The Cimmerian Continent (or Cimmeria, Cimmerian terrane, Cimmerian blocks) was detached from eastern Gondwana in the Late Paleozoic as a sliver/ribbon of continental strip rifting elements. Recently, these elements belong to an almost continuous long belt (ca. 13,800 km) from central Italy trough Greece, Turkey, Iran, Afghanistan, Tibet, SW China, Myanmar, Thailand up to Indonesia (Sumatra). The palaeogeographic position and relationship of some elements during Permian-Mesozoic times is still matter of discussion. The Qiangtang and Lhasa blocks (present-day Tibet) belong to these elements and their location in space and time and their relationship causes a lot of controversies. Their position alongside eastern Gondwana in the mid-Early Permian (ca. 290–285 Ma) are suggested both by palaeomagnetic and facies studies. Palaeomagnetic studies indicated this position one decade ago, which has been confirmed by recent studies. The Cimmerian Continent [Iran (Alborz)-Qiangtang-Baoshan-Tengchong-Sibumasu] was separated from the Gondwanian part of Pangea during mid-Early Permian time by rifting and drifting. Northwards migration of it took place during Permian-Triassic times caused wide opening of the Bangong‐Nujiang Tethyan Ocean and closing of the Paleotethys Ocean but the Lhasa block was still southern margin of the Bangong‐Nujiang Ocean. The Triassic Indosinian Orogeny has been one of the most spectacular geotectonic event reflecting collision of this continent with Indochina block and closure of the Paleotethys Ocean. The separation of the Lhasa block from Gondwana is enigmatic but most probably took place during earliest Jurassic times. This separation was followed by quick shift northward. Intensive sedimentological studies of the Late Triassic (Carnian-Norian) several flysch-type turbidites in the eastern Tethyan Himalaya (e.g. Qulonggongba, Pane Chaung, Langjiexue, Quehala, Duoburi formations/groups) indicate that their provenance was connected with Lhasa block, which has been their source area during early-stage evolution of the Neotethys. The late Early Permian rift-related basaltic magmatism in northern Baoshan (in SW China) and sourrounding regions was connected with first step of separation from Gondwana margin of this block (together with South Qiangtang and Sibumasu blocks and simultaneously with opening of the Bangong‐Nujiang Ocean before the Middle Permian) – independently of Lhasa block which was separated later, the most probably during Late Triassic or Triassic/Jurassic transition time with very wide space of the Bangong‐Nujiang Tethyan Ocean between Qiangtang and Lhasa blocks (2,600 km ±710 km – 23.4° ±6.4° during the Middle Jurassic with its maximum width in the Late Triassic). From the palaeobiogeographic point of view, the worldwide distribution of Pliensbachian-Early Toarcian large bivalves of the so-called Lithiotis-facies, dominated by Lithiotis, Cochlearites, Litioperna genera revealed by the authors’ studies, indicates very rapid expansion of such type of bivalves alongside southern margin of Neotethys, and could be good evidence of palaeogeographic position of the Lhasa block in this time. Himalayan and Tibetan (Nyalam area) occurrences of Lithiotis and/or Cochlearites bivalves could help to place the Lhasa block nearby the Gondwana during Early Jurassic times. This palaeobiogeographic research contradict another interpretation based on different fossils (Permian fusulinids and brachiopods) interpreted as subtropical fauna, which could occur in low subtropical latitudes together with other parts of the Cimmerian Continent.
Jurassic and Cretaceous evolution of Tethys Ocean is characterized by extension of oceans basins, rifting, development of carbonate platforms and sea level fluctuations. Ocean basins and platform margins were sides of records of collaboration of oceanic, sea level and climate changes in different scales. Deposition of organic sediment increased on the margins of the ocean basins at certain time intervals due to changes in oceanic circulation and chemistry, productivity, climate and sea level. Oceanic Anoxic Events (OAE) stated to took place at aperiodic time intervals and generally associated with organic matter deposits and anoxic water columns. Records of oceanic anoxic event can also be associated by potential source rocks in Jurassic and Cretaceous along Tethys Ocean basins and can be tracked by stable isotope shifts, turnover of fossil groups, presence of black shales/organic rich mudstones, change in redox sensitive elements. Volcanic contribution in oceans is also considered as one of the collaborators of OAE generations. OAE records in Jurassic is seen in Toarcian interval and stated as Toarcian OAE. In Cretaceous, OAE records can be stated as Weissert, Faraoni, Selli (OAE1a), Noir, Fallot, Jacop, Kilian, Paquier (OAE1b), Leenhardt, Amadeus (OAE1c), Breistroffer (OAE1d), Bonarelli (OAE2), and OAE3. Generally, Cretaceous OAE are globally correlated or at least hemispherical. Some of them can be weakly correlated due to different duration and magnitude. Stratigraphic positions of OAE can also be used better marker levels in sequence stratigraphic interpretations. Therefore, positions of OAE are very important in terms of higher resolution for platform to basin correlations and even basin to basin. Cretaceous Oceanic Anoxic Events in eastern Tethys Ocean in Pontides and Taurides can be seen in Cretaceous successions (Mid-Barremian, Aptian, Albian, Cenomanian-Turonian) of Central Pontides (NW Turkey) and Central Taurides (S Turkey) (Yilmaz et al., 2004, 2010, 2012) as presence of black shales. The Mid-Barremian black shales (MBE) have been recorded within turbidite succession in deep marine setting in central Sakarya zone of Pontides following the drowning of the platform (Yilmaz et al., 2012). 