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EN
Available reconstructions of Jurassic global sea level changes differ and are in need of an update. New stratigraphical charts and palaeogeographical developments for a number of large continental blocks or their portions of these (e.g., Germany, India, northeast Africa, northwest Australia, the Russian Platform and western Siberia) reveal regional long-term shoreline shifts (i.e., transgressions and regressions) during the Bajocian Stage (168.3–170.3 Ma). A comparison of these allows to document only a single coherent feature, namely the earliest Bajocian transgression, in the majority of the continental blocks considered. Undoubtedly, this event was triggered by a eustatic rise. However, long-term shoreline shifts were either weak to absent or differed between the blocks during almost the entire Bajocian, thus providing evidence of the apparent stability of global sea level and the importance of regional tectonic activity as a control mechanism on particular transgressions and regressions. Interestingly, it appears that the earliest Bajocian eustatic rise was a constituent of a long-term eustatic pattern; the nature of this event has yet to be fully understood. Generally, the findings presented here are in better agreement with Anthony Hallam’s view of Jurassic eustasy and question some other global sea level reconstructions.
EN
Carbonate minerals in the Middle Jurassic sideritic rocks from the Polish Lowlands, north-eastern margin of the Holy Cross Mountains and the Częstochowa region have been studied applying accessible instrumental methods. The following techniques were applied: polarization microscope, staining with the Evamy’s solution, cathodoluminescence, microprobe, fluid inclusions and isotopic analyses. Most of these methods were not available either in the 20ies of the past century when studies of sideritic iron ores in Poland had begun, or in 50ies and 60ies when they were in full progress. The sideritic rocks are mainly represented by clayey siderites (they contain also muddy and sandy varieties), sideritic sandstones and sideritic coquina, less frequently by sideritic conglomerates and mudstones. Sideroplesite is the main carbonate mineral that builds the sideritic rocks, while pistomesite and siderite are less frequent. Fe-calcite and Fe-dolomite, ankerite, and sporadic dolomite occur in lesser amounts. Syderoplesite and siderite have crystallized in the early diagenesis (eodiagenesis), in the zone of microbiologic methanogenesis, at temperatures of about 20°C, from the porous waters of marine origin, or from marine waters mixed with fresh waters. Sideroplesite enriched in magnesium, pistomesite, calcite and ankerite sequently have formed at the later diagenetic stage (mezodiagenesis). These minerals have crystallized at temperatures above 60°C, from the porous waters of marine origin, or from the fluid which interacted with the adjacent rocks. Fe-calcite was formed in the zone of microbiologic methanogenesis, while the ankerite – in the zone of thermal decarboxylation.
XX
Na podstawie dostępnych obecnie metod instrumentalnych zbadano minerały węglanowe skał syderytowych jury środkowej z Niżu Polskiego, północno-wschodniego obrzeżenia Gór Świętokrzyskich i rejonu Częstochowy. Zastosowano: mikroskop polaryzacyjny, barwienie roztworem Evamy’ego, katodoluminescencję, mikrosondę energetyczną, analizę inkluzji fluidalnych i izotopową. Większość z tych metod nie była dostępna w latach dwudziestych, kiedy rozpoczęto badania syderytowych rud żelaza w Polsce, ani w latach pięćdziesiątych i sześćdziesiątych, kiedy były kontynuowane. Skały syderytowe są reprezentowane głównie przez: syderyty ilaste (obejmują również odmiany mułkowe i piaszczyste), piaskowce syderytowe i muszlowce syderytowe, rzadziej przez zlepieńce syderytowe i mułowce syderytowe. Głównym minerałem węglanowym budującym skały syderytowe jest syderoplesyt, rzadziej pojawiają się pistomesyt i syderyt. W zmiennych ilościach występują Fe-kalcyt oraz Fe-dolomit i ankeryt, sporadycznie dolomit. Syderoplesyt i syderyt krystalizowały we wczesnej diagenezie (eodiagenezie) w strefie mikrobiologicznej metanogenezy w temperaturze ok. 20°C z wód porowych pochodzenia morskiego lub wód morskich zmieszanych z wodami słodkimi. W późniejszym etapie diagene¬zy (mezodiagenezie) tworzyły się w kolejności: syderoplesyt z większą zawartością magnezu, pistomesyt, kalcyt i ankeryt. Minerały te krystalizowały w temperaturze powyżej 60°C z wody porowej pochodzenia morskiego lub wody, która weszła w reakcję z otaczającymi skałami. Fe-kalcyt tworzył się w strefie mikrobiologicznej metanogenezy, natomiast ankeryt w strefie termalnej dekarboksylacji.
