New data are presented for the Aalenian deposits of the New Siberian Islands archipelago. Based on the first findings of ammonites of the genus Pseudolioceras and bivalves of the genus Retroceramus in well cores drilled in the southeastern part of Kotelny Island and in Gedenstrom Bay, the presence of both lower and upper Aalenian strata is substantiated. The Aalenian mollusk assemblages exhibit low taxonomic diversity and are compositionally similar to coeval faunas from other Arctic regions. Palynological analysis refines the composition of high-latitude Aalenian dinocyst assemblages: the early Aalenian is characterized by a higher diversity resembling that of the late Toarcian, whereas the late Aalenian records a marked decline. These changes are interpreted as ecosystem responses to pronounced cooling events. For the first time, representative Aalenian species of bivalves, ammonites, and palynomorphs from this region are figured. U–Pb dating of detrital zircon indicates that the Grenvillian–Sveconorwegian, Timanian, Caledonian, and Hercynian orogenic belts—or reworked products of their erosion—supplied clastic material to the Aalenian sedimentary basin. A comparison of detrital zircon age spectra from Jurassic deposits across the Arctic reveals strong similarity to those of the Barents Sea region. This supports a tectonic connection between the New Siberian Islands and the Barents Shelf during the Jurassic.
Ershova et al. (Sun,) studied this question.