Siirt – Madenköy açık işletme sahasında gerçekleşen kütle hareketleri ile bölgesel yağış ilişkisinin saptanması
Determining the relationship between mass movements occurred in Siirt – Madenkoy open mining site and regional precipitation
Yazar: DENİZ DOLMA
Danışman: DOÇ. DR. ENVER VURAL YAVUZ
İstanbul Teknik Üniversitesi / Lisansüstü Eğitim Enstitüsü / Jeoloji Mühendisliği Ana Bilim Dalı / Jeoloji Mühendisliği Bilim Dalı
Derece: Yüksek Lisans, 2023
Konu: Jeoloji Mühendisliği = Geological Engineering
Dizin: Kütle hareketleri = Mass movements ; Mühendislik jeolojisi = Engineering geology ; Siirt-Şırvan-Madenköy = Siirt-Şırvan-Madenköy ; Yağışlar = Rainfall

Özet:
Türkiye'nin ikinci en büyük işlenebilir bakır madeni olan Madenköy Açık Ocak Bakır Madeni İşletmesi, Siirt ili, Şirvan ilçe sınırları içerisinde bulunmaktadır. MTA burada çalışmalarına 1980'li yıllarda başlamış olup, 27.273.000 ton rezerv öngörmüştür. Siirt Madenköy Bakır Yatağı, Güneydoğu Anadolu tektonik birimleri ile Bitlis Masifi üzerinde bulunur. Yaklaşık olarak 30-60 km genişliğindeki yatak, batıdan doğuya doru 500 km'lik bir mesafe boyunca uzanır. Siirt-Madenköy bakır yatağı pirit ve kalkopirit saçınımlı killeşme ve kloritleşmeyle başlar. Yukarıdan aşağıya doğru pirit, pirit + kalkopirit, pirit + kalkopirit + sfalerit, pirit + kalkopirit + manyetit, manyetit şeklinde bir zonlanma izlenir. Cevherleşme pirit-kalkopirit-manyetit veya yalnız manyetit saçınımlı killeşme-kloritleşme ve yer yer çatlak dolgulu cevherleşme ile sona ermektedir. Pirit, kalkopirit, manyetit, sfalerit, markazit, galenit, pirotin, bornit, kovellin, kalkosin, valerit, bravoit, linneit, fahlerz, altın ve gümüş başlıca cevher minerallerini; kuvars, klorit, barit, siderit, karbonat da gang minerallerini oluştururlar. 2015 yılının Ekim ve Aralık ve 2016 yılının Ekim ayında, Açık Ocak İşletmesinin Kuzeybatı şevinde 3 adet çatlak hattı tespit edilmiştir. Yerinde yapılan incelemeler sonucu işçi sağlığı, iş güvenliğini ve sürdürülebilir madencilik açısından tehdit edici boyutta olduğu saptanmıştır. Oluşan bu çatlak hatlarını gözlemlemek ve olası blok hareketlerine neden olabilecek bir hareketi saptamak amacıyla, gerçek zamanlı şev gözetleme aracı olan İtalyan IDS menşeli IBIS-M kullanılarak çatlak sistemi izlenmiştir. 
Bu çalışmada gözlemlenen çatlaklar ile 2016 yılında gerçekleşen kütle hareketinin bölgesel yağış ile ilişkisinin olup olmadığı ve varsa bu ilişkinin değerlendirilmesi amaçlanmıştır. Bu kapsamda İBİS-M cihazı tarafından saptanan, çatlak hatlarına ait deplasman hareketi ve deplasman hızı verileri tablo haline getirilerek değerlendirilmiştir. Aynı zamanda, Açık Ocak işletmesi şevlerine ait kaya mekaniği deneyleri incelenerek, kütle hareketinin gerçekleştiği yamaç molozu biriminin dayanım özellikleri değerlendirilmiştir. 
Yağış verileri ise Madenköy etrafında yer alan, çalışma alanındakine benzer morfolojik koşullara (bölgesel bulunuş, kot) sahip olan Şirvan, Hizan ve Pervari DMİ'leri yanı sıra uzun yıllar meteorolojik kayıtları bulunması ve bölgesel ölçekteki yakınlığı nedeniyle seçilen Siirt DMİ'dir. Meteorolojik verilerin bölgesel bütünlük içerisindeki durumlarının incelenmesi sonucunda, "Hizan DMİ" ve "Siirt DMİ" verilerinin kullanılması uygun bulunmuştur.
Çalışma sahasına ait hidrojeolojik veriler incelenerek, kaya kütlelerinin, az geçirimli birimler üzerindeki etkileri saptanmaya çalışılmıştır. Bölgede, Ekim ayından itibaren yağışlı sezona geçilmektedir. Aralık ayından itibaren kar yağışı gözlenmektedir ve yağan kar erimeden toprak üstünde kalmaktadır. Bu çalışma sonucunda bu aylar da gözlenen sürekli yağış ve karın erimesiyle şev yüzeylerinin kayma direncinin azalması ve/veya zeminin su içeriğinin artmasına bağlı olarak kütle hareketi ile yağış arasında ki ilişki değerlendirilmiştir.

Abstract:
Madenköy Copper Deposit is Turkey's second largest machinable copper reserve. Madenköy is located within the borders of Şırvan district of Siirt province. It is known that the Madenköy copper deposit has been operated since ancient times. The historical mining equipment unearthed as new underground galleries are opened in the bed and the slag found on the edge of the village prove that this place was operated in the past.
