Please cite this article in press as: Sipahi, F., et al., Geochemical and Sr–Nd isotopic characteristics of Murgul (Artvin) volcanic rocks in the Eastern Black Sea Region (Northeast Turkey). Chemie Erde - Geochemistry (2013), http://dx.doi.org/10.1016/j.chemer.2013.08.005 ARTICLE IN PRESS G Model CHEMER-25276; No. of Pages 12 Chemie der Erde xxx (2013) xxx–xxx Contents lists available at ScienceDirect Chemie der Erde jou rn al homepage: www.elsevier.de/chemer Geochemical and Sr–Nd isotopic characteristics of Murgul (Artvin) volcanic rocks in the Eastern Black Sea Region (Northeast Turkey) Ferkan Sipahi a,∗ , M. Burhan Sadıklar b , Cüneyt S ¸ en b a Jeoloji Müh. Bölümü, Müh. Fak., Gümüs ¸ hane University, TR-29000 Gümüs ¸ hane, Turkey b Jeoloji Müh. Bölümü, Müh. Fak., Karadeniz Technical University, TR-61080 Trabzon, Turkey a r t i c l e i n f o Article history: Received 5 January 2012 Accepted 17 August 2013 Keywords: Fractional crystallization Petrogenesis Sr–Nd isotope Dacite Turkey a b s t r a c t The studied volcanic rocks are footwall and hanging wall dacites from the Murgul mine and the surround- ing area. Moreover, the hanging wall dacites contain enclaves. Footwall dacite contains biotite, whereas hanging wall dacitic rocks contain hornblende as a ferromagnesian mineral. The enclaves in the hang- ing wall dacite have sizes that range from 1 cm to 20 cm and contain hornblende as a ferromagnesian mineral. The volcanic rocks show tholeiitic and transitional affinities. They are rich in large ion lithophile element and light rare earth element with pronounced depletion of high field strength elements. The chondrite-normalized rare earth element patterns (La N /Lu N = 1.47–5.12) show low to medium enrich- ment, which reveal that the rocks were obtained from similar sources in Murgul volcanic rocks. The initial 87 Sr/ 86 Sr values range from 0.70442 to 0.70525, and the initial 143 Nd/ 144 Nd values range from 0.512741 to 0.512770. The main solidification processes involved in the evolution of the volcanic rocks consist of fractional crystallization with minor amounts of crustal contamination and magma mixing. All geochem- ical data support that these rocks originated from andesitic magma, and that the parental magma of the rocks were probably derived from an enriched upper mantle, previously modified by subduction-induced metasomatism in a geodynamic setting. © 2013 Elsevier GmbH. All rights reserved. 1. Introduction The dacitic rocks from the Eastern Black Sea metallogenic belt are a host to numerous volcanogenic massive sulfide (VMS) deposits. The rocks are widely spread within an area extend- ing about 350 km in the east–west direction and 60 km in the north–south direction in the Eastern Black Sea Region of Turkey. The Eastern Black Sea metallogenic belt represents an island arc system of volcanites developed during the Jurassic through the Miocene epoch. In the region, VMS deposits (e.g., Murgul- Artvin, Kutlular-Trabzon, Köstere-Gümüs ¸ hane, Istala-Gümüs ¸ hane, Köprübas ¸ ı-Giresun, Lahanos-Giresun, and Kızılkaya-Giresun) in Late Cretaceous felsic volcanic rocks are common (C ¸ a˘ gatay and Boyle, 1977; Leitch, 1981; Schneider et al., 1988; C ¸ a˘ gatay, 1993; Tüysüz, 2000; Gökc ¸ e and Spiro, 2002; Abdio˘ glu and Arslan, 2008). The VMS deposits contain significant amounts of Cu, Pb, and Zn. These deposits are commonly found within intensely altered felsic volcanic rocks (Leitch, 1981; C ¸ a˘ gatay, 1993; Antonovi’c et al., 1996; ∗ Corresponding author at: Gümüs ¸ hane Üniversitesi, Müh. Fakültesi, Jeoloji Mühendisli˘ gi Bölümü, 29000 Gümüs ¸ hane, Turkey. Tel.: +90 456 2337425 1221; fax: +90 456 2337567. E-mail addresses: ferkansipahi@gmail.com, ferkansipahi@gumushane.edu.tr (F. Sipahi). Barrett and MacLean, 1999; Akc ¸ ay and Moon, 2001; Abdio˘ glu and Arslan, 2008). The Murgul mine (Artvin, Turkey) contains one of the largest VMS deposits in Turkey and is host to many dacitic rocks. Previous studies on dacitic rocks in the study area are descriptive and of limited use in exploration. The present study investigates the petrography, petrology, and Sr–Nd isotope studies of footwall and hanging wall dacitic rocks in the Murgul mine and its surrounding areas. 2. Geological setting The Eastern Black Sea metallogenic province is located along the Alpine metallogenic belt, which developed as an island arc during the subduction of the Tethyan oceanic crust from the Jurassic to the Miocene period (Dixon and Pereira, 1974; S ¸ engör and Yılmaz, 1981; Okay and S ¸ ahintürk, 1997). Bektas ¸ (1987) proposed that the subduction occurred southward, whereas S ¸ engör and Yılmaz (1981) suggested that the subduction of the Tethyan oceanic crust occurred northward. Subduction was completed during the Middle Eocene epoch (Adamia et al., 1981; Okay and S ¸ ahintürk, 1997). The geological setting of the Eastern Black Sea is mainly the result of three main Neo-Tethyan volcanic cycles during the Jurassic, Late Cretaceous, and Tertiary periods. Liassic volcanic rocks are transi- tional, Late Cretaceous rocks are subalkaline, and Eocene volcanic 0009-2819/$ – see front matter © 2013 Elsevier GmbH. All rights reserved. http://dx.doi.org/10.1016/j.chemer.2013.08.005