2‰ shifts in carbon isotope curve is recorded in parallel with European basins, but with low TOC value. The Aptian black shales (OAE1a) are recorded in pelagic carbonate slope environments in central and north of Sakarya zone of Pontides and represented by a negative carbon isotope shift with 2‰, and TOC around 2% (Yilmaz et al., 2004; Hu et al., 2012). In Sakarya zone of Pontides, OAE2 is recorded in pelagic slope carbonates with carbon isotope curve more than 1‰ positive shift and >2% TOC. Another OAE2 was recorded in Antalya Nappes of Taurides without carbon isotope curve but TOC > 20% (Yurtsever et al., 2003, Bozcu et al., 2011). OAE1a equivalent in Tauride Carbonate platform can be interpreted as presence of dark colored thick stromatolite bearing platform carbonates transgressivley overlying the karstic sequence boundary. The OAE1a and OAE2 levels recorded in Turkey can easily be correlated with European examples and mainly controlled by sea level and tectonics in largescale and climate and oceanographic changes in small-scale. The most extensive distribution of the OAE records in Turkey belong to OAE1a and OAE2, and display potential for source rocks for hydrocarbon exploration.
The Stormberg Group comprises the Molteno, Elliot and Clarens formations and is one of four stratigraphical groups that make up the Karoo Supergroup in South Africa. The group is the highest unit in the Karoo Basin, representing the final phase of preserved sedimentation. The major problem with the Stromberg Group is that the mode of transport, hydrodynamic energy conditions and depositional environment are still poorly understood. For the present paper, grain size and lithofacies studies on selected sandstones from the Molteno, Elliot and Clarens formations were performed so as to elucidate their textural characteristics, depositional processes, sedimentation mechanisms and hydrodynamic energy conditions and to discriminate different depositional environments. The statistical parameters of grain size distribution (mean grain size, standard deviation, skewness and kurtosis) show that the sandstones are predominantly unimodal, fine grained, moderately well sorted, mesokurtic and near symmetrical. The bivariate diagrams of the aforementioned statistical parameters demonstrate that river and aeolian dune had the greatest impact on the depositional environments. Likewise, the C-M pattern (Passega diagram) shows that the sandstones were mostly deposited through tractive current process. Furthermore, the C-M diagram reveals the prevalence of rolling, suspension and graded suspension modes of sediment transportation. Seventeen sedimentary lithofacies were identified and grouped into seven lithofacies associations. These lithofacies associations indicate braided channel, overbank and swamp deposits for the Molteno Formation, alluvial fan/floodplain and playa deposits for the Elliot Formation and aeolian deposits for the Clarens Formation.
Głównym celem monografii jest odtworzenie historii depozycji i rozwoju facjalnego utworów górnej jury i dolnej kredy, występujących w podłożu zapadliska przedkarpackiego, w oparciu o dostępne dane z otworów wiertniczych oraz sejsmikę 3D. Rejon badań usytuowany jest w środkowej części przedgórza Karpat, pomiędzy miastami Dąbrowa Tarnowska na północnym zachodzie i Dębica na południowym wschodzie. Nowe dane, uzyskane w roku 2015, w postaci zdjęcia sejsmicznego 3D, jak również informacji z głębokiego otworu O-1 przewiercającego pełen profil utworów mezozoiku, pozwoliły na znacznie lepsze rozpoznanie i udokumentowanie wielu szczegółów budowy geologicznej tego, dotąd słabo rozpoznanego, rejonu. Sedymentacja badanych utworów węglanowych przedgórza Karpat w epokach późnojurajskiej i wczesnokredowej odbywała się w strefie szelfowej północnego, pasywnego brzegu oceanu Tetydy. Cechą charakterystyczną utworów górnej jury jest ich duże zróżnicowanie facjalne, wynikające głównie z obecności rozbudowanych kompleksów biohermowych oraz pakietów warstwowanych osadów marglisto-wapiennych. W rozdziale 2 przedstawiono budowę geologiczną rejonu badań, uwzględniając wszystkie piętra strukturalne, rozwój litologiczny utworów poszczególnych jednostek, stosowane podziały litostratygraficzne i regionalne ramy paleogeograficzne. W rozdziale 3 szczegółowo omówiona została historia badań oraz aktualny stan rozpoznania kompleksu węglanowego górnej jury i dolnej kredy przedgórza Karpat. Rozdział 4 zawiera charakterystykę litologiczną badanych utworów węglanowych z podziałem na jednostki litostratygraficzne. Charakterystyka ta opracowana została na podstawie analizy cech makroskopowych dostępnego materiału rdzeniowego oraz profilowań geofizyki otworowej. Zamieszczone profile litostratygraficzne wybranych głębokich otworów wiertniczych z obszaru badań lub jego bliskiego