Rokytnice nad Jizerou Ore Deposit in Krkonoše Mts. (Riesengibirge Mts.), Czech Republic

Dalibor Velebil – National museum, Prague, Czech republic
Bull. mineral.-petrolog. Odd. Nár. Muz. (Praha) 9 (2001), 154–161


Several minor occurences of polymetalic ore deposites are located around Rokytnice nad Jizerou in Krkonose Mts. where silver and copper were mined in 16th and 17th centuries and 19th century, respectively. The polymethalic ore mineralization is developed within the variegated serie (dolomitic marbles, quartzites, erlans etc.) which forms interbeds in grey or graphitic phyllite. Sulphidic mineralization appears in the form of grains and aggregates spread within the rock or in conform lens-shaped bodies of quartz or veins of quartz of the thickness in the range of cm to dm. The mineralization has a stratabound character. Main minerals are tetrahedrite, chalcopyrite, bornite, chalcocite, galenite, sphalerite, pyrite and arsenopyrite. The primary sulphidic minerals were subject to intensive oxidation the products of which include, in particular chrysocolla, hemimorphite, cerusite, malachite, bindheimite and azurite. The age of the mineraliazion is assumed to be pre-Variscian, the origin is associated with Lower Paleozoic volcanism. The rock of the variegated serie acted as a barrier or a collector of hydrothermal solutions that caused its methasomatic mineralization. During the Variscian metamorphosis and prior to the late Variscian intrusion of so called Krkonose-Jizera granite, the mineralization was partly remobilized.

Keywords: copper ores, crystalline complex, hemimorphite, mining history, stratabound mineralization