It is known that the first prospecting studies in the field were carried out in 1947, 1958 and 1962. The first more detailed study was carried out in 1970, and the first reserve amount was revealed with 18,500 meters of drilling in 66 locations. In 1981, Outokumpu and MTA carried out a joint feasibility study and as a result of these studies, 24 million tons of reserves with 2.03% Cu grade were found in the field. In 1985, the site was transferred to Etibank and operational preparations began with a consortium established by Preussag, Alarko and Etibank. However, this consortium was dissolved in 1989 and later on, the field was put out to tender by Etibank.
Siirt Madenköy Copper Deposit is located on the thrust zone between the Southeastern Anatolian Edge Fold tectonic units and the Bitlis Metamorphic Massif. This zone, 30-60 km wide, extends from west to east for a distance of 500 km. Along the belt, from west to east, there are Sivrice (Helezür)-Elazig, Maden-Ergani-Elazig, Lice Mizak and Karadere-Diyarbakır and Madenköy-Siirt copper deposits. Siirt-Madenköy copper deposit starts with pyrite and chalcopyrite disseminated argillization and chloritization. From top to bottom, a zoning is observed as pyrite, pyrite + chalcopyrite, pyrite + chalcopyrite + sphalerite, pyrite + chalcopyrite + magnetite, magnetite. The mineralization ends with pyrite-chalcopyrite-magnetite or only magnetite disseminated argillization-chloritization and occasionally crack-filled mineralization. The ore body slopes 50o-60o north. The mineralization developed entirely within pillow lavas. 0.46-0.60% Cu was detected in the analysis of rock samples containing pyrite and chalcopyrite scatterings and undergoing weathering. Mine microscopy studies on the Siirt-Madenköy copper deposit shows that pyrite, chalcopyrite, magnetite, sphalerite, marcasite, galenite, pyrrhotite, bornite, covelline, chalcosine, valerite, bravoite, linneite, fahlerz, gold and silver are the main ore minerals; quartz, chlorite, barite, siderite, carbonate forms gangue minerals. The proportions of minerals in the deposit vary between 0-2.75% for zinc, 0-0.3% for lead, 0.3- 8.55% for copper and 0.0005- 0.014% for cadmium. Average grades are 0.67% Zn, 0.059% Pb, 2.33% Cu. Siirt-Madenköy Copper Deposit "Cyprus" with recent studies on mineralizations in the Southeast Anatolian Ophiolite Belt. Type is described as "Massive Sulphite" deposit.
The project area, whose geological features were first defined on the basis of the 1/25.000 scaled regional study area, was separated on the basis of the lithostratigraphic units of the formations, based on the lithological information obtained from the drillings opened in the open pit area. Lithostratigraphic units were used to define geohydraulic environment characteristics in the first stage. In the second stage, the types of hydrogeological environments defined by the spatial relationship between geohydraulic environments, their distributions and characteristics were revealed.
The nature of the general groundwater storage environment in the study area and its surroundings; The "groundwater productivity level" in "formations containing local groundwater" was determined as "weak".
The Slope Debris unit, where mass movement takes place, is a unit that has been found to exhibit plastic behavior and high permeability considering its strength properties, and is classified as a weak rock. This unit contains recrystallized limestone, limestone pieces and blocks, and has a permeable granular environment according to its ability to contain and transmit groundwater. It has been understood that the Slope Debris unit is permeable and suitable for water saturation and has semi-water bearing properties on the less permeable units.
In October 2015, 2 crack systems were observed on the Northwest slopes of the Open Pit Plant. As a result of on-site investigations, it has been determined that it is threatening in terms of worker health, occupational safety and sustainable mining. The crack system was monitored by using the Italian IDS origin IBIS-M, a real-time slope monitoring tool. In this study, it is aimed to correlate and evaluate the observed crack system and the mass movement that took place in 2016 with the regional precipitation. In this context, the displacement motion and displacement velocity data of the crack systems measured by the IBIS-M device were tabulated and evaluated. At the same time, the rock mechanics tests of the slopes of the Open Pit pit were examined and the strength properties of the units were evaluated. 
Considering the strength properties, the rocks in the study area were classified as weak rock. Precipitation data are Şirvan, Hizan and Pervari DMIs located around Madenköy, which have similar morphological conditions (regional presence, elevation, etc.) to those in the study area, as well as Siirt DMI, which was chosen due to its long-term meteorological record and proximity on a regional scale. As a result of the examination of the meteorological data within the regional integrity, it was found appropriate to use the "Hizan DMI" and "Siirt DMI" data. By examining the hydrogeological data of the study area, it has been concluded that the rock masses on the northwest slopes are permeable and suitable to become saturated with water on the less permeable units. In the region, the rainy season starts from October. Snowfall has been observed since December and the falling snow stays on the ground for a long time without melting. As a result of this study, the relationship between mass movement and precipitation was evaluated due to the continuous precipitation observed in these months and the decrease in the shear resistance of the level surfaces and/or the increase in the water content of the ground due to the long-term melting of the snow. Later, it was determined that the melting of snow caused a serious increase in the amount of movement as the precipitation turned into rain. 
Accordingly, it is revealed that there is a linear relationship between mass movement and precipitation, depending on the decrease in the sliding resistance on the slope surfaces and/or the increase in the water content of the ground with the melting of the precipitation and accumulated snow. With respect to, if the crack line was continued to be traced in the time deformation graph created for the I. Crack line where the mass movement occurred, it is seen that the crack line would show a decreasing and then permanent deformation tendency in the rainy period depending on the decrease in precipitation over time. 
As a result, in this study, which was prepared to correlate the mass movements occurring in the cracks seen in the Northwest slope and the southern steps of the Open Pit Copper Mine located in Siirt Province- Şirvan District- Madenköy area, with precipitation and displacement data, proved to be a factor.