sąsiedztwa dokumentują obecny stan wiedzy na temat litostratygrafii i rozwoju facjalnego utworów górnej jury i dolnej kredy. W rozdziale 5 przedstawiono charakterystykę mikrofacjalną i mikropaleontologiczną badanych utworów węglanowych, jak również przeprowadzono dyskusję dotyczącą możliwości określenia zasięgu wiekowego poszczególnych wydzieleń litostratygraficznych w oparciu o wyniki wieloletnich badań oraz dane literaturowe. W rozdziale 6 zaprezentowano wyniki analizy obrazu sejsmicznego, wykonanej w oparciu o wybrane atrybuty sejsmiczne. W ramach pracy omówiono następujące atrybuty: RMS Amplitude, Envelope, Instantaneous phase, Dominant frequency, Instantaneous bandwidth, Apparent polarity, Relative acoustic impedance, First derivative, Iso-frequency component, Time gain, Chaos, Variance (Edge method), Local flatness. Przeprowadzona analiza pozwoliła na uzyskanie dodatkowych istotnych informacji odnośnie wykształcenia litologicznego i rozprzestrzenienia utworów poszczególnych ogniw litostratygraficznych, jak również dała możliwość uszczegółowienia lokalizacji dyslokacji. Na podstawie interpretacji zapisu sejsmicznego w obrębie badanego kompleksu skalnego udokumentowano również występowanie niezgodności kątowych, stref zaburzeń i deformacji związanych z tektoniką synsedymentacyjną oraz przypuszczalnych osadów spływów grawitacyjnych. W rozdziale 7 zamieszczono przekroje litofacjalne, skonstruowane wzdłuż wybranych przekrojów sejsmicznych, prezentujące przestrzenny rozkład i wzajemne relacje pomiędzy utworami poszczególnych ogniw litostratygaficzych. W rozdziale 8 przeanalizowano rozmieszczenie kompleksów biohermowych górnej jury względem morfologii podłoża jury. Analiza rozmieszczenia wykartowanych na podstawie zapisu sejsmicznego budowli organicznych, należących do serii wielkich bioherm gąbkowo-mikrobialnych, wskazuje na dwa główne obszary ich występowania, tj. rejon NW (kompleks biohermowy „N”), w którym występuje dosyć rozległy kompleks biohermowy, a jego dokładny zasięg jest trudny do ustalenia ze względu na późniejsze procesy regionalnej dolomityzacji oraz rejon centralny (kompleks biohermowy „S” w okolicach otworu O-1), w którym stwierdzono kompleks kilku wysokich budowli o dosyć stromych krawędziach. Rozdział 9 poświęcony jest zagadnieniu historii depozycyjnej późnojurajsko-wczesnokredowego basenu sedymentacyjnego przedgórza Karpat oraz omówieniu roli najważniejszych czynników wpływających na rozkład facji w obszarze badań. Wykazano, że cechą charakterystyczną znacznej części osadów jurajskich jest silnie diachroniczny charakter rozprzestrzenienia poszczególnych facji, uwarunkowany głównie paleogeomorfologią dna zbiornika sedymentacyjnego, jak również czynnikami lokalnymi, związanymi z tektoniką synsedymentacyjną. Seria gąbkowo-globuligerinowa, rozpoczynająca profil utworów górnej jury i reprezentująca najgłębszy etap sedymentacji w warunkach otwartego szelfu, cechuje się stosunkowo dużą jednorodnością wykształcenia na całym obszarze przedgórza. Kompleks biohermowy „S” rozwinął się w nadkładzie elewowanej strefy, złożonej z kilku mniejszych elementów tektonicznych, natomiast kompleks biohermowy „N” wykształcił się na rozległej, wyniesionej części strefy zrębowej, gdzie w podłożu występuje jeden główny blok tektoniczny. Intensywnie rozwijające się kompleksy biohermowe „N” i „S” wywierały coraz większy wpływ na dalszy rozwój sedymentacji osadów górnej jury w badanym rejonie, dostarczając jednocześnie materiału dla osadów redeponowanych w głębsze partie zbiornika w wyniku podmorskich spływów grawitacyjnych. W strefie przylegającej od SE do kompleksu biohermowego „S”, na profilach sejsmicznych dostrzegalny jest charakterystyczny, wysokoamplitudowy zapis obejmujący cały pakiet refleksów sejsmicznych o zmiennych kątach upadów. Częste zmiany polarności, dostrzegalne w obrębie tej strefy w odtworzeniu atrybutu Apparent polarity, podobnie jak i skrajnie zmienny zakres wartości atrybutu Relative acoustic impedance, świadczą o silnym zróżnicowaniu litologicznym tego kompleksu skalnego. W tytonie, w trakcie sedymentacji utworów serii koralowcowo-onkolitowej, nastąpiło wyraźne ujednolicenie warunków sedymentacji na całym obszarze przedgórza Karpat, związane głównie z zanikiem paleomorfologicznego zróżnicowania powierzchni dna morza. Przypuszczalnie w tym samym czasie miał miejsce kolejny etap reaktywacji dyslokacji, o czym świadczy powierzchnia niezgodności kątowej, i związane z nią efekty erozji osadów starszych. Rozprzestrzenione na całym obszarze badań utwory serii muszlowcowo-oolitowej dolnej reprezentują różnego typu płytkowodne środowiska sedymentacji (w tym środowisko równi pływowej, lagunowe i stref barierowych), jakie wykształciły się na obszarze przedgórza Karpat, na pograniczu późnej jury i wczesnej kredy. Środowisko sedymentacji utworów serii marglisto-muszlowcowej, datowanej na berias, określić można jako skrajnie płytkowodne, z facjami lagunowymi i wpływem środowisk brakicznych. Utwory najwyższych serii dolnej kredy (tj. mułowcowo-wapiennej i muszlowcowo-oolitowej górnej) reprezentują facje płytkomorskie związane z transgresją morską, która miała miejsce w walanżynie. Przedstawiona historia depozycyjna późnojurajsko-wczesnokredowego basenu sedymentacyjnego przedgórza Karpat, w połączeniu z opisem cech makroskopowych rdzeni wiertniczych, analizą mikrofacjalną i mikropaleontologiczną poszczególnych jednostek litostratygraficznych oraz interpretacją obrazu sejsmicznego, pozwala na kompleksową charakterystykę analizowanych utworów oraz wskazanie procesów mających największy wpływ na obecny charakter i stan zachowania badanych serii skalnych.
