Bibliographies thématiques / Bulk petrography

Sommaire

Articles de revues
Thèses
Chapitres de livres
Actes de conférences
Rapports d'organisations

Littérature scientifique sur le sujet « Bulk petrography »

Auteur : Grafiati

Publié le 9 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « Bulk petrography ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "Bulk petrography"

Gleason, James D., David A. Kring, Dolores H. Hill et William V. Boynton. « Petrography and bulk chemistry of Martian lherzolite LEW88516 ». Geochimica et Cosmochimica Acta 61, n^o 18 (septembre 1997) : 4007–14. http://dx.doi.org/10.1016/s0016-7037(97)00196-8.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Sajid, Muhammad, Muhammad Yaseen, Muhammad Zeeshan Ullah et Ghulam Murtaza. « Textural Implications in Assessment of Physico-Mechanical behaviour of Metavolcanic Rocks from Dir Upper, north western Pakistan ». International Journal of Economic and Environmental Geology 11, n^o 3 (4 décembre 2020) : 1–10. http://dx.doi.org/10.46660/ijeeg.vol11.iss3.2020.469.

Texte intégral

Résumé :

The Dir-Utror meta-volcanics from the south western portion of the Kohistan arc in northern Pakistan areanalyzed in term of their petrography, physico-mechanical properties. Field observations and petrography show thecollected representative samples to be fine-grained meta-andesites (FMA), coarse-grained meta-andesites (CMA) andagglomerate (AG). The relationship between petrography and physico-mechanical properties has been investigatedwhich inferred the grain size to be the major factor, alongside grains’ shape, arrangement and size distribution as wellas degree of mineral alteration significantly affecting the mechanical behavior of rocks. The CMA yield more strength(98 MPa) than FMA (93 MPa) due to its lesser degree of mineral alteration, inequigranular texture, lack of preferredmineral alignment, relatively low porosity and water absorption. The lower strength of agglomerate (57 MPa)corresponds to abundance of soft minerals (calcite), exotic rock fragments and coarse-grained texture. Based onphysico-mechanical properties including specific gravity, bulk density, aggregate impact value, Los Angeles abrasionvalue and unconfined compressive strength (UCS), these rocks fall within permissible range to be utilized for multipleengineering purposes including dimension stones and foundation materials for other civil structures. However,petrographic investigations reveal excessive amount of reactive silica in these rocks making them prone to alkali-silicareactivity in concrete works with ordinary Portland cement (OPC). Hence these rocks are not recommended for use assole aggregate material or low-alkali cement is recommended, if used.

Styles APA, Harvard, Vancouver, ISO, etc.

NISHIOKA, Yoshiharu. « Petrography and bulk chemical composition of the Miyako zoned pluton, Kitakami Mountains. » JOURNAL OF MINERALOGY, PETROLOGY AND ECONOMIC GEOLOGY 92, n^o 8 (1997) : 291–301. http://dx.doi.org/10.2465/ganko.92.291.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Kim, Yoon Kyu. « Petrology of Ulreung Volcanic Island, Korea - Part2. Petrography and bulk chemical composition. » Journal of the Japanese Association of Mineralogists, Petrologists and Economic Geologists 80, n^o 7 (1985) : 292–303. http://dx.doi.org/10.2465/ganko1941.80.292.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Guice, George, Iain McDonald, Hannah Hughes, Denis Schlatter, Kathryn Goodenough, John MacDonald et John Faithfull. « Assessing the Validity of Negative High Field Strength-Element Anomalies as a Proxy for Archaean Subduction : Evidence from the Ben Strome Complex, NW Scotland ». Geosciences 8, n^o 9 (8 septembre 2018) : 338. http://dx.doi.org/10.3390/geosciences8090338.

