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1

The margins of the Early Jurassic Trento Platform (Southern Alps)

Riva Alberto, Gianolla Piero, Caggiati Marcello

Geotourism / Geoturystyka

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2023

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nr 1-2 (72-73)

59--59

EN

Examples of Lower Jurassic carbonate platform margins are rare, probably due to the scarcity of good outcrops. One of the major palaeogeographic units of the Mesozoic Tethys, the Trento Platform, however, shows two different margin types facing the Belluno and the Lombardian basins. While the western margin, facing the Lombardian Basin, is showing an ooidal unit with frequent mud mounds (Massone Oolite), the eastern margin was poorly characterized, mainly due to difficult stratigraphic definition and problematic accessibility of outcrops. The eastern platform margin characteristics are strictly controlled by tectonic activity and the type of carbonate factory; the differences between the eastern and the western margin could be linked to windward-leeward position of the platform margin, more protected to the west than to the east. Subsidence increased since Late Triassic, due to the opening of the Alpine Tethys, defining shallow water areas, dominated by subtidal and peritidal muddy carbonates, and deeper basins, such as the Belluno and Lombardian Basin. More than 500 m of mud-dominated carbonates developed until Early Sinemurian, when major switch in the carbonate factory occurred. The Hettangian-Early Sinemurian margin is usually not well exposed and is strongly dolomitized and appears to be a tectonically controlled escarpments. Since Late Early Sinemurian, the carbonate factory changed and led to a huge production of peloids and ooids, promptly shed in the surrounding basin: in the Eastern Trento Platform we recognize a 400/500 m thick wedge of Sinemurian to Pliensbachian ooidal calcarenites pinching-out towards the basin, with scattered bioconstructions made of calcareous sponges across the margin. This wedge pinches out also towards the platform interior, showing that the ooids were poorly preserved on the platform top. The preserved slope shows an angle of about 20-25°. In the western margin, the resedimented ooids are more limited, probably due to the limited size of the marginal carbonate factory. In the Late Pliensbachian, probably in the Margaritatus zone, a drowning phase affected part of the eastern carbonate platform, switching to encrinitic calcarenites, while in the western one carbonate production continued until Bajocian. These encrinites are extremely thin on the platform top, but a resedimented wedge in the proximal basin highlights the position of the topographic margin. The margins of the Trento Platform is a rare example of Early Jurassic carbonate platform margin that can be used as a reference for coeval carbonate platform depositional systems.

2

Profil sedymentologiczny przedkelowejskich (jurajskich) utworów silikoklastycznych w otworze badawczym Cianowice 2 (okolice Krakowa)

Pieńkowski G.

Biuletyn Państwowego Instytutu Geologicznego

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2014

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nr 459

147--156

PL

W otworze Cianowice 2 (okolice Krakowa), bezpośrednio na niezgodności erozyjnej ze zmetamorfizowanymi łupkami neoproterozoiku (ediakaru), a pod węglanowymi utworami jury środkowej (keloweju), występuje ponad 20-metrowy kompleks utworów silikoklastycznych (brekcje, zlepieńce, piaskowce, mułowce z podrzędnymi wkładkami węgli, syderytów i margli). Wykonane w czterech próbkach analizy palinologiczne pozwoliły uzyskać stosunkowo ubogi zespół miosporowy o szerokim zasięgu stratygraficznym, niedający rozstrzygających rezultatów, potwierdzający bardzo ogólnie jedynie jurajski wiek utworów (Jadwiga Ziaja, inf. ustna). Pozycja stratygraficzna tych utworów nie jest jasna – mogą one należeć zarówno do wczesnej jury, do środkowej jury, jak i obu tych epok, a najniższe warstwy grubookruchowe mogą być jeszcze starsze i reprezentować późny trias. Cały nawiercony kompleks silikoklastyczny został podzielony na pięć wyraźnych sukcesji. W poszczególnych sukcesjach dominują podrzędne cykle proste o ziarnie (i energii przepływu) malejący ku górze. Sukcesja 1 składa się z brekcji i zlepieńców o nieuporządkowanej strukturze, co wskazuje na spływy mułowe (soliflukcyjne), przechodzące być może w spływy wodne w środowisku stożków aluwialnych. Sukcesja 2 składa się z pięciu cykli prostych piaszczysto-mułowcowych, ze śladami wegetacji roślinnej, utworzonych na równi rzecznej. Sukcesja 3 składa się w całości z mułowców o genezie jeziorno-bagiennej, z licznymi śladami wegetacji roślinnej i węglami w stropie. Sukcesje 4 i 5 to ponownie sukcesje złożone z cykli prostych o genezie rzecznej. Cały profil badanych utworów silikoklastycznych wykazuje peneplenizację żywej początkowo rzeźby obszarów źródłowych i ciągły spadek energii procesów depozycyjnych ku górze aż do stropu sukcesji 3 z węglami, a następnie ponowny nawrót równi rzecznej. Poszczególne sukcesje są oddzielone powierzchniami nieciągłości (przeważnie erozyjnymi, jedynie spąg sukcesji 3 ma charakter odpowiednika powierzchni mogącej być korelatywną powierzchnią transgresji), które mogą stanowić regionalne powierzchnie korelacyjne (zwłaszcza dolne granice sukcesji 1, 3 i 5). Sukcesje o dolnych granicach erozyjnych mogą odpowiadać sekwencjom depozycyjnym. Porównania regionalne otworu wiertniczego Cianowice 2 z otworem Parkoszowice 58 BN położonym ok. 40 km na północny zachód skłaniają do uznania tych utworów wstępnie za jurę dolną (najprawdopodobniej pliensbach–toark), grubookruchowe utwory sukcesji 1 w spągu otworu mogą reprezentować także wiek późnotriasowy. Do czasu uzyskania bardziej precyzyjnych danych biostratygraficznych lub chemostratygraficznych nie można potwierdzić tego z całą pewnością ponad stwierdzenie, że są to utwory jurajskie starsze od keloweju.

