Mineralogy and geochemistry of the argentiferous Pb – Zn and Cu veins of the C ¸ olaklı ´ area, Elazig, Eastern Turkey Ahmet Sagiroglu * , Ahmet Sasmaz Department of Geology, Firat University, Elazig 23119, Turkey Received 3 October 2002; revised 20 March 2003; accepted 20 March 2003 Abstract The studied Pb – Zn and Cu veins occur as N – S trending and vertically dipping features in quartz diorite of Coniacian – Campanian Elazig Magmatic Complex. The complex has characteristics typical of arc magmatism and is composed of granitoids and, volcanic, subvolcanic and pyroclastic rocks. The veins are 0.5–2.5 m. thick and their lengths reach up to 750 m. The ore of veins are either massive or disseminated in gangue of carbonate minerals, quartz and barite. The veins display two sets of mineral assemblages: (1) Pb – Zn veins are composed of galena, freibergite, barite, sphalerite, chalcopyrite, pyrite, a Pb – Cl phase and native silver; (2) Cu veins have a mineral association of chalcopyrite, pyrite, galena, sphalerite, cubanite, bismuthinite and fahlore. The ore bodies are accompanied by narrow but intensely developed wall rock alterations of argillization, carbonatization and silicification. Chemical analyses of ore samples indicate high Pb, Ag, Sb, Zn, Ba and Cu contents in the veins and high correlation values between Pb – Ag, Pb–Ba, Pb–Zn, Sb–Ag, Cd–Sb and Ba–Cd. The REE geochemistry points to ore deposition under acidic conditions and probably as a product of the final stages of magmatism. Field, microscopic and geochemical data also indicate that the ores are related to the last phases of the magmatic activity of the Elazig Magmatic Complex. q 2003 Elsevier Ltd. All rights reserved. Keywords: Ag–Pb–Cu veins; Freibergite; Pb–Cl phase; Elazig Magmatic Complex; Eastern Turkey 1. Introduction The studied veins are located in the vicinity of C ¸ olaklı ´ village in the Elazig province which itself is located in the Eastern Tauride Region and is well known for many valuable ore deposits. These include examples of Alpin type chromite deposits at Guleman, several Cyprus- type massive sulphide deposits along the Southeastern Thrust Zone and argentiferous Pb–Zn deposits at Keban (Fig. 1). Other mineral resources of the province and the ore formations associated with the Elazig Magmatic Complex, have been the subject of several studies in recent years: Cu ores in granitic rocks by Sagiroglu (1986) and Sagiroglu and Preston (1987), vein type Pb–Zn and Cu ores by Sasmaz and Sagiroglu (1990, 1999), pyrometasomatic Fe and Ti mineralizations by Sagiroglu (1992) and Akgu ¨ l and Sasmaz (1996). The general geology of the area and petrography of Elazig Magmatic Complex are described by Yazgan (1984), Bingo ¨l (1984), Asutay (1985) and Akgu ¨l (1993). The C ¸ olaklı ´ ore veins are located north of C ¸ olaklı ´ village, 20 km north of Elazig town (Fig. 2) and occur in quartz diorite of the Elazig Magmatic Complex. This study investigates the geology, mineralogy, wall rock alteration, and geochemistry of the argentiferous ore and discusses formation conditions and sources of mineralizing fluids. 2. Geology Two lithologic units are present in the study area (Fig. 2), (a) Coniacian – Campanian Elazig Magmatic Complex and, (b) its sedimentary cover the Eocene Kı ´rkgec ¸it Formation. The Elazig Magmatic Complex crops out over large areas in the Elazig and neighboring Malatya and Tunceli provinces. It consists of plutonic (gabbro, diorite, 1367-9120/03/$ - see front matter q 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S1367-9120(03)00101-9 Journal of Asian Earth Sciences 23 (2004) 37–45 www.elsevier.com/locate/jseaes * Corresponding author. E-mail address: sagirogluahmet@hotmail.com (A. Sagiroglu).