The new lithostratigraphic units in rank of bed in the Gogolin Formation (Middle Triassic) in the Opole Silesia region

Ogniwo wapienia krynoidowego z Zakrzowa zostało rozdzielone na trzy jednostki podrzędne: warstwę wapienia pelitowego z Krapkowic zbudowaną z cienkoławicowych, falisto-gruzłowych, marglistych wapieni pelitowych, warstwę wapienia organodetrytycznego z Dąbrówki utworzoną z grubo- i średnioławicowych, warstwowanych przekątnie wapieni organodetrytycznych (krynoidowych), warstwę wapienia organodetrytycznego z Podboru składającą się z cienko- i średnioławicowych wapieni organodetrytycznych, wapieni pelitowych oraz podrzędnie zlepieńców śródformacyjnych. Dolna część leżącego powyżej ogniwa margla ze Skały, zbudowana lokalnie ze zlepieńca śródformacyjnego z dużymi intraklastami przykrytego zlepieńcem śródformacyjnym z małymi intraklastami, została wydzielona jako warstwa zlepieńca śródformacyjnego z Kociny. Leżące powyżej ogniwo wapienia komórkowego z Emilówki zostało rozdzielone na dwie jednostki podrzędne: warstwę wapienia organodetrytycznego z Karłubca zbudowaną z cienko- i średnioławicowych wapieni organodetrytycznych i pelitowych oraz warstwę wapienia marglistego z Otmętu utworzoną z silnie porowatych, cienkoławicowych wapieni marglistych (dedolomitów).The Zakrzów Crinoidal Limestone Member is subdivided into the three subordinate units: the Krapkowice Pelitic Limestone Bed built of thin-bedded, wavy-bedded and crumpled marly pelitic limestones, the Dąbrówka Bioclastic Limestone Bed consisting of thick- to medium-bedded, cross-bedded bioclastic limestones (crinoidal), the Podbór Bioclastic Limestone Bed built of thin- to medium-bedded bioclastic limestones, pelitic limestones and intraformational conglomerates. The lower part of the Skała Marl Member consisting locally of the intraformational conglomerate with big intraclasts covered by the intraformational conglomerate with small intraclasts is designed as the Kocina Intraformational Conglomerate Bed. The Emilówka Cellular Limestone Member is subdivided into the two subordinate units: the Karłubiec Bioclastic Limestone Bed built of thin-to medium-bedded bioclastic and pelitic limestones and the Otmęt Marly Limestone Bed consisting of strongly porous, thin-bedded marly limestones (dedolomites)

Variability of trace element uptake in marine reptile bones from three Triassic sites (S Poland): Influence of diagenetic processes on the host rock and significance of the applied methodology

Diagenetic alternation of apatite building vertebrate bioclasts is a complex process. It is influenced by numerous factors, but the impact of diagenetic processes affecting the host rock is commonly underestimated. The present study aims at identifying the causes of different concentration levels and distribution patterns of REE, and at examining the significance of the material chosen for normalisation. We measured REE and other trace element concentrations in three bone assemblages of Triassic marine reptiles using LA-ICP-MS, and in the host rocks using ICP-MS. Two groups of hard parts reveal clearly different trace element contents and distribution patterns. The remains from Gogolin show a distinct MREEN enrichment, which must have been caused by replacement involving numerous substitutions, that was possible due to a relatively high porosity of the host rocks, and the presence of pore water. The MREEN enrichment and low concentrations of Mg and Sr, combined with a relatively high content of U in these bones, indicate solutions derived from meteoric water as the source of the incorporated ions. The reductive dissolution of Fe oxyhydroxides that are abundant in the host rock matrix and that likely were an important source of REE, may have influenced and controlled the REE uptake. The significant HREEN enrichment over LREEN, as revealed in the rust-coloured bones from Raciborowice Gorne, is likely connected with local acidification of the pore water, resulting from aqueous oxidation of pyrite, infilling the pore spaces in the bones. The material selected for normalisation of the chemical composition of apatite can have a significant impact on values of the normalised data used further for interpretations, particularly when vertebrate bioclasts from carbonate host rocks are involved. The carbonate rocks have element ratios that differ from those characterising the commonly used PAAS and NASC normalisation materials. In particular, Ce anomaly values can distinctly vary depending on the applied normalisation procedure. Vertebrate hard parts, that definitely spent more time in a host rock than in an animal body, must be rigidly handled as a constituent of a specific rock, never as a separate item. (C) 2015 Elsevier B.V. All rights reserved

Bonebeds with Dactylosaurus (Reptilia, Sauropterygia) from the Röt (Lower Triassic, Olenekian) in the Opole Silesia region (S Poland)

Two bonebeds with numerous remains of Dactylosaurus (Reptilia, Sauropterygia) and ganoid fishes were discovered in the uppermost Rot (Lower Triassic, Olenekian), exposed in the vicinity of Gogolin (Opole Silesia, SPoland). The lower bonebed, which is up to 5 cm thick, is built of several laminae. On the top of the individual laminae, vertebrae, teeth, long and flat bones of reptiles, as well as fish scales, teeth and a skull fragment have been found. The upper bonebed, which is up to 2 cm thick, contains smaller bones of reptiles (mainly vertebrae and long bones), and also fish scales. The bonebeds are particularly abundant in vertebrate remains: 1 m2 usually contains several dozens of them. All remains are disarticulated. Gogolin is probably the third or second site with Rot deposits where remains ofDactylosaurus have been found, and the richest one