Texte intégral

Résumé :

The relative depletion of high field strength elements (HFSE), such as Nb, Ta and Ti, on normalised trace-element plots is a geochemical proxy routinely used to fingerprint magmatic processes linked to Phanerozoic subduction. This proxy has increasingly been applied to ultramafic-mafic units in Archaean cratons, but as these assemblages have commonly been affected by high-grade metamorphism and hydrothermal alteration/metasomatism, the likelihood of element mobility is high relative to Phanerozoic examples. To assess the validity of HFSE anomalies as a reliable proxy for Archaean subduction, we here investigate their origin in ultramafic rocks from the Ben Strome Complex, which is a 7 km2 ultramafic-mafic complex in the Lewisian Gneiss Complex of NW Scotland. Recently interpreted as a deformed layered intrusion, the Ben Strome Complex has been subject to multiple phases of high-grade metamorphism, including separate granulite- and amphibolite-facies deformation events. Additional to bulk-rock geochemistry, we present detailed petrography, and major- and trace-element mineral chemistry for 35 ultramafic samples, of which 15 display negative HFSE anomalies. Our data indicate that the magnitude of HFSE anomalies in the Ben Strome Complex are correlated with light rare earth-element (LREE) enrichment likely generated during interaction with H2O and CO2-rich hydrothermal fluids associated with amphibolitisation, rather than primary magmatic (subduction-related) processes. Consequently, we consider bulk-rock HFSE anomalies alone to be an unreliable proxy for Archaean subduction in Archaean terranes that have experienced multiple phases of high-grade metamorphism, with a comprehensive assessment of element mobility and petrography a minimum requirement prior to assigning geodynamic interpretations to bulk-rock geochemical data.

Styles APA, Harvard, Vancouver, ISO, etc.

Gleason, James D., David A. Kring, Dolores H. Hill et William V. Boynton. « Petrography and bulk chemistry of Martian orthopyroxenite ALH84001 : Implications for the origin of secondary carbonates ». Geochimica et Cosmochimica Acta 61, n^o 16 (août 1997) : 3503–12. http://dx.doi.org/10.1016/s0016-7037(97)00173-7.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Sato, Daisuke, Ichiro Matsumoto et Atsushi Kamei. « Petrography and bulk rock composition of the Wakurayama Dacite from Matsue City, Shimane Prefecture, Southwest Japan ». Journal of the Geological Society of Japan 117, n^o 8 (2011) : 439–50. http://dx.doi.org/10.5575/geosoc.117.439.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Al-Juboury, A. I., T. McCann et M. M. Ghazal. « Provenance of Miocene sandstones in northern Iraq : constraints from framework petrography, bulk-rock geochemistry and mineral chemistry ». Russian Geology and Geophysics 50, n^o 6 (juin 2009) : 517–34. http://dx.doi.org/10.1016/j.rgg.2008.09.005.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

V, Thirukumaran, Biswal T.K, Sundaralingam K, Sowmya V, Boopathi S et Mythili R. « Strain Pattern Analysis of Mylonites From Sitampundi-Kanjamalai Shear Zone, Thiruchengode, South India ». International Journal of Civil, Environmental and Agricultural Engineering 1, n^o 1 (30 mai 2019) : 25–34. http://dx.doi.org/10.34256/ijceae1914.

Texte intégral

Résumé :

This study aims to investigate the petrography and strain pattern of mylonites from parts of N-S trending Sitampundi-Kanjamalai Shear Zone (SKSZ) around Thiruchengode. The petrographic study indicates the presence of recrystallized quartz, K-feldspar, plagioclase, biotite and some hornblende. The kinematic analysis of Mylonites was done with the help of shear sense indicators such as recrystallized type quartz (quartz ribbon) around the cluster of feldspar, S-C fabric shows dextral shear sense and some sinisterly shear sense in some parts of SASZ which can be considered as a product of partitioning of both strain and vorticity between domains. These all indicates the simple shear extension along E-W direction and the mylonitic foliation shows the pure shear compression along N-S direction. Further the study of bulk strain analysis by Flinn plot method using L and T section of mylonite shows k<1 which lies in the field of flattening zone of finite strain. The kinematic vorticity number is calculated by Rxz/β method which gives the value of 0.36 indicating the general shear. The rigid grain graph shows that the pure shear component is more dominant than the simple shear component. The analysis leads to the conclusion that the mylonite has experienced a high temperature shearing of above 700°cat deep crustal level.

Styles APA, Harvard, Vancouver, ISO, etc.

