Open AccessRadiolarians of family Heliodiscidae Haeckel, 1881 from the upper cretaceous (campanian–maastrichtian) chert deposits of the Vaamychgyn unit of Yanranai accretionary complex, Koryak upland
Author(s) -
Л. Г. Брагина,
Л. Г. Брагина,
N. Yu. Bragin,
Nikita Bragin
Publication year - 2019
Publication title -
stratigrafiâ. geologičeskaâ korrelâciâ
Language(s) - English
Resource type - Journals
ISSN - 0869-592X
DOI - 10.31857/s0869-592x272123-133
Subject(s) - terrane , geology , cretaceous , paleontology , stratigraphy , assemblage (archaeology) , tectonics
Campanian–Maastrichtian radiolarians from the section of Vaamychgyn unit in Yakenmyveem River (Koryak Upland, Ekonai terrane) were studied for the first time. The age of studied assemblage is determined as Campanian–Maastrichtian due to common presence of Excentrosphaerella vivenkensis (Lipman), Lithomespilus mendosa (Krasheninnikov) and Stichomitra livermorensis Campbell et Clark. Representatives of family Heliodiscidae Haeckel are abundant. This family is widely common in boreal and austral regions and can be of high value for stratigraphy and paleobiogeographic reconstructions. New data allow to refine the time of first appearance of Excentrosphaerella teuria (Hollis), that was previously known only from the Early Paleocene. The species Cromyosphaera vivenkensis Lipman is assigned here to genus Excentrosphaerella Dumitrica.