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The proposal of a GSSP for the Berriasian Stage (Cretaceous System): Part 1

Wimbledon William A.P., Reháková Daniela, Svobodová Andrea, Elbra Tiiu, Schnabl Petr, Pruner Petr, Šifnerová Krýstina, Kdýr Šimon, Dzyuba Oksana, Schnyder Johann, Galbrun Bruno, Košťák Martin, Vaňková Lucie, Copestake Philip, Hunt Christopher O., Riccardi Alberto, Poulton Terry P., Bulot Luc G., Frau Camille, De Lena Luis

Volumina Jurassica

2020

Vol. 18, no. 1

53--106

Here in the first part of this publication we discuss the possibilities for the selection of a GSSP for the Berriasian Stage of the Cretaceous System, based on the established methods for correlation in the Tithonian/Berriasian interval. This will be followed, in the second part, by an account of the stratigraphic evidence that justifies the locality of Tré Maroua (Hautes-Alpes, SE France) as the proposed GSSP. Here we discuss the possibilities for correlation in the historical J/K boundary interval, and the evolution of thinking on the positioning of the boundary over recent generations, and in relation to research in the last ten years. The Tithonian/Berriasian boundary level is accepted as occurring within magnetosubzone M19n.2n. The detailed distribution of calpionellids has been recorded at numerous sites, tied to magnetostratigraphy, and the base of the calpionellid Alpina Zone is taken to define the base of the Berriasian Stage. This is at a level just below the distinctive reversed magnetic subzone M19n.1r (the so-called Brodno reversal). We discuss a wide range of magnetostratigraphic and biostratigraphic data from key localities globally, in the type Berriasian areas of France and wider regions (Le Chouet, Saint Bertrand, Puerto Escaño, Rio Argos, Bosso, Brodno, Kurovice, Theodosia etc.). The characteristic datums that typify the J/K boundary interval in Tethys and its extensions are detailed, and the correlative viability of various fossil groups is discussed. The boundary level is correlated to well-known J/K sections globally, and a series of secondary markers and proxies are indicated which assist wider correlation. Particularly significant are the primary basal Berriasian marker, the base of the Alpina Subzone (marked by dominance of small Calpionella alpina, Crassicollaria parvula and Tintinopsella carpathica) and secondary markers bracketing the base of the Calpionella Zone, notably the FOs of the calcareous nannofossil species Nannoconus wintereri (just below the boundary) and the FO of Nannoconus steinmannii minor (just above). Notable proxies for the boundary are: 1) the base of the A rctoteuthis tehamaensis Zone in boreal and subboreal regions, 2) the dated base of the Alpina Subzone at 140.22 ±0.14 Ma, which also gives a precise age estimate for the system boundary; and 3) the base of radiolarian “unitary zone” 14, which is situated just above the base of the Alpina Subzone.

The Cambrian trilobites of Jordan - taxonomy, systematic and stratigraphic significance

Elicki O., Geyer G.

Acta Geologica Polonica

2013

Vol. 63, no. 1

1-56

Marine carbonates and siliciclastic rocks of the Burj Formation in Jordan include paucispecific trilobite associations of the (traditional) Lower. Middle Cambrian boundary interval. Comprehensive new material of these trilobites allows a review of their taxonomy and systematic positions as well as a refined morphological description and a reconsideration of previous interpretations of their stratigraphic position and thus the correlation of the fossiliferous beds. In addition to the classic species Kingaspis campbelli (King, 1923) and Redlichops blanckenhorni Richter and Richter, 1941, Timnaella? orientalis (Picard, 1942) and Hesa problematica Richter and Richter, 1941, the discussed trilobites include Issalia gen. nov. with Issalia scutalis gen. nov., sp. nov., Tayanaspis gen. nov. with Tayanaspis bulbosus gen. nov., sp. nov., Uhaymiria gen. nov. with Uhaymiria glabra gen. nov., sp. nov., Cambrunicornia? jafnaensis sp. nov., Myopsolenites palmeri (Parnes, 1971), M. hyperion sp. nov., and Enixus cf. antiquus (Chernysheva, 1956). Myopsolenites boutiouiti Geyer and Landing, 2004 is now regarded as a junior synonym of Myopsolenites altus (Lian and Gozalo, 1986). A detailed discussion of the correlation with a focus on global aspects provides clues for the utility of potential index fossils for the global Cambrian Series 3 and Stage 5.

Pliensbachian to Aalenian radiolarian biochronology and global correlation

Carter E., Gorican S., Guex J., De Wever P., Dumitrica P., Hori R., Matsuoka A., O'Dogherty L., Whalen P.

Volumina Jurassica

2006

Vol. 4, no. 1

151-152

A new UA radiolarian zonation for the Pliensbachian to Aalenian interval is established using 145 distinctive, widely-distributed species. The data are from biostratigraphic sections in: Queen Charlotte Islands, NE British Columbia, Baja California Sur, Japan, Oman, Turkey, Slovenia and Austria. A catalogue of 280 species (with revised taxonomy) is completed. For the zonation, about half these species were eliminated from the total dataset, because they are either rare (e.g. Danubea, Farcus, Pseudopoulpus, Rolumbus), long-ranging (e.g. Pseudocrucella, Orbiculiformella, Paronaella) or non-diagnostic with wide limits of variability (e.g. some species of Bagotum, Droltus, Parahsuum). Rich well-preserved radiolarians from thick continuous stratigraphic sections in Queen Charlotte Islands provide the most detailed record for this stratigraphic interval, and all collections are tied with North American ammonite zones or assemblages. An initial sequence of 25 UAs (including ammonite data) was determined from this material only. Subsequently, data from other areas were added and a global sequence of nine radiolarian zones was obtained. These zones can be correlated worldwide and link previously established UA zonations for the Hettangian-Sinemurian (Carter et al. 1998) and the Middle to Upper Jurassic (Baumgartner et al. 1995).