Science and earth science

Acta Geologica Polonica

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Acta Geologica Polonica | 2023 | vol. 73 | No 2

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Abstract

This contribution presents the record of an abundant assemblage of well-preserved, thallophytic noncalcified algae and of an epibiotic form that has been recognised as a putative graptolite from the upper Silurian (Ludlow, Gorstian–Ludfordian) of Podolia (western part of Ukraine). The sediments represent a shallow peritidal zone of the shelf. A new genus and species, Voronocladus dryganti, belonging to the Dasycladales Pascher, 1931, is established. Most of the specimens representing the algal thallus are overgrown by problematical epibiotic graptolites, described as Podoliagraptus algaeoides gen. et sp. nov. This phenomenon is explained as an epiphytic mode of life of the putative graptolite on algae, and is herein compared to recently known coexistences of algae with other organisms. The excellent state of preservation, and the abundance of studied Dasycladales algae and epibiotic problematics indicate that the investigated mudstone layer can be treated as a ‘Konservat Lagerstätte’ sensu Seilacher (1970).
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Authors and Affiliations

Stanisław Skompski
1
Anna Kozłowska
2
Wojciech Kozłowski
1
Piotr Łuczyński
1

  1. University of Warsaw, Faculty of Geology, Żwirki i Wigury 93, 02-089 Warszawa, Poland
  2. Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warszawa, Poland
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Abstract

A novel stratigraphical scheme within the Folge Concept is described for the Cenomanian Chalk of England that is particularly suitable for investigating the regional changes in the lithofacies, diagenesis, geochemistry, and mineralogy of the sediments of the Chalk Sea leading up to the Cenomanian–Turonian Oceanic Anoxic Event. It is based on “isochronous” marker bands defined largely by calcitic macrofossil assemblages, and it avoids problems caused by the poor or non-preservation of ammonite assemblages and lateral changes in chalk lithofacies. Eight folgen are based on one, two, or more marker bands. Their sequences, lithologies and calcitic macrofossil assemblages are described from 33 exposures in the Northern Chalk Province of England. The folgen are named, in ascending order, the Belchford, Stenigot, Dalby, Bigby, Candlesby, Nettleton, Louth and Flixton, after villages in Lincolnshire and Yorkshire, England. The folgen are traced throughout the Transitional and Southern Chalk provinces of England. They are present in the Cenomanian chalk of northern Germany and northwest France. Regionally, an individual folge may display considerable vertical and lateral variation in general lithology and lithofacies whilst still maintaining their defining marker bands. The possibility of further refinement to the scheme is discussed.
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Authors and Affiliations

Christopher Vincent Jeans
1

  1. Department of Earth Sciences, University of Cambridge, Downing Place, Cambridge CB2 3EN, UK
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Abstract

The extinct arachnid order Trigonotarbida Petrunkevitch, 1949 is reported here for the first time from Ukraine. The material consists of an opisthosoma preserved in ventral view from the upper Carboniferous (lower Moscovian; Paralegoceras–Eowellerites ammonoid zone) of the Gorlivka locality in the Donets Basin, eastern Ukraine. Formal assignment to a family or genus is difficult, but the preserved ventral anatomy is consistent with a member of the families Aphantomartidae Petrunkevitch, 1945, Kreischeriidae Haase, 1890 or Eophrynidae Karsch, 1882. It is noteworthy for expanding the known distribution of trigonotarbids in Europe and is only the second Palaeozoic arachnid to be formally described from Ukraine; the other being the carapace of a whip scorpion (Thelyphonida Latreille, 1804) from Lomovatka in the Luhansk Region, also in the Donets Basin.
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Authors and Affiliations

Jason A. Dunlop
1
Vitaly S. Dernov
2

  1. Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, D-10115 Berlin, Germany
  2. Institute of Geological Sciences, National Academy of Sciences of Ukraine, Oles Honchar Street 55b, 01054 Kyiv, Ukraine
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Abstract

New findings of crustacean decapod brachyurans from the Rupelian period (lower Oligocene) in Iran are presented in this study. In particular, Lophoranina sp. and Palaeocarpilius cf. P. rugifer Stoliczka, 1871, from the Rupelian strata were found in two previously unexplored localities, Abshar and Vezg near Yasuj in the southwestern region of Iran. The discovery contributes to fill the gap in the record of brachyuran decapod crustaceans in Iran during the Eocene and Miocene periods. The presence of both genera in the Oligocene of Iran suggests a certain degree of faunal similarity among brachyurans on both sides of the Tethys Realm.
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Authors and Affiliations