Kilias, Stephanos P., Magnus Ivarsson, Ernest Chi Chi Fru, Jayne E. Rattray, Håkan Gustafsson, Jonathan Naden et Kleopatra Detsi. « Precipitation of Mn Oxides in Quaternary Microbially Induced Sedimentary Structures (MISS), Cape Vani Paleo-Hydrothermal Vent Field, Milos, Greece ». Minerals 10, n^o 6 (13 juin 2020) : 536. http://dx.doi.org/10.3390/min10060536.

Texte intégral

Résumé :

Understanding microbial mediation in sediment-hosted Mn deposition has gained importance in low-temperature ore genesis research. Here we report Mn oxide ores dominated by todorokite, vernadite, hollandite, and manjiroite, which cement Quaternary microbially induced sedimentary structures (MISS) developed along bedding planes of shallow-marine to tidal-flat volcaniclastic sandstones/sandy tuffs, Cape Vani paleo-hydrothermal vent field, Milos, Greece. This work aims to decipher the link between biological Mn oxide formation, low-T hydrothermalism, and, growth and preservation of Mn-bearing MISS (MnMISS). Geobiological processes, identified by microtexture petrography, scanning and transmission electron microscopy, lipid biomarkers, bulk- and lipid-specific δ13Corganic composition, and field data, and, low-temperature hydrothermal venting of aqueous Mn2+ in sunlit shallow waters, cooperatively enabled microbially-mediated Mn (II) oxidation and biomineralization. The MnMISS biomarker content and δ13Corg signatures strongly resemble those of modern Mn-rich hydrothermal sediments, Milos coast. Biogenic and syngenetic Mn oxide precipitation established by electron paramagnetic resonance (EPR) spectroscopy and petrography, combined with hydrothermal fluid flow-induced pre-burial curing/diagenesis, may account for today’s crystalline Mn oxide resource. Our data suggests that MISS are not unique to cyanobacteria mats. Furthermore, microbial mats inhabited by aerobic methanotrophs may have contributed significantly to the formation of the MnMISS, thus widening the spectrum of environments responsible for marine Mn biometallogenesis.

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Thèses sur le sujet "Bulk petrography"

RESENTINI, ALBERTO. « Quantitative provenance analysis of modern sands : bulk petrography, heavy minerals apatite fission tracks ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2011. http://hdl.handle.net/10281/19000.

Texte intégral

Résumé :

