Sedimentology and ichnology of Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Kraków- Silesia Homocline, Poland

2012 ◽  
Vol 62 (3) ◽  
pp. 281-296 ◽  
Author(s):  
Paulina Leonowicz
Keyword(s):  
Bottom Sediment ◽  
Middle Jurassic ◽  
Trace Fossil ◽  
Fair Weather ◽  
Nearshore Area ◽  
Sedimentary Structures ◽  
Sea Bottom ◽  
Sw Poland ◽  
Storm Deposits ◽  
Marine Basin

ABSTRACT Leonowicz, P. 2012. Sedimentology and ichnology of Bathonian (Middle Jurassic) ore-bearing clays at Gnaszyn, Krakow-Silesia Homocline, Poland. Acta Geologica Polonica, 62 (3), 281-296. Warszawa. The lithology, sedimentary structures and trace fossil association from the Bathonian organic-rich mudstones from Krakow-Silesia Homocline (SW Poland) are described and a preliminary interpretation of the palaeoenvironment is presented. The ore-bearing clays exposed in the Gnaszyn clay-pit are developed as dark grey claysilt deposits with a few horizons of sideritic concretions. Sedimentological analysis has revealed that these deposits originated in the offshore part of a marine basin, below the fair weather wave base. Relict parallel lamination suggests that the predominant mechanism of deposition was quiet settling from suspension. However, locally preserved storm deposits indicate that the sea bottom was affected by offshore flows, deriving coarser material from the nearshore area. The degree of bioturbation is high but the diversity of the trace-fossil association is low. It consists mainly of Chondrites, Trichichnus, pyritized burrows and less common Palaeophycus. Other traces, including Thalassinoides, Planolites, Taenidium and some undetermined burrows, occur mainly in the lower part of the succession. This ichnoassociation combines features of distal Cruziana and Zoophycos ichnofacies, suggesting poor oxygenation of the bottom sediment. Temporary improvements in bottom oxygenation, linked with more intense mixing of water during major storms, resulted in the more diverse trace fossil suite that is found in some intervals of the succession.

scholarly journals Coniacian sandstones from the North Sudetic Synclinorium revisited: palaeoenvironmental and palaeogeographical reconstructions based on trace fossil analysis and associated body fossils

Geologos ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 29-53 ◽  
Author(s):  
Alina Chrząstek ◽  
Monika Wypych
Keyword(s):  
Trace Fossils ◽  
Trace Fossil ◽  
Fair Weather ◽  
Soft Substrate ◽  
Southeastern Part ◽  
Shallow Marine ◽  
The North ◽  
Low Diversity ◽  
Storm Deposits ◽  
Interesting Compound

AbstractThe Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils:Gyrochorteisp.,Ophiomorpha nodosaLundgren, 1891,Ophiomorphaisp.,Phycodescf.curvipalmatum(Pollard, 1981), ?Phycodesisp.,Planolitescf.beverleyensis(Billings, 1862),Thalassinoides paradoxicusWoodward, 1830 and ?Thalassinoidesisp. Moreover, interesting compound burrow systems, here referred to asThalassinoides-Phycodescf.palmatusand ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorteisp.,Phycodescf.flabellum(Miller and Dyer, 1878) and ?Treptichnusisp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropodNerinea bicinctaBronn, 1836 and the bivalveLima haidingeriZittel, 1866 were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by Scupin (1912–1913). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha,Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte,Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha,Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes,Gyrochorteand ?Treptichnus). The assemblage of trace fossils is characteristic of theSkolithosichnofacies andCruzianaichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member sandstones by Leszczyński (2010). That author interpreted the Coniacian sandstones as bar and storm deposits laid down in a shallow epicontinental sea (mainly the foreshore-upper shoreface; up to the middle shoreface) under normal oxygenation and salinity, in soft substrate, above fair-weather wave base. The deposition of the Żerkowice Member sandstones is linked to a regression that started after uplift of the southeastern part of the North Sudetic Synclinorium.

Trace fossils from the Lower Muschelkalk of Raciborowice Górne (North Sudetic Synclinorium, SW Poland) and their palaeoenvironmental interpretation

2013 ◽  
Vol 63 (3) ◽  
pp. 315-353n ◽  
Author(s):  
Alina Chrząstek
Keyword(s):  
Trace Fossils ◽  
Carbonate Ramp ◽  
Trace Fossil ◽  
Germanic Basin ◽  
Sw Poland ◽  
Bathymetric Changes ◽  
Lower Muschelkalk ◽  
Short Episode

