The Biga Peninsula, located in northwestern Turkey, is a sector of the Tethyan Metallogenic Belt (TMB), which stretch out from Europe to Iran. The peninsula hosts numerous epithermal Au–Ag deposits including high-(HS), low-(LS), and intermediate-sulfidation (IS) styles, porphyry Au–Cu–Mo, and base-metal skarn systems. Cenozoic calc-alkaline magmatism, spanning 52 to 18 Ma, shaped the deposits, which are associated with collisional and post-collisional tectonic regimes. Our knowledge about the magmatic-hydrothermal history and ore formation of this region is still fragmentary, particularly district-scale characteristics. Although recent scientific studies and exploration activities of the mineral industry have revealed the ore-forming potential of the region on a large scale, not much detailed data are available on a district scale for a better understanding of the magmatic-hydrothermal evolution of the area. Moreover, these deposits cluster in a narrow area and show a spatial-temporal relationship.
This thesis focuses on the Kirazlı district, which exhibits, in many ways, the common spatial-temporal relationship and overprinting features of mineral deposits found throughout the peninsula. The Kirazlı district is located at the center of the Biga Peninsula and hosts HS epithermal Au-Ag deposit and porphyry Cu mineralization with unclear temporal relationships. The purpose of this thesis is to reconstruct the magmatic-hydrothermal evolution of the Kirazlı district on the basis of field studies and micro-/macro scale observations combined with new analytical data acquired during this study.
The new analytical data include (1) the LA-ICP-MS zircon U-Pb ages, and (2) lithogeochemistry of magmatic host rocks, (3) 40Ar/39Ar muscovite ages, (4) K-Ar illite ages, (5) Re-Os molybdenite ages, (5) automated mineral identification (QEMSCAN) and short wavelength infrared (SWIR) reflectance spectroscopy, (6) stable isotope (S-O-H) values of alteration and ore minerals, (7) fluid inclusion petrography and microthermometric data, (8) whole-rock Sr-Nd isotopic data.
This multidisciplinary approach has allowed the understanding of the temporal association between the HS epithermal Au-Ag deposit and the porphyry Cu event together with the Eocene to Oligocene magmatic-hydrothermal evolution of the Kirazlı district (Chapter 1). Alteration mapping with the help of short wavelength infrared (SWIR) reflectance spectroscopy helped to identify the types and spatial distribution of the hydrothermal alteration to understand the alteration-mineralization processes at the Kirazlı district (Chapter 2). The ore-bearing fluid characteristics and source of materials for a better understanding of the evolution of hydrothermal alteration and mineralization were identified (Chapter 3). The final part of the thesis focuses on the magmatic source of host rocks in the Kirazlı district. This chapter presents a set of Sr-Nd isotope data of the magmatic rocks identified by the integrated automated mineralogy and petrography system (Chapter 4).
