. They likely coincide with stadial conditions in the central Mediterranean (Melisey I and II pollen zones in Monticchio) and low global sea levels during MIS 5d and 5b. However, our data do not support the current hypothesis of an almost complete desiccation of the Dead Sea during the earlier of these lake level low stands based on a recovered gravel layer. Based on new petrographic analyses, we propose that, although it was a low stand, this well-sorted gravel layer may be a vestige of a thick turbidite that has been washed out during drilling rather than an in-situ beach deposit. Two intervals of higher lake stands at ∼108–93 ± 6 and ∼87–75 ± 7 ka correspond to interstadial conditions in the central Mediterranean, i.e. pollen zones St. Germain I and II in Monticchio, and GI 24 + 23 and 21 in Greenland, as well as to sapropels S4 and S3 in the Mediterranean Sea. These apparent correlations suggest a close link of the climate in the Levant to North Atlantic and Mediterranean climates during the time of the build-up of Northern Hemisphere ice shields in the early last glacial period.
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Meng, Ning Ning, Guang Xue Zhang, Gao Qun Wei, and Xin Lv. "Study on Three-Dimensional Geological Modeling of Reservoir in Hei46 Block." Advanced Materials Research 1073-1076 (December 2014): 2349–52. http://dx.doi.org/10.4028/www.scientific.net/amr.1073-1076.2349.
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Three dimensional (3D) geologic modeling is used to study the reservoir quantitatively from a three-dimensional angle, and its core is the prediction to reservoir of multi-disciplinary integration, quantitative and visualization. Compared with traditional reservoir research, it has a significant advantage. This paper makes geological modeling research and builds structural models sedimentary micro-facies models and phased property model for Hei46 block of Daqingzi oilfield by utilizing 3D geologic modeling technique and petrel software on the basis of integrated using of geology, logging, oil production test, production of dynamic information, thus it provide a reliable basis for reservoir's development and adjustment.
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Hughes, G. Wyn ap G., Shameem Siddiqui, and R. Kumbe Sadler. "Shu’aiba rudist taphonomy using computerised tomography and image logs, Shaybah field, Saudi Arabia." GeoArabia 8, no. 4 (2003): 585–96. http://dx.doi.org/10.2113/geoarabia0804585.
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ABSTRACT Rudist fossils in cored carbonates from the Shu’aiba reservoir in the Shaybah field have been used to aid the interpretation of lithofacies and reservoir facies in uncored horizontal development wells. The rudists are sufficiently large fossils that they provide well-developed and easily identified images on computerised tomography (CT) scans of cores. The CT images provide valuable information on the rudist orientation prior to damage caused by plugging and slabbing procedures. CT images, combined with the core-based fossil information, are then used to interpret the images on the formation micro-imager (FMI) logs. As the various rudist species are known to have preferentially occupied different environments during the deposition of the Shu’aiba carbonates, depositional environments can now be interpreted from the FMI logs. Specimen orientation in the core provides supplementary information on the depositional environment by discriminating between in-situ and displaced assemblages. Rudist identification in FMI images is a new tool in uncored vertical wells. In long horizontal wells, this is a major achievement and will assist in modelling the 3-D lithofacies and associated reservoir facies distribution for improving the reservoir model.
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ΧΡΙΣΤΟΔΟΥΛΟΠΟΥΛΟΥ, Τ. Α., Π. ΤΣΩΛΗ - ΚΑΤΑΓΑ, Γ. Χ. ΚΟΥΚΗΣ, and Ν. ΚΟΝΤΟΠΟΥΛΟΣ. "The study of the microstructures of clay sediments: a case study of marly sediments from N. Péloponnèse." Bulletin of the Geological Society of Greece 34, no. 2 (2018): 745. http://dx.doi.org/10.12681/bgsg.17352.