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The main subject of this monograph is a reconstruction of the history of deposition and facial development of Upper Jurassic and Lower Cretaceous deposits in the basement of the Carpathian Foredeep, based on data available from boreholes and a 3D seismic survey. The research area is located in the central part of the Carpathian Foreland, between two cities: Dąbrowa Tarnowska in the north-west and Dębica in the south-east. The new 3D seismic survey made in 2015 and the O-1 deep borehole – drilled in the same year and portraying a full profile of the Mesozoic sediments – allowed for much better recognition and documentation of many details of the geological structure of this previously poorly mapped area. The sedimentation of the carbonate formations of the Carpathian Foreland during the Late Jurassic and the Early Cretaceous took place in the shelf zone of the northern, passive margin of the Tethys Ocean. A characteristic feature of the Upper Jurassic sediments is their high facies diversity, due mainly to the presence of biohermal complexes and sets of layered marly-limestone sediments. Chapter 2 presents the geological structure of all structural stages in the area under study, including the lithological development, the lithostratigraphic divisions applied, and the regional palaeogeographic frameworks. Chapter 3 discusses both the history of research and the current state of knowledge regarding the Upper Jurassic and Lower Cretaceous carbonate sediments of the Carpathian Foreland. Chapter 4 describes the lithological characteristics of the carbonate sediments, considering lithostratigraphic units. This characterisation is based on a macroscopic examination of the available core material and analysis of the well logs. The lithostratigraphic profiles of selected deeper boreholes from the research area and its close vicinity document the current state of knowledge on lithostratigraphy and the facies development of the Upper Jurassic and Lower Cretaceous deposits. Chapter 5 features the microfacies and micropalaeontological characteristics of the carbonate sediments under study. Based on the results of many years of research and literature data, the possibilities of determining the age of every lithostratigraphic unit are discussed. Chapter 6 presents the analysis of the seismic 3D image based on selected seismic attributes. As part of the work, the following attributes are discussed: RMS Amplitude, Envelope, Instantaneous phase, Dominant frequency, Instantaneous bandwidth, Apparent polarity, Relative acoustic impedance, First derivative, Iso-frequency component, Time gain, Chaos, Variance (Edge method), and Local flatness. The analysis revealed additional important information regarding both the lithological development and the spatial range of sediments of individual lithostratigraphic units, at the same time facilitating the detailed location of fault zones. Based on the interpretation of the seismic image within the studied rock complex, the occurrence of angular unconformity, disturbance, and deformation zones related to synsedimentary tectonic as well as probable gravity-flow deposits are also documented. Chapter 7 presents lithofacial cross-sections constructed along selected seismic sections reflecting the spatial distribution and relationships between the sediments of individual lithostratigraphic units. Chapter 8 analyses the distribution of Upper Jurassic biohermal complexes in relation to the morphology of the Jurassic base surface. An analysis of the distribution of organic buildups belonging to the Huge Sponge-Microbial Bioherms Series, interpreted indirectly from seismic image, indicates two main areas where they can be found. These are the north-west part of the study area – where a quite extensive biohermal complex occurs (‘Complex N’), the exact range of which is difficult to determine due to later regional dolomitisation processes – and the area located in the central part of the seismic survey, where a complex of several very tall buildups with steep edges was found (‘Complex S’). Chapter 9 is devoted to the issue of the depositional history of the Late Jurassic–Early Cretaceous sedimentary basin of the Carpathian Foreland and to a discussion of the role of the most important factors influencing facies distribution in the research area. It has been shown that a characteristic feature of a large part of the Jurassic sediments is the strongly diachronic nature of the distribution of facies controlled by the varying bottom relief of the sedimentation basin and by some local factors related to synsedimentary tectonic episodes. The Sponge-Globuligerinid Series, beginning the profile of the Upper Jurassic sediments and representing the deepest sedimentation stage in the open shelf conditions, is characterised by a relatively high homogeneity of lithology in the whole Carpathian Foreland area. The ‘S’ biohermal complex developed over the elevated zone composed of several