EN
The paper presents the results of new mineralogical and petrographic analyses of Middle Jurassic sideritic rocks in the Kujawy area. The scope of the research has been extended to the Ciechocinek-Brześć Kujawski-Wojszyce zone, where clayey and sandy siderites and sideritic coquina form only inserts in siliciclastic rocks. Early diagenetic sideroplesite and mesodiagenetic sideroplesite, Fe-dolomite, ankerite, pistomestite and calcite occur among carbonate minerals. They are accompanied by an early diagenetic green mineral called chamosite and identified as berthierine in the XRD analysis. The richest mineral composition occurs in the sideritic coquina containing various shell elements, often also ooids. It is suggested that the formation of the coquina in the Klodawa-Łęczyca anticline area was caused by saline movements of the Cimmerian orogeny. The start-up and blending of salt masses and the rockfracture contributed to the intensive circulation of mineralizing solutions and the development of diagenetic processes, especially the replacement of unstable components and the cementation of Jurassic sediments throughout the Kujawy area.
PL
Utwory jury środkowej na obszarze przedgórza Karpat polskich występują w dwóch rejonach, północno-wschodnim (Księżpol-Nowy Lubliniec-Lubaczów) opracowanym przez autora w 2004 r. i południowym (Wadowice-Busko-Rzeszów), będącym tematem monografii. Jura środkowa rejonu Wadowice-Busko-Rzeszów jest zbudowana głównie z utworów silikoklastycznych o miąższości przekraczającej 300 m, reprezentujących wiek co najmniej od bajosu do keloweju włącznie. W monografii przedstawiono wyniki badań uzyskane w 148 otworach wiertniczych, skorelowanych na podstawie wykresów geofizyki wiertniczej oraz oznaczeń fauny i flory. Szczegółowo omówiono stosunki dotyczące miąższości utworów poszczególnych poziomów środkowojurajskich oraz przedstawiono tektonikę i paleogeografię tych skał. Podkreślono przekraczające ułożenie utworów i transgresywny postęp morza tetydzkiego, stopniowo zwiększającego zasięg i zajmującego coraz większe obszary lądowe.
EN
Middle Jurassic sediments in the Polish Carpathian Foreland occur in two regions: northern (Księżpol-Nowy Lubliniec-Lubaczów) described by Author in 2004 and the southern (Wadowice-Busko-Rzeszów), considered here. The latter contains mainly siliciclastic sediments of thickness exceeding 300 m, whose age range from (at least) Bajocian to Callovian. The study presents results obtained from boreholes, correlated on the basis of logging diagrams and the fauna and flora. The thickness of particular Middle Jurassic series, their tectonics and palaeogeography are discussed in details. The transgressive arrangement of the sediments and the transgressive advance of the Tethyan Ocean, which gradually covered increasingly large areas of land, is evidenced.
PL
Kamieniołom Kowalskiego w Wieluniu jest jednym z ważniejszych obiektów poeksploatacyjnych w pasie Jury Polskiej pod względem potencjału naukowego i edukacyjnego. Można w nim zobaczyć rzadko dostępne na powierzchni skały z pogranicza jury środkowej i górnej, które formowały się w morskim środowisku około 165 -160 mln lat temu. Kamieniołom ten odegrał też istotne znaczenie w historii kształtowania się miasta, bowiem właśnie stąd pochodził charakterystyczny twardy, żółty kamień (geza), z którego powstały jego najstarsze, średniowieczne budowle. Przemysłowej eksploatacji w kamieniołomie Kowalskiego zaprzestano w latach 60. XX w. Walory przyrodnicze kamieniołomu oraz jego położenie dały początek idei stworzenia w nim parku łączącego rekreację z interdyscyplinarną i interaktywną edukacją wysuwającą na pierwszy plan zagadnienia geologiczne. Projekt zmierza do ukazania Wielunia, jako północnych „wrót” Jury Polskiej, atrakcyjnego turystyczne regionu pomiędzy Wieluniem, Częstochową, a Krakowem.