Sediment petrography and heavy mineral analysis represent two key techniques to decipher the pieces of information stored in the sedimentary record, shedding light on source rocks compositon, weathering conditions and paleodrainages. Traditionally, even though orogenic detritus has always received large attention, orogenic provenance has been recognized as “composite”, thus preventing clear classification. Notwithstanding the composite nature of collision orogens, the detrital fingerprints of neometamorphic axial belts, largely experiencing strong exhumation and erosion, can be regarded as the diagnostic signature of orogenic detritus. We thus decided to focus our attention on the analysis of modern river sands from the Alpine belt, getting full quantitative information both on bulk compositions and heavy mineral assemblages. Within the Austroalpine Cretaceous and Penninic Eocene axial belts of the Alps, we ideally distinguish three structural levels, each characterized by diagnostic detrital fingerprints. The shallow level chiefly consists of offscraped remnant-ocean turbidites and unmetamorphosed continental-margin sediments, and mostly produces lithic to quartzolithic sedimentaclastic sands yielding very-poor heavy-mineral suites including ultrastable minerals. The intermediate level includes low-grade metasediments and polymetamorphic basements, and sheds quartzolithic to feldspatholithoquartzose metamorphiclastic sands yielding moderately-rich epidote-amphibole suites with chloritoid or garnet. The deep level contains eclogitic remnants of continent-ocean transitions, and supplies feldspatholithoquartzose/feldspathoquartzose high-rank metamorphiclastic to lithic ultramaficlastic sands yielding rich to extremely-rich suites dominated by garnet, hornblende, or epidote depending on protoliths (continental vs. oceanic) and pressure/temperature paths during exhumation. Although widely overprinted under greenschist-facies or amphibolite-facies conditions, occurrence of ultradense eclogite in source areas is readily revealed by the Heavy Mineral Concentration (HMC) index, which mirrors the average density of source rocks in the absence of hydraulic-sorting effects. Rather than the pressure peak reached at depth, the Metamorphic Index (MI) and Hornblende Colour Index (HCI) reflect peak temperatures reached at later stages, when subduction is throttled by arrival of thicker continental crust and geothermal gradients increase, as documented in detritus derived from the Tauern window and Lepontine dome. Experience gained from modern sediments, and appropriate statistical techniques provides fundamental help to decrypt the information stored in the sedimentary record, and thus to identify and reconstruct subduction events of the past. Besides the fundamental contribution that modern sediment analysis can bring in understanding ancient sandstone successions, it can also give insights on short-term erosion distribution over wide areas and readily detect potential area of focused erosion. We tested a new quantitative approach based on the integration of compositional data and detrital apatite fission-tracks in two valleys of the western Alps (Arc and Dora Baltea basins). Samples for bulk-petrography and fission-track analysis were collected at different closure sections along the trunk, in order to investigate how the detrital signal evolves when detritus from different sub-basins is progressively added to the system. Fission-track analysis is a powerful integration tool to quantify sediments mixing if source areas experienced contrasting exhumation paths. Fission-track grain-age distributions provide not only information on long-term exhumation patterns, based on the age of the peaks, but also provide first-order constraints on short-term erosion rates by comparison between the size of the peaks and the size of potential source areas. In the Dora Baltea catchment, the apatite load derives from two major fault-bounded blocks, the Western one yielding 43% of the total amount of apatite, and the Eastern one yielding the remaining 57%. In the Arc catchment, contribution is 29% from the Eastern Block, 14% from the Houiller-Subbriançonnais units and 57% from the Belledonne-Dauphinois units. We assessed apatite fertility in source-rocks by measuring apatite content in processed sediments, after checking for anomalous hydraulic concentrations by geochemical analyses. The lack of compositional anomalies for elements between Y and Cr, largely hosted in ultradense minerals, grants that source-rocks distribution in the basin is faithfully reflected by detrital assemblages. Results demonstrate that erosional processes were focused in different areas of the Western Alps at long-term and short-term timescales, and are now concentrated in the External Massifs. No clear relationship between erosion and climate or relief is observed in this sector of the belt, where endogenic forces may represent the main controlling factor on both long-term and short-term erosion rates.

Styles APA, Harvard, Vancouver, ISO, etc.

Thornberry, Trista L. « The Petrography of the Buck Creek Dunite Body, Clay County, NC : Implications about its Origin and Emplacement ». Oberlin College Honors Theses / OhioLINK, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=oberlin1411990381.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Chaumba, Jefferson B. « The Russell Lake Allochthon, southern Appalachians structure, petrography, bulk-rock and mineral chemistry, O, H, and Sm-Nd isotope geochemistry / ». 2009. http://purl.galileo.usg.edu/uga%5Fetd/chaumba%5Fjefferson%5Fb%5F200908%5Fphd.

Texte intégral

Résumé :

Thesis (Ph. D.)--University of Georgia, 2009.
Directed by Michael Roden. For abstract see https://getd.libs.uga.edu/pdfs/chaumba%5Fjefferson%5Fb%5F200908%5Fphd.pdf. Includes bibliographical references (leaves 246-279).

Styles APA, Harvard, Vancouver, ISO, etc.

Chapitres de livres sur le sujet "Bulk petrography"

Livingston, Richard A., Walairat Bumrongjaroen, Samuel Essien et Amde M. Amde. « Application of Individual Glass Particle Data to Estimate Uncertainties in Bulk Fly Ash Chemical Compositions ». Dans Advances in Cement Analysis and Concrete Petrography, 41–54. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959 : ASTM International, 2016. http://dx.doi.org/10.1520/stp161320180006.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Drake, Michelle K., Ivano W. Aiello et A. Christina Ravelo. « Gamma-ray attenuation bulk density as an indicator of diatom valve abundance and fragmentation in Pleistocene biosiliceous sediments of the Bering Sea ». Dans Understanding the Monterey Formation and Similar Biosiliceous Units across Space and Time. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.2556(13).