EN

In the Cianowice 2 borehole (located in the vicinity of Kraków), straight on the erosional unconformity on the top of metamorphosed Neo-Proterozoic (Ediacaran) shales and below carbonate deposits of Callovian, 20 meters thick interval of siliciclastic rocks has been encountered. The siliciclastic rocks are composed of conglomerates, sandstones, mudstones and subordinate intercalations of coal, siderite and marls. Stratigraphical position of this interval can be inferred based on poorly-preserved miospore assemblage, spanning relatively long geological time (Jadwiga Ziaja, pers. comm.) – it can represent either Early or Middle Jurassic, or both of those epochs, while the lowermost coarse-grained package can be even of an older, i.e. Triassic age. The interval was subdivided into 5 well-distinguished sedimentary successions, separated by bounding surfaces, mostly of erosional character – only succession 3 starts with sharp lithological contrast between sandy deposits and overlying mudstones, which reflects flooding and rapid retrogradation (either lacustrine or lagoonal). All these bounding surfaces (particularly bottoms of successions 1, 3 and 5) are of regional correlative significance-erosional bounding surfaces can represent sequence boundaries, while bottom of the succession 3 can represent correlative surface of a transgression. In each succession, except for the lowermost one, subordinate fining-upward cycles are dominating. They represent diminishing-upward energy of transport. The succession 1 is composed of breccia and conglomerates with chaotic structure, indicative of mudflow – dominated fans, possibly passing into alluvial fans and back to the mudflow fan again in the top. There is a marked lithological contrast (possibly connected also with considerable hiatus) between the coarse-grained deposits of succession 1 and following successions built of fine-grained sandstones, siltstones, mudstones and claystones. The succession 2 is composed of five fining-upward cycles, indicative of fluvial environment (fluvial plain), with traces of plant vegetation. The succession 3 is entirely composed of mudstones of lacustrine origin, with numerous traces of plant vegetation, siderite concretions and bands and coals at the top. Successions 4 i 5 again contain typical fining-upward fluvial cycles with traces of plant vegetation. The overall profile shows peneplanation of a landscape and continuous diminishing of energy of sedimentary processes up to the top of succession 3 marked with coals. Then, fluvial sedimentation returned. Regional comparison of the Cianowice 2 borehole with borehole Parkoszowice 58 BN, located some 40 km to NW tends to suggest the Early Jurassic (most probably Pliensbachian–Toarcian) age of the profile (the lowermost coarse-grained part can be of a Triassic age), but until more reliable biostratigraphical or chemostratigraphical evidences are obtained, these more detailed interpretations of stratigraphical division remain tentative.

3

Tropy dinozaurów z wczesnojurajskiego ekosystemu z Sołtykowa w Górach Świętokrzyskich

Niedźwiedzki G.

