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Palaeocene-early Eocene southern subtropical to subpolar silicoflagellate biostratigraphy

McCartney K., Witkowski J., Szaruga A.

Acta Geologica Polonica

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2018

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Vol. 68, no. 2

219--248

EN

Early Palaeocene through early Eocene silicoflagellate assemblages were examined from five southern subtropical through subpolar deep-sea sites: DSDP Holes 208 and 524, and ODP Holes 700B, 752A, and 1121B. For each site, the taxonomic composition of the silicoflagellate assemblage is documented in detail; Pseudonaviculopsis gen. nov., Dictyocha castellum sp. nov. and Stephanocha? fulbrightii sp. nov. are proposed, along with several new combinations. More importantly, however, these observations enable a considerable refinement to the existing Palaeocene–Eocene silicoflagellate biostratigraphic zonation that for the first time uses datums calibrated to the Geomagnetic Polarity Timescale. The Corbisema aspera Interval Zone occurs immediately above the K/Pg boundary and is here described from Seymour Island. The Corbisema hastata Partial Range Zone extends from near the K/Pg boundary to late early Palaeocene and has been observed in Hole 208. The Pseudonaviculopsis disymmetrica Acme Zone occurs in Holes 208 and 700B. The Dictyocha precarentis Partial Range Zone, observed in Holes 208, 700B, 752A and 1121B, is subdivided into D. precarentis, Naviculopsis primativa, N. cruciata and Pseudonaviculopsis constricta subzones. The Naviculopsis constricta Partial Range Zone occurs in Holes 524, 700B, 752A and 1121B. This study is also the first to consider syn- and/or diachroneity in Palaeogene silicoflagellate biostratigraphy.

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Foraminiferal stratigraphy of Palaeogene deep-water red facies in the Gorce Mountains (Magura Nappe, Polish Outer Carpathians)

Bąk K., Bąk M., Cieśla M., Paul Z.

Annales Societatis Geologorum Poloniae

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2013

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Vol. 83, No. 3

201--212

EN

The deposition of red and variegated mudstones and claystones characterized the ancient Tethys Ocean during Cretaceous and Palaeogene times, including in its north-western part, the Alpine–Carpathian deep-water basins. Palaeogene variegated sediments, containing red mudstone and claystone layers, crop out in the Gorce Mountains (Rosocha creek, near Lubomierz) in the Magura Nappe (Bystrica Subunit) of the Polish Outer Carpathians. These sediments occur as layers 1–10 cm thick and as packages of layers 2–3 m thick that are associated with very thin-bedded turbidites. The entire succession is tectonically disturbed and parts of it belong to the Ropianka, Łabowa Shale and Beloveža Formations. The sediments studied contain 27 genera and 59 species that belong to deep-water agglutinated foraminiferal (DWAF) assemblages. Tubular taxa, which are frequent in various Mesozoic–Cenozoic flysch sediments are relatively rare in the section studied. The assemblages are moderately diverse (3–20 taxa per sample). Excluding tubular forms, the most common taxa belong to Trochamminoides – Paratrochamminoides spp., Saccammina placenta, glomospirids, Recurvoides – Recurvoidella spp. and karrerulinids. The oldest part of the red sediments, referable to the Ropianka Formation, represents the upper part of the Rzehakina fissistomata Zone (probably the Upper Palaeocene). The youngest red sediments, forming thin intercalations in the Beloveža Formation, represent the acme of Reticulophragmium amplectens (middle Lutetian). Owing to tectonic disturbances, most of the Lower Eocene part of the variegated facies of the Łabowa Shale Formation is not preserved in the section studied. The upper part of it, a package 2 m thick, represents the lower part of the Reticulophragmium amplectens Zone. The small thickness (10–15 m) of the Łabowa Shale Formation in the section studied is similar to other sections in the southern part of the Bystrica Subunit. It is probably of a sedimentary nature, reflecting a decreasing number of mud-rich, gravitational flows in the southern part of the Magura Basin during the Early Eocene. Nevertheless, the strong tectonic disturbances that took place in this area during the Oligocene–Miocene folding and overthrusting influenced the reduction in thickness of these sediments.

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Sedimentary environment and palaeogeography of the ?Palaeocene-Middle Eocene Kashkan Formation, Zagros fold-thrust belt, SW Iran

Yeganeh Bizhan Yousefi, Feiznia Sadat, Loon A. J. (Tom)

Geologos

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2012

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Vol. 18, No. 1

13--36

EN

The Kashkan Formation (?Palaeocene to Middle Eocene) in the Zagros fold-thrust belt, SW Iran, which is intercalated between to marine limestone formations, consists of conglomerates, sandstones and siltstones. The sedimentology and the palaeogeography of the Kashkan Formation had not received any attention thus far, but have now been studied in seven sections, situated in the province of Lorestan. The sediments form twelve lithofacies, three ichnosubfacies and seven architectural elements, which are described, depicted and analysed. The analysis leads to the conclusion that most sediments accumulated in a low-sinuosity, low-gradient braided-river system (characterised by mainly unidirectional palaeocurrent directions, and by sheetfloods), that occasionally showed meandering characteristics (represented by overbank deposits and large bars). The deposits of this system closely resemble those of the South Saskatchewan River in Canada, which is considered as the classical example of a sand-bed braided river. The river flowed roughly from North to South, as deduced by palaeocurrent indicators such as imbrication and large- to medium-scale trough cross-stratification (direction measured in the trough axes). This current direction is supported by the southward to south-westward thinning of the formation and by the diminishing average grain size in the same direction. The trace fossils in the Kashban Formation fit all in the Skoyenia ichnofacies, which has here three ichnosubfacies which allow a more detailed palaeoenvironmental reconstruction, indicating that the braided stream passed into the low-energy shoreface zone of a tidally-influenced sea.