Texte intégral

Résumé :

ABSTRACT Multisensor track measurements are a nondestructive method to produce continuously measured high-resolution physical property data sets that are a great asset to a wide range of research, including geotechnical studies and paleoceanography. Interpretation of these physical property data can be challenging because they are typically influenced by multiple variables. This paper specifically focuses on the interpretation of gamma-ray attenuation (GRA) data (a proxy for sediment bulk density) in biosiliceous sediments. The Bering Sea is a basin dominated by biosiliceous sediment, and the late Pleistocene to present core record of Sites U1340 and U1339, drilled during Integrated Ocean Drilling Program (IODP) Expedition 323, has subtle meter-scale changes in the concentration of fine-grained siliciclastic sediment that produce lithologic alternations between diatom ooze and diatom mud. We produced a detailed sedimentologic data set that combined smear slide petrography, scanning electron microscopy, and grain-size analysis for both Sites U1340 and U1339 and correlated it to shipboard GRA bulk density measurements. Results show that bulk density is negatively correlated with diatom abundance and positively correlated with the fragmentation of diatom valves. This study argues that diatom abundance and fragmentation influence sediment packing and drive down-core variability in GRA bulk density. Therefore, denser diatom mud is a result of tightly packed, highly fragmented diatom valves, and diatom ooze is a less dense sediment dominated by whole and less fragmented diatom valves. We suggest that GRA data can be used as a proxy for diatom abundance and an indicator of diatom fragmentation. We include a discussion of how these results may impact the interpretation of ancient bedded siliceous rocks.

Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "Bulk petrography"

Khalifa, Aqeel, Paul Tarabbia, Mohammad A. Alrowaie et Mohamed Soua. « Significance and Implications of Diagenetic Nodular Anhydrite on Sandstone Reservoirs Quality ». Dans SPE Annual Technical Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/210403-ms.

Texte intégral

Résumé :

Abstract Diagenetic nodular anhydrite observed in fluvio-aeolian-lacustrine and glacial sandstones has significant implications to reservoir quality. This type of nodular cement is spatially and volumetrically variable within these reservoirs. Its presence impacts subsurface formation evaluation and porosity calculations. Thus, the investigation of these nodules was carried out using: core image analysis; thin sections petrography; micro computed tomography (MicroCT) scans; bulk rock X-Ray Diffraction (XRD); sulfur & strontium isotope analyses. Where core was unavailable, geochemical data and resistivity-based image logs were used to expand the anhydrite characterization to derive field wide distributions. Bulk rock XRD and thin section-based petrographic studies indicate that the mineralogy of the study sandstones is dominated by quartz (>90%), with minor clay, and the presence of variable amounts of localized anhydrite as diagenetic nodular cements. The habitat of anhydrite nodules displays a substantial size variation, with nodules ranging from millimeters to several centimeters in scale. The larger nodules are easily identified visually in core samples and on borehole image logs. To investigate the origin of the anhydrite, sulfur and strontium isotope analysis were used to understand the relative timing of the nodule's development within the paragenetic sequence. Results from the sulfur and strontium isotopic analyses are consistent with the understanding that the anhydrite nodules are a late stage emplacement. A semi-quantitative "Anhydrite Abundance Index" (AAI) was calculated across key wells within the fields to establish the anhydrites regional distribution. The AAI uses the dry weight fraction of calcium and sulfur from geochemical logs to determine the volume of anhydrite. These volumes were further calibrated to volumes obtained through geochemical analysis of core samples, which is key to calculating the correct anhydrite volume required for formation evaluation. Regional distribution mapping created from this volume data suggests a widespread presence of the anhydrite nodular cementation. Understanding the relative abundance of anhydrite volumes is important when investigating the reservoir quality, especially if underestimating its presence may affect log-based porosity calculations and subsequently permeability calculations. The in-place quantification of the anhydrite nodular cement in 1D also enabled research to further the understanding of post-depositional, geochemical and geographic controls on the subsurface modelling and reservoir quality prediction.

Styles APA, Harvard, Vancouver, ISO, etc.

