Diagenesis of the Central Basque-Cantabrian Basin (Iberian Peninsula) based on illite-smectite distribution

AbstractX-ray diffraction was used to analyse the distribution of clay minerals in the <2 µm fraction of the lutitic and marly facies from the centre of the Basque-Cantabrian Basin (Basque Arc), where the sedimentary section is 2000 to 10,000 m thick. Most of the deposits were laid down during the Cretaceous and Paleogene and were related to the opening and closing of the Bay of Biscay. The most noteworthy variations are in kaolinite, smectite and mixed-layered (R = 0, R = 1 and R ≥ 3) illite-smectite, which can be ascribed both to provenance and to diagenesis. A general diminution in expandability is related to the gradual transformation of smectite to illite from south to north, and with depth. Temperature, residence time and chemical activity during diagenesis are the factors that had greatest influence on the changes in the original mineral assemblages inherited from the source area. On the basis of the clay minerals and the Kübler index, a general scheme is proposed for the diagenetic evolution of the area from the initial stages to anchimetamorphism.

Download Full-text

Clay minerals as provenance indicators in continental lacustrine sequences: the Leza Formation, early Cretaceous, Cameros Basin, northern Spain

Clay Minerals ◽

10.1180/0009855054010157 ◽

2005 ◽

Vol 40 (1) ◽

pp. 79-92 ◽

Cited By ~ 6

Author(s):

J. Alonso-Azcárate ◽

M. Rodas ◽

J. F. Barrenechea ◽

J. R. Mas

Keyword(s):

Clay Mineral ◽

Source Area ◽

Local Source ◽

Northern Spain ◽

Source Areas ◽

Kübler Index ◽

Facies Associations ◽

Mineral Assemblages ◽

Cameros Basin

AbstractVariations in clay mineral assemblages, changes in Kübler index (KI), and the chemical composition of chlorites are used to identify source areas in the lacustrine materials in the Lower Cretaceous Leza Limestone Formation of the Cameros Basin, northern Spain. This formation has fairly homogeneous lithological characteristics and facies associations which do not allow for identification and characterization of local source areas. The Arnedillo lithosome of the Leza Limestone Formation contains a clay mineral association (Mg-chlorite, illite and smectite) indicative of its provenance. Chlorite composition and illite KI values indicate that these minerals were formed at temperatures higher than those reached by the Leza Formation which indicates its detrital origin. The similarity in the Mg-chlorite composition between the Arnedillo lithosome and the Keuper sediments of the area indicates that these materials acted as a local source area. This implies that Triassic sediments were exposed, at least locally, at the time of deposition of the Leza Formation. The presence of smectite in the Leza Formation is related to a retrograde diagenesis event that altered the Mg-chlorites in some samples.

Download Full-text

Mineralogy and geochemical affinities of bentonites from Kapıkaya (Eskişehir, western Turkey)

Clay Minerals ◽

10.1180/claymin.2009.044.3.339 ◽

2009 ◽

Vol 44 (3) ◽

pp. 339-360 ◽

Cited By ~ 4

Author(s):

A. Yildiz ◽

İ. Dumlupunar

Keyword(s):

