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Fate of swelling clay minerals during early diagenesis: a case study from Gdańsk Bay (Baltic Sea)

Kisiel Marta, Skiba Michał, Damrat Mateusz, Kuligiewicz Artur, Maj-Szeliga Katarzyna, Makiel Magdalena, Zajączkowski Marek, Salata Dorota

Annales Societatis Geologorum Poloniae

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2023

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Vol. 93, No. 3

305--322

EN

The aim of the study was to recognize the early diagenetic transformations of clay minerals likely taking place in the brackish environment of Gdańsk Bay (Baltic Sea). The Vistula River loads and sediments of the Vistula delta front and prodelta were studied. The mineral compositions of the clay fractions were determined by X-ray diffractometry. The average layer charge (LC) of the expandable interlayers was determined using the O-D vibrational spectroscopy method. The major element content of the studied clays was determined by inductively coupled plasma optical emission spectrometry. The <0.2 μm clay fraction, separated from the river sediments, contained illite-smectite mixed layered minerals, rich in high-charge, dioctahedral smectite (Ilt-Sme), illite, and kaolinite. The same clay fraction, separated from the delta-front sediments, was also composed mainly of Ilt-Sme, illite, kaolinite, and hydroxy-interlayered minerals. The <0.2 μm clay fraction from the prodelta sediments was depleted in Ilt-Sme and enriched in illite and chlorite, relative to the clays from both the river and the delta-front sediments. The LCs (0.45 to 0.56 per formula unit) were higher for clays from the river and the delta front sediments, relative to the clays from the prodelta. The <0.2 μm clay fractions from the prodelta sediments were enriched in MgO, Fe2O3, and K2O, relative to the fine clay fraction from the river. The results indicated that the smectite component of Ilt-Sme, deposited by the Vistula in Gdańsk Bay, underwent chloritization and likely illitization. The chloritization most likely proceeded via formation of hydroxy-interlayers within the smectite. Illite-like minerals, formed at the expense of the smectite with high LC, due to selective adsorption and fixation of K+ from seawater.

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Dolomite-illitic rocks (dolillite) : the product of hydrothermal replacement of carbonate rocks in the Holy Cross Mts., Poland : a possible guide to ores

Nieć Marek, Pawlikowski Maciej

Geological Quarterly

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2019

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Vol. 63, No. 2

275--295

EN

The dolomites altered to dolomite-illitic rocks were foundac companying marcasite-pyrite-hematite mineralization within the Middle Devonian carbonate rocks in the eastern part of the Holy Cross Mts. (Poland) in the fault zones and their close vicinity. The alteration consist of dolomite recrystallization and replacement by illite, accompanied by small amounts of sillca, K-feldspars and disseminated pyrite or hematite. The final product of dolomite replacement by illite are massive, dolotmite-illitic rocks unevenly distributed within the unaltered dolomites or in fault breccia. They form irregular metric-sized nest-like bodies most often with blurred boundaries, or in some places sharp delineated veins and lenses. Illite crystallinity, demonstrates its hydrothermal origin. Altered rocks are characterized by elevated contents of REE, Rb, and sometimes other trace metal (Zr, Ti, Zn, U, Th, Ba and al.), compared to unaltered dolomites. The enrichment in REE, Zr and Ti implies their mobility in hydrothermal solutions. The lamprophyre intrusions present in the close vicinity may be considered as the probable source of potassium rich hydrothermal fluids. The peculiar features of dolomite-illitic rocks such as: their composition and occurrence close to the sulphide and hematite mineralization, allow supposing, that they may be a guide to deeply seated unknown ore deposits.

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Mineralizacja markasytowo-hematytowo-ankerytowa w południowo-wschodniej części Gór Świętokrzyskich

Nieć M., Pawlikowski M.

Przegląd Geologiczny

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2015

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Vol. 63, nr 4

219–-227

EN

The occurrences of previously unknown, iron sulphide (marcasite-pyrite)-hematite and ankerite mineralization have been recorded in the eastern part of the Holy Cross Mts. They are located in the fault zones within Middle Devonian dolomites. Irregular recrystalization of dolomite and its replacement by illite is an accompanying peculiar feature. Similar disseminated pyrite-hematite mineralization is known in the hanging wall of the Rudki iron sulphide ore deposit. The occurrence and mineral composition of this mineralization allow to suppose it was formed by low temperature hydrothermal processes, close to the end of the Variscan orogeny.

4

What do the K-Ar ages of illite tell us about the diagenesis of Rotliegend sandstones of the Fore-Sudetic Monocline, SW Poland?

Biernacka J.

Geological Quarterly

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2015

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Vol. 59, No. 2

257--270

EN

The all available K-Ar data of authigenic illite from Rotliegend aeolian sandstones of the Fore-Sudetic Monocline, including the results from six samples examined in the present study, are reviewed in terms of their geological meaning, relation to diagenetic processes occurring in the sandstones, and implications for a petroleum system. The majority of ages fall in the range between 195 and 150 Ma, i.e. they correspond to Jurassic times. The results may be grouped in several time intervals, which are almost identical to those identified for Rotliegend sandstones of central and western Europe, and which are interpreted as pulses of intensive illite growth. The K-Ar data corroborate the long-held assumption that throughout the entire Southern Permian Basin Jurassic illite growth was triggered by the same, large-scale underlying processes, which manifested themselves in enhanced heat flow. These processes may also have caused the expulsion of hydrocarbons from source rocks.