EN
The Kowalski’s quarry at Wieluń is one of the most important post-exploited objects in the Polish Jura area both from its scientific and educational potentials. It shows the rocks rarely accessible on the surface from the transition of the Middle and Upper Jurassic which originated about 165-155 millions of years ago in sea environment. The quarry played an important role in development of Wieluń because it yielded the characteristic hard yellow-coloured rock (geizas) being the rough material for construction of the town. The industrial exploitation in the quarry was checked in sixties of the twenty century. The natural value of the quarry and its location gave the assumption for its treatment as a place for the future park foundation where the interdisciplinary and interactive education with special attention to geology could be realized. The project is aimed at accentuation of the position of the Wieluń Town as the northern “gate” of the Polish Jura – the attractive touring region.
EN
The Lower Jurassic and the lower part of the Middle Jurassic deposits corresponding to the Sołtysia Marlstone Formation of the Lower Subtatric (Krížna) nappe in the Kopy Sołtysie mountain range of the High Tatra Mts and the Płaczliwa Skała (= Ždziarska Vidla) mountain of the Belianske Tatra Mts in the eastern part of the Tatra Mts in Poland and Slovakia are described. The work concentrates both on their lithological and facies development as well as their ammonite faunal content and their chronostratigraphy. These are basinal deposits which show the dominant facies of the fleckenkalk-fleckenmergel type and reveal the succession of several palaeontological microfacies types from the spiculite microfacies (Sinemurian–Lower Pliensbachian, but locally also in the Bajocian), up to the radiolarian microfacies (Upper Pliensbachian and Toarcian, Bajocian–Bathonian), and locally the Bositra (filament) microfacies (Bajocian–Bathonian). In addition, there appear intercalations of detrital deposits – both bioclastic limestones and breccias – formed by downslope transport from elevated areas (junction of the Sinemurian and Pliensbachian, Upper Toarcian, and Bajocian). The uppermost Toarcian – lowermost Bajocian interval is represented by marly-shaly deposits with a marked admixture of siliciclastic material. The deposits are correlated with the coeval deposits of the Lower Subtatric nappe of the western part of the Tatra Mts (the Bobrowiec unit), as well as with the autochthonous-parachthonous Hightatric units, but also with those of the Czorsztyn and Niedzica successions of the Pieniny Klippen Belt, in Poland. The character of the deposits in the sequences, and their biostratigraphical analysis, show that sedimentation during the Early Jurassic, and up to the Late Bajocian, was controlled by rifting phases which were active at the junction of the Sinemurian and Pliensbachian (Zliechov Phase), during the Late Pliensbachian and Toarcian (Devín Phase), and during the Bajocian (Krasín Phase). The onset of pelagic sedimentation overlying the rift strata took place during the latest Bajocian. Selected ammonite taxa are illustrated and discussed.
EN
Aromatic hydrocarbons are present in the fossil wood samples in relatively small amounts. In almost all of the tested samples the dominating aromatic hydrocarbon is perylene and its methyl and dimethyl derivatives. The most important biomarkers present in the aromatic fraction are dehydroabietane, siomonellite and retene, compounds characteristic for conifers. The distribution of discussed compounds is highly variable due to such early diagenetic processes affecting the wood as oxidation and the activity of microorganisms. MPI1 parameter values (methylphenanthrene index) for the majority of the samples are in the range of 0.1 to 0.5, which results in the highly variable values of Rc (converted value of vitrinite reflectance) ranging from 0.45 to 0.70%. Such values suggest that MPI1 parameter is not useful as maturity parameter in case of Middle Jurassic ore-bearing clays, even if measured strictly on terrestrial organic matter (OM). As a result of weathering processes (oxidation) the distribution of aromatic hydrocarbons changes. In the oxidized samples the amount of aromatic hydrocarbons, both polycyclic as well as aromatic biomarkers decreases.