Rare Earth ◽

Clay Minerals ◽

Volcanic Rocks ◽

X Ray Diffraction ◽

Western Turkey ◽

X Ray ◽

Geochemical Properties ◽

Mineral Assemblages ◽

Parent Rocks ◽

Dioctahedral Smectite

AbstractThere are numerous bentonite deposits, formed by the alteration of volcanic rocks, in the Kapıkaya area (Eskişehir, western Turkey). These deposits can be classified into three groups according to their stratigraphical levels. X-ray diffraction (XRD), scanning electron microscope (SEM), major, rare-earth and trace-element analyses of bentonites and their parent rocks from the Kapıkaya area were used to evaluate the mineralogical and geochemical properties of bentonites and their parental affinities. Mineral assemblages resulting from bentonite deposits consist mostly of clay minerals, gypsum, cristobalite/opal-CT, quartz, feldspar, calcite and dolomite. The clay minerals are represented mainly by dioctahedral smectite and lesser amounts of illite and chlorite. The enrichment and depletion of the elements indicates open-system alteration conditions. The enrichments in MgO, Fe2O3, TiO2, Co, Pb, Zn, and Ni are related to the precipitation of hydrothermal solutions channelled throughout ultramafic sources. The main differences in mineralogy and geochemistry of bentonites from the Kapıkaya area are in the smectite composition and the contents of major, rare-earth and other trace elements. The data obtained show that the types of parent rock the influenced the mineralogical and geochemical compositions of the bentonites.

Download Full-text

ÍNDICE DE CRISTALINIDADE DA ILITA E CARACTERIZAÇÃO DOS ARGILOMINERAIS DA FORMAÇÃO PIMENTA BUENO – BACIA DOS PARECIS

Revista Geonomos ◽

10.18285/geonomos.v24i1.825 ◽

2016 ◽

Author(s):

Jéssica Melanya Sisti de Paiva ◽

Gislaine Amorés Battilani ◽

Rubia Ribeiro Viana ◽

Maurício José dos Reis

Keyword(s):

Clay Minerals ◽

Clay Fraction ◽

X Ray Diffraction ◽

Average Width ◽

X Ray ◽

Kübler Index ◽

Half Height ◽

Intracratonic Basins ◽

Bottom To Top

ResumoA Bacia dos Parecis é uma das maiores bacias intracratônicas brasileiras e poucos são os estudos relacionados à sua gênese. A Formação Pimenta Bueno, objeto desse estudo, é constituída, da base para o topo, de calcários, folhelhos, siltitos e arenitos. O presente estudo tem como principal objetivo estimar o provável estágio diagenético/metamórfico em que essas rochas foram submetidas, por meio do estudo de difratogramas de raios-X da fração argila e dos parâmetros do Índice de Kübler (Índice de Cristalinidade da Ilita). Os resultados indicam que essas rochas encontram-se na Epizona e, a média das medidas da largura a meia altura (FWHM) é de 0,16°. A análise de difratometria de raios – X indicou a presença de clorita, ilita, pirofilita, caulinita e esmectita (montmorilonita). Além das espécies bem definidas, identificou-se, também, argilominerais interestratificados de ilita/esmectita e clorita/esmectita.Palavras Chave: Cristalinidade da ilita; Bacia dos Parecis; Formação Pimenta Bueno.AbstractINDEX CRYSTALLINITY OF ILLITE AND CHARACTERIZATION CLAY MINERALS OF PIMENTA BUENO FORMATION – PARECIS BASIN. The Parecis basin is one of the largest Brazilian intracratonic basins and few are the studies related to its genesis. Pimenta Bueno Formation, object of this study, is represented, from bottom to top, by limestones, shales, siltstones and sandstones. To achieve the objectives of this study, knowing the diagenetic stage and / or metamórphic degree to which were subjected the Parecis Basin rocks, were developed diffraction studies of X-ray of the clay fraction, followed by the calculation of the Kübler Index parameters (crystallinity of iIlita). The results indicated that these rocks are at the Epizone and the average width measured at half height (FWHM) is 0.16 °. The X-ray diffraction indicated the presence of the chlorite, illite, pyrophyllite, kaolinite and smectite (montmorillonite). Likewise were identified interstratified phases of Illite/ smectite and chlorite / smectite.Keywords: Crystallinity of Ilita; Parecis Basin; Pimenta Bueno Formation.