Biuletyn Państwowego Instytutu Geologicznego

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2011

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nr 447

49--98

PL

W artykule została przedstawiona rekonstrukcja wczesnojurajskiego zespołu dinozaurów (sprzed około 200 milionów lat) na podstawie danych paleoichnologicznych (skamieniałości śladowych – tropów dinozaurów). W latach 1997–2009 autor zebrał ze stanowiska w Sołtykowie materiał badawczy liczący kilkadziesiąt okazów, wykonał również szereg dokumentacji fotograficznych oraz replik gipsowych (odlewów) z okazów pozostawionych w terenie. Ten materiał to tropy dinozaurów drapieżnych – teropodów oraz roślinożernych zauropodomorfów i wczesnych dinozaurów ptasiomiednicznych. Artykuł zawiera również charakterystykę środowiska abiotycznego oraz innych znalezisk paleontologicznych i paleoichnologicznych (skamieniałości śladowe bezkręgowców). Odsłonięcie Sołtyków reprezentuje unikatowy zapis wczesnojurajskiego ekosystemu lądowego, związanego z rozwojem rzeki anastomozująco-meandrującej oraz przyległych do niej obszarów równi zalewowej. Stanowisko to dostarcza danych paleoichnologicznych użytecznych do określenia różnorodności biologicznej, stanu ewolucyjnego i biologii wczesnych dinozaurów oraz innych ówczesnych kręgowców lądowych (gadów ssakokształtnych wczesnych ssaków, lepidozaurów, pterozaurów i wczesnych krokodylomorfów).

EN

This paper presents reconstruction of the Early Jurassic dinosaurs assemblage (about 200 million years old) based on paleoichnological data (trace fossils – tracks of dinosaurs). In 1997–2009, the author collected paleontological material counting several tens of specimens from the Sołtyków clay-pit and made photographic documentation in the site, as well as replica plaster (casts) from specimens left in the field. This material contains predatory dinosaur tracks and tracks of herbivorous sauropodomorphs and early ornithischia. This publication also includes description of the abiotic environment and other paleontological finds (e.g., insects, bivalves fossils) and paleoichnological finds (invertebrate trace fossils). The Early Jurassic deposits from Sołtyków represent a unique record of an ecosystem of in-land environment connected with the development of an anastomosing-meandering river and adjacent flood plains. This locality provides paleoichnological data valuable for determining biodiversity, evolutionary position and biology of the early dinosaurs and other terrestrial vertebrates (mammal-like reptiles, early mammals, lepidosaurs, pterosaurs and early crocodylomorphs).

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Taxonomy and palaeoecology of the Early Jurassic macroflora from Odrowąż, central Poland

Barbacka M., Ziaja J., Wcisło-Luraniec E.

Acta Geologica Polonica

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2010

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Vol. 60, no. 3

373-392

EN

The locality of Odrowąż is an Early Jurassic section in central Poland, with a taxonomically relatively poor flora. The available material is composed of both macro- and microremains. The macroremains, represented by 720 specimens (491 suitable for study), consist mainly of leaves, shoots, rhizomes, as well as male and female cones and fragments of other fructifications. sphenophytes, pteridophytes, pteridosperms, bennettites, cycads, ginkgophytes, conifers are represented by single taxa, only ferns are more diverse. The material is dominated by the conifer Hirmeriella muensteri (schenk) Jung and the benettite Pterophyllum alinae Barbacka sp. nov. Taxonomically, the ferns are the most diverse group (five species belonging to five genera). Most of the plants show adaptations to wet conditions, which corresponds well to the proposed sedimentary environment, a river plain. The complete material shows, however, that the floral remains originated from a wider area situated along the river and on its banks. One new genus, Odrolepis, three new species, Odrolepis liassica, Pterophyllum alinae, Paracycas minuta, and one new forma, Todites princeps, forma trilobata, are described. some forms are left in open nomenclature.

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Paleogeografia południowo-wschodniej Azji i jej związek z rozmieszczeniem wczesnojurajskich budowli małżowych (z grupy Lithiotis) na tle wielkiego wymierania trias/jura

Krobicki M., Golonka J.

Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2009

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T. 35, z. 3/1

79-90

EN

The separation of Laurasia and Gondwana, which was initiated by the Triassic break-up of Pangea, continued during Early-Middle Jurassic times. The origin of the narrow sea strait. so-called "Hispanic Corridor", took place between these two continents and connection of the Panthalassa Ocean (Proto-Pacific) and western (Alpine) Tethys gradually started in Early Jurassic, most probably in Sinemurian-Pliensbachian times. Recovery of marine fauna after Triassic/Jurassic mass extinction event was mainly marked by world-wide distribution of Lithiotis-type bivalve buildups. They indicate mainly shallow-marine/lagoon-type carbonate sedimentation and palaeogeographic/geodynamic regimes during break-up of Pangea in Pliensbachian-Early Toarcian times.

6

Zagadkowa roślina z wczesnej jury Gór Świętokrzyskich

Gierliński G.D., Ploch I., Sabath K., Ziaja J.

