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

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.

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Clay minerals as palaeoenvironmental indicators in the Bathonian (Middle Jurassic) ore-bearing clays from Gnaszyn, Kraków-Silesia Homocline

Acta Geologica Polonica ◽

10.2478/v10263-012-0016-9 ◽

2012 ◽

Vol 62 (3) ◽

pp. 297-305 ◽

Cited By ~ 3

Author(s):

Teresa Dudek

Keyword(s):

Clay Minerals ◽

Middle Jurassic ◽

Mineral Content ◽

Sedimentary Rocks ◽

Climatic Conditions ◽

Source Rocks ◽

X Ray Diffraction ◽

X Ray ◽

Clay Mineral Assemblage ◽

Mechanical Erosion

ABSTRACT Dudek, T. 2012. Clay minerals as palaeoenvironmental indicators in the Bathonian (Middle Jurassic) ore-bearing clays from Gnaszyn, Kraków-Silesia Homocline. Acta Geologica Polonica, 62 (3), 297-305. Warszawa. This paper reports the results of X-ray diffraction quantitative mineralogical studies of the clay-rich Middle Jurassic sedimentary rocks from Gnaszyn, central Poland and their palaeoenvironmental interpretation. The palaeoenvironmental interpretation is aided by the fact that the sediments have not been significantly altered by diagenesis. The mineral composition is uniform throughout the succession: quartz, K-feldspar, plagioclase, calcite, gypsum, anhydrite, pyrite, illite, kaolinite, chlorite, and glauconite. The clay assemblage is dominated by illite, which alone accounts for about 20 wt% of the total mineral content. Kaolinite amounts usually <10 wt% and chlorite and glauconite occur in subordinate quantities. The clay mineral assemblage is largely of detrital origin and indicates rather cool and/or dry climatic conditions favouring mechanical erosion of the source rocks.

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Geochemical Significance of Clay Minerals and Elements in Paleogene Sandstones in the Center of the Northern Margin of the Qaidam Basin, China

Minerals ◽

10.3390/min10060505 ◽

2020 ◽

Vol 10 (6) ◽

pp. 505 ◽

Cited By ~ 1

Author(s):

Guoqiang Sun ◽

Meng Wang ◽

Jiajia Guo ◽

Yetong Wang ◽

Yongheng Yang

Keyword(s):

Clay Minerals ◽

Chemical Weathering ◽

Qaidam Basin ◽

Sedimentary Environment ◽

Climatic Conditions ◽

Northern Margin ◽

Magmatic Arc ◽

Average Value ◽

Geochemical Significance ◽

Continental Magmatic Arc

The average thickness of Paleogene sandstones reaches about 3000–4000 m at the northern margin of the Qaidam Basin. However, the provenance and sedimentary environment of these sandstones are uncertain; thus, more comprehensive research is needed. Integrated research is conducted on the provenance and weathering process based on petrographic characteristics, clay minerals, and geochemical compositions of sandstones in the center of the northern Qaidam Basin. The results of lithofacies analysis show that the Paleogene sandstones were mainly derived from an active continental magmatic arc, subduction accretion, or a fold-thrust belt. The average illite content in the Paleogene clay minerals is more than 50%, followed by chlorite and smectite, which reflect climatic and environmental characteristics that were arid to semi-arid, whereas the characteristics of carbon–oxygen isotopes reveal a mainly freshwater sedimentary environment. The corrected chemical index of alteration (CIAcorr) is between 56.3 and 75.7, with an average value of 66.5. These results indicate that the provenance of the Paleogene sandstones in the center of the northern Qaidam Basin mainly formed under cold and dry climatic conditions and experienced limited chemical weathering with a small amount that underwent intermediate chemical weathering under warm and humid conditions.

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Chemical weathering east and west of the emerging Caledonides in the Silurian – Early Devonian, with implications for climate

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2015-0156 ◽

2016 ◽

Vol 53 (8) ◽

pp. 774-780 ◽

Cited By ~ 3

Author(s):

Enli Kiipli ◽

Tarmo Kiipli ◽

Toivo Kallaste ◽

Tiiu Märss

Keyword(s):