Download Full-text

Thermal models and clay diagenesis in the Tertiary-Cretaceous sediments of the Alava block (Basque-Cantabrian basin, Spain)

Clay Minerals ◽

10.1180/0009855064140219 ◽

2006 ◽

Vol 41 (4) ◽

pp. 791-809 ◽

Cited By ~ 22

Author(s):

J. Arostegui ◽

F. J. Sangüesa ◽

F. Nieto ◽

J. A. Uriarte

Keyword(s):

Clay Mineralogy ◽

Source Area ◽

The Other ◽

Small Scale ◽

Low Permeability ◽

Thermal Flow ◽

X Ray Diffraction ◽

X Ray ◽

Characteristic Features ◽

Basque Cantabrian Basin

AbstractDiagenesis in the Cretaceous and Tertiary sediments of the Alava Block (Basque- Cantabrian basin) has been studied using the clay mineralogy (X-ray diffraction) of cuttings from three representative wells of a N—S cross-section. More than 5500 m of various lithologies (marls, mudstones and sandstones) have been drilled in the northern part of the domain, and 2100 m in the southern zone. The illitization of smectite and the disappearance of kaolinite, due to diagenesis, are the most characteristic features in the northern well. Evolution of smectite to illite has been differentiated into four zones, from top to bottom of the series, each showing specific I-S interstratified clay assemblages. The disappearance of smectite and the distribution of kaolinite in the other two wells are explained based on source-area considerations. Burial and thermal history have been reconstructed, revealing a northward increase in thermal flow until the Oligocene (Alpine orogeny paroxysm). In the northern well, the thermal model suggests temperatures of 160 and 270°C for the disappearance of smectite (R0) and illite-smectite (I-S) mixed-layer R1 clay minerals, respectively. The disappearance of kaolinite is related to a temperature of 230°C, a temperature never attained in the other two wells. Retardation of these processes, in relation to temperature values in the literature, is a consequence of the poor reactivity of marly lithologies, due to the low availability of cations. In this regard, the scarcity of reactants (K-bearing phases) and the absence of pathways (low permeability) for their access and circulation imply that illitization could have taken place in a closed system, by diffusion, on a very small scale, i.e. that of the original smectite grains.

Download Full-text

The Control of Diagenesis and Mineral Assemblages on Brittleness of Mudstones

Frontiers in Earth Science ◽

10.3389/feart.2021.758046 ◽

2021 ◽

Vol 9 ◽

Author(s):

Jiazong Du ◽

Jingong Cai ◽

Shengxiang Long ◽

Bo Gao ◽

Dongjun Feng ◽

...

Keyword(s):

Clay Minerals ◽

Mineral Composition ◽

Potential Control ◽

Mineral Assemblages ◽

Microscopic Features ◽

Clay Matrix ◽

Rigid Contact ◽

Late Diagenesis ◽

Diagenetic Evolution ◽

Rock Brittleness

The variation in mineral composition will affect the rock brittleness, thus the change of mineral assemblages during diagenesis has a potential control on the brittleness of mudstones. In this study, thin section, X-ray diffraction (XRD), and Scanning Electron Microscope (SEM) analyses were used to investigate compositional and microscopic features of mudstones. With the enhancement of diagenesis, three mineral assemblages were divided due to the diagenetic evolution of minerals. Quartz, feldspar, dolomite, chlorite, and illite were regarded as brittle minerals and (quartz + feldspar + dolomite + illite + chlorite)/(detrital mineral + carbonate + clay mineral) was defined as the brittleness evaluation index The mudstone brittleness changed slightly during early diagenesis but increased gradually with enhancement of diagenesis in the late diagenesis stage. Quartz and feldspar were scattered above the clay matrix and the contact of grains was limited, therefore, the contribution of detrital minerals to the brittleness was affected by the properties of clay minerals. The diagenetic transformation of clay minerals resulted in the reduction of ductile components (smectite/I-Sm and kaolinite) and increase of brittle components (illite and chlorite), leading to the enhancement of integral rigidity of the mudstones. Meanwhile, the improved crystallization of carbonate in late diagenesis stage enlarged the carbonate grains which resulted in rigid contact between grains. These results highlighted the influence of diagenesis on mudstone brittleness. Therefore, for evaluation of mudstone brittleness, attention should be paid to the diagenesis process besides mineral composition.