smaller tectonic elements, whilst the ‘N’ biohermal complex developed on a large, elevated part of the horst zone. The intensively developing ‘N’ and ‘S’ biohermal complexes affected successive deposition of the Late Jurassic sedimentary basin in the study area more and more. Those biohermal complexes were the source of the material redeposited into deeper parts of the sedimentary basin. On seismic profiles in the south-east neighbourhood of the ‘S’ biohermal complex, there is a characteristic high-amplitude record including the entire reflection set of variable dip angles. The frequent polarity changes which are visible within this zone in the Apparent polarity attribute, as well as the extremely variable range of values the Relative acoustic impedance attribute, prove the strong lithological differentiation of this rock complex. During the Tithonian time (sedimentation of the Coral-Oncolite Series), there was clear unification of the sedimentation conditions in the entire Carpathian Foreland area, mainly due to disappearance of the bottom relief diversity. At the same time another stage of dislocation reactivation occurred, as evidenced by the angular unconformity and the erosion traces of older sediments associated with this unconformity. The deposits of the Lower Shellbed-Oolite Series scattered throughout the research area represent various types of shallow-water sedimentation environments (including tidal, lagoon, and barrier zones) that developed in the Carpathian Foreland area on the borderline between the Late Jurassic and the Early Cretaceous. The sedimentation environment of the Marly-Shellbed Series dated to the Berriasian can be described as extremely shallow-water, with lagoon facies and under the influence of brackish environments. The sediments of the last two series of the Lower Cretaceous (i.e. the Mudstone-Limestone and Upper Shellbed-Oolite Series) represent the shallow-marine facies associated with marine transgression that took place during the Valanginian. The processes that have had the greatest impact on the current character and preservation of the rock series under study can be pinpointed and a comprehensive characterisation of these formations can be undertaken thanks to the depositional history of the Late Jurassic – Early Cretaceous sedimentary basin of the Carpathian Foreland presented herein, the macroscopic examination of the available core material, the microfacial and micropalaeontological analysis of individual lithostratigraphic units, and the interpretation of the seismic image.
Three trackways attributable to the ichnospecies Bifurculapes laqueatus Hitchcock, 1858 found in Lower Jurassic rocks of the Newark Supergroup in northeastern North America are preserved in association with current lineations. Each trackway takes turns so that parts of the trackway parallel the current lineations. This parallelism is interpreted as evidence that the trackmakers were entrained in flowing water and had to change course due to the current. If this interpretation is correct, then morphological differences between B. laqueatus and terrestrial insect trackways could be explained by the trackmaker moving subaqueously. Further, B. laqueatus would constitute only the second insect trackway from this region to be recognized as being made subaqueously. From an ecological standpoint, the aquatic insects that made B. laqueatus were probably near the base of the local food chain, the apex predators of which were piscivorous theropod dinosaurs.
An excavation dug out in the glacially transported rock masses at Golaszyn near Łuków (eastern Poland), revealed the presence of deposits unknown so far in this area. These are older than the only known so far here glacially transported clays containing concretions with splendidly preserved ammonites of late Callovian at Łapiguz brickyard of Łuków. The succession exposed consists of sands and sandstones of Middle Callovian age which rest on red-brownish clays. The latter may be compared with the Triassic - Buntsandstein deposits of the northwestern Lithuania, that is the home area of glacially transported rock masses, commonly occurring in eastern Poland in the Łuków area. The new geological discoveries markedly increase a set of attractions for the promotion of the Łuków region for the education and geotourism purposes.
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Information on Jurassic palynomorphs from the Greater Caucasus is potentially of great importance, but its availability to the international research community is severely limited. New palynological data for Toarcian deposits of the Western Caucasus are recorded in the present paper. Particularly, dinoflagellate cysts are described for the first time from the Bagovskaja Formation; palynomorphs are found in sandstone levels within this unit. The most representative assemblage includes pollen (with predominant bisaccate pollen), spores (Cyathidites being commonest), and dinoflagellate cysts amongst which the predominant taxon is Nannoceratopsis spiculata. The dinocyst assemblage implies a late Toarcian age for the upper part of the Bagovskaja Formation. On the basis of these new palynostratigraphical results, the range of the formation is extended; previously, only the lower part had been dated on ammonite evidence.
