AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU

Özlem Toygar Sağın; Duru Cesur; Gökcem Sağın; Selahattin Kadir

doi:10.31796/ogummf.1813459

TR EN

AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU

Öz

Akbaştepe Au–Ag cevherleşmesi, İzmir–Ankara–Erzincan Kenet Zonu’nun (İAEKZ) kuzeyinde, Söğüt (Bilecik, KB Türkiye) ilçesinin yaklaşık 6 km güneydoğusunda yer almaktadır. Bölgede hâkim litoloji, Alt Karakaya Kompleksi’ne ait Triyas yaşlı Nilüfer Formasyonu’nun yeşilşist fasiyesindeki kayaçlardan oluşmaktadır. Cevherleşme, yaklaşık K70B doğrultulu, ortalama 5 m kalınlığa ve yaklaşık 2 km uzunluğa sahip bir damar boyunca gelişmiştir. Bu çalışmada, daha önce tanımlanmamış alterasyon zonlarının mineralojik özelliklerinin ortaya konulması amaçlanmıştır. Bu kapsamda, X-ışını difraksiyonu (XRD) ile taramalı elektron mikroskobu–enerji dağılımlı spektroskopi (SEM–EDS) analizleri gerçekleştirilmiştir. Elde edilen bulgular, cevherli zonun kompakt ve katmanlı yapılı, smektitçe zengin bir karakter sergilediğini; yan kayaçta ise düzensiz kenarlı, yığınlar halinde gelişmiş ve birbirine paralel yönlenme gösteren kloritin baskın olduğunu ortaya koymaktadır. Smektit ve klorit arasında genel olarak ters yönlü bir dağılım ilişkisi belirlenmiştir. Ayrıca, karbonatlaşma evresine ait dolomit, Fe-oksit fazları, vermiküler şekilli kaolinit ve yapraksı illit tanımlanmıştır. Smektit ile birlikte kuvars, feldispat, kalsit/aragonit, ankerit/dolomit, götit, hematit ve pirit mineralleri ile yer yer höylandit–klinoptilolit, analsim, amfibol ve piroksen varlığı saptanmıştır. Sonuç olarak, tanımlanan mineral toplulukları ve alterasyon tipleri, Akbaştepe Au–Ag cevherleşmesinin çok evreli bir hidrotermal akışkan–kayaç etkileşimi sürecine sahip olduğunu göstermektedir. Bu süreç; (i) erken evrede kloritik–propilitik alterasyon zonu, (ii) orta–ileri evrede smektit/kaolinit ağırlıklı arjilik alterasyon ile birlikte gelişen Fe–Mg karbonatlaşma ve silisleşme, (iii) geç/süperjen evrede ise Fe-oksitlenmenin belirginleştiği oksidasyon zonu ile temsil edilmektedir.

Anahtar Kelimeler

altın , alterasyon , smektit , klorit , Fe-oksit

CHARACTERIZATION OF ALTERATION MINERALOGY IN THE AKBAŞTEPE (SÖĞÜT-BILECIK) AU-AG DEPOSIT

Abstract

The Akbaştepe Au–Ag mineralization is located 6 km southeast of Söğüt (Bilecik, NW Türkiye), on the northern margin of the İzmir–Ankara–Erzincan Suture Zone (IAESZ). The lithology of the study area consists of greenschist-facies rocks of the Triassic Nilüfer Formation belonging to the Lower Karakaya Complex. The mineralization developed along a vein striking approximately N70W, with an average thickness of about 5 m and a length of nearly 2 km. This study aims to determine the mineralogical characteristics of alteration zones. For this purpose, X-ray diffraction (XRD) and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM–EDS) analyses were carried out. The results indicate that the ore zone is compact, well-layered, and enriched in smectite, whereas the host rock is dominated by chlorite occurring as irregular aggregates with parallel orientations. An overall inverse spatial relationship between smectite and chlorite was identified. In addition, dolomite related to the carbonatization stage, Fe-oxide phases, vermicular kaolinite, and platy illite were recognized. Smectite-associated mineral assemblages include quartz, feldspar, calcite/aragonite, ankerite/dolomite, goethite, hematite, and pyrite, as well as locally occurring heulandite–clinoptilolite, analcime, amphibole, and pyroxene. The identified mineral assemblages and alteration types indicate that the Akbaştepe Au–Ag mineralization developed through a multistage hydrothermal fluid–rock interaction process. This process is represented by (i) an early-stage chloritic–propylitic alteration zone, (ii) a middle to advanced-stage argillic alteration dominated by smectite and kaolinite accompanied by Fe–Mg carbonatization and silicification, and (iii) a late/supergene stage characterized by pronounced Fe-oxidation forming an oxidation zone.