Download Full-text

Origin and occurrence of clay minerals in the Ariyalur Group of sedimentary rocks, Cauvery basin, Tamil Nadu, India

Journal of Nepal Geological Society ◽

10.3126/jngs.v19i0.32092 ◽

1999 ◽

Vol 19 ◽

Author(s):

J. Madhavaraju ◽

S. Ramasamy

Keyword(s):

Clay Minerals ◽

Tamil Nadu ◽

Chemical Weathering ◽

Sedimentary Rocks ◽

Climatic Conditions ◽

Temperate Climate ◽

X Ray Diffraction ◽

Mineral Assemblages ◽

Lower Maastrichtian ◽

Climatic Transition

Clay mineral assemblages in the Ariyalur Group of sedimentary rocks were studied by X-ray diffraction analysis. The results of the study indicate that illite and smectite are the predominant clay minerals whereas kaolinite and chlorite occur in minor amounts. The Campanian-Lower Maastrichtian rocks (i.e., Sillakkudi and Kallankurichchi Formations) contain a large amount of illite. The study reveals that these sediments were derived from the continental erosion of pre-existing rocks that were subjected to low intensity chemical weathering associated with a temperate climate. A significant decrease in illite content is observed in the Ottakkovil Formation. It implies a climatic transition (from temperate to warm) during the Middle Maastrichtian time. On the other hand, a high content of pedogenic smectite in the Kallamedu Formation is indicative of warm climatic conditions with alternating dry and wet periods during the formation of this mineral.

Download Full-text

Application of the capillary method in micro X-ray diffractometry (µ-XRD): A useful technique for the characterization of small amounts of clay minerals

Central European Geology ◽

10.1556/24.2020.00005 ◽

2020 ◽

Author(s):

Ivett Kovács ◽

Tibor Németh ◽

Gabriella B. Kiss ◽

Zsolt Benkó

Keyword(s):

Clay Minerals ◽

Clay Mineral ◽

Diffraction Method ◽

X Ray Diffraction ◽

Rapid Preparation ◽

Thin Sections ◽

X Ray ◽

Capillary Method ◽

Mineral Assemblages ◽

Ph Conditions

AbstractThe laboratory micro X-ray diffraction (μ-XRD) technique is a suitable method to study minerals in-situ in whole-rock specimens without any sample preparation or in polished thin sections, and even in small amounts in powdered form. The micro X-ray diffraction method uses the conventional, closed-tube X-ray generator, but modifications were needed in the diffraction column, sample holder and detector in order to achieve μ-XRD capability.In this paper, we present a case study of the capillary method used in µ-XRD on hydrothermal clay mineral assemblages that formed in the Velence Mts (Hungary). The capillary method in µ-XRD has many advantages in the investigation of small amounts of clay minerals: (1) easy and rapid preparation of randomly oriented, powdered samples; (2) rapid measurements; (3) accurate diffraction patterns. By using the capillary method, the formation of preferred orientation can be eliminated; thus the (hkl) reflection of the clay minerals can be precisely measured. Illite polytype quantification and the investigation of (060) reflection of clay minerals can be used satisfactorily in µ-XRD.Hydrothermal clay mineral assemblages are indicative of temperature and pH. Their examination can determine the physicochemical parameters of the hydrothermal fluids that interacted with the host granite in the Velence Mts. The analyzed hydrothermal clay minerals from the western part of the mountains suggest lower temperatures (150–200 °C) and intermediate pH conditions. In contrast, the clay mineral assemblages' characteristics for the eastern part of the mountains indicate more intense argillization and higher temperatures (∼220 °C) and intermediate pH conditions.