EN
Macroscopic observations, microscopic studies and literature data revealed that Middle Jurassic wood from Częstochowa area has a different state of preservation, and various types and degrees of mineralization and oxidation. Obtained results of organic matter fractionation illustrate a clear domination of polar fraction in the obtained extracts revealing low thermal maturity stage. Total organic carbon (TOC) values for analysed samples are in a wide range from 1.06% to 68.50%. The highest amount of TOC were measured in not or poorly mineralized wood samples but most of them are mineralized wood fragments, showing the TOC values in the range of 2% - 10%. Percentage content of carbonate in fossil wood constitute in a wide range from less than 1% CaCO3 to above 85% CaCO3. The resulting percentage of the total sulfur content is very varied and do not show convergence with other data such as TOC, carbonate content, etc and is most probable connected with pyritisation range. Unlike the Middle Jurassic clay samples, where long-chain and short-chain n-alkanes occur in similar concentrations, in wood samples always short-chain n-alkanes dominated, in the range from 15 to 23 carbon atoms in molecule. The values of the CPI are generally higher than 1 which indicates the contribution of organic matter derived from higher plant waxes, which are characteristic of e.g. needles from gymnosperm plants. Under the influence of postdiagenetic oxidation in mineralized wood samples distribution of n-alkanes is changing. Diaster-13(17)-enes with 28 and 29 carbon atoms in molecule are present in the wood samples, while those with 29 atoms strongly prevail.
PL
Makroskopowe obserwacje, mikroskopowe badania i dane literaturowe wykazały, że środkowojurajskie drewno z okolic Częstochowy ma różny stan zachowania oraz różne rodzaje i stopień mineralizacji oraz utlenienia. Uzyskane wyniki rozdziału frakcyjnego pokazują wyraźną przewagę frakcji polarnej w badanych ekstraktach. Wartości TOC dla badanych próbek wahają się w szerokim zakresie od 1,06% do 68,50 %. Największa ilość TOC występuje w nie zmineralizowanych lub słabo zmineralizowanych próbkach drewna. Większość próbek to zmineralizowane fragmenty drewna, pokazując wartości TOC w zakresie od 2% - 10%. Zawartość procentowa węglanów w badanych próbkach znajduje się w szerokim zakresie od mniej niż 1% CaCO3 do ponad 85% CaCO3. Procentowa zawartość siarki całkowitej jest bardzo zróżnicowana i nie wykazuje zbieżności z innymi danymi, takimi jak TOC czy zawartość węglanów, itp. W odróżnieniu od środkowojurajskich iłów, gdzie długołańcuchowe i krótkołańcuchowe n-alkany występują w podobnych stężeniach , w próbkach drewna zawsze przewyższają n-alkanów krótkołańcuchowe, występujące w zakresie od 15 do 23 atomów węgla w cząsteczce. Wartości wskaźnika CPI są generalnie wyższe niż 1, co wskazuje na udział materii organicznej pochodzącej z wosków roślin wyższych. Pod wpływem post-diagenetycznego utleniania zmineralizowanych próbek drewna zmienia się dystrybucja n-alkanów. W badanych próbkach obecne są diaster-13 (17)-enes o 28 i 29 atomów węgla w cząsteczce, natomiast te o 29 atomów znacznie przeważają.
EN
The lithology, sedimentary structures and trace fossil association from the Bathonian organic-rich mudstones from Kraków-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.
EN
The palynological organic matter of dark clays from Bathonian ore-bearing clays exposed at Gnaszyn (Częstochowa, Kraków-Silesia Homocline, Poland) consists of high proportions of land-derived particles; aquatic elements (mainly dinoflagellate cysts) are comparatively rare. Terrestrial particles include black opaque phytoclasts, dark brown phytoclasts, cuticle remains and subordinate sporomorphs. The latter are represented by eighty-four taxa of spores and pollen grains. They represent various groups of plants, including Bryophyta, Sphenophyta, Lycophyta, Pteridophyta, Pteridospermophyta, Cycadophyta or Ginkgophyta and Coniferophyta. The most frequent sporomorphs in almost all samples from Gnaszyn are Callialasporites (Araucariaceae), Cerebropollenites and Perinopollenites elatoides (Taxodiaceae) pollen grains, fern spores with triradiate tetrad mark, bisaccate pollen grains belonging to conifers (Pinaceae or Podocarpaceae) and also to Pteridospermophyta. Quantitative analysis of the palynofacies shows fluctuations of particular element ratios, which correlate with lithology. Clay intervals that contain siderite concretion levels yielded lower amounts of cuticles in relation to sporomorphs (mainly pollen grains) and dinoflagellate cysts. Intervals of monotonous clays and silts are characterized by a higher ratio of cuticles in relation to other elements, especially dinoflagellate cysts. Also, quantitative analysis of the sporomorphs shows changes in frequency of the representatives of various plant communities, which coexisted during the Jurassic: Upland, Lowland, River, Pioneer, Coastal and Tidally-influenced. These changes might have reflected sealevel fluctuations, which affected vegetation growing on adjacent land. However, the dominance of Callialasporites pollen grains, which belong to the Coastal community, indicates that the Gnaszyn assemblage was mainly influenced by the seashore vegetation. The high frequency of Araucariaceae pollen grains and the presence of ferns representing the Osmundaceae, Cyatheaceae, Dicksoniaceae, Schizeaceae, Gleicheniaceae and Matoniaceae indicate a warm climate without large seasonal amplitudes during the deposition of the Gnaszyn succession.
