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Wyświetlanie 1-4 z 4
Tytuł:
Development and chronology of the Late Jurassic shallow-water carbonate deposits of the Holy Cross Mountains area, central Poland
Autorzy:
Wierzbowski, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/28883744.pdf
Data publikacji:
2023
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
history of sedimentation
cyclicity
climatic factors
tectonic factors
ammonite stratigraphy
Late Oxfordian
Kimmeridgian
Early Tithonian
historia sedymentacji
cykliczność
czynniki klimatyczne
czynniki tektoniczne
stratygrafia amonitów
późny oksford
wczesny tyton
Opis:
The Late Jurassic shallow-water carbonates with intervening clayey-marly deeper-water deposits in the Holy Cross Mts. area formed over large bank of the elevated part of the Northern Tethyan Shelf during about 12 myr. They comprise three main successions (I, II and III) deposited partly in different environmental conditions, controlled by tectonic and climatic factors, and still preserved in the  north-eastern margin, the north-western margin and the south-western margin of the Holy Cross Mountains. The history of sedimentation is presented according to the concept of the large tectono-stratigraphic units COK, LUK and KVB, which owe their origin to variable rates of tectonic subsidence, as introduced by Kutek (1994) for the area of central Poland. The studied deposits of the COK megasequence cor- responding to the Upper Oxfordian and the Lower Kimmeridgian up to the Hypselocyclum Zone consist of coral limestones, various grained (including oolitic) limestones, and micritic limestones formed over the gradually enlarging shallow-water carbonate platform of the Holy Cross Mts. This platform was subsequently subdivided into two elevated areas, separated by a depressed zone in the middle, bounded by the Nowe Miasto–Iłża–Bałtów Fault Zone in the north-east and the Holy Cross Fault System in the south. The younger mega- sequence LUK with it strongly transgressive character marks the successive stages of the marine transgression which entered the central, lowered part of the area of the Holy Cross Mts. from the west, where it appeared already in the early Hypselocyclum Chron. It succes- sively spread across the Holy Cross Mts. area towards the north-east and south bringing everywhere the deposition of various oyster lu- machelles and marls with ammonites at the end of the Hypselocyclum Chron and during the Divisum Chron of the Early Kimmeridgian to the Acanthicum/Mutabilis Chron of the earliest Late Kimmeridgian. The following megasequence KVB is represented by the detrital lu- machelles and chalky limestones with nereineids of the Eudoxus Chron of the Late Kimmeridgian marking the development of still younger shallow-water carbonate platform in the uplifted areas in the north-eastern and possibly the south-western margins of the moun- tains, allegedly subdivided by a deeper area of sedimentation of marly deposits. The youngest Late Jurassic deposits of the Holy Cross Mts., are very fragmentarily preserved, mostly because of Early Cretaceous uplift and erosion. They suggest an initial episode of complete drowning of the carbonate platform which became covered by marly deposits during the Early Tithonian, and the subsequent restoration of shallow-water carbonate sedimentation at the end of the Early Tithonian.
Źródło:
Volumina Jurassica; 2023, 21; 39--82
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biostratigraphy and sequence stratigraphy of the Lower Cretaceous in the NW part of the Mid-Polish Trough
Autorzy:
Dziadzio, Piotr
Ploch, Izabela
Smoleń, Jolanta
Powiązania:
https://bibliotekanauki.pl/articles/2058689.pdf
Data publikacji:
2021
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Lower Cretaceous
ammonite
foraminifera
ostracod biostratigraphy
nannoplankton biostratigraphy
depositional systems
sequence stratigraphy
relative sea-level changes
NW Poland
Opis:
By comparison with the Lower Cretaceous of central and SE Poland, that of NW Poland (the Pomeranian, Szczecin, and Mogilno-Łódź troughs) has scarce biostratigraphic data. But, despite the lack of Lower Cretaceous exposure in the NW Polish Lowlands, borehole data, including borehole-cores and geophysical logs, allow analysis of complete successions. We refine the stratigraphic units using parallel studies of ammonites, microfauna and calcareous nannoplankton collected from the same intervals, and by correlating age-defined intervals with geophysical logs. Ostracod zones F to A are documented by the presence of ostracod assemblages representing the interval between the Upper Tithonian (ostracod zone F) and the lower part of the Upper Berriasian (ostracod zones E to A). The fragmentary and poorly preserved ammonites allowed only for distinguishing the uppermost Middle and Upper Berriasian (Ryazanian), while the informal subdivisions from the central part of the basin could not be identified unequivocally. Nannoplankton recognized in the succession analysed was very rare due to shallow marine facies of the strata. Only one nannoplankton zone was recognized in the lower part of the succession studied: the CC2 Stradneria crenulata Zone (uppermost Middle and Upper Berriasian and lowermost Valanginian). An additional study only on nannoplankton enabled recognition of certain boreal taxa typical of the BC2 zone of the Uppermost Riazanian. Valaginian ammonites occur in core material located closer to the central part of the trough. Some planktonic foraminiferal species indicate the Lower Aptian. Some Upper Cretaceous nannoplankton zones were also recognized: the CC9 Eiffellithus turriseiffeli (Uppermost Albian to Lower Cenomanian) and UC0, UC1-2 and UC3 zones which correspond to the Upper Albian and Lower as well as Middle Cenomanian. The sequence stratigraphic interpretation was based on geophysical logs with the application of gamma-ray, neutron-gamma, spontaneous potential and resistivity logging, as well as caliper logging. These studies allowed recognition and correlation of sedimentary sequences within the part of the sedimentary basin analysed, characterized by a similar cyclic pattern of geological phenomena described using depositional sequences as in the central and SE part of the Polish Basin. Third-order depositional sequences with maximum flooding surfaces were distinguished. Effective correlation of depositional cycles with biostratigraphy and with the global sea level curve was demonstrated for several boundaries, confirming the applicability of this method for the Polish part of the the Central-European Basin. Other boundaries recognized that are not correlatable and shifted relative to Haq’s curve may reflect autogenous factors (e.g., local tectonics) overlapping with the global changes controlled by allogenic processes
Źródło:
Geological Quarterly; 2021, 65, 4; s. 237--257
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Early Kimmeridgian succession at Kodrąb (Radomsko elevation, central Poland) and its palaeogeographical and palaeotectonic implications
Autorzy:
Wierzbowski, A.