Abstract The following trace fossils have been recognised in the Lower Muschelkalk of Raciborowice Gorne (North Sudetic Synclinorium, SW Poland): Archaeonassa fossulata, Balanoglossites triadicus, ?Gastrochaenolites isp., Lockeia isp., Palaeophycus tubularis, Palaeophycus isp., ?Planolites beverleyensis, P. montanus, Planolites isp., ?Protovirgularia isp., Rhizocorallium commune var. auriforme, R. commune var. irregulare, R. jenense, Skolithos linearis, Thalassinoides suevicus and Trypanites weisei. Coprolites and an unidentified trace fossil A are also described. The trace fossils allow the discrimination of five ichnoassociations in the Raciborowice Gorne section: (IA 1) Rhizocorallium- Pholeus, (IA 2) Rhizocorallium-Palaeophycus, (IA 3) Thalassinoides, (IA 4) Trypanites-Balanoglossites and (IA 5) Planolites-Palaeophycus. The Lower Muschelkalk succession was deposited on a shallow carbonate ramp affected by frequent storms. Deposition commenced with sedimentation in a restricted lagoon on the inner ramp with a short episode of sabkha formation. It continued on the middle and outer ramp and then on a skeletal shoal of the outer ramp and in an open basin. Ichnoassociation IA 5 is related to a maximum transgression that commenced with the deposition of the Spiriferina Bed and which probably marked the opening of the Silesian-Moravian Gate. The basin underwent two shallowing episodes, as evidenced by ichnoassociations IA 3-IA 4, resulting in the formation of hardgrounds. Bathymetric changes in the Raciborowice Gorne section correspond well with a general transgressive trend in the Germanic Basin.

scholarly journals Distinguishing Late Holocene Storm Deposit From Shore-normal Beach Sediments From the Gulf of Thailand

2021 ◽  
Vol 9 ◽  
Author(s):  
Stapana Kongsen ◽  
Sumet Phantuwongraj ◽  
Montri Choowong
Keyword(s):  
Grain Size ◽  
Late Holocene ◽  
Luminescence Dating ◽  
Storm Events ◽  
Beach Ridge ◽  
Sedimentary Structures ◽  
Mean Grain Size ◽  
Beach Sediments ◽  
Storm Deposits ◽  
Shell Fragments

Grain size, as one of sedimentological proxies, coupled with a detailed description of the sedimentary structures and luminescence dating were used to unveil the sediment sources and transport process of the Holocene ancient coastal storm events recorded in the beach ridge plain, wet swale and muddy environments at Prachuap Khiri Khan, in the Southern Peninsula of Thailand. In this study, a total of 141 sand samples were collected from the shore-normal ridge-swale topography and analyzed for layers of candidate storm deposits, revealing at least 21 candidate coastal storm events. The grain size distribution of beach sediments was, in general, unimodal, while the candidate storm sediments revealed a mixed combination of multimodal, bimodal and unimodal distributions. Plots of mean grain size against skewness and kurtosis and of skewness against kurtosis could differentiate storm deposits from shore-normal beach sediments. Sedimentary structures preserved in the ancient coastal storm deposits included parallel and inclined landward laminations, mud rip-up clasts, layers of shell fragments, a pebble grain, normal and reverse grading and sharp lower and upper contacts. Candidate storm layers overlain on a dry beach ridge intervened with mud in a swale showed a finer and thinner landward deposit. Marine shell fragments, smaller foraminifers, ostracod and scaphopod (tusk shell), were well preserved. Based on optically stimulated luminescence dating and a correlated accelerator mass spectrometry age, multiple layers of sand derived from different frequencies of coastal storms were deposited over the middle to late Holocene.

scholarly journals The new encrusting microproblematicum <i>Circumpodium enigmaticum</i> and its attachment trace <i>Circumpodichnus serialis</i> from the Middle Jurassic of Normandy (France)

Fossil Record ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 77-90
Author(s):  
Max Wisshak ◽  
Liane Hüne
Keyword(s):  
Middle Jurassic ◽  
Alternative Interpretation ◽  
Trace Fossil ◽  
Single Specimen ◽  
Morphological Criteria ◽  
A Chain ◽  
Lateral Walls

Abstract. A single specimen of an enigmatic new attachment etching, together with an unknown calcareous encruster partly preserved in situ, has been identified on a belemnite rostrum from the Marnes de Dives Formation (Callovian, Middle Jurassic) of the Falaises des Vaches Noires in Normandy, France. The trace fossil, here established as the new ichnotaxon Circumpodichnus serialis igen. et isp. n., is a uniserial arrangement of very shallow depressions, oval to fusiform in outline, with peripheral pouches and central pits. The trace maker has a morphology unlike any other known calcareous epibiont, fossil or recent, and is consequently described as the new microproblematicum Circumpodium enigmaticum gen. et sp. n. Its calcitic skeleton is composed of a chain of segments with perforate basal and lateral walls, anchored to the attachment trace in the substratum by vertical protrusions in the centre and feet-like protrusions in the periphery. The hypothetical upper wall of the segments was either organic-walled and has decayed or it was calcitic and has been abraded. Based on morphological criteria and the capacity to bioerode, C. enigmaticum can best be compared to encrusting bryozoans and foraminiferans. Candidate bryozoans are aberrant arachnidiid ctenostomes, early cheilostomes, or stomatoporid cyclostomes. Among the foraminiferans, webbinellid or ramulinid polymorphinids are closest in their characters. In addition, tintinnid or folliculinid ciliophorans are considered as an alternative interpretation, and similarities to the Palaeozoic microproblematicum Allonema are discussed.

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