society of economic geologists, inc. metu student chapter...demir export geologists introduced the...

Society of Economic Geologists, Inc. METU Student Chapter

SEG METU Student Chapter 2019 Field Trip Report

By

Koray Tasbicen (Treasurer) Hilal Ergili (Member)

I. Dogancan Yasar (President)

April 2020

Tasbicen, Ergili, Yasar April, 2020

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Table of Contents List of Figures ........................................................................................................................... II 1 Introduction ........................................................................................................................ 1 2 Field Itinerary and Participants .......................................................................................... 3

2.1 Itinerary ...................................................................................................................... 3 2.2 Participants ................................................................................................................. 4

3 Mine Sites & Deposits ....................................................................................................... 5 3.1 Ekinbaşı Underground and Dumluca Open-Pit Mines .............................................. 5 3.2 Divriği Fe-Placer Mine .............................................................................................. 7 3.3 Bakırtepe Gold Mine .................................................................................................. 8

4 Conclusions and Acknowledgments ................................................................................ 10 5 References ........................................................................................................................ 11


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List of Figures Fig. 1. Distribution of the skarn and potential IOCG deposits and prospects of Turkey with

emphasis on host-rock lithology (Yiğit, 2009). The field location within the Divriği district is marked. ............................................................................................................... 2

Fig. 2. Chapter members with Çiftay Mining geologists at the Ekinbaşı underground mine entrance. ............................................................................................................................. 5

Fig. 3. (A) Tunnel face photograph of pyrite clusters within massive magnetite; (B) hand specimen of magnetite covered by hematite. ..................................................................... 6

Fig. 4. Photographs of (A) underground diamond drilling operation, (b) ore plant facility with the underground mine. ....................................................................................................... 6

Fig. 5. Fe-skarn Dumluca open-pit mine view from terrace. ..................................................... 7Fig. 6. Chapter members in the Fe-Placer Fe mine operated by Demir Export. ....................... 7Fig. 7. A slope photograph of the open pit includes magnetite and hematite blocks within

Quaternary conglomerate. .................................................................................................. 8Fig. 8. Core samples with variety of textures: (A) stockwork, (B) comb, (C) lattice bladed. ... 9Fig. 9. A hand specimen of nugget native gold on hematite within quartzite. .......................... 9


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1 Introduction The METU SEG Student Chapter 2019 Field Trip took place between 27th to 30th of September 2019 with 12 student chapter members. The field trip was guided by our academic advisor Dr. Mesut Soylu. After visiting the major mine sites in Western and North-Western Turkey in 2017 and 2018 field trips, 2019 field trip focused on some of the important deposits located in Eastern Turkey, specifically the Sivas area (Fig. 1). Two mining districts have been visited by our student chapter; Divriği and Bakırtepe. Sivas is located in the northwestern part of Central Anatolian Crystalline Complex and Divriği district is known by its iron deposits and main mineralization sites within the area are named as A-Kafa, B-Kafa and C-placer. Furthermore, Bakırtepe Gold Mine is located 75 km west of Divriği. In Divriği district, three iron mines were visited; (1-2) Two Fe-skarn deposits (one underground and one open-pit) operated by Çiftay Mining and (3) Fe-placer deposits in which ore is mainly extracted from magnetite by Demir Export. Bakırtepe Gold mine, operated by Demir Export, is located in Kangal, Sivas. Deposit type is debated; although mineralization is currently attributed to veinlets that have developed with the progression of deformation, company geologists indicated that fluid inclusion studies combined with its metamorphic facies and alteration types indicates a possibility of a mesothermal nature. Due to confidentiality agreements, detailed maps, geochemical data and core depths are not presented in this report. This report is written in a way to demonstrate observations that were made during this field trip with supportive literature, for further detailed information on the deposits/mines, the listed additional articles in the references section can be examined.


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Fig. 1. Distribution of the skarn and potential IOCG deposits and prospects of Turkey with emphasis on host-rock lithology (Yiğit, 2009). The field location within the Divriği district is marked.


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2 Field Itinerary and Participants

2.1 Itinerary Day 1 (September 27th, 2019):

• Leave for Divriği, Sivas from the Geological Engineering Department at 08.30. • Arrive Divriği, Sivas at 18.00. • Stay at hotel for the night.