Głowniak, E.
Powiązania:
https://bibliotekanauki.pl/articles/2060417.pdf
Data publikacji:
2018
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
Radomsko elevation
Early Kimmeridgian
ammonite stratigraphy
palaeogeography
synsedimentary tectonics
Opis:
The Early Kimmeridgian succession in the Rogaszyn Quarry at Kodrąb (Radomsko elevation) represents mostly shallow-water carbonate platform deposits that, over wide areas of central Poland were controlled by the activity of the tectonic zone being the prolongation of the Holy Cross lineament. The ammonites collected enable precise recognition of ammonite zones – the Platynota and the Hypselocyclum zones, some subzones and horizons. The precise dating enables detailed correlation of the particular units of the succession with those recognized at the eastern and northern borders of the Wieluń Upland and the NW margin of the Holy Cross Mts. The deposits at Kodrąb from the top of the Planula Zone, through the Platynota Zone, up to the lower part of the Hypselocyclum Zone, reveal markedly smaller thicknesses equaling ~15–20% of those of coeval deposits from the adjoining areas. The differences in sedimentary evolution at Kodrąb during the Early Kimmeridgian resulted mostly from local synsedimentary tectonic movements of fault blocks. Beginning from the late Hypselocyclum Chron, these differences markedly diminished, which resulted from the uniform subsidence of a wider area, and disappearance of the shallow-water deposits of the carbonate platforms, being replaced by deeper-water deposits of the Burzenin Formation.
Źródło:
Geological Quarterly; 2018, 62, 3; 509--521
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A potential stratotype for the Oxfordian/Kimmeridgian boundary: Staffin Bay, Isle of Skye, UK
Autorzy:
Wierzbowski, A.
Coe, A.
Hounslow, M.
Matyja, B.
Ogg, J.
Page, K.
Wierzbowski, H.
Wright, J.
Powiązania:
https://bibliotekanauki.pl/articles/2061313.pdf
Data publikacji:
2006
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
ammonite succession
Oxfordian/Kimmeridgian boundary
microfossils
isotope stratigraphy
magnetostratigraphy
Opis:
A coastal exposure of the Staffin Shale Formation at Flodigarry, Staffin Bay, Isle of Skye, Scotland, UK fulfils the criteria for definition as the Global Stratotype Section and Point (GSSP) for the base of the Kimmeridgian Stage (Upper Jurassic). This marine shale succession was deposited during a long-term transgression, and is part of a complete, relatively well-expanded stratigraphic succession. A rich fauna of ammonites above and below the Oxfordian/Kimmeridgian boundary allows recognition of the Evoluta Subzone (Pseudocordata Zone) and Rosenkrantzi Subzone (Rosenkrantzi Zone) of the Subboreal and Boreal uppermost Oxfordian, and the Densicostata Subzone (Baylei Zone) and the Bauhini Zone of the Subboreal and Boreal lowermost Kimmeridgian). A suitable level for the boundary is thus marked by the replacement of the Subboreal Ringsteadia (M)/Microbiplices (m) by Pictonia (M)/Prorasenia (m), and by the first appearance of Boreal Amoeboceras (Plasmatites). Detailed study of the microfossils reveals an excellent dinoflagellate succession. A variety of stratigraphically important dinoflagellates are found, the assemblages being intermediate in character between Boreal and Subboreal ones. The magnetostratigraphic data, though rather troublesome to extract, shows a polarity pattern which can be confidently correlated to other UK boundary sections. The upper boundary of a normal magnetozone falls at, or very near, the proposed Oxfordian/Kimmeridgian boundary. The 87Sr/86Sr ratio at the boundary, based on an analysis of belemnites, lies between 0,70689 and 0,70697, averaging 0.70693. Matching worldwide trends, no distinct change in the ratio is seen across the boundary. A lack of variations in the carbon isotope composition of belemnites across the Oxfordian/Kimmeridgian boundary does not indicate perturbation in the global carbon cycle. However, high ?13C values and their scatter suggest the influence of local fractionation affecting isotope composition of dissolved inorganic carbon (DIC) in the partly isolated Boreal sea. A fall in the belemnite ?18O values in the Upper Oxfordian and Lower Kimmeridgian compared to the Mid Oxfordian suggests a slight rise in seawater temperature.
Źródło:
Volumina Jurassica; 2006, 4, 1; 17-33
1896-7876
1731-3708
Pojawia się w:
Volumina Jurassica
Dostawca treści:
Biblioteka Nauki
Artykuł
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