EN
This paper presents the results of an investigation into the variability of echinoderm assemblages from Bathonian ore-bearing clays from Gnaszyn. Remains of Crinoidea, Asteroidea, Ophiuroidea, Echinoidea, and Holothuroidea have been studied from 38 rock samples. The most common echinoderms represented are the crinoids Balanocrinus berchteni and Chariocrinus andreae and a few species of the holothurian genera Priscopedatus, Calclamna, Staurocaudina, Eocaudina, Achistrum, Theelia and Hemisphaeranthos. The echinoderms from Gnaszyn show various life strategies: benthic or epibenthic forms, sessile sestonophages (Crinoidea), motile macrophages (Asteroidea) and detritivores (Asteroidea, Ophiuroidea, Echinoidea), infaunal and epifaunal detritus feeders, sediment feeders or rake-feeders (Holothuroidea). Their presence suggests well oxygenated and presumably relatively cold bottom marine waters. The parts of the Gnaszyn section around concretion horizons and characterized by the ubiquitous occurrence of the holothurian Theelia and echinoids were deposited during phases of optimal living conditions with sufficient influx of plant detritus and good oxygenation of the sea bottom. These parts commonly host echinoderm associations dominated by crinoid remains, which occasionally are still articulated (or disarticulated but remaining intact) - this points to a quiet environment with normal oxygenation of the bottom waters but anaerobic/dysaerobic conditions in the sediment.
EN
A succession of Middle-Upper Bathonian (Subcontractus.Retrocostatum zones) ore-bearing clays exposed at Gnaszyn has been investigated for the presence of dinoflagellate cysts. The assemblages are dominated by Ctenidodinium. However, analysis of diversity shows some subtle differences throughout the succession, possibly related to the palaeoenvironmental conditions in the photic zone. Impoverished assemblages, dominated by Ctenidodinium, occur mainly in monotonous muddy intervals. More diverse assemblages, albeit also dominated by Ctenidodinium, occur in intervals which contain siderite concretion levels. The taxonomic composition of the former assemblage seems to reflect slightly restricted conditions in the photic zone, possibly related to a minor reduction in salinity and/or increase in nutrient availability. More diverse dinoflagellate cyst assemblages reflect periods of less intense terrigenous influx and relatively higher, possibly normal, salinity. These changes were possibly caused by variable intensity of freshwater influx into the basin, controlled by sea-level fluctuations. Sea-level changes may be related to migrations of Tethyan water masses, which were probably partly responsible for the composition of the dinoflagellate cyst assemblages.
EN
This paper provides introductory data for multidisciplinary studies on palaeoenvironmental reconstructions of the Bathonian (Middle Jurassic) ore-bearing clays exposed at Gnaszyn, southern Poland. These dark-coloured fine-clastic deposits have been studied for micropalaeontology, sedimentology and geochemistry (published in separate papers within this volume). Brief outlines of the Middle Jurassic palaeogeography of the Polish epicontinental basin and the geology of the Kraków-Silesia Homocline are given. A description of the ore-bearing clays succession exposed in the clay-pit at Gnaszyn is provided, including locations of the sections studied, their ammonite biostratigraphy, brief lithology and macrofossil distribution. The sample positions collected for micropalaeontological and geochemical studies are specified.
