TY JOUR TI K–Ar Ages of Adularia-Quartz Veins from the Tutkhlivayam Ore Occurrence (Kamchatka) KW Ossora ore district KW epithermal deposits KW forming duration JO Russian Journal of Earth Sciences AU Schweigert, P.E. AU Bukhanova, D.S. AU Zhegunov, P.S. PY 2026 IS 26 PB Geophysical Center of the Russian Academy of Sciences