The first find of massive pyrolusite in a deep-water basin of the Sea of Japan

Abstract

Data are presented on the chemical composition and the content of microelements including REEs in samples of pyrolusite, todorokite, and birnessite collected from a depth of 3500-3200 m by dredging a nameless elevation in the Central Basin of the Sea of Japan. The samples of pyrolusite are characterized by high hardness and density (3.35 g/cm 3 ). The conclusion of their hydrothermal genesis is made.