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Acanthodians from the Lower Devonian (Emsian) ‘Placoderm Sandstone’, Holy Cross Mountains, Poland

Burrow C. J., Szrek P.

Acta Geologica Polonica

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2018

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Vol. 68, no. 3

307--320

EN

The Lower Devonian ‘Placoderm Sandstone’ in the Holy Cross Mountains (HCM) is filled with abundant impressions of disarticulated vertebrate remains. The only acanthodian macroremains named to date are fin spines of Machaeracanthus polonicus Gürich. Fin spine impressions in slabs from the Winna Formation (Emsian) at Podłazie Hill (near Daleszyce) in the southern HCM, and also the Barcza Formation (?Lochkovian) at Barcza Quarry, Miedziana Góra Conglomerate (?Lochkovian), Gruchawka, and Zagórze Formation (middle–upper Emsian) at Bukowa Mountain in the northern HCM, reposited in the University of Warsaw, Polish Geological Institute-National Research Institute, Warsaw, and Natural History Museum, London collections, have been cast and studied in order to better document this poorly known taxon. As noted in other Machaeracanthus species, we have found that M. polonicus has two different morphotypes of spines, which abut lengthwise to form a pair of spines. Our investigations show that the fin spine assemblage includes Onchus overathensis as well as M. polonicus, and probably another undetermined acanthodian. The affinities of O. overathensis are reassessed. It is here considered to be a diplacanthiform, and reassigned to the genus Striacanthus, as S. overathensis. Acanthodian scapulocoracoids have also been identified, as well as tightly spiralled toothwhorls which could be from an acanthodian.

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From carbonate platform to euxinic sea – the collapse of an Early/Middle Devonian reef, Cantabrian Mountains (Spain)

van Loevezijn G. B. S., Raven J. G. M.

Geologos

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2017

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Vol. 23, No. 3

143–-161

EN

The Santa Lucía Formation represents the major phase in Devonian reef development of the Cantabrian Zone (Cantabrian Mountains, northwest Spain). In the present study the transition from the carbonate platform deposits of the Santa Lucía Formation to the overlying euxinic basinal deposits of the Huergas Formation is described. These transitional strata are connected to the Basal Choteč Event and represent a condensed sedimentation of micritic dark-grey and black limestones with an upward increase of dark shale intercalations with iron mineralisation surfaces and storm-induced brachiopod coquinas. The transitional beds are grouped into a new unit, the Cabornera Bed, which consists of lime-stone, limestone-shale and shale facies associations, representing a sediment-starved euxinic offshore area just below the storm wave base. Four stages in reef decline can be recognised: a reef stage, an oxygen-depleted, nutrient-rich stage, a siliciclastic-influx stage and a pelagic-siliciclastic stage. Additional geochemical and geophysical investigations are needed to verify the results presented herein.

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Palinologia dolnodewońskich i środkowodewońskich osadów klastycznych z otworu wiertniczego Trojanowice 2

Filipiak P.

Biuletyn Państwowego Instytutu Geologicznego

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2014

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nr 459

7--31

PL

Kompleksowe badania palinologiczne przeprowadzono na 37 próbkach z otworu wiertniczego Trojanowice 2, z interwału 502,0–558,8 m. Na podstawie rozpoznanych gatunków miospor wyróżniono dwa standardowe poziomy miosporowe: Emphanisporites annulatus-Camarozonotriletes sextantii z emsu oraz Grandispora douglastownense-Ancyrospora eurypterota z pogranicza emsu i eiflu. Przeprowadzone anlizy palinofacjlne pozwoliły określić środowisko sedymentacji spągowych partii profilu na morskie, bliskiego brzegu, z intensywną dostawą materiału organicznego z lądu.W części stropowej stwierdzono natomiast nieco głębsze warunki depozycji, w większym oddaleniu od obszarów źródłowych. Analiza kolorystyczna wykazała dojrzały stopień przeobrażenia termicznego materii organicznej. Formalnie opisano po raz pierwszy dwa nowe gatunki miospor: Camptozonotriletes reticulum sp.n. i Perotrilites asymmetricus sp.n.

EN

The palynological investigation were carried out on 37 samples from the Trojanowice 2 borehole from a depth interval of 502.0–558.8 m. Based on the presence of index and important microflora species two standard miospore zones were recognized: Emphanisporites annulatus-Camarozonotriletes sextantii, from the Emsian and Grandispora douglastownense-Ancyrospora eurypterota from the Emsian/ Eifelian transition interval. Palynofacies from the lower part of the section indicate marginal marine palaeoenvironmental conditions. Palynofacies from the upper part prove deeper marine conditions further from the shoreline. Additionally, spore colour analyses revealed a high degree of thermal transformation. Two new miospore taxa have been formally erected: Camptozonotriletes reticulum sp.n. and Perotrilites asymmetricus sp.n.