14
Content available remote Copepod-infested Bathonian (Middle Jurassic) echinoids from northern France
EN
New examples of Bathonian (Middle Jurassic) parasitic exocysts on acrosaleniid echinoid tests are recorded from northern France. These exocysts can be attributed to the life activity of copepod crustaceans and are considered to have been formed as a result of copepod larval settlement in these echinoids by way of the gonopores. Sexual dimorphism is recognised in copepod-infested Acrosalenia spinosa L. Agassiz, 1840, on the basis of size and position of gonopores, those in females being larger and wider apart, those in males smaller and situated subcentrally. The previous stratigraphic range of copepod cysts of this type (i.e., Middle Oxfordian to Middle Kimmeridgian) can now be extended down to the base of the Bathonian (convergens Subzone).
EN
According to the present authors the decline of the Bajocian crinoidal limestone sedimentation in the Pieniny Klippen Basin corresponded to a general subsidence of the Czorsztyn Ridge which promoted the appearance of nodular limestones of the pelagic Ammonitico Rosso facies (Czorsztyn Limestone Fm., Niedzica Limestone Fm.). As proved by ammonite faunas recognized in the Czorsztyn, Niedzica and Czertezik successions, this replacement of the facies (sometimes related with hiatus) took place during the latest Bajocian. A different interpretation of stratigraphy of the crinoidal limestones is given by Birkenmajer (1977, 2007) who postulates a wider stratigraphical range of these deposits, in the Czertezik Succession, but also in the Czorsztyn Succession, from the Bajocian up to base or even end of the Callovian. According to this author the crinoidal limestones span in these two successions a large stratigraphical interval of the Middle Jurassic being partly a lateral equivalent of the nodular limestones of the Niedzica Limestone Fm. of the Niedzica Succession. The present authors investigations, based on new findings of ammonites (parkinsoniids—Parkinsonia (Parkinsonia) parkinsoni (Sow.), Parkinsonia cf. bomfordi Arkell), in the typical area of occurrence of the Czertezik Succession, indicate the presence of the uppermost Bajocian–lowermost Bathonian red nodular limestones of the Niedzica Limestone Formation, and along with older ammonite datings from the Czorsztyn Succession prove that the onset of sedimentation of the nodular limestones was almost coeval in the Czertezik Succession, the Czorsztyn Succession and the Niedzica Succession. Additionally, the ammonite fauna indicates that sedimentation of the crinoidal limestones in the Czertezik Succession took place during the Bajocian, similarly as in other successions of the Pieniny Klippen Belt. These new findings show that differences between the Czertezik Succession, and other successions of the Pieniny Klippen Belt are much smaller than hitherto proposed (Birkenmajer, 1959), and confirm an earlier interpretation of the present authors (Wierzbowski et al., 2004).
EN
Ore Bering Częstochowa Clay Formation (Middle Jurassic) was taken into consideration of spore-pollen analysis. Preliminary research indicates presence of taxa belonging to Lycopodiales, Equisetales, Filicales, Coniferales and Mesozoic pteridosperms. Changes of frequency of sporomorphs possibly indicate variability of climate.
EN
The Jurassic crinoidal limestones in the Pieniny Klippen Belt in Poland consist of three formations (Smolegowa, Flaki and Krupianka Limestone formations), and constitute an important segment of the Middle Jurassic sequence in the Czorsztyn, Niedzica and Czertezik successions. The onset of the crinoidal sedimentation, as proved by ammonite faunas, took place during the Early Bajocian and it was preceded by a marked stratigraphical hiatus. This hiatus corresponds to the origin and uplift of the Czorsztyn Ridge. The evidences of condensation event at the beginning of crinoidal limestones sedimentation are marked by numerous sedimentological features in the lowermost part (10-20 cm in thickness) of these limestones (e.g. phosphatic concretions concentration, pyrite concretions, large clasts of green micritic limestones). Occurrence of such important correlation horizon indicates primary thickness of investigated crinoidal limestones (from ca 10 m up to 100 m), and suggests origin of synsedimentary tectonic blocks and troughs, which influenced on their original, not recently tectonically reduced, differentiation of their thickness. This Bajocian tectonic activity within Pieniny Klippen Basin corresponds very well with others Middle Jurassic Western Tethyan geodynamic reorganizations.