Possible plate tectonic controls on faunal diversity dynamics have been discussed in the geological literature for around 50 years. The new model of plate tectonic processes is here linked to Jurassic generic diversity (simple α-diversity) of brachiopods. This comparison offers three observations, four hypotheses and three unresolved issues. Most importantly, changes in the global plate root mean square speed coincided with brachiopod diversity dynamics, which can be explained hypothetically by either environmental disturbance triggered by more active plate motion or activity of any process (such as eustasy) tied to plate tectonic mechanisms and with an impact on marine benthic communities. It is also established that global generic diversity dynamics of brachiopods during the Jurassic coincided with the regional picture as established for the Northern Caucasus and the Swiss Jura Alps; this coincidence is difficult to explain with regard to plate tectonics. These and other speculative considerations do not clarify the role of the plate tectonic factor in Jurassic generic diversity dynamics of brachiopods, and, thus, they indicate important issues for further research.
The shallow-marine carbonate deposits of the Reuchenette Formation (Kimmeridgian, Upper Jurassic) in northwestern Switzerland and adjacent France yield highly diverse bivalve associations, but only rarely contain remains of pinnid bivalves. The three occurring taxa Pinna (Cyrtopinna) socialis d’Orbigny, 1850, Stegoconcha granulata (J. Sowerby, 1822) and Stegoconcha obliquata (Deshayes, 1839) have been revised. A lectotype for Pinna (C.) socialis was designated and the taxon is assigned herein to P. (Cyrtopinna) Mörch, 1853, the first record of the subgenus from the Jurassic. A brief review of Stegoconcha Böhm, 1907 revealed two species groups within the genus. Species close to the type species S. granulata are characterized by a nearly smooth anterior shell, followed posteriorly by deep radial furrows and rows of pustules covering the dorsal flank. Another group comprises radially ribbed species related to S. neptuni (Goldfuss, 1837). It includes among others the Paleogene species S. faxensis (Ravn, 1902), extending the known range of Stegoconcha from the Middle Jurassic into the Paleogene. The paper suggests a relationship between Stegoconcha and the Cretaceous Plesiopinna Amano, 1956, with S. obliquata as a possible intermediate species leading to Plesiopinna during the Early Cretaceous. Furthermore, a possible relationship between Stegoconcha and Atrina Gray, 1842 is discussed.
The radiolarian biostratigraphy of the Middle–Upper Jurassic pelagic siliceous sediments (Czajakowa Radiolarite Formation) in the Niedzica succession of the Pieniny Klippen Belt (Carpathians) is interpreted in terms of their age in a stratotype section, and facies equivalents in other tectonic-facies units of this region. The siliceous sediments are represented by radiolarian cherts and silicified limestones which are underlain and overlain by red nodular limestones, equivalents of the Rosso Ammonitico facies. The radiolarian association includes thirty-seven taxa belonging to twenty one genera which represent the Northern Tethyan Palaeogeographic Province. Key radiolarians recorded provide a means of correlation with zonation schemes based on Unitary Associations defined for the Jurassic Tethyan sediments. The age of the Czajakowa Radiolarite Formation in the stratotype section is determined as U.A.Z.9 to U.A.Z.11 corresponding to middle Oxfordian up to Kimmeridgian. Comparison of radiolarian biozones from the stratotype section with other facial equivalent sections in the Pieniny Klippen Belt reveals a significant diachronism for both the lower and the upper limits of the Jurassic pelagic siliceous facies.
Neptunian sills at Rocca Busambra, a fragment of the Trapanese/Saccense Domain in western Sicily, host the most abundant ammonite and gastropod fauna which has ever been recorded from the Jurassic of the western Tethys. The fauna is dominated by parautochthonous organisms which were swept into the sills by gentle transport. Ammonites are characterized by perfect preservation and small size, a feature which is due to the predominance of microconchs but also of stunting. The most complete sill is 0.7 m thick and could be separated into 17 levels which range in age from the early Toarcian into the late Kimmeridgian, thus representing the most extreme case of palaeontologically and depositionally documented stratigraphic condensation in Earth history. The unique feature of the Rocca Busambra sills is due to the interaction of three processes: extreme stratigraphic condensation on the sea floor, weak tectonic fracturing of the host rock and repeated reopening on top of already existing sills. Contrasting percentages of gastropods in individual levels reflect sea-level oscillations which correspond to long known low- and highstands during the Jurassic of the western Tethys. Comparisons with other ammonite-bearing sill faunas reveal several similarities, but represent only short-timed phases of tectonic pulses and deposition.
Stwierdzono, iż zbiorowiska zaroślowe typu czyżnie (Rubo fruticosi-Prunetum spinosae) występujące w północnej części Wyżyny Krakowsko-Częstochowskiej są siedliskami rzadkich w Polsce porostów z rodzaju Usnea. Spośród 8 przebadanych zbiorowisk zaroślowych w połowie z nich (4) odnotowano brodaczki, co potwierdza fakt ich stałej obecności w opisywanych siedliskach na Jurze. Odkryte siedlisko porostów z rodzaju Usnea jest nowe i nigdy dotąd nie było opisane. Dotychczas w literaturze opisywano występowanie brodaczek głównie w starych, naturalnych lasach typu puszczańskiego, których były, między innymi wskaźnikami. Zbiorowiska zaroślowe z obecnością brodaczek w pełni zasługują na ochronę oraz szczególną uwagę w trakcie wykonywanych przez leśników prac pielęgnacyjnych.