Vincke, O. « An estimation of bulk moduli of sandstones as a function of confining pressure using their petrographic and petrophysic description ». Dans Rock Mechanics in Petroleum Engineering. Society of Petroleum Engineers, 1994. http://dx.doi.org/10.2118/28038-ms.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Irsani, N. ,. S. ,. « Depositional Environment and Petroleum System Analysis Based on Outcrop Analogue in Sukolilo Outcrop, Tuban Regency, East Java Province ». Dans Digital Technical Conference. Indonesian Petroleum Association, 2020. http://dx.doi.org/10.29118/ipa20-sg-345.

Texte intégral

Résumé :

The North East Java Basin has become one of the most promising basins in Indonesia. Over 150 million barrels of oil have been extracted from the Rembang Zone in the North East Java Basin. The Sukolilo outcrop, located in Sukolilo, Bancar, Tuban Regency, East Java, represents all the components of an exposed Middle Miocene petroleum system. The objective of this study is to present an excellent analogue for the depositional environment and petroleum system of the Middle Miocene formation of the Rembang Zone that can be expected in similar subsurface settings and as a tool for outcrop preservation with modelling using photogrammetry. Data consists of measured section, photogrammetry data, petrographic analysis, TOC content measurement and Rock-Eval Pyrolysis. Observed formation at this outcrop includes Ngrayong, Bulu, and Wonocolo Formation. The facies distributed in this outcrop consist of claystone-carbonaceous shale bedded, cross-bedded quartz sandstone, foraminiferal limestone and calcareous siltstone intercalated calcareous sandstone. Based on depositional environment analysis, the depositional environment changes from Lagoon – Tidal Flat – Shallow Marine – Shelf. The result of petrographic analysis shows that quartz sandstone porosity from the Ngrayong Formation can be identified as reservoir rock. Seal rock potential is shown by carbonate minerals diagenesis of the foraminiferal limestone sample. Source rock potential which is identified using TOC content and Rock-Eval Pyrolysis, reveals that the sample tends to be gas prone (kerogen type III) and has low thermal maturity (immature). Ductile deformation (conical anticline) and brittle deformation (normal fault) is predicted to be the migration path for this petroleum system.

Styles APA, Harvard, Vancouver, ISO, etc.

Abu-Mahfouz, Israa S., Maria Ardila et Volker Vahrenkamp. « Geochemical and Petrographic Characteristics of Lithofacies from Upper Cretaceous Organic-Rich Source Rocks, Jordan ». Dans International Petroleum Technology Conference. IPTC, 2022. http://dx.doi.org/10.2523/iptc-21914-ms.

Texte intégral

Résumé :

Abstract The Upper Cretaceous source rocks of Jordan are organic-rich carbonate mudrocks that represent excellent source rocks but are essentially still immature to just entering the oil window. Therefore, they offer a unique opportunity to study lithology, source rock composition, and geochemistry prior to the onset of maturation and expulsion of hydrocarbons. Our study aims to examine the lithological and geochemical characteristics of these high-quality source rocks. The study utilizes an integrated petrographic and geochemical approach to define the different microfacies in the studied source rock sequence and understand their intrinsic variability. Representative subsurface samples were collected from 13 vertical cores drilled in the Upper Cretaceous interval across Jordan for bulk elemental geochemistry and microfacies analysis. To define the different microfacies and examine the mineralogical and geochemical changes, the samples were investigated for their composition, texture and lithofacies (using both optical microscopy and scanning electron microscopy (SEM/EDS)), mineralogy (XRD/XRF), and geochemistry (total organic carbon, (TOC) and total Sulphur content using a LECO elemental analyzer, and maturity using Rock-Eval). Five laminated and non-laminated carbonate and siliceous lithofacies associations were identified, all containing significant organic content (TOC varies from 7 to 29 wt.%) and Sulphur contents (2-7.5 wt.%). The rocks are of type II-S kerogen with high HI (Hydrogen Index) values of >600 mg HC/g TOC. XRD results show that the rocks are mainly composed of calcite (15-94%, 75% on average) and quartz (0-53%, 10.47% on average). Minor amounts of apatite (average 5.9%, range 0 to 27%), clay (< 7%), pyrite (up to 6%), gypsum (up to 4%) and dolomite (up to 2.7%) are also exist. Our results indicate a predominance of the organic-rich calcareous microfacies association, evidenced by the abundant foraminifera grains and the high preservation of organic matter as disseminated throughout the matrix and/or filling interparticle micropores and microfractures. This reflects the deposition in a restricted basin under anoxic conditions. The integration of the data obtained through the different techniques used in this study together with the unique characteristics of these source rocks allowed the characterization of the geological and geochemical properties of the defined lithofacies associations in these immature, organic-rich Upper Cretaceous source rocks. This, in turn, helped to achieve a better evaluation of the occurrence and distribution of the different litho- and organic facies and estimation of hydrocarbon source potential.