Ali Bahrami
1
Àlex Ossó
2
Mehdi Yazdi
1
Heshmatollah Ansari
1

  1. Department of Geology, Faculty of Sciences, University of Isfahan, 81746, Iran
  2. Llorenç de Villalonga, 17B, 1-1, 43007 Tarragona, Catalonia
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Abstract

This article discusses the impacts of overprinting of tectonic and plutonic events on the mineralization of the Duna Pb-Ba ore deposit, according to geologic settings and fluid inclusion studies. The Duna carbonate-hosted deposit contains a significant amount of Ag (18.9–264.3 ppm ), Cu (77–41600 ppm), Sb (32.7–11000 ppm), Sr (63.5– 15100 ppm), and Fluid inclusions with 7.34–23.65 wt.% NaCl equivalent. The homogenization temperature of about 110–285°C, as well as the paragenesis of the minerals shows a difference compared with other Pb-Zn deposits such as the Irish-type and MVT. The ore mineralization in the Duna mine occurred as stratabound, open space-filling, and along the brecciated fault zones. The concordant (stratabound) type of mineralization, with salinity and homogenization temperature of 18.54 to 23.65 wt.% NaCl equivalent, and 113°C to 165°C respectively, is usually typical of MVT-ore deposits, which in this area evolved during the Early Cimmerian orogeny and was later interrupted by mineralization along younger brecciated fault zones with salinity and homogenization temperature of 7.34 to 23.65 wt.% NaCl equivalent, and 113°C to 285°C respectively. This discordant mineralization, which occurred along the faults, formed by the end of the Late Cretaceous and during the Cenozoic as a result of the intrusion of a plutonic mass, and is comparable to the Irish-type ore deposits.
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Authors and Affiliations

Alireza Sadeghi
1
Saeid Hakimi Asiabar
2
Nima Nezafati
1 3
Alireza Ganji
2
Soumyajit Mukherjee
4

  1. Department of Earth Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
  2. Department of Geology, Lahijan Branch, Islamic Azad University, Lahijan, Iran
  3. German Mining Museum, Department of Archaeometallurgy, Bochum, Germany
  4. Department of Earth Sciences, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, India
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Abstract

This article describes silver specimens of the size of tenths to a few millimetres, found in small pegmatites and quartz veinlets of the porphyritic granitoid area in 22 sites in the eastern part of the Variscan granitoid Karkonosze pluton, from 20 of which native silver occurrences were previously not known. The sites are scattered on the whole surface of the granitoid. The native silver occurred in wire, rod, platy, dendritic, anhedral granular and euhedral cubic and octahedral habits; in some specimens twins and fenster faces were also found. Associated with native silver small amounts of acanthite crystallized commonly, sometimes apparently formed by sulphur diffusion into silver. Inclusions of native gold, electrum, galena, chalcopyrite and pyrite occurred in the native silver. The parent fluids of the specimens were epithermal, because the homogenization temperature (Th) of inclusions in quartz, calcite and cleavelandite that were the host minerals of the native silver was generally 91–165ºC and for individual samples the Th range was 4–11ºC. The total salinity of the fluid was 2.4–7.2 wt. % with Na and Ca (hydro)carbonates as the main dissolved components and admixtures of K, Mg, Fe, Al, S, Cl and F. The parent granitoid contains Ag in trace amounts (0.034–0.056 ppm) and was probably the source of this element for the crystals of native silver. Migration of Ag was made easier by the presence of fluoride ions in fluids.
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Authors and Affiliations

Andrzej Kozłowski
1
Witold Matyszczak
1

  1. University of Warsaw, Faculty of Geology, Żwirki i Wigury 93, 02-089 Warszawa, Poland
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Abstract

The article presents the results of CRL research on glacial till contaminated with JET A1 aviation fuel and mineral oil 15W40. The conducted research has shown that the compressibility of fine grained soils contaminated with hydrocarbons during a constant rate of loading tests depends on the physical properties of the soil, properties of oil contaminants, their content in the soil pores as well as the adopted loading velocity. The implemented laboratory test program shows that the contamination of glacial till with hydrocarbons increases their compressibility. Moreover, this research shows that the CRL test method may be recommended in the compressibility research of fine grained soils contaminated with hydrocarbons.
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Authors and Affiliations

Piotr Stajszczak
1

  1. Geoteko Geotechnical Consultants Ltd., ul. Wałbrzyska 14/16, 02-739 Warszawa, Poland

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