LA-ICP-MS analysis of rare earth elements in marine reptile bones from the Middle Triassic bonebed (Upper Silesia, S Poland): Impact of long-lasting diagenesis, and factors controlling the uptake

The rare earth elements (REE) contained in fossil bones are widely used for provenance and palaeoenvironmental studies. Earlier works suggested that the REE uptake is limited to early diagenesis, but more recent research provided evidence of long-term open-system diffusion in fossil bones. We analysed thin-walled reptile bones, all collected from the same Middle Triassic (similar to 245 Ma) marine bonebed, comprising vertebrate remains of likely different ages, to check the influence of the long-term diagenesis on the concentrations of REE, in terms of impact of pore water; the upper parts of the bones are contained in a low-permeability crinoidal limestone, whereas their lower parts have been affected by diagenetic fluids for a long time. We measured REE and other trace element contents in 29 bones using LA-ICP-MS (totally 660 spots in 45 depth profiles). Neither the absolute concentrations of the REE and the REE intra-bone PAAS-normalised patterns, nor the inter-element ratios and the La, Ce and Eu anomalies appear useful to distinguish between the likely older and younger bones in the bonebed. The MREEN enrichment combined with the flat intra-bone distributions of the REE lead to conclusion that REE fractionation and substitution for Ca were the most important processes responsible for the selective uptake. The low-permeability host rock and diagenetic fluids had a significant impact on the trace element uptake and their intra-bone distribution patterns. The lower parts of the bones that likely had a long-lasting contact with the diagenetic fluids reveal a relative enrichment in the REE and their easier diffusion into the bone centres. The ability of fossil bones to incorporate trace elements over a long time-span strongly limits the usage of particularly the older samples for provenance and palaeoenvironmental reconstructions. Additionally, the presented new analyses fill the gap between the available databases of trace element concentrations in fossil bones with regard to Middle Triassic samples. (C) 2013 Elsevier B.V. All rights reserved

Marine flooding event in continental Triassic facies identified by a nothosaur and placodont bonebed (South Iberian Paleomargin)

Sudden marine flooding within otherwise continental successions of the Triassic is unusual. The Tabular Cover of the SE paleomargin of the Iberian Massif is characterized by continental Triassic redbed facies composed of sandstones and siltstones, with gypsum-rich levels in the transition to Jurassic limestones. These Triassic deposits were developed in a fluvial-coastal system and they are 300 m thick in the Puente G,nave-Villarrodrigo area, eastern Ja,n Province, Spain. An unexpected sandstone-limestone unit in the lower part of this formation, recognized over more than 30 km, contains marine reptile bones in a storm bed or tsunami deposit. The lower part of this unit is characterized by a sandstone with sedimentary structures indicative of high-energy conditions as well as by fossil remains of marine reptiles. This bed ranges from 0 to 90 cm in thickness, and in some outcrops pinches out rapidly within a few meters. The upper part of the studied unit is a limestone with common trace fossils and abundant remains of marine reptiles, comprising isolated and fragmented pieces of sauropterygians (nothosaurs, pachypleurosaurs, and placodonts). Most abundant are vertebrae and ribs. In some outcrops, the top of this bed presents a dense accumulation of well-preserved small gastropods. The limestone is overlain by red siltstones and sandstones. The studied unit is interpreted as a marine deposit representing a high-energy event and records exceptional marine flooding in a distal fluvial environment, in fact the only open-marine deposit in the Villarrodrigo section. The sedimentary structures in the lower part of the unit are typical of high-energy deposits and indicate deposition in a single episode, probably related to a storm surge or a tsunami. The fragmentation, disarticulation, and dispersion of the vertebrate bones and the imbrication of bioclasts are consistent with a high-energy event that favored the concentration of bones according to size and density.</p

Ophiuroids Discovered in the Middle Triassic Hypersaline Environment

Echinoderms have long been considered to be one of the animal phyla that is strictly marine. However, there is growing evidence that some recent species may live in either brackish or hypersaline environments. Surprisingly, discoveries of fossil echinoderms in non-(open)marine paleoenvironments are lacking. In Wojkowice Quarry (Southern Poland), sediments of lowermost part of the Middle Triassic are exposed. In limestone layer with cellular structures and pseudomorphs after gypsum, two dense accumulations of articulated ophiuroids (Aspiduriella similis (Eck)) were documented. The sediments with ophiuroids were formed in environment of increased salinity waters as suggested by paleontological, sedimentological, petrographical and geochemical data. Discovery of Triassic hypersaline ophiuroids invalidates the paleontological assumption that fossil echinoderms are indicators of fully marine conditions. Thus caution needs to be taken when using fossil echinoderms in paleoenvironmental reconstructions