Çanakkale yöresi Kartaldağ ve Madendağ epitermal altın cevherleşmelerinin karşılaştırmalı jenetik incelemesi.


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Türkiye

Tezin Onay Tarihi: 2010

Tezin Dili: İngilizce

Öğrenci: Ezgi Ünal

Eş Danışman: Nilgün Güleç, NİLGÜN TÜRKAN GÜLEÇ

Özet:

This thesis study is concerned with the genetic investigation of two epithermal gold deposits (Madendağ and Kartaldağ) in Çanakkale, NW Turkey. The methodology comprises field and integrated laboratory studies including mineralogic-petrographic, geochemical, isotopic, and fluid inclusion analysis. Kartaldağ deposit, hosted by dacite porphyry, is a typical vein deposit associated with four main alteration types: i) propylitic, ii) quartz-kaolin, iii) quartz-alunite-pyrophyllite, iv) silicification, the latter being characterized by two distinct quartz generations as early (vuggy) and late (banded, colloform). Primary sulfide minerals are pyrite, covellite and sphalerite. Oxygen and sulfur isotope analyses, performed on quartz (δ18O: 7.93- 8.95 ‰) and pyrite (δ34S: -4.8 ‰) separates, suggest a magmatic source for the fluid. Microthermometric analysis performed on quartz yield a temperature range of 250-285 ºC, and 0-1.7 wt % NaCl eqv. salinity. Madendağ deposit, hosted by micaschists, is also vein type associated with two main alteration types: illite and kaolin dominated argillization and silicification, characterized by two distinct quartz phases as early and late. Oxygen isotope analyses on quartz (δ18O: 9.55-18.19 ‰) indicate contribution from a metamorphic source. Microthermometric analysis on quartz yield a temperature range of 235-255 ºC and 0.0-0.7 wt % NaCl eqv. salinity. The presence of alunite, pyrophyllite and kaolinite, vuggy quartz and covellite suggest a high-sulfidation epithermal system for Kartaldağ. On the other hand, Madendağ is identified as a low- sulfidation type owing to the presence of neutral pH clays and typical low temperature textures (e.g. colloform, comb, banded quartz).