Przegląd Geologiczny

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2006

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Vol. 54, nr 2

139-141

EN

Fossils plants (less than 0.5 m high) preserved in upright position were found in Śmiłów Quarry (E of Szydłowiec) at the northern slope of the Holy Cross Mountains. The plants were preserved as impressions of ascending narrow-leafed stems in fine-grained sandstone of the Drzewica Formation (upper Pliensbachian). The leaves are 5-25 cm long and about 2-5 mm wide; the angle between them and the short main axis ranges within 20-30o. Morphology of the plant resembles schizeacean ferns, but also that of Aethophyllum stipulare Brongniart 1828 from Anisian of France, recognized by Grauvogel-Stamm (1978) as an herbaceous gymnosperm. Grauvogel-Stamm (1978) supposed that the leaves Podozamites and cone scales Swedenborgia, common in Jurassic strata of higher palaeolatitudes, are derived from descendants of Aethophyllum. Podozamites leaves often occur in many dinosaur track-bearing horizons in the Polish Jurassic. Thus, herbaceous conifers might have played an important and often underestimated role in the Mesozoic ecosystems (possibly as a substantial part of dinosaur diet). The possiblity of coniferous equivalents of Cenophytic herbaceous angiosperms, as well as a possibility of their coevolution with Mesozoic low browsing and grazing herbivore megafauna is worth further palaeobotanical and palaeoecological studies.

7

Ślady wielkich teropodów z wczesnojurajskich osadów Gór Świętokrzyskich

Niedźwiedzki G.

Przegląd Geologiczny

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2006

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Vol. 54, nr 7

615-621

EN

Numerous gigantic and large theropod dinosaur footprints were recently discovered in the Lower Jurassic deposits of the Holy Cross Mountains (central Poland). These finds provide paleoichnological evidence for the occurrence of gigantic predatory dinosaurs in the earliest Jurassic (Hettangian) times. The gigantic and large theropod tracks came from two well-known lower Hettangian tracksites at Sołtykow and Gromadzice. The Sołtyków outcrop represents a siliciclastic coal-bearing lithofacies association of a fairly well-watered alluvial plain. The sequence from the Gromadzice site is dominated by typical meandering river deposits with lenticular, incised channels and overbank mudstones, rich in drifted flora and plant roots. Hitherto, twenty four specimens of gigantic theropod Eubrontes-like footprints (50–65 cm long) were found at Sołtyków tracksite. Another large theropod footprints (30–45 cm) identified at Sołtyków, resemble Kayentapus-like ichnites and classic ichnotaxa of the Newark Supergroup (i.e., Eubrontes giganteus Hitchcock, 1845 sensu Olsen et al., 1998). In the Gromadzice site, large Eubrontes giganteus, Eubrontes sp., and cf. Eubrontes sp. footprints were identified. The intriguing gigantic ichnites from Sołtyków are more similar to the large prints left by Middle–Late Jurassic theropods than to other finds from the Early Jurassic.

8

Sołtyków - unikalny zapis paleoekologiczny wczesnojurajskich utworów kontynentalnych

Pieńkowski G.

Volumina Jurassica

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2004

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Vol. 2, no. 1

1-16

EN

The Sołtyków exposure is an old, long time abandoned clay pit. This exposure became known as a classical outcrop of alluvial-lacustrine deposits. Floral remains point to the earliest Jurassic (Lias 1-2) age, and the sequence stratigraphic correlation allows to narrow its age range to the Early Hettangian (Planorbis biochronozone). Sołtyków exposure fits the avulsion-controlled (crevassing- anastomosing) fluvial sedimentation model, however, some features such as laterally-accreted bedding point also to presence of high-sinuosity/meandering streams. Relatively thick and individualised package of lacustrine deposits occurring in the Sołtyków outcrop points to some permanency of the lake/swamp area during deposition of the sediments visible in the outcrop. Palaeosols are both of Podzol and Histosol type. The plant fossils in the Sołtyków exposure are very abundant and well preserved. The list of plants includes Neocalamites, the matoniacean, osmundacean and other indeterminate ferns, as well as pteridosperms, benettitaleans and conifers. Non-marine trace fossils comprise Coprinisphaera, Scoyeniaand aquatic Mermia ichnofacies. Other fossils that occur in Sołtyko?w are represented by Unionidae freshwater bivalve assemblage, insect remains, fresh-water ostracodes and scales of palaeoniscid fish. The Sołtyków exposure is well known Early Jurassic tracksite with numerous dinosaur footprints, mainly left by theropods and sauropods, and early mammalian footprints. The dinosaur nesting ground was also described. Recently, the Sołtyków exposure has been declared a natural reserve. Nature conservation problems are discussed. Due to many unique finds in Sołtyków (the oldest known evidence of gregarious ethology of dinosaurs, the biggest known Early Jurassic theropod footprints, rich and well-preserved invertebrate ichnoforms and plant remains, this exposure should be enlisted on the UNESCO World Heritage List (in geological cathegory). Moreover, the idea of “Kamienna Valley” geopark, comprising Sołtyków and other valuable outcrops in the region, is introduced.