EN
It was found out that the plant communities of the scrub type (Rubo fruticosi-Prunetum spinosae) occurring in the northern part of the Cracow-Czestochowa Upland are habitats of rare in Poland lichens of the Usnea genus. Among 8 studied scrub communities, Usnea was observed in half of them which testifies its permanent presence in described habitat of Jura. The discovered habitat of the Usnea lichens is new one and was not reported till now. The occurrence of Usnea was reported so far mainly from old natural primeval forests for which it is considered an indicator. Scrub communities with Usnea presence deserve protection and have to be especially attended by foresters during maintenance works.
Na terenie rezerwatu „Zielona Góra” odnotowano 34 gatunki porostów w dwóch grupach ekologicznych: porosty epifityczne i epiksyliczne. 56% bioty stanowiły gatunki o plechach skorupiastych, a 44% porosty o plechach listkowatych i krzaczkowatych. Najbogatszą biotę porostów stwierdzono na zboczu ostańca wapiennego „Zielonej Góry” o ekspozycji SE. W rezerwacie odnotowano występowanie chronionego w Polsce gatunku Graphis scripta (L.) Ach. [1] na powierzchni ok. 0.7 ha. Gatunek ten występował w rezerwacie „Zielona Góra” tylko na korze pni grabu na wysokości od 3 cm do 1 m na stanowiskach badawczych 1–4. Spośród gatunków z regionalnej listy porostów podlegających ochronie w województwie śląskim odnotowano dwa gatunki Parmeliopsis ambiqua i Parmelia saxatilis [2]. Niewielka liczba taksonów stwierdzonych w rezerwacie była wynikiem bardzo silnego zanieczyszczenia tego obszaru chronionego przez aglomerację częstochowską, a w szczególności hutę „Częstochowa” leżącą zaledwie 1 km od „Zielonej Góry”.
EN
34 lichen species in two ecology groups: epiphytic and epixylic lichens were identified at the area of “Zielona Góra” forest reserve. 56% of the biota was composed of species with a crustose thallus and 44% constituted lichens with foliose and fruticose thalli. The richest lichen biota was noticed on the slope of limestone outlier of “Zielona Góra” with SE exposure on the area of 0.7 ha. The occurance of Graphis scripta (L.) Ach. species was recorded on this area [1]. The mentioned species occured in “Zielona Góra” reserve only on the bark of harnbeam on the hight between 3 cm up to 1 m on the states 1–4. Four epiphytic species were identified among species under treath from silesian regional list of lichens: Parmeliopsis ambiqua and Parmelia saxatilis [2]. A small number of taxa recorded in the reserve resulted from heavy pollution of that protected area caused by Czestochowa agglomeration and in particular by the Czestochowa Steelworks located only 1 km from “Zielona Góra” area.
The Middle to Late Jurassic succession of the Jhura Dome (Jhurio and Jumara formations) of the Mainland Kachchh, western India, comprises a ~500 m thick succession of clastic carbonates and mixed siliciclastic-carbonates, intercalated with shales. The sequence, as based on sedimentological characteristics, exhibits six sedimentary facies and four subfacies. Certain exceptional bands of the ripplemarked calcareous sandstone, shale and oolitic limestone facies are rich in ammonites, belemnites, brachiopods and bivalves. Thirty four ichnogenera were also identified and analysed paleoecologically. These trace fossils represent five ethological categories and six ichnoassemblages. Seventeen ichnoguilds are demonstrated based on space utilization for characterising the ecological complexity of ichnoassemblages. Bathymetric control of the trace fossils resulted with development of Skolithos, Cruziana and Zoophycos ichnofacies type conditions. The sedimentological and ichnological data analysis revealed seven distinctive depositional regimes ranging from offshore shelf below storm wave base to middle shoreface.
The Jurassic succession west of Wulong village, Tingri County, southern Tibet, is described. Lithostratigraphical classification uses pre-existing terminology for formations, and an informal subdivision into members is proposed. An important structural dislocation, in the form of a small-scale flower structure, affects the Zhamure Formation straddling the Triassic/Jurassic boundary but does not affect the underlying Derirong Formation (Rhaetian) or the overlying Wulong Formation (Lower Jurassic). No other major structural discontinuities could be recognised. New finds of ammonites in situ include a new genus and species of possible schlotheimiid, Womalongiceras inflatum, with a probable age of Sinemurian or slightly younger. Two separate beds yielded rich assemblages of crushed ammonites identified as Nyalamoceras nyalamensis Chao and Wang (1956) here interpreted as a hammatoceratid. The age of these is reinterpreted as uppermost Aalenian on the basis of an accompanying specimen of ?Pseudolioceras (Tugurites) sp. nov. and poorly preserved ammonites from higher beds identified as graphoceratids (?Graphoceras).