EN
This paper deals with a fragment of geological history of Middle Jurassic black spherosideritic shales outcropping in upper part of the Homole Gorge (Skrzypny Shale Formation, Niedzica succession). These important deposits belong to the Flackenmergel facies, widespread in oceanic Tethyan deposits. This formation represents one of the oldest rocks of the Pieniny Klippen Belt. Dark colour of these rocks (total organic carbon content in them amounts to about 1 wt.%) and the occurrence of siderite concretions indicate reducing conditions of their origin but oxidizing environment of waters above them in sedimentary basin. Oxic conditions of organic matter sedimentation are confirmed by the elevated values of pristine to phytane ratio. Moreover the results based on n-alkanes indicate mixed terrestrial/marine origin of organic matter with prevalence of the last one. These information are slightly obliterated because of advanced thermal maturity of organic matter caused by post-sedimentation processes. Microstructural features of deposits of the Skrzypny Shale Formation and the composition of clay minerals occurring in them indicate late diagenetic conditions. In SEM images we observe one-directional orientation of clay minerals and rotation of mica flakes, often chloritized. Clay minerals are represented by high-illitic illite/smectite, micas, post-biotitic chlorite and subordinately kaolinite. As follows from authors studies, these macroscopically nearly "mute" clay rocks, little interesting in outcrops, particularly when they occur in such attractive geological objects as the Homole Gorge, can be the source of important information concerning the history of sedimentation basins.
PL
Praca przedstawia fragment historii geologicznej środkowojurajskich czarnych łupków sferosyderytowych ukazujących się w niewielkim odsłonięciu w górnej części wąwozu Homole (formacja lupków ze Skrzypnego, sukcesja niedzicka). Te ważne utwory należą do facji Fleckenmergiel szeroko rozpowszechnionej w oceanie Tetydy. Formacja łupków ze Skrzypnego reprezentuje jedne z najstarszych skał pienińskiego pasa skałkowego. Ciemna barwa badanych skał (zawartość całkowitego węgla organicznego około 1% wag.) oraz występowanie w nich konkrecji syderytowych, wskazują na warunki redukcyjne panujące w osadzie, natomiast na obecność natlenionych wód nad osadem w środowisku ich sedymentacji. Sedymentację substancji organicznej w warunkach raczej utleniających potwierdzają badania związków organicznych, tj. wysokie wartości stosunku pristan/fitan. Wyniki tych badań wskazują ponadto na mieszane, lądowo/morskie pochodzenie substancji organicznej z przewagą ostatniej z wymienionych. Informacje te są nieco zatarte z powodu dużej dojrzałości termicznej substancji organicznej spowodowanej procesami postsedymentacyjnymi. Cechy mikrostrukturalne utworów formacji łupków ze Skrzypnego oraz skład występujących w nich minerałów ilastych wskazują na warunki odpowiadające późnej diagenezie. W obrazach elektronomikroskopowych (SEM) widoczna jest bowiem jednokierunkowa orientacja minerałów ilastych i rotacja blaszek mik, często schlorytyzowanych. W składzie minerałów ilastych występuje zaś wysokoillitowy illit/smektyt, miki, pobiotytowy chloryt i podrzędnie kaolinit. Z przeprowadzonych badań wynika, że makroskopowo niemal "nieme" skały ilaste, niepozorne wyglądające w odsłonięciu, szczególnie jeśli występują obok atrakcyjnych obiektów geologicznych jak to ma miejsce w wąwozie Homole, są źródłem ważnych informacji dotyczących historii basenów sedymentacyjnych. Warto więc zwrócić na nie uwagę.