Styles APA, Harvard, Vancouver, ISO, etc.

Zhang, Baosen, Xin Jin, Yitian Xiao, Yunzhe Hou, Jin Meng, Zhenkai Huang et Meng Han. « Quantitative Identification of Sandstone Lithology Based On Thin-Section Micrographs Using the U-net and U-net++ Semantic Segmentation Network ». Dans International Petroleum Technology Conference. IPTC, 2023. http://dx.doi.org/10.2523/iptc-22865-ea.

Texte intégral

Résumé :

Abstract Quantitative identification of sandstone microscopic images is an essential task for sandstone reservoir characterization. The widely-used classical Gazzi-Dickinson point-counting method can be subjective, inconsistent and time-consuming. Furthermore, by directly putting labeled microscopic images of all rock types into image recognition models for training, most previous studies did not address the petrographic principle of artificial identification. In this study, U-Net and U-Net++ semantic segmentation networks that incorporated the sandstone petrographic principle in quantitative identification of sandstone was introduced. Automatic identification of sandstone microscopic images requires prior knowledge learned from the identified sandstones with similar compositions. First, hundreds of thin-sections of typical sandstone reservoirs were selected from several key petroleum basins in China. Second, one-to-one single and orthogonal polarized images were taken for them. Third, the annotation software was used to label the type of each skeleton grain, including quartz, feldspar, lithic fragment and pore. Finally, 480 sets of data, each of which includes single and orthogonal polarized images and their ".json" format annotation results, were obtained for training and testing of the U-Net model to quantitatively analyze sandstone microscopic images. Within the 480 sets of data, 6798 sandstone skeleton grains, including 4542 quartzes, 796 feldspars, 1248 lithic fragments and 212 pores were labeled. The sandstone thin-section quantitative identification model trained by 392 data sets achieved a training accuracy of 96% with the intersection over union at 78% for quartz, and a training accuracy of 88% with the intersection over union at 56% for lithic fragments. The remaining 88 data sets were used for testing, and the accuracy was 87% with its intersection over union at 74% for quartz and a training accuracy of 77% with the intersection over union at 54% for lithic fragments. As a classic fully convolutional network that excels in processing medical images, the U-Net or U-Net++ semantic segmentation network has also performed very well in quantitative identification of sandstone microscopic images. After the proportion of each sandstone skeleton grain has been identified, the simple subdivision descriptive petrographic classification of the sandstone was determined according to the classic Dickinson sandstone taxonomic criteria. In other words, most current deep learning algorithms classify sandstones at the bulk rock level, but this U-Net model has been extended to the mineral level for comprehensive identification. Our vision-based sandstone lithology identification model has not only improved the accuracy of artificial identification but also reduced the instability and subjectivity of the traditional manual processing and expert decision-making approach. In the future, we plan to increase the number and coverage of labeled thin-section images to evaluate the impact on the accuracy and consistency of the U-Net or U-Net++ model, and to expand the approach to identify other terrigenous clastic rock. Furthermore, we hope to improve the capability of the model to identify grains, such as monocrystalline and polycrystalline quartz from "quartz", K-feldspar and plagioclase from "feldspar", and igneous, metamorphic and sedimentary lithic fragments from "lithic fragments".

Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "Bulk petrography"

Magnall, J. M., S. A. Gleeson et S. Paradis. SEDEX mineralisation, Macmillan Pass (Yukon) : petrography, mineralogy and bulk geochemistry of the Tom and Nidd deposits. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 2014. http://dx.doi.org/10.4095/293105.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!