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This paper deals with the systematic study of the microstructural characteristics of clay sediments. These characteristics which are closely connected to the physical and mechanical character of the sediments, are concerned with: a)the structural constituents, b)the microporosity and c)the structural bonds of the sediments. For the determination of the structural characteristics of clay sediments the Scanning Electron Microscope (SEM) and the Optical Microscope are widely used with a supplementary mineralogical analysis of sediment components and the determination of several physical and mechanical characteristics. The observations under the microscope must be focused on the distribution of mineralogical facies and micropores, on the size and shape of clay (micro-)aggregates, as well as on the kind of authigenic facies (e.g. micrite, sparry calcite) which play the role of cementing material. The proposed methodology was applied to the study of the microstructures of marly sediments from Northern Péloponnèse and the following types of microstructures were determined: a)matrix-skeletal, mixed type, coarse dispersed of low orientation, b)matrix, coagulative, medium dispersed of medium orientation and c)crystallized-cementated, fine or medium dispersed of low orientation.
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MANZOTTI, PAOLA, and MICHELE ZUCALI. "The pre-Alpine tectonic history of the Austroalpine continental basement in the Valpelline unit (Western Italian Alps)." Geological Magazine 150, no. 1 (2012): 153–72. http://dx.doi.org/10.1017/s0016756812000441.
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AbstractThe Valpelline unit is a large slice of continental crust constituting the Austroalpine Dent Blanche nappe (NW Italy). The pre-Alpine evolution of this unit holds important clues about the Palaeozoic crustal structure at the northern margin of the Adria continent, about the history of rifting in the Alpine region, and thus about the thermomechanical conditions that preceded the Alpine convergent evolution. Several stages of the deformation history and of partial re-equilibration were identified, combining meso- and micro-structural analyses with thermobarometry. Reconstructed pre-Alpine P–T–t–d paths demonstrate that the Valpelline unit experienced an early stage at pressures between 4.5 and 6.5 kbar followed by migmatite formation. A subsequent stage reached amphibolite to granulite facies conditions. This stage was associated with the development of the most penetrative fabrics affecting all of the Valpelline lithotypes. The pre-Alpine evolution ended with a weak deformation associated with a local mineral-chemical re-equilibration under greenschist facies conditions at ≈ 4 kbar and T < 450°C. A Permo-Mesozoic lithospheric extension is thought to be responsible for asthenosphere upwelling, thereby causing high temperature metamorphism at medium pressure and widespread partial melting, which led to upper crustal magmatic activity.
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Chen, Guo Min, Li Sun, and Xiang Sheng Bao. "3D Stochastic Modeling for Reservoir Characterization and Application." Advanced Materials Research 1010-1012 (August 2014): 1353–58. http://dx.doi.org/10.4028/www.scientific.net/amr.1010-1012.1353.
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The reservoir is the accumulation spaces and development targets of hydrocarbon, always draw attention of researchers who participated in hydrocarbon exploration and development. The goal of reservoir characterization is to delineate precisely and completely the geologic variations for reservoirs in 3D distribution by the application of all kinds of useful data channel, so that it can give a reliable reference for the further reservoirs development. However, stochastic modeling has become the dominant tool for reservoir characterization because it can both simulate the reservoir heterogeneity and quantitatively characterize reservoir. Aimed at reservoirs in well block X26-X27 of Xiazijie Oilfield, on basis of reservoir structure, sedimentary microfacies, logging interpretation and reservoir heterogeneity research, the geologic dataset is established, and the 3D models, such as reservoir structure, logging interpretation and reservoir attributes, were all worked out by the application of stochastic modeling technique and 3D visualized technique to this area, furthermore, the testing and modification for facies analysis and classification were conducted in order to unravel the consistent micro-facies and reservoir property distribution, so that it will serve well for the identification and fine description and reservoir dynamic simulation.
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Słowakiewicz, M., E. Perri, and Maurice E. Tucker. "MICRO- AND NANOPORES IN TIGHT ZECHSTEIN 2 CARBONATE FACIES FROM THE SOUTHERN PERMIAN BASIN, NW EUROPE." Journal of Petroleum Geology 39, no. 2 (2016): 149–68. http://dx.doi.org/10.1111/jpg.12638.
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Ahmad, Sajjad, Sohail Raza, and Suleman Khan. "Facies and Hydrocarbon Reservoir Rock Characterization of the Paleozoic Rocks of Peshawar Basin, Northwest Pakistan." Earth and Planetary Science 2, no. 2 (2023): 55–67. http://dx.doi.org/10.36956/eps.v2i2.874.
