New data on the stratigraphy, volcanism, and zeolite mineralization of the Cenozoic Vanchinskaya depression in primorye

摘要

This paper presents the results of studying the Cenozoic volcanogenic-sedimentary cover of the Vanchinskaya depression of Sikhote Alin. It was established that, in terms of the taxonomic composition of the fossil plants, the basal part of the Cenozoic section is attributed to the Paleocene, while the overlaying coal-bearing sequence, to the Early Eocene. The geochronological (K-Ar) dating showed that the volcanic rocks intruding and overlaying the coal-bearing deposits are Middle Eocene in age: rhyolites-44. 7 ± 1. 0; trachyandesites-43. 7 ± 1. 4 Ma. The petrographic and geochemical characteristics of the volcanic and volcanogenic-sedimentary rocks and related zeolitites are described. The zeolitized rocks containing plant detritus differ in their extremely high contents of Y and HREE. The zeolitization of the volcanic glass in tuffs, tuffites, and perlites was caused by hydrothermal solutions that ascended along NW fault zones from the subsurface magmatic chamber.