Keywords

gold , alteration , smectite , chlorite , Fe-oxide

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Details

Primary Language

Turkish

Subjects

Geological Sciences and Engineering (Other)

Journal Section

Research Article

Authors

Özlem Toygar Sağın ^*
0000-0002-2516-4250
Türkiye

Duru Cesur
0009-0000-6188-8267
Türkiye

Gökcem Sağın
0000-0002-4784-6789
Türkiye

Selahattin Kadir
0000-0002-3132-090X
Türkiye

Publication Date

April 20, 2026

Submission Date

October 30, 2025

Acceptance Date

January 27, 2026

Published in Issue

Year 2026 Volume: 34 Number: 1

DOI

https://doi.org/10.31796/ogummf.1813459

IZ

https://izlik.org/JA97XJ35JD

APA

Toygar Sağın, Ö., Cesur, D., Sağın, G., & Kadir, S. (2026). AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU. Eskişehir Osmangazi Üniversitesi Mühendislik Ve Mimarlık Fakültesi Dergisi, 34(1), 2133-2143. https://doi.org/10.31796/ogummf.1813459

AMA

1.Toygar Sağın Ö, Cesur D, Sağın G, Kadir S. AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU. Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi. 2026;34(1):2133-2143. doi:10.31796/ogummf.1813459

Chicago

Toygar Sağın, Özlem, Duru Cesur, Gökcem Sağın, and Selahattin Kadir. 2026. “AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU”. Eskişehir Osmangazi Üniversitesi Mühendislik Ve Mimarlık Fakültesi Dergisi 34 (1): 2133-43. https://doi.org/10.31796/ogummf.1813459.

EndNote

Toygar Sağın Ö, Cesur D, Sağın G, Kadir S (April 1, 2026) AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU. Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi 34 1 2133–2143.

IEEE

[1]Ö. Toygar Sağın, D. Cesur, G. Sağın, and S. Kadir, “AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU”, Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi, vol. 34, no. 1, pp. 2133–2143, Apr. 2026, doi: 10.31796/ogummf.1813459.

ISNAD

Toygar Sağın, Özlem - Cesur, Duru - Sağın, Gökcem - Kadir, Selahattin. “AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU”. Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi 34/1 (April 1, 2026): 2133-2143. https://doi.org/10.31796/ogummf.1813459.

JAMA

1.Toygar Sağın Ö, Cesur D, Sağın G, Kadir S. AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU. Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi. 2026;34:2133–2143.

MLA

Toygar Sağın, Özlem, et al. “AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU”. Eskişehir Osmangazi Üniversitesi Mühendislik Ve Mimarlık Fakültesi Dergisi, vol. 34, no. 1, Apr. 2026, pp. 2133-4, doi:10.31796/ogummf.1813459.

Vancouver

1.Özlem Toygar Sağın, Duru Cesur, Gökcem Sağın, Selahattin Kadir. AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU. Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi. 2026 Apr. 1;34(1):2133-4. doi:10.31796/ogummf.1813459

AKBAŞTEPE (SÖĞÜT-BİLECİK) AU-AG CEVHERLEŞMESİNDE ALTERASYON MİNERALOJİSİNİN KARAKTERİZASYONU

Öz

Anahtar Kelimeler

CHARACTERIZATION OF ALTERATION MINERALOGY IN THE AKBAŞTEPE (SÖĞÜT-BILECIK) AU-AG DEPOSIT

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