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The present study details the facies description and hydrocarbon reservoir characterization of the Paleozoic rocks of Peshawar Basin, northwest Pakistan. The outcrop samples from the Cambrian-Devonian rocks along the famous Nowshera-Risalpur Road and Turlandi Village Section were investigated. The analysis of outcrop data revealed significant information regarding the facies and their depositional environments. Based on its detailed sedimentological data, it is believed that the Ambar Formation is deposited in shallow shelf-tidal flat settings, while the protolith of the Misri Banda Quartzite came from the wide beaches. The protolith of the Panjpir Formation was deposited in the shelf conditions, which shows an overall shallowing when moving up the section from the argillites and phyllites to crinoidal limestone. The Nowshera Formation was deposited as a reef complex on the shelf edge having reef core, reef breccia and a back-reef lagoon. The techniques of petrography, XRD and SEM were used for the bulk geochemical composition of the rocks focusing on their matrix, mineralogy, micro-porosity and pore-filling materials. The presence of micrite, goethite, kaolinite and illite as intergranular mass, dolomitization-induced porosity, twin cleavage plane and high dissolution porosity in the Ambar Formation can provide significant pore space to the reservoir fluids migration. Hematite with minor kaolinite, illite and chlorite as alteration products of unstable framework grains as intergranular mass and a deep seated burial diagenesis has minimized the reservoir potential in Misri Banda Quartzite. The coarse and fine calcite, dolomite, chlorite and kaolinite occur as pore-filling material between the framework grains while the high intensity of intragranular dissolution and micro intergranular connecting porosity in the Nowshera Formation makes it a promising reservoir.
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Kanamaru, Kinuyo, Pierre Francus, Roger François, Mark Besonen, and Carlo Laj. "New insight into Saanich Inlet varved sediments (British Columbia, Canada) from micro-scale analysis of sedimentary facies and micro-XRF core scanning analyses." GFF 135, no. 3-4 (2013): 316–39. http://dx.doi.org/10.1080/11035897.2013.833430.
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Leonova, L. V., A. A. Galeev, and A. A. Galeev. "Microfossils in bottom-hydrothermal sediments of the Saf'yanovskoe Cu-Zn deposit (Middle Urals)." LITHOSPHERE (Russia) 22, no. 3 (2022): 376–90. http://dx.doi.org/10.24930/1681-9004-2022-22-3-376-390.
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Research subject. Framboidal pyrites and sulfide micro-concretions in carbonaceous-siliceous and ore rocks of the Safyanovskoye deposit (Middle Urals). Aim. To identify the signs of vital activity of microbial communities in bottomhydrothermal deposits using the example of the Safyanovskoye sulfide deposit. The methods. Scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). Results. TThe analyzed ore and carbonaceous-siliceous rock samples showed the presence of mineralized silicon dioxide films covering framboidal pyrites. Micro-concretions were found to consist of microfossils of filamentous organisms and framboids. Pyrite samples included the remains of tubular casts of sulfidized vestimentifera and polychaetes, associated with framboids. The possibility of using fossilized remains of microbial communities for distinguishing bottom-hydrothermal facies among pyrite deposits was confirmed. Conclusions. Hydrothermal-sedimentary deposits are characterized by the traces of specific microbial communities, since prokaryotic organisms were pioneers in hydrothermal oases. Their long active existence created a basis for the second trophic link, i.e. filter feeding macrofauna and endosymbiotrophs. These organisms, in turn, formed another level in the food chain of the trophic pyramid. It is believed that micro-concretions and framboidal pyrites are indicators of the vital activity of microbial communities.
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ZHONGYING, ZHANG. "A new Palaeoproterozoic clastic-facies microbiota from the Changzhougou Formation, Changcheng Group, Jixian, north China." Geological Magazine 134, no. 2 (1997): 145–50. http://dx.doi.org/10.1017/s0016756897006699.
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Abundant microfossils have recently been discovered in the late Palaeoproterozoic Changzhougou Formation, Changcheng Group, Jixian, north China. The Changzhougou microbiota consists dominantly of sphaeromorph acritarchs and some osillatoriacean cynobacterial filaments. The micro-fossils were recovered from shales and are compressed on bedding surfaces. The sphaeromorph acritarchs, ranging from 8.4 to 237.8 μm in diameter, are morphologically simple. On the basis of their dimensions and morphological considerations, the sphaeromorph acritarchs are interpreted as probably representing the resistant, reproductive cysts of unicellular protists. This assemblage is evidently among the oldest known clastic-facies microbiotas in the geological record and provides evidence of protist eukaryotes being extant at 1848 Ma.
