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The lower and middle Berriasian in Central Tunisia: Integrated ammonite and calpionellid biostratigraphy of the Sidi Kralif Formation

Maalaoui K., Zargouni F.

Acta Geologica Polonica

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2016

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Vol. 66, no. 1

43--58

EN

The lower and middle Berriasian sedimentary succession of the Sidi Kralif Formation has been a subject of biostratigraphic study in two key sections in Central Tunisia. Our contribution is an attempt to better define the basal Berriasian interval, between the Berriasella jacobi Zone and the Subthurmannia occitanica Zone. Zonal schemes are established using ammonites and calpionellids, and these permit correlation with other regions of Mediterranean Tethys and beyond. The use of biomarkers afforded by microfossil groups has allowed characterization and direct correlation with four widely accepted calpionellid sub-zones, namely Calpionella alpina, Remaniella, Calpionella elliptica and Tintinopsella longa. The two ammonite zones of Berriasella jacobi and of Subthurmannia occitanica are recognised on the basis of their index species. The parallel ammonite and calpionellid zonations are useful as a tool for correlation and calibration in time and space, thus allowing a better definition of a J/K boundary. The presence of four Berriasian calpionellid bioevents is recognised: (1) the ‘explosion’ of Calpionella alpina, (2) the first occurrence of Remaniella, (3) the first occurrence of Calpionella elliptica and (4) the first occurrence of Tintinopsella longa. The last is here documented as coeval with the presence of Subthurmannia occitanica, which marks the lower/middle Berriasian boundary.

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Foraminiferal bioevents in the upper Campanian to lowest Maastrichtian of the Middle Vistula River section, Poland

Peryt D., Dubicka Z.

Geological Quarterly

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2015

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Vol. 59, No. 4

814--830

EN

The Upper Campanian–Lower Maastrichtian interval of the Middle Vistula River Valley section records the following benthic foraminiferal bioevents in ascending stratigraphical order: LO of Globorotalites michelinianus, FO and LO of Globorotalites emdyensis (=G. hiltermanni), FO of Bolivina incrassata, FO of Bolivinoides miliaris, FO of Angulogavelinella gracilis (=A. bettenstaedti), LO of Gavelinella monterelensis, FO of Osangularia navarroana, FO of Bolivina decurrens and FO of Neoflabellina reticulata. These events are recorded in very similar stratigraphic positions in the Lägerdorf-Kronsmoor succession (northern Germany) and in the succession of eastern England and, at least some of them, in eastern Europe. Accordingly they can serve as important markers for stratigraphic correlation across Europe. The FOs of the planktonic species, Rugoglobigerina milamensis, R. hexacamerata and R. pennyi, in the uppermost part of the “Inoceramus” redbirdensis Zone,are very close to the Campanian–Maastrichtian boundary as defined by inoceramid bivalves (Walaszczyk, 2004) and we propose these planktonic foraminiferal bioevents as a good proxy for this boundary in temperate regions.

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Ammonite biozonation and litho-/chronostratigraphy of the Cretaceous in Sakhalin and adjacent territories of Far East Russia

Yazykova E.

Acta Geologica Polonica

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2004

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Vol. 54, no. 2

273--312

EN

The stratigraphy and ammonite faunas of the Cretaceous succession in Sakhalin are discussed. A high-resolution biostratigraphic zonation (24 zones in total) is proposed; it is correlated with adjacent areas and corresponds well to inoceramid and radiolarian zones. The definition of all stage and some substage boundaries in Sakhalin is discussed, and possibilities for interregional and global correlations are assessed. In addition, the main mass extinction and faunal turnover events recognised in these sections are taken into consideration.