Download Full-text

THE CLAY MINERALS IN SOME BRITISH COLUMBIA SUBSOILS

Canadian Journal of Soil Science ◽

10.4141/cjss62-039 ◽

1962 ◽

Vol 42 (2) ◽

pp. 296-301 ◽

Cited By ~ 2

Author(s):

J. S. Clark ◽

J. E. Brydon ◽

H. J. Hortie

Keyword(s):

British Columbia ◽

Diffraction Analysis ◽

Clay Minerals ◽

Clay Mineralogy ◽

X Ray Diffraction ◽

The South ◽

Parent Materials ◽

X Ray ◽

Northeastern Part ◽

Montmorillonitic Clay

X-ray diffraction analysis was used to identify the clay minerals present in fourteen subsoil samples that were selected to represent some more important clay-bearing deposits in British Columbia. The clay mineralogy of the subsoils varied considerably but montmorillonitic clay minerals tended to predominate in the water-laid deposits of the south and illite in the soil parent materials of the Interior Plains region of the northeastern part of the Province.

Download Full-text

Lithofacies Analysis and Qualitative Minerology of the Sediments of #3 Well in the Greater Ughelli Depobelt, Niger Delta Basin

Journal of Scientific Research ◽

10.3329/jsr.v13i2.49948 ◽

2021 ◽

Vol 13 (2) ◽

pp. 601-610

Author(s):

K. Itiowe ◽

R. Oghonyon ◽

B. K. Kurah

Keyword(s):

Physical Properties ◽

Clay Minerals ◽

Niger Delta ◽

Reservoir Quality ◽

X Ray Diffraction ◽

X Ray ◽

Sandy Shale ◽

Heterogeneous Nature ◽

Niger Delta Basin ◽

Shaly Sandstone

The sediment of #3 Well of the Greater Ughelli Depobelt are represented by sand and shale intercalation. In this study, lithofacies analysis and X-ray diffraction technique were used to characterize the sediments from the well. The lithofacies analysis was based on the physical properties of the sediments encountered from the ditch cuttings. Five lithofacies types of mainly sandstone, clayey sandstone, shaly sandstone, sandy shale and shale and 53 lithofacies zones were identified from 15 ft to 11295 ft. The result of the X-ray diffraction analysis identified that the following clay minerals – kaolinite, illite/muscovite, sepiolite, chlorite, calcite, dolomite; with kaolinite in greater percentage. The non-clay minerals include quartz, pyrite, anatase, gypsum, plagioclase, microcline, jarosite, barite and fluorite; with quartz having the highest percentage. Therefore, due to the high percentage of kaolinite in #3 well, the pore filing kaolinite may have more effect on the reservoir quality than illite/muscovite, chlorite and sepiolite. By considering the physical properties, homogenous and heterogeneous nature of the #3 Well, it would be concluded that #3 Well has some prospect for petroleum and gas exploration.

Download Full-text

The separation of clay mineral fractions with linear heavy liquid density gradient columns

Clay Minerals ◽

10.1180/claymin.1969.008.1.07 ◽

1969 ◽

Vol 8 (1) ◽

pp. 59-69 ◽

Cited By ~ 13

Author(s):

G. Halma

Keyword(s):

Clay Minerals ◽

Density Gradient ◽

Gradient Centrifugation ◽

Heavy Liquid ◽

List Type ◽

Liquid Density ◽

X Ray Diffraction ◽

Surface Active Agents ◽

Density Gradient Centrifugation Method ◽

Surface Active

Because of increased interest in mineralogical analysis of soils a rapid, generally applicable method to separate clay minerals is needed, and such a method is described here. The technique is a modification of the heavy liquid density gradient centrifugation method which is commonly applied in mineralogical practice. Modifications are:(1)The use of suitable surface active agents to overcome the flocculation problem.(2)The use of the ultra centrifuge at about 33,000 g to hasten sedimentation.(3)The use of a linear density gradient which supplies in addition a quick identification of the mineral composition.Preliminary experiments, evaluating different variables (e.g. cation form, ultrasonic treatment, influence of surfactant), reveal the scope and limitations of the procedure presented.Clay minerals of different density can be separated. However, if the clay minerals of a mixture have overlapping densities, or if they contain a series of mixed-layer minerals, only a broad fractionation is possible. This is shown by X-ray diffraction and electron microscope studies of isolated zones (or parts of them) which develop in the centrifuged density gradient columns containing various pre-treated natural clays or clay mixtures.

Download Full-text