- Tytuł:
- Early Pliocene calcareous and siliceous microfossils of the Sawai Bay Formation, Car Nicobar Island, northern Indian Ocean
- Autorzy:
-
Chakraborty, Arindam
Ghosh, Amit K.
Mccartney, Kevin
Saxena, Stuti
Dey, Rikee
Roy, Lopamudra - Powiązania:
- https://bibliotekanauki.pl/articles/1835597.pdf
- Data publikacji:
- 2021
- Wydawca:
- Polska Akademia Nauk. Czytelnia Czasopism PAN
- Tematy:
-
Zanclean
calcareous nannofossils
radiolarians
diatoms
silicoflagellates
sponge spicules
Andaman islands
Nicobar islands
India
nanoplankton wapienny
radiolarie
okrzemki
wyspy Andaman
wyspy Nicobar
Indie - Opis:
- The present contribution provides a study of calcareous nannofossils and siliceous microfossils from the Sawai Bay Formation on Car Nicobar Island, northern Indian Ocean. Two stratigraphically short sediment intervals near Sawai Bay have been examined. Qualitative and quantitative microfossil analyses show the Sawai Bay ‘A’ Section to be devoid of siliceous microfossils, while 24 well-preserved calcareous nannofossil taxa are identified. The Sawai Bay ‘B’ Section yields 18 calcareous nannofossil, 33 radiolarian and 25 diatom taxa. The calcareous nannofossil index taxa (Ceratolithus armatus Müller, 1974a and C. cristatus Kamptner, 1950) indicate both sections to be from zones NN12 (CN10b) and NN13 (CN10c) of early Pliocene (Zanclean) age. The radiolarian taxa, i.e., Didymocyrtis avita Riedel, 1953, Euchitonia spp., Siphocampe lineata (Ehrenberg) Nigrini, 1977, Stichocorys peregrina Riedel, 1953, Semantis spp. and Stylochlamydium sp. are common in the Sawai Bay ‘B’ Section, which is assigned to Zone RN9. Most of the diatom taxa are represented by rep-resentatives of the genera Actinocyclus Ehrenberg, 1837, Azpeitia Peragallo in Tèmpere and Peragallo, 1912, Coscinodiscus Ehrenberg, 1839a, Grammatophora Ehrenberg, 1841 and Triceratium Ehrenberg, 1839b, with the benthic diatom species Triceratium favus Ehrenberg, 1839b being predominant (~35% of the total diatom count). Siliceous microfossils are also represented by silicoflagellates dominated by Dictyocha spp. and sponge spicules dominated by astrophorids.
- Źródło:
-
Acta Geologica Polonica; 2021, 71, 2; 175-198
0001-5709 - Pojawia się w:
- Acta Geologica Polonica
- Dostawca treści:
- Biblioteka Nauki
Artykuł