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Fossils from the Silesian-Subsilesian series of the Polish Western Carpathians : the implications for changes in sea-level and the marine environment during the Albian-Turonian

Szydło A., Jugowiec-Nazarkiewicz M., Olszewska M.

Geological Quarterly

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2015

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Vol. 59, No. 1

215--228

EN

Fossils and exotics from the Albian-Cenomanian deposits of the Western Polish Carpathians are discussed in relation with changes in depositional environments. Environmental conditions were controlled by geotectonic activity, sea-level changes and also anoxic and biotic events. During the Albian-the Early Cenomanian, and in the Turonian the fall in sea level led to increased supply of coarse-grained material rich in siliceous and sometimes calcareous bioclasts and exotics. This cyclic process has contributed to changes in the marine biota. In the Albian monogenic foraminiferal assemblages with the surficial epifauna corresponding to the organic influx and oxygen deficiency (OAE 1b) were evolved into more variable associations including deep infauna, which indicated more aerobic conditions. Under these conditions also preserved planktonic and calcareous benthic fossils, which indicated the supply of terrigenous material from shallow-water environments and land. During the Albian-Turonian transition intensive subsidence and volcanic activity associated with eustatic sea-level rise led to intensive production of phytoplankton. The sea-surface productivity and enhanced upwelling resulted in expanded short-term oxygen minima at the end of the Albian (OAE 1d) and the Cenomanian (OAE 2). In the latter interval benthic forms almost extinct while siliceous and calcareous plankton survived. In the Turonian changes in sea-level and sedimentary regime led to recolonization of the basin bottom.

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Vestiges of Cadomian back-arc environments in the Nové Mesto belt and the western part of the Orlica-Snieżnik Dome

Ilnicki S., Szczepański J., Pin C.

Geologia Sudetica

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2014

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Vol. 42

31--32

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Zaprawy odporne na środowiska agresywne

Januszewski M.

Rocznik Ochrona Środowiska

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2009

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Tom 11

497-506

PL

Problem utrzymania oraz należytego wykonania obiektów betonowych i żelbetowych jest w ostatnich latach bardzo istotnym argumentem prowadzącym do tworzenia coraz to nowych, lepszych materiałów. Zagadnienia odpowiedniej ochrony budowli przed ciekłymi środowiskami agresywnymi i czynnikami atmosferycznymi są na tyle istotne, że poświęca się im coraz więcej miejsca w różnego rodzaju publikacjach. Uszkodzenia betonu najczęściej są spowodowane: 1.oddziaływaniem chemicznym (głównie kwasów - soli odladzających, a także chlorków), 2.oddziaływaniem mechanicznym, 3. szkody spowodowane cyklicznym zamrażaniem i rozmrażaniem.

EN

This paper presents the results of the investigations of concrete on the basis of various cements available on the building market and subject to the influence of various aggressive environments (chloride, sulfate and ammonium). Considering a wide scale of the issue, attention was paid to basic tests (compression and bending) of samples after 28, 60, 90 and 180 days of their stay in an aggressive environment. The tests demonstrated that the phase composition of cements, and especially of the main components (alite, belite, celite and brownmillerite) have a fundamental influence on the durability of concrete exposed to any aggression. The images of the microstructure show differences in the created post-hydration forms and suggest the influence of aggressive environments on the cement stone set. Small quantities of calcium hydroxide and Friedel's salt have an advantageous influence on the effectiveness of the protection of concrete by a significant concentration of the microstructure and smaller pores in the material. As consequence, the possibility is limited for aggressive ions to penetrate deeper parts of the materials, which results in its better protection. Another conclusion from the investigations carried out is the greatest versatility of the application of CEM III/A 42,5 HSR/NA metallurgical cement, whose application with a low content of lime tri-carbonate silicate on the level of 29.29 per cent and a relatively large content of lime tri-carbonate aluminate (4.67%) gives statistically the best results in the form of concrete protection from among all the cements tested.

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Importance of the Mellala section (Traras Mountains, NW Algeria) for the correlations of the Pliensbachian/Toarcian boundary

Elmi S., Marok A., Sebane A., Almeras Y.

Volumina Jurassica

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2006

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Vol. 4, no. 1

158-160

EN

The Mellala profile has a great importance as international reference section because it exposes a continuous and very fossiliferous record through the Pliensbachian/Toarcian boundary (Fig. 1). This boundary is situated within the hemipelagic Bayada Formation (alternating marls and marly limestones) yielding Zoophycos and Steinmannia bronni (shells and “filaments”). It has been deposited in a small subbasin (umbilicus) that was strongly subsiding and deepening during the Late Pliensbachian and the Early Toarcian. The sequence evolution is globally stratodecreasing and deepening upward until the middle part of the Early Toarcian (early Levisoni Zone). The Bayada Fm. begins in the Upper Domerian. The Emaciatum Zone is divided in two parts. The lower (Solare Subzone, thickness 8 m) is documented by several Pleuroceras solare (Phillips) occurring alone in the lower part of the subzone, but associated with Emaciaticeras upwards. Brachiopods include Phymatothyris kerkyrae (Renz) and Quadratirhynchia quadrata Buckman. The upper part (Elisa Subzone) is characterized by Tauromeniceras elisa (Fucini), Canavaria finitima (Fucini), Paltarpites bettonii (Fucini) associated with numerous P. kerkyreae (Renz) and rare Lobothyris punctata (Sowerby). The main part of the brachiopod assemblage consists of small sized species: Nannirhynchia pygmoea (Davidson), Koninckella liasina (Davidson) and Cadomella cf. moorei (Davidson). This is the Koninckella fauna (previously named Leptaena fauna). Leioceratoides gr. serotinus (Bettoni) has been found in the upper part of the Elisa Subzone. The base of the lowermost Toarcian (Mirabile Subzone) is marked by a decimetric bed (n° 38) with Paltarpites paltus (Buckman) but without Eodactylites at the present state of the research. The following calcareous bed (n° 40) has yielded several Dactylioceras (Eodactylites) polymorphum (Fucini) and D. (E.) pseudocommune (Fucini). The brachiopods are represented by Liospiriferina subquadrata (Seguenza), Lobothyris sp. and the Koninckella fauna: C. moorei, N. pygmoea and K. liasina. Upwards, the Eodactylites becomes abundant at 10 to 12 m, especially in the bed n° 44. At 3.50 m under the top of the subzone, a marker-bed (48) corresponding to a lenticular level of bioclastic quartziferous limestones occurs. The overlying 15 m are attributed to the Semicelatum Subzone (Tethyan nomenclature). At the base, there occurs a level with D. (Orthodactylites) crosbeyi (Simpson) associated with Lobothyris arcta (Dubar) which allows a good correlation with the Clevelandicum Subzone (or Horizon) of northwestern Europe. The topmost 5 m of the deposits are dated to the Levisoni Zone with Eleganticeras sp. The anoxic event at the beginning of this Zone is only indicated by an abnormal variability of the foraminifera. The presence of Lenticulina obonensis (Cubaynes) mg Planularia indicates stressing conditions.