(Two associations of native elements in Eocene acid volcanic rocks from eastern Sikhote-Alin.

The native elements in these SE Russian acidic volcanic rocks occur in complex mineral aggregates in the form of lamellae, spheres or globules. Two associations are recognized: in one, the native elements comprise the bulk of lamellar or spherical aggregates which are essentially unoxidized. These aggregates were named hepoxides (M.A. 86M/3746); their native elements include Pb, Sn, Sb and Zn, with trace amounts of Cu, Ni, Fe, Au, Ag and graphite. The other association is present in magnetite- and ilvaite-bearing globular aggregates: their native elements are Cu and alpha -Fe. -R.A.H.