EPITHERMAL ZONES OF THE PORPHYRY-SKARN-EPITHERMAL ORE COMPLEX AT RECSK Ferenc Molnár, Péter Jung, László Kupi, Attila Pogány, Edina Vágó, Orsolya Viktorik Eötvös Loránd University of Science, Department of Mineralogy, Budapest molnar@abyss. elte.hu Zoltán Pécskay ATOMKI, Debrecen pécskay@namafia. atomki.hu Abstract: The epithermal gold - porphyry copper - skarn ore complex at Recsk is an uniquely preserved intrusive-volcanic system of the Alpean subduction related metallogeny. The high sul- phidation type ore is located peripherally in relation to a diorite intrusion, whereas low sulphida- tion type epithermal zones are located above the apexes of a subvolcanic body. High sulphidation type enargite-luzonite and gold ore is hosted by a crystal tuff-diatrema breccia unit with advanced argillic alteration (vuggy silica, dickite, silicification, pyritization). Gold is concentrated in the vuggy silica and various breccia and strockwork structures. Early stage alteration took place around 240- HOO'C followed by ore mineralization between 150-250°C (enargite fluid inclusion data). Increase of fluid salinities during ore deposition suggests to upwelling of saline fluids from the magmatic reser voir. Low sulphidation type epithermal zones are hosted by dacite and its tuff and characterized by microcrystalline and banded-brecciated siliceous veins, drusy quartz stockwork and hydrothermal breccia dikes. The most typical alteration is illitisation. Gold enrichments is associated with occur rences of adularia in the matrix of breccia. Fluid inclusion data confirm boiling of fluids and 150- 300°C temperature for hydrothermal processes. Age of mineralization is Oligocene (28 Ma, adularia and illite K-Ar data). 1. INTRODUCTION The ore complex at Recsk consists of Cu(-Mo-Au)-porphyry, Cu-Zn-skarn and metasomatic Pb-Zn ores at depth (at min. 500m below the present surface), as well as high sulphidation (HS) and low sulphidation (LS) type epithermal Cu- As-Au and Au-Ag-Pb-Zn ores in the shallow zones of the volcanic cover. The epithermal gold potential of the shallow zones has been recognized by the Enargit Ltd. of Hungary and joint venturing with the Australia based Rhodes Mining Ltd. resulted in completing of 71 diamond drilling and determination of 36.5 mill. T resource of HS type gold ore (1.47 g/t @ 0.5 g/t; Földessy et al., 2002). Exploration 99