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Foraminiferal palaeodepth indicators from the lower Palaeogene deposits of the Subsilesian Unit (Polish Outer Carpathians)

Waśkowska-Oliwa A.

Studia Geologica Polonica

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2005

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Vol. 124

297-324

EN

The presented research results are an attempt at establishing the relative depth of sediment deposition in the Subsilesian zone of the Carpathian basin. To estimate palaeodepth calcareous and agglutinated foraminifera were investigated, taking into account the preservation conditions, life environment, and bathymetrical preferences of individual species of the calcareous benthic forms. Micropalaeontological analysis were carried out on foraminiferal assemblages from the Palaeocene- Middle Eocene deposits of the Lanckorona-Żegocina Tectonic Zone and the Żywiec Tectonic Window (Subsilesian Unit), which are represented by the Szydłowiec sandstones (Palaeocene part), the Czerwin sandstones, the Gorzeń sandstones, the Radziechowy sandstones, the Lipowa beds as well as shales, that occur above or between these sandstones. The microfauna assemblages indicate that a change in the sedimentation depth of the individual lithosoms is conspicuous in the Early Palaeocene. During the Early Palaeocene the depth was between the CCD and the foraminiferal lysocline (FL); however, during the Late Palaeocene and the Early Eocene a deepening related to the CCD is evident or local shallowing of the CCD. Deposition took place in the lower part of the range between the CCD and FL, achieving the maximum palaeodepth in the latest Palaeocene. The depth changes of the Subsilesian basin zone can be correlated with global trends of the raising level of the World Ocean, and also with a period of increased subsidence of the Carpathian basins.

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Provenance analyses of the Late Cretaceous-Palaeocene deposits of the Magura Basin (Polish Western Carpathians) : evidence from a study of the heavy minerals

Oszczypko N., Salata D.

Acta Geologica Polonica

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2005

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Vol. 55, no. 3

237-267

EN

The Late Cretaceous-Palaeocene sequence of the Magura Nappe in Poland is underlain by the Albian-Cenomanian spotty marls at the base and overlapped by the Palaeocene/Early Eocene variegated shales at the top. The spotty marls are followed by variegated shales and then by turbiditic deposits. The upper boundary of the variegated shales is diachronous - older in the Raca zone (Santonian) and younger in the Krynica zone (Campanian/Maastrichtian). The turbiditic deposits of the marginal (northern) zone of the Magura Nappe display palaeocurrent directions from the NW in the western part and from the NE in the eastern part. In other parts of this unit palaeocurrent directions from the SE and E were observed. The northern source area of the Magura Basin is commonly connected with the Silesian Ridge, while the south-eastern one could be connected with an accreted fragment of the Inner Carpathians.The heavy mineral assemblages of the Magura Nappe are dominated by stable and ultrastable species. Chromian spinels occur additionally in the Krynica zone and to some extent in the Bystrica and Raca zones. Investigation of the chemical composition of the heavy minerals showed that that the southern source area was built of low- to medium-grade metamorphic rocks, as well as igneous rocks associated with ophiolite sequences. The chemical composition of minerals deriving from the NW indicates that they crystallized mainly in low- to high-grade metamorphic rocks and granitoids.

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Upper Maastrichtian ammonites and nannofossils and a Palaeocene nautiloid from Richards Bay, Kwa Zulu, South Africa

Klinger H.

Acta Geologica Polonica

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2001

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Vol. 51, nr 3

273-291

EN

Temporary exposures of Upper Maastrichtian to Palaeocene sediments of the Richard Bay area, Kwa Zulu yielded Maastrichtian and Danian cephalopod faunas. The lower Upper Maastrichtian assemblage, dated to nannofossil standard biozone CC25b, or UC20a^TP of BURNETT (1998), is: Anagaudryceras politissimum (KOSSMAT, 1895), Pseudophyllites indira (FORBES, 1846) (abundant), Desmophyllites diphylloides (FORBES, 1846) Pachydiscus (P.) australis HENDERSON & McNAMARA, 1985, Menuites fresvillensis (SEUNES, 1890), Diplomoceras cylindraceum (DEFRANCE, 1816), Baculites ambatryensis COLLIGNON, 1971, Eubaculites carinatus (MORTON, 1834), and E. latecarinatus (BRUNNSCHWEILER, 1966). The Danian yields a monospecific assemblage of Hercoglossa madagascariensis COLLIGNON, 1951. The Maastrichtian assemblage has strong similarities to the lower Upper Maastrichtian fauna of the Miria Formation of Western Australia, and is made up of cosmopolitan and latitudinally restricted taxa: there are no endemic elements.