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Wyświetlanie 1-3 z 3
Tytuł:
Stratigraphy of the Albian-Cenomanian (Cretaceous) phosphorite interval in central Poland: a reappraisal
Autorzy:
Machalski, Marcin
Olszewska-Nejbert, Danuta
Wilmsen, Markus
Powiązania:
https://bibliotekanauki.pl/articles/24024713.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Polska
Cretaceous
phosphorites
rare earth elements
biostratigraphy
sequence stratigraphy
Polska
kreda
fosforyty
metale ziem rzadkich
REE
biostratygrafia
stratygrafia sekwencji
Opis:
Several closely-spaced phosphorite beds stand out at the Albian–Cenomanian transition in the mid-Cretaceous transgressive succession at the northeastern margin of the Holy Cross Mountains, central Poland. They form a distinctive condensed interval of considerable stratigraphical, palaeontological, and economic value. Here, we correlate the classical section at Annopol with a recently investigated section at Chałupki. We propose a new stratigraphic interpretation of the phosphorite interval, based on lithological correlations, Rare Earth Elements and Yttrium (REE+Y) signatures of phosphorites, age-diagnostic macrofossils, and sequence stratigraphic patterns. This interval has long been considered as exclusively Albian in age. However, new macrofossil data allow us to assign the higher phosphorite levels at Annopol and Chałupki, which were the primary target for the phosphate mining, to the lower Cenomanian. In terms of sequence stratigraphy, the phosphorite interval encompasses the depositional sequence DS Al 8 and the Lowstand System Tract of the successive DS Al/Ce 1 sequence. The proposed correlation suggests that lowstand reworking during the Albian–Cenomanian boundary interval played an important role in concentrating the phosphatic clasts and nodules to exploitable stratiform accumulations. Our conclusions are pertinent to regional studies, assessments of natural resources (in view of the recent interest in REE content of the phosphorites), and dating of the fossil assemblages preserved in the phosphorite interval. On a broader scale, they add to our understanding of the formation of stratiform phosphorite deposits.
Źródło:
Acta Geologica Polonica; 2023, 73, 1; 1--31
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated biostratigraphy and palaeoenvironments of the Upper Cretaceous in the Petrich section (Central Srednogorie Zone, Bulgaria)
Autorzy:
Pavlishina, Polina
Dochev, Docho
Wagreich, Michael
Koukal, Veronika
Powiązania:
https://bibliotekanauki.pl/articles/24024712.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Upper Cretaceous
campanian
calcareous nannofossil
dinoflagellate cysts
inoceramids
biostratigraphy
palaeoenvironments
górna kreda
kampan
nanoplankton wapienny
cysty bruzdnicowe
inoceramy
biostratygrafia
paleośrodowisko
Opis:
The Upper Cretaceous succession (Coniacian to lowermost Maastrichtian, with focus on the Campanian) at Petrich, Central Srednogorie Zone in Bulgaria, is described and calibrated stratigraphically based on nannofossils, dinoflagellate cysts and inoceramids. The following standard nannofossil zones and subzones are identified: UC10-UC11ab (middle to upper Coniacian), UC11c-UC12-UC13 (uppermost Coniacian to Santonian), UC14a (lowermost Campanian), UC14bTP-UC15cTP (lower Campanian to ‘middle’ Campanian), UC15dTP-UC15eTP (upper Campanian), UC16aTP (of Thibault et al. 2016; upper part of the upper Campanian), and UC16b (Campanian-Maastrichtian boundary). The base of the Campanian is defined by the FO of Broinsonia parca parca (Stradner) Bukry, 1969 and Calculites obscurus (Deflandre) Prins and Sissingh in Sissingh, 1977 (a morphotype with a wide central longitudinal suture). The Areoligera coronata dinoflagellate cyst Zone (upper lower Campanian to upper upper Campanian) is identified, corresponding to the UC14bTP-UC16aTP nannofossil subzones. The inoceramid assemblage indicates the ‘Inoceramus’ azerbaydjanensis-‘Inoceramus’ vorhelmensis Zone, correlated within the interval of nannofossil subzones UC15dTP-UC15eTP. The composition of the dinoflagellate cyst assemblages and palynofacies pattern suggest normal marine, oxic conditions and low nutrient availability within a distal shelf to open marine depositional environment during the Campanian.
Źródło:
Acta Geologica Polonica; 2023, 73, 1; 33--62
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A marker band folgen stratigraphy for the Cenomanian Chalk of England and its extension to northen Germany and France
Autorzy:
Jeans, Christopher Vincent
Powiązania:
https://bibliotekanauki.pl/articles/27323962.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
Cretaceous
cenomanian chalk
folge stratigraphy
marker bands
England
Northern Germany
Northwest France
Cenomanian–Turonian Anoxic Event
kreda
stratygrafia
Anglia
Niemcy Północne
północno-zachodnia Francja
cenoman
turon
Opis:
A novel stratigraphical scheme within the Folge Concept is described for the Cenomanian Chalk of England that is particularly suitable for investigating the regional changes in the lithofacies, diagenesis, geochemistry, and mineralogy of the sediments of the Chalk Sea leading up to the Cenomanian–Turonian Oceanic Anoxic Event. It is based on “isochronous” marker bands defined largely by calcitic macrofossil assemblages, and it avoids problems caused by the poor or non-preservation of ammonite assemblages and lateral changes in chalk lithofacies. Eight folgen are based on one, two, or more marker bands. Their sequences, lithologies and calcitic macrofossil assemblages are described from 33 exposures in the Northern Chalk Province of England. The folgen are named, in ascending order, the Belchford, Stenigot, Dalby, Bigby, Candlesby, Nettleton, Louth and Flixton, after villages in Lincolnshire and Yorkshire, England. The folgen are traced throughout the Transitional and Southern Chalk provinces of England. They are present in the Cenomanian chalk of northern Germany and northwest France. Regionally, an individual folge may display considerable vertical and lateral variation in general lithology and lithofacies whilst still maintaining their defining marker bands. The possibility of further refinement to the scheme is discussed.
Źródło:
Acta Geologica Polonica; 2023, 73, 2; 135--180
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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