Day 2 (September 28th, 2019):

• Depart hotel at 8.30. • Arrive Fe-Skarn Mine operated by Çiftay Mining at around 9.00. • Mine tour [Open-Pit&Underground] guided by Çiftay geologists. • Lunch at mine at 13.00. • Leave Fe-Skarn Mine [Çiftay Mining] for Fe-Skarn Mine [Demir Export] at 14.00. • Mine tour guided by Demir Export geologists. • Leave mine at 17.30 to Divriği. • Stay at hotel for the night.


• Depart hotel at 8.30. • Arrive Bakırtepe Gold Mine at around 10.00. • Mine tour guided by Demir Export geologists. • Lunch at mine at 13.00. • Mine tour continued. • Leave for Kangal Demir Export Guesthouse at 17.30. • Stay at Guesthouse for the night.


• Leave for Ankara at 10.00. • Arrive Geological Engineering Department at 22.00.


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2.2 Participants Field excursion was guided by Dr. Mesut Soylu. 12 chapter members listed below attended the field trip.

Name/Surname Grade

§ Akın Çil (Graduate - PhD) § İ. Doğancan Yaşar (Graduate - MSc) § Alperen Durudoğan (Undergraduate - 4th Grade) § Hilal Ergili (Undergraduate - 4th Grade) § Göktuğ Harmancı (Undergraduate - 4th Grade) § Furkan Oğuz (Undergraduate - 4th Grade) § Mert Kılıç (Undergraduate - 4th Grade) § Serap Şen (Undergraduate - 4th Grade) § Koray Taşbiçen (Undergraduate - 4th Grade) § Evrim Özkan (Undergraduate - 3rd Grade) § Damla Buse Gümüşboğa (Undergraduate - 3rd Grade) § Sera Tual Başer (Undergraduate - 3rd Grade)


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3 Mine Sites & Deposits

3.1 Ekinbaşı Underground and Dumluca Open-Pit Mines METU Student Chapter visited Ekinbaşı Underground and Dumluca Open-pit mines on September 28th, 2019. Ekinbaşı Fe-skarn mine is located 15 km northwest of Divriği, Sivas and operated by Çiftay Mining. The program started with health & safety briefings and introduction of the company. Afterwards, chapter members, accompanied by company geologists and mining engineers, entered the underground mine site (Fig. 2).

Fig. 2. Chapter members with Çiftay Mining geologists at the Ekinbaşı underground mine entrance.

Company geologists introduced the geology of the site while the group examines the tunnel faces, hand specimens, and core samples. Ekinbaşı Fe-skarn deposit has been formed due to the intrusion of Murmano Pluton and subsequent hydrothermal alteration of Güneş ophiolites and Akdağ limestone. Plutonic rocks have undergone metasomatism and mineralization occurred within as endoskarn (Yılmazer et al., 2003). Main ore mineral is magnetite whereas hematite and pyrite are also extracted as by-products (Fig. 3).


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Fig. 3. (A) Tunnel face photograph of pyrite clusters within massive magnetite; (B) hand specimen of

magnetite covered by hematite.

Furthermore, participants had the opportunity to observe underground diamond drilling operations, and the geologists explained the procedures and types of drillings that are proceeded in their operation (Fig. 4-A). In addition, the ore plant located within the underground mine was visited, and the procedures on ore extraction and processing were introduced (Fig. 4-B).

Fig. 4. Photographs of (A) underground diamond drilling operation, (b) ore plant facility with the

underground mine.


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Afterwards, our student chapter visited Dumluca Fe-skarn open-pit mine in which ore is extracted from A-Kafa mineralization (Fig. 5). A-Kafa and B-Kafa are separated with a faulted contact. A-Kafa mineralization mainly occurred within monzonitic Murmano pluton or at contact metasomatism of ultramafic and monzonitic rocks. On the other hand, B-Kafa is more deformed and faulted, and mineralization is confined within these faulted zones. Mineralization of B-Kafa is a result of late stage activities of magmatic fluid intercalating with meteoric waters at lower temperatures (Yılmazer et al., 2003).

Fig. 5. Fe-skarn Dumluca open-pit mine view from terrace.

Finally, during the mine visit, chapter members had the chance to witness blasting. Before the blasting took place, company geologist introduced the precautions taken before, during, and after blasting to prevent any accident during and shortly before blasting.