Chemical Weathering ◽

Sedimentary Rocks ◽

Clay Fraction ◽

Climatic Conditions ◽

Chemical Compositions ◽

Tropical Zone ◽

Early Devonian ◽

Marine Carbonates ◽

Latitudinal Position ◽

Mountain Chain

The late Llandovery (Silurian) – early Lochkovian (Devonian) climate of the tropical zone is tracked considering orogenesis, global glaciation events, and cratonic drift. Mineral and chemical compositions of clay fractions of Canadian (the Franklinian Basin) and Estonian (the Baltoscandian Basin) sedimentary rocks from different sides of the emerging Caledonides were studied, using clay as an index of climatic conditions of the provenance area. Illite is the main clay mineral, with addition of orthoclase, muscovite, and chlorite in both regions. Authigenic chert is present in some Canadian sections. The similarity of clay minerals and elemental composition in the two regions suggest common chemical weathering conditions. Nevertheless, the Al/Ti ratio of the <1 μm clay fraction, the proxy for climate’s aridity–humidity and weathering intensity, reveals differences. The Franklinian Basin in Laurentia shows a shift of climate from humid to semi-humid in pace with the uplift of the Caledonides. The sub-meridional mountain chain in the east reduced the amount of rainfall and, therefore, caused drier climate than could have been expected from the low latitudinal position of the area. The material from the Baltoscandian Basin reveals semi-arid and arid climate for most of the Silurian. Although the southern part of the Fennoscandian Shield was situated in desert latitudes, the evidence from the provenance of clay suggests that the climate was not fully arid. In Baltoscandia, covariation between low Al/Ti of clay and negative shifts of δ13C of marine carbonates is recorded at some stratigraphical levels, suggesting a link between humid climatic episodes in mainland and waning of glaciers at the South Pole.

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New Alumosilicate Fillers Based on Sedimentary Rocks for Asphalt Concrete

MRS Proceedings ◽

10.1557/opl.2014.762 ◽

2014 ◽

Vol 1611 ◽

pp. 81-87

Author(s):

Valeria Strokova ◽

Mikhail Lebedev ◽

Irina Potapova ◽

Konstantin Sobolev

Keyword(s):

Clay Minerals ◽

Asphalt Concrete ◽

Water Resistance ◽

Asphalt Binder ◽

Sedimentary Rocks ◽

Frame Structure ◽

Filler Materials ◽

X Ray Diffraction ◽

X Ray

ABSTRACTAsphalt concrete is the most common material for highway and motorway construction. The quality of asphalt is determined, to a large extent, by properties of asphalt binder. Fillers, which are mineral powders from carbonate rocks and aggregates fines, such as limestone and dolomite, are often used in the composition of bitumen mastics affecting the performance of asphalt.This article explores the feasibility of using the fines of aluminosilicate sedimentary rocks as fillers. These materials are composed of clay minerals, which change their properties upon the contact with water. Normally, the use of such fillers is restricted because of poor water resistance and swelling of asphalt concrete. In order to improve the performance of these fillers, the thermal modification at moderate temperatures of 500–600 °C has been proposed. Such treatment provides sufficient structural stability of obtained materials and results in the reduction of water absorption of asphalt, improved water resistance (up to 2.5 times) and also, in reduced swelling (up to 9 times).It has been demonstrated that improvement in the filler performance can be achieved by a heat treatment. Such treatment induces changes in the mineral composition and converts the structure of clay minerals into the frame structure of zeolite, as confirmed by X-ray diffraction and infrared spectroscopy. Due to thermal treatment, there is a change in the acid-base properties of the surface of the filler, which is reflected in the profiles of the main adsorption centers. As a result, due to chemisorption, the modified aluminosilicate fillers are able to interact with bitumen. The application of new filler materials in asphalt concrete enables to enhance the performance.

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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.

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Formation of clay minerals in andosoils under temperate climate

Clay Minerals ◽

10.1180/claymin.1977.012.4.03 ◽

1977 ◽

Vol 12 (4) ◽

pp. 299-307 ◽

Cited By ~ 10

Author(s):

J. M. Hetier ◽

N. Yoshinaga ◽

F. Weber

Keyword(s):

Clay Minerals ◽

Quantitative Estimation ◽

Late Phase ◽

Temperate Climate ◽

X Ray Diffraction ◽

Accurate Identification ◽

Massif Central ◽

Strongly Connected ◽

Mineral Cements ◽

Comparison Of The Results

AbstractThe principal methods for studying clay minerals in andosoils differ especially by the succession of the pretreatments, i.e. differential dissolution of amorphous mineral cements before (first method) or after (second method) the dispersion and recovery of granulometric fractions.The first method permits a rapid total quantitative estimation of amorphous components and an accurate identification of crystallized clay minerals by means of X-ray diffraction. The second method only proves the presence of allophane and imogolite.The two methods were applied in two different laboratories on the same soils from the Massif Central. The comparison of the results emphasizes the profit of using the two methods, especially if hypotheses on the mechanisms of clay genesis are to be proposed.These results, if placed in the context of a more comprehensive study, suggest the existence of two principal phases of clay genesis, strongly connected to the evolution of organic matter in andosoils, as follows: (i) an early, prepedologic phase during which halloysites and smectites would form; (ii) a late phase giving rise especially to some kaolinite and gibbsite.