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

Dudek T.

Acta Geologica Polonica

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2012

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Vol. 62, no. 3

297-305

EN

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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Observations on the effect of proximity to rhyolitic intrusions on Kübler index

Diskin S., Coetzee S. H.

Mineralogia

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2010

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Vol. 41, iss. 1/2

75--94

EN

The Upper Ordovician sedimentary succession of southeast Ireland is riddled with almost synsedimentary igneous intrusions. A study was required to determine any effects of these intrusions on Kübler Index (KI) so that further sampling for a regional study could be undertaken and the results would be unbiased. Sampling was carried out on the low-grade metapelites (Southeast Ireland) around the rhyolitic and doleritic intrusions, which were intruded into the still soft sediment. Clay mineralogy was determined using X-ray diffractometry and KI values were measured; SEM and whole rock elemental analyses were applied to complement the results of the XRD work. KIs immediately around rhyolitic intrusions were observed in all cases to be lower than the regional KI, however this was not seen around doleritic intrusions. SEM work shows illite grain sizes following the KI trend and K2O were noted to be highest where KI was lowest. Rare earth elements (REEs) show some mobilization which also follows the KI trend. This is considered to be a residual effect of hydrothermal fluids / volatiles hosted by the rhyolites but not encountered in the dolerites. Chlorite crystallinity is not affected as it most likely crystallized after the hydrothermal event. The KI is often used as a proxy for illite crystallinity in studies of low grade metamorphism but is influenced by many parameters and care should be taken when applying this technique to studies of regional metamorphism.

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Trace elements and mineral assemblage as palaeoenvironmental markers in the Cenomanian/Turonian Magierowa Member (Pieniny Klippen Belt, West Carpathians)

Wójcik-Tabol P.

Studia Geologica Polonica

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2008

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Vol. 131

247-268

EN

The studied sediments of the Magierowa Member corespond to the Cenomanian/Turonian OAE 2. A better understanding of the genesis and palaeoenvironmental setting of this unit was achieved by means of geochemical indicators integrated with mineral composition. It suggests a strong influence of palaeoproductivity/redox cycles. The black shales are characterised by the enhanced accumulation and preservation of marine-derived organic matter. Lamination and enrich- ment of redox-sensitive elements (e.g., Ag, Cd, Mo, V) imply periodic prevalence of anoxic/euxinic conditions within the sediment (pore water) occasionally extending to the sediment/water interface. The bioturbated claystone intervals record periods of low productivity and development of more normal-marine conditions on the bottom. Furthermore, low Mn-contents, broad pyrite size-distribu- tion and presence of marine-origin organic matter suggest that an oxygen minimum zone (OMZ) must have existed within the water column during accumulation. The mineral assemblage of the Magierowa Mbr includes clay minerals, quartz, feldspar and iron minerals. Mineralogical data comparing with some gechemical ratios: Ti/Al, K/Al, Rb/Al suggest pelagic regime of deposition. Well-crystallised illite corresponding with high kerogen maturation and large iron mineral point to advanced diagenesis.

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Wpływ illitu na parametry geotechniczne niektórych skał i gruntów spoistych

Jaremski J.

Zeszyty Naukowe. Budownictwo / Politechnika Śląska

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2007

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z. 111

177-183

PL

Zwietrzeliny margli, zwietrzeliny fliszu, grunty spoiste teras rzecznych i grunty lessowe wykazują pewne progowe zawilgocenia, przy których tracą wytrzymałość. Wykonane badania doprowadziły do stwierdzenia, że przyczyną tej wspólnej cechy wspomnianych ośrodków gruntowych jest obecność minerałów ilastych. W pracy przedstawiono wpływ illitu na parametry geotechniczne zwietrzeliny margli opolskich i fliszu karpackiego. Nawiązano także do koncepcji budowy małych zbiorników retencyjnych na obszarze górzystym Podkarpacia.

EN

Weathered marls, flysch weathering, cohesive soils of the river terraces and loess soils reveal the threshold moistures in condition of loss of their strength. The executed tests have resulted in statement that existence of clay minerals was a reason of this common characteristic for mentioned grounds. In the contribution influence of illite on geotechnical parameters of weathered Opole marls and the Carpathian flysch has been presented. This work refers also to the conception of building of small storage reservoirs in mountainous area of Podkarpacie.

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New data on the post-impact material in radiolarian horizons in Outer Flysh Carpathians and search for a source crater

Paul Z., Halas S., Wójtowicz A.

Geochronometria

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2007

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Vol. 27

17-22

EN

In the Outer Carpathians in Barnasiówka radiolarian shale formation, there is an intercalation underlied by bentonite. There were found very rare elements and minerals in this intercalation. It was recognized that this horizon has been filled with products of a big object collision with Earth. The age of the manganese-iron intercalation was determined by potassium-argon (K-Ar) dating of illites to be (89.3±1.2) Ma. Similar age, (85.2±0.6) Ma, was found for the post-impact glass from the Boltysh crater in Ukraine. It was concluded that the formation of this intercalation was synchronous with the Boltysh crater formation at the Cenomanian/Turonian boundary. The research for the K-Ar age of the crater creation in Logoisk (Belarus) established its formation to (124.2±1.2) Ma ago.