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Garayeva, T. J., Z. A. Novruzov, and Kh A. Allakhverdiyeva. "Biomagnetostratigraphy of the Eastern Gobustan’s paleogene rocks." Scientific Petroleum, no. 1 (June 30, 2024): 2–10. http://dx.doi.org/10.53404/sci.petro.20240100050.
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On the territory of Azerbaijan, Paleogene deposits are widespread and often have facies alteration. To address the issues of stratigraphic, paleogeography, facies and paleoecological directions, a detailed stratigraphic basis of both the region as a whole and its individual sections is required. This article presents the results of joint magnetobiostratigraphic studies of the Paleogene deposits of the Greater Caucasus (Azerbaijan) in order to clarify the boundaries of the Paleocene, Eocene, Oligocene and Miocene. Biostratigraphically dated Paleogene deposits of the Khilmili, Pirakushkul, Dzhangi sections (southern slope of the Greater Caucasus) were chosen as the object of study. Paleomagnetic studies of the Paleogene deposits of Azerbaijan showed frequent reversals of the geomagnetic field of this period. The results of scientific studies of the southern slope of the Greater Caucasus confirmed this fact. We have identified two paleomagnetic zones: 1) Khorem (Maastrichtian 70 Ma - Eocene 45 Ma) (zones of reverse polarity prevail in it, but the upper part of the Paleocene has a direct polarity) and 2) Sogdiana (RN-Oligocene and Miocene - characterized by alternating direct and reverse polarity paleomagnetic field). In the Lower Paleocene, 2 subzones of direct polarity were distinguished: Danian and Selandian. The position of the R-zone made it possible to draw the boundary between the Danian and Selandian stages. The identification of a paleomagnetic zone of reverse polarity contributed to the determination of the boundary between the Selandian and Thanetian stages. This result was confirmed by identifying changes in the micro-faunistic composition of deposits and observing the nature of variations in micro-floristic complexes. Such a paleomagnetic zone of reverse polarity is the benchmark (plug) for establishing the boundary between the Mons and Thanetian stages. Keywords: paleomagnetism; southern slope of the Greater Caucasus; Paleogene; magnetostratigraphic boundaries.
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Aigbadon, G. O., and N. S. Igbinigie. "Micropaleontological and sedimentological analyses of carbonates rocks in parts of Sokoto Basin, Nigeria: implications for paleoecological interpretation and exploration efforts." Scientia Africana 23, no. 3 (2024): 273–86. http://dx.doi.org/10.4314/sa.v23i3.26.
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This study presents a detailed analysis of the Paleocene and Maastrichtian marine sediments in the Sokoto Basin, Nigeria, using boreholes GSN – BH – 2051 and GSN – BH – 4051, respectively. This study is aimed at integrating sedimentological, micropaleontological and petrographic data in paleoecologic interpretation of depositional environments of the Sokoto Basin. The methods adopted in this research involved the examination of ditch cuttings, carbonate thin sections, and microfossils analyses from the boreholes drilled in Sokoto Basin. The sedimentological data from the borehole showed that the studied stratigraphic unit comprises mainly fine to medium-grained limestone facies, sparitic intraclastic packstone and oolitic-elmicrite wackestone facies. The microfacies obtained from petrography data revealed micro-fossils abundance and diversity associated with the onset of shallow marine transgression which resulted in the deposition of the Dange and Kalambaina Formations, respectively. The assemblages of the larger foraminifera (Opercullnoides bermudezi) and the larger ostracod (Bairdia iIaroensis) in the borehole sections further suggested marginal marine depositional environment for the Kalambaina and Gamba Shale Formations. The paleoecological interpretation suggests varying salinities and dysaerobic conditions during deposition, with implications for understanding basin evolution. The study concludes by highlighting the importance of integrating multiple methods for a detailed understanding of paleoecological and depositional environment of Sokoto sedimentary basin.