Roşia Montană, Romania: Europe’s Largest Gold Deposit

Abstract

ABSTRACT Roşia Montană, Romania, is Europe’s largest gold deposit, with a current identifıed resource of ~400 Mt at 1.3 g/t Au and 6 g/t Ag. The deposit is hosted by a Miocene age maar-diatreme complex emplaced into Cretaceous flysch-type sedimentary rocks and intruded by dacite domes. High-resolution 40Ar/39Ar dating of adularia associated with gold-bearing veins suggests a protracted period of episodic mineralization spanning about 500,000 years. The major gold mineral is electrum, associated with pyrite, base-metal sulfıdes, and a variety of Au-Ag sulfosalts and minor tellurides. The overall aspect of the gangue and alteration mineral assemblages, as well as the sulfıde assemblage, is characteristic of intermediate sulfıdation-state epithermal deposits.