Ph.D. Tezi Görüntüleme

Student: Enver AKARYALI
Supervisor: Prof. Dr. Necati TÜYSÜZ
Department: Jeoloji Mühendisliği
Institution: Graduate School of Natural and Applied Sciences
University: Karadeniz Technical University, Turkey
Title of the Thesis: Geologic, Mineralogic, Geochemical and Genetic Studies of Arzular (Gümüşhane,) Gold Deposit NE-Turkey
Level: Ph.D.
Acceptance Date: 1/9/2010
Number of Pages: 174
Registration Number: Di798
Summary:

      Arzular mineralization (Gümüşhane, NE Turkey) has emplaced as fault-controlled

into NE-SW trending and NW dipping, and also about EW trending and North dipping

      fractures within the Eocene aged Alibaba Formation. The main mineralizations have

developed along a N70E trending fracture zone in Kuzdağı Sırtı area. Ore-bearing silica

      veins exhibit 0.1-0.3 m thicknesses and do not show continuity in the field. Cavity-filling

and banded structures are widely observed in mineralizations. The main ore minerals consist of

      galena, sphalerite, pyrite, chalcopyrite and tetrahedrite, and also trace amounts of gold.

Mineral chemistry analyses indicate that pyrite contains low Co and Ni values, Zn displays

      a negative correlation with Cu and Fe in chalcopyrites, Fe behaves similarly with Cd and

Mn in sphalerites and there is an ion exchange between Zn and Fe. In addition, it was

      determined that all fahlerz minerals are tetrahedrite in composition and silver does not

exist in galenas except tetrahedrites.

      Quartz, sericite, K-Feldspar, kaoline, Fe chlorite, albite, Mg chlorite and epidote are

most common alteration minerals from ore towards wall rock. Zr, Hf, Nb, Al and Ti are

      immobile elements in the profiles that laid out along a line perpendicular to the vein.

Relative (%) and net (g/100g) mass change calculations done considering these immobile

      elements indicated mass gains in 1, 3 and 5 numbered profiles, mass losses in 2 and 4

numbered profiles.

      Homogenezation temperatures measured from fluid inclusions are between 130°C -295 °C

in quartz and 90°C -133°C in sphalerites. In NaCl±KCl±MgCl2-H2O system, ore-forming fluids

      have salinities between 0.7 and 12.4 wt. % NaCl eq and densities between 0.79 and 0.97 g/cm3.

These values reveal that minerilazations were generated in an epithermal system. Sulphur

      isotope analysis results obtained from pyrite, galena and sphalerite minerals are between -

1.2 ‰ and 3 ‰, marking magmatic origin for sulphur. The average heat of formation was

      calculated as between 244°C and 291°C by sulphur isotope thermometry. Oxygen and

hydrogen isotope values are between 15.0 ‰-16.7 ‰ and -87 ‰ -91 ‰, respectively.

      Key Words: Gümüşhane, Arzular, Epithermal, Gold, Mass Gains and Losses, Fluid

Inclusions, Stable isotope