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Clay mineralogy and geochemistry of early Jurassic sedimentary rocks from the Moezian Platform, northern Bulgaria

Clay Minerals ◽

10.1180/0009855023730053 ◽

2002 ◽

Vol 37 (3) ◽

pp. 413-428 ◽

Cited By ~ 1

Author(s):

E. Hrischeva ◽

S. Gier

Keyword(s):

Clay Minerals ◽

Clay Mineral ◽

Sedimentary Rocks ◽

Depositional Environments ◽

Early Jurassic ◽

Source Rocks ◽

Shallow Marine ◽

Fine Grained ◽

Depositional Processes ◽

Mineral Assemblages

AbstractClay minerals in early Jurassic sequences of shales, siltstones and sandstones deposited in non-marine, transitional and shallow marine environments have been examined by X-ray diffraction, electron microscopy and chemical analysis to study the relationship between clay minerals, their environment of deposition and subsequent diagenetic modifications.The inherited clay mineral composition of the fine-grained sediments reflects the influence of climate, relief, source rocks and depositional processes. Inhomogeneous clay mineral assemblages, comprising abundant kaolinite and varying proportions of illite, I-S, chlorite and vermiculite, characterize fine-grained sediments from the non-marine and transitional environments. In shallow marine depositional environments clay mineral assemblages are more uniform, dominated by illite+I-S with minor kaolinite and chlorite.The principal diagenetic process affecting fine-grained sedimentary rocks is the smectite–illite transformation. In sandstones, the authigenic formation of kaolinite, chlorite and illite appears to have been primarily determined by the environment of deposition.

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

Clay Minerals ◽

10.1180/claymin.1991.026.4.08 ◽

1991 ◽

Vol 26 (4) ◽

pp. 535-548 ◽

Cited By ~ 17

Author(s):

J. Aróstegui ◽

M. C. Zuluaga ◽

F. Velasco ◽

M. Ortega-Huertas ◽

F. Nieto

Keyword(s):

Clay Minerals ◽

General Scheme ◽

Source Area ◽

X Ray Diffraction ◽

Kübler Index ◽

Mineral Assemblages ◽

Diagenetic Evolution ◽

Opening And Closing ◽

Gradual Transformation ◽

Basque Cantabrian Basin

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.

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The assemblages of transparent heavy minerals in Quaternary sediments of the Kielce-Łagów Valley (Holy Cross Mountains, Poland)

Geologos ◽

10.2478/logos-2013-0007 ◽

2013 ◽

Vol 19 (1-2) ◽

pp. 95-129 ◽

Cited By ~ 3

Author(s):

Małgorzata Ludwikowska-Kędzia

Keyword(s):

Chemical Weathering ◽

Climatic Conditions ◽

Parent Material ◽

Heavy Minerals ◽

Quaternary Sediments ◽

Quaternary Deposits ◽

Holy Cross Mountains ◽

Mineral Assemblages ◽

Sandy Sediments ◽

The Impact

Abstract The composition of the transparent heavy-mineral assemblages (0.25-0.1 mm) in Quaternary slope, karst, glacial, fluvioglacial and fluvial deposits with different parent material was investigated in the Kielce-Łagów Valley (the central part of the Palaeozoic core of the Holy Cross Mountains). For the purpose, 93 samples of mostly sandy sediments were examined. Some marker and some supporting minerals can be distinguished. Slope and karst deposits are dominated by the abrasion-resistant minerals zircon, tourmaline, staurolite and rutile. This assemblage points at a source consisting of strongly weathered pre-Quaternary bedrock. Glacial and fluvioglacial deposits are dominated by medium-resistant and non-resistant minerals (garnet, amphibole, pyroxene and biotite). The two types of parent material of the heavy minerals are typical of the Quaternary deposits in the Polish uplands. The two sources are most clear in the younger (Vistulian and Holocene), mostly fluvial sediments. The results of the analysis imply that the impact of Pleistocene glaciers on the central part of the Holy Cross Mountains was neither large enough to hide the local mineralogical background, nor sufficient to dominate over the main processes transforming the mineral composition under the variable climatic conditions of the Quaternary, including aeolian processes and chemical weathering.

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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.

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