3.2 Divriği Fe-Placer Mine Chapter members visited the Fe-placer mine operated by Demir Export, on September 28th, 2019 (Fig. 6). The day again started with health & safety briefings and introduction of the company, followed by introduction of the geology, mineralization and operations of the mine site.

Fig. 6. Chapter members in the Fe-Placer Fe mine operated by Demir Export.


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Main ore extracted from the mine is magnetite. Ore minerals are transported due to faulting and erosional activities and deposits within Quaternary brown conglomerates. Heavy minerals are transported slower, compared to the light minerals during transportation (i.e. heavy minerals such as hematite and magnetite are separated from the rest of the transported material). This separation process causes the enrichment in the heavy minerals encompassed within the mine, thus, increases the tonnage of the placer deposits. In addition, it was observed that the magnetite and hematite blocks within the Quaternary brown conglomerates differs in size, probably due to the variation in travel distances (Fig. 7).

Fig. 7. A slope photograph of the open pit includes magnetite and hematite blocks within Quaternary

conglomerate.

3.3 Bakırtepe Gold Mine Chapter members spent the whole day of September 29th, 2019 on Bakırtepe Gold Mine. First, Demir Export geologists introduced the mine site geology and discussed about the mineralization styles. Following this introduction, several locations within the mine site were visited, hand specimens and slope faces were examined. Secondly, the resource/reserve estimation and modelling of the orebody of this deposit was introduced. Mineralization within the deposit is observed mainly within the quartzite and chlorite schist contact. Northern and southern parts of the mine reveals different grades of mineralization due to several phases of deformation. After examining these contacts, core samples were examined, and lithologies, contacts, and textures were distinguished (Fig. 8), alteration, and related mineralization were presented by company geologists. Furthermore, nuggets of native gold located to the north of the site were examined (Fig. 9).


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Fig. 8. Core samples with variety of textures: (A) stockwork, (B) comb, (C) lattice bladed.

Fig. 9. A hand specimen of nugget native gold on hematite within quartzite.


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4 Conclusions and Acknowledgments METU Student Chapter 2019 field trip was funded by the Stewart R. Wallace Fund, Demir Export and Çiftay Mining. Trip took place between September 27th and 30th. The group, consisting of 12-chapter members and academic advisor Dr. Mesut Soylu, visited four operating mines: (1) Ekinbaşı Fe-Skarn Mine, (2) Dumluca Fe-Skarn Mine, (3) Divriği Fe-Placer Mine, and (4) Bakırtepe Gold Mine. We would like to use this opportunity to give our most sincere thanks to İsmail Cihan, Exploration Director of Demir Export and Emre Zeytin, Exploration Manager of Çiftay Mining for giving us their full support. Furthermore, we would like to give our gratitude to geologists Akın Yıldız of Demir Export and Mutlu Kaan Denizbaşı of Çiftay Mining, as well as the other employees of both companies for sharing their time, knowledge and experiences at the mine sites and during the organization of this field trip.


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5 References Yiğit, Ö. (2009). Mineral Deposits of Turkey in Relation to Tethyan Metallogeny: Implications for Future Mineral Exploration. Economic Geology, 104: 19-51. Yılmazer, E., Kuşcu, İ., Demirela, G. (2003). A-B-Kafa Mineralizations in Divriği: Alteration zoning and zoning. Geological Bulletin of Turkey, 46(7): 17-34. [In Turkish with English abstract and extended summary]. For additional information on the deposits/mines: Dumanlılar, Ö., Cihan, İ., Ekmekçi, M., Kanaat, G., Aydoğan, C., Turunç, O. (2019). Conceptual model of formation and enrichment phases of Bakırtepe (Sivas-Kangal) gold mineralizations. Bulletin of the Earth Sciences Application and Research Centre of Hacettepe University, 40(2): 136-167. [ In Turkish with English abstract]. Kuşcu, İ. (2019). Skarns and Skarn Deposits of Turkey. Mineral Resources of Turkey, Modern Approaches in Solid Earth Sciences, 16: 283-336. Ünlü, T., Dumanlılar, O., Tosun, L., Akıska, L., Tiringa, D. (2019). Turkish Iron Deposits. Mineral Resources of Turkey, Modern Approaches in Solid Earth Sciences, 16: 225-260.

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