EN
Early to Middle Bathonian ammonites of the families Sphaeroceratidae Buckman and Tulitidae Buckman have been carefully examined. Specimens were collected from fine grained sediments, which belong to Middle Jurassic "Częstochowa Ore-bearing Clay Formation" of the Polish Jura Chain. Usually ammonites were found within sphaerosiderite nodules. Nodules were collected from numerous clay-pits of Częstochowa suburbs, and from underground mines of Włodowice and Zawiercie regions. Single, well preserved specimen of the rare, Early Bathonian genus Praetulites Westermann (P. rugosus sp. nov.) is the only representative of the family Sphaeroceratidae Buckman. It was discovered in iron-ore mine, in Włodowice, and it represents the youngest known evolutionary member of the genus Praetulites. Family Tulitidae Buckman is widely represented among examined ammonites. It consists of representatives of two subfamilies: Tulitinae Callomon, Dietl, Niederhöfer (genera and subgenera: Tulites Buckman, Rugiferites Buckman, Morrisiceras Buckman and Holzbergia Torrens), and Bullatimorphitinae Callomon, Dietl, Niederhöfer (genera: Sphaeroptychius Lissajous and Bullatimorphites Buckman). New evaluation of the age of subgenera Tulites and Rugiferites is of special interest. Despite previous opinions about their occurrence only within Tulites subcontractus Zone (Middle Bathonian), they have been found within Lower Bathonian of Włodowice, Rudniki, and vicinity of Częstochowa regions. These subgenera were represented by both: new species, and widely known taxa, characteristic for Middle Bathonian of Western Europe. Other representatives of the subfamilies Tulitinae (Morrisiceras, Holzbergia), and Bullatimorphitinae (Sphaeroptychius, Bullatimorphites) were present mostly within upper parts of Middle Bathonian, which confirms previous observations. State of preservation (as sideritic internal moulds with final growth stages of conchs preserved) allowed in many cases to make existing species’ diagnosis more complete.
PL
Szczegółowym badaniom poddano znaleziska dolno- i środkowobatońskich amonitów, należących do rodzin Sphaeroceratidae Buckman i Tulitidae Buckman, pochodzące z serii osadów mułowcowo-ilastych, wchodzących w skład środkowojurajskiej formacji osadowej Jury Polskiej (Polish Jura Chain) częstochowskich iłów rudonośnych. Amonity występowały najczęściej w sferosyderytach, odsłaniających się w licznych gliniankach na obrzeżach Częstochowy oraz w podziemnych wyrobiskach kopalnianych w rejonie Włodowic i Zawiercia. Rodzinę Sphaeroceratidae Buckman, w tym zespole fauny, charakteryzował jeden, dobrze zachowany, pochodzący z dolnego batonu okaz. Należy on do bardzo rzadko stwierdzanego rodzaju Praetulites Westermann (P. rugosus sp. nov.). Znaleziony w kopalni rud żelaza we Włodowicach reprezentuje najmłodsze, z dotychczas poznanych, ogniwo ewolucyjne rodzaju Praetulites. Rodzina Tulitidae była w badanym zespole amonitów znacznie liczniej reprezentowana. Tworzy ją szereg gatunków, często nowych, należących do rodzajów i podrodzajów: Tulites Buckman, Rugiferites Buckman, Morrisiceras Buckman i Holzbergia Torrens (podrodzina Tulitinae Callomon, Dietl, Niederhöfer) oraz taksony podrodziny Bullatimorphitinae Callomon, Dietl, Niederhöfer, na którą składają się gatunki rodzajów Sphaeroptychius Lissajous i Bullatimorphites Buckman. Szczególnie interesująca okazała się ocena wieku znalezionego we Włodowicach i Rudnikach, oraz w bliżej nieokreślonym stanowisku w okolicach Częstochowy, zespołu gatunków z podrodzajów Tulites i Rugiferites. Wbrew dotychczasowym poglądom o ich wyłącznym występowaniu w europejskim środkowym batonie (poziom Tulites subcontractus), znaleziska te odkryte zostały w dolnym batonie. Reprezentowane były zarówno przez nowe gatunki, jak i przez taksony dotychczas uznawane za typowe dla zachodnioeuropejskiego batonu środkowego. Kolejni reprezentanci podrodziny Tulitinae (Morrisiceras, Holzbergia) i Bullatimorphitinae (Sphaeroptychius, Bullatimorphites) zgodnie z dotychczasowymi obserwacjami grupowały się w wyższych odcinkach środkowego batonu. Bardzo dobry na ogół stan ich zachowania (zsyderytyzowane ośródki z końcowymi stadiami wzrostowymi muszli) pozwalał częstokroć uzupełniać dotychczasowe diagnozy gatunkowe.
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