A Newly Identified Skarn Mineralization in the Yolindi Area, Biga Peninsula, NW Turkey: New Evidence From Micochemical and Stable Isotope Data

The main objective of this study is a comprehensive investigations of the skarn ore forming  processes, including both prograde and retrograde alterations. The investigation reveals the critical influence of magmatic fluids originating from the Şaroluk granitoid on assisting the evolution of polymetallic skarn mineralogy, with a particular emphasis on the formation of iron and copper-rich calc-silicate minerals. Further, the study conducts a thorough geochemical analyses in order to identify the geochemical exchange and relationship between the Şaroluk granitoid and the adjacent Torasan Formation. This analysis sheds light on the occurred metasomatic processes and illustrates the important role of magmatic fluids in the alteration and interaction of skarn minerals with copper and iron, thereby providing a comprehensive geological and mineralogical framework for understanding the Yolindi Fe-Cu Skarn mineralization.

Moreover, the dissertation delves into the isotopic ratios of sulfur, carbon, and oxygen within the deposit. These isotopic studies reveal a complex interplay of various sources and processes in the formation of the mineralization. The sulfur isotopic data suggest a combination of magmatic, sedimentary, and potentially organic sulfur sources. Conversely, the carbon and oxygen isotopic compositions indicate interactions with high-temperature magmatic fluids and meteoric waters, reflecting the complex and dynamic environment of ore formation. This extensive investigation of the Yolindi Fe-Cu Skarn mineralization not only enhances the geological understanding of this specific mineralization but also provides valuable insights that have broader implications for the study of Cu-Fe skarn deposits globally. This research, therefore, signifies notable progress in the discipline of geology, establishing an entirely new framework for future explorations in similar geological contexts.

General features of the endoskarn zone within the ¸Saroluk intrusive body (a) Changes from the low-altered magnetite-bearing granodiorite to the magnetite-bearing endoskarn in the Maden Deresi area. (b,c) Magnetite-bearing granodiorites. (d) Magnetite occurred in the granodiorite in the Maden Deresi area. (e–g) Magnetite-bearing endoskarns containing andradite and epidote, as well as magnetite and goethite minerals. (h–k) Magnetite- and pyrite-bearing granodiorite having quartz, plagioclase, microperthite, biotite, diopside, actinolite, and sphene with magnetite, pyrite, and hematite. Abbreviations: actinolite (act), andradite (adr), biotite (bt), epidote (ep), goethite (gth), hornblende (hb), magnetite (mag), microperthite (mp), plagioclase (pl), pyroxene (px), pyrite (py), quartz (qz), sphene (spn).

(a) Magnetite occurred within the granodiorite in Maden Deresi. (b) Magnetite and pyrite in magnetite-containing endoskarn. (c) Magnetite’s martitization to hematite in the proximal exoskarn zone. (d) Chalcopyrite and pyrite in the proximal retrograde zone. (e) In the retrograde proximal zone, there is chalcopyrite, pyrite, and specular hematite. (f) Chalcopyrite occurs, along with sphalerite and specular hematite. (g) Pyrite with bornite in the proximal retrograde zone. (h) Clusters of specular hematite flakes that are shiny, metallic, and flat. (i) Specular hematite is seen in association with pyrite. (j,k) Cerussite and covellite are the alteration products of galena in the distal zone. (l) Malachite and goethite are the alteration products of chalcopyrite and pyrite, respectively, in the distal zone. Abbreviations: bornite (bo), cerussite (cer), chalcopyrite (cp), covellite (cv), galena (gn), goethite (gth), hematite (hem), magnetite (mag), malachite (mal), pyrite (py), and sphalerite (sp).