An integrated study based on calcareous nannofossils, organic-walled dinoflagellate cysts, and ammonites from the Washtawa and Kanthkot formations of the Wagad Uplift have allowed a detailed documentation of the stratigraphic position of these formations within the Oxfordian and Kimmeridgian sediments of the Kachchh Basin, western India. The nannofossil assemblages from the lower part of the Nara Shale Member exposed in the Nara and Washtawa domes, the Kanthkot Ammonite Beds along the Trambau River section, and the Patasar Shale Member exposed along the Trambau River section and the Patasar Tank section in the eastern part of the Wagad Uplift belong to the NJ 14 Cyclagelosphaera margerelli Zone of the Early Oxfordian, the NJ 15a Lotharingius sigillatus Zone of the Middle Oxfordian, and the NJ 15b Cretarhabdus conicus of Early Kimmeridgian age, respectively. Zonation schemes, based on calcareous nannofossils, dinoflagellate cysts, and ammonites were calibrated highlighting their biostratigraphic potential. These studies may represent a reference biochronology for Oxfordian–Kimmeridgian age strata applicable to the Tethyan realm of which India was a part during Late Jurassic times.
Two dinosaur footprints: Eubrontes cf. giganteus and Grallator tenuis, both attributed to theropods, have been found in the Lower Jurassic Thaiat Member of the Lathi Formation at the Thaiat ridge, near Jaisalmer in western Rajasthan, India. The footprints were left in sediments of a tidal origin, located in profile a few meters above a marked transgressive/flooding surface. They show different states of preservation – the smaller Grallator tenuis represents a well-preserved concave epirelief footprint on the upper surface of a sandstone containing nerineid gastropod shells, while the bigger Eubrontes cf. giganteus footprint shows a rare state of preservation as a positive epirelief on the top of a calcareous sandstone bed, where recent erosion exposed the footprint cast by removing the mud above and around the footprint. The Thaiat ridge section has been amended in its lower part, to indicate the marked transgressive surface. Geochemical analyses and calculated weathering indices (such as CIA) show that the hinterland climate was seasonal to semi-arid during deposition of that part of the succession.
Przedstawiono charakterystykę i wyniki mikrotermometrycznych badań inkluzji fluidalnych występujących w spoiwie skał osadowych wieku od kambru po perm oraz od jury po paleogen i miocen. Inkluzje mają charakter pierwotny i wtórny; na ogół są jedno- lub dwu-, rzadziej trójfazowe. Wypełniają je paleofluidy o zróżnicowanym składzie i różnej gęstości. Temperatura homogenizacji, która stanowi przybliżenie temperatury zamknięcia fluidu w minerale, wykazuje zmienność związaną z rodzajem spoiwa i z historią geologiczną badanego obszaru. Zasolenie fluidów również jest zmienne i zależy od rodzaju spoiwa i od lokalizacji. Połączenie analiz inkluzji np. z badaniami izotopowymi pozwala na szerszą interpretację wyników oznaczeń mikrotermometrycznych.
EN
Characteristics and results of microthermometric studies of fluid inclusions which occur in the cements of sedimentary rocks of the age oscillating form Cambrian to Permian and from Jurassic to Paleogene and Miocene are presented. The inclusions studied are primary and secondary in origin. They display one, two or, less frequently, three phases. The inclusions are filled by the paleofluids of variable compositions and densities. The homogenization temperature, which corresponds to the minimum estimation of the trapping temperature, shows variability in respect to the cement type and geological history of the study area. Salinities of fluids are also variable in respect to the cement type and locality. Wider interpretation of the microthermometric analyses is enabled when they are combined, e.g., with the isotopic studies.
Wykonano badania mineralogiczne i geochemiczne mineralizacji septarii z ciemnych iłów występujących w Gnaszynie koło Częstochowy. Reprezentują one dolną część środkowego batonu. Rozpoznana mineralizacja to piryt, sfaleryt, galena, syderyt i kalcyt, które lokują się we wnętrzu septarii. Spękania septarii mogą być związane z procesami diagenezy lub ze zjawiskami tektonicznymi, które w miękkich iłach są niewidoczne. Mineralizacja ma charakter wtórny. Obecność niewielkich ilości kruszców może być związana z siarczkami triasu i niższej części jury redeponowanymi do zbiornika jurajskiego. Roztwory mineralizujące septarie zostały po sedymentacji iłów i czasie ich diagenezy. Po spękaniu septarii roztwory te wnikały w powstałe w septariach szczeliny prowadząc do ich mineralizacji.
EN
Mineralogical and geochemical examination of septaria from dark silts present in Gnaszyn near Częstochowa was conducted. They represent the lower part of the Middle Bathonian. Recognized mineralization includes pyrite, sphalerite, galena, siderite and calcite, localized inside the septaria. The cracks in septaria may be connected with the processes of diagenesis or with tectonic phenomena that are invisible in soft silts. The mineralization is secondary. Presence of small amounts of ores may be linked with the Triassic and lower Jurrasic sulphides redeposited in the Jurrasic pool. Mineralizing solutions were left after silts sedimentation and during their diagenesis. After the septaria cracked, the solutions were absorbed into the cracks, causing their mineralization.
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