MENDERES PROJECT WORK SUMMARY 2012

Transcription

1 MENDERES PROJECT WORK SUMMARY 2012

2 MENDERES PROJECT WORK SUMMARY 2012 ABSTRACT Despite Anatolia s long history of mining, modern concepts of ore geology have not been fully applied to mineral exploration until the last couple of decades. The Turkish Geological Survey (MTA), founded in 1935, has produced mineral inventories (Maden Tetkik Arama [MTA], 1980) and metallogenic maps (MTA, 1993a) of the country. Changes in the mining law in 1985 resulted in the resuscitation of mineral exploration by multinational companies using modern exploration techniques with successful results; at least 10 gold discoveries have been made in recent years (Yiğit, 2006). The present study is aimed at utilizing classical methods for gold exploration through an approach of establishing a relationship between the known deposit in Efemcukuru region and similiar occurences in the study area. Classical methods are including geological mapping, geochemical sampling, geophysics survey and drilling.

3 CHAPTER ONE INTRODUCTION 1.1 General The history of mining in Anatolia dates back to 7000 B.C., with the oldest artifacts found near Ergani Diyarbakir, which were made from native copper and malachite (Cambel and Braidwood, 1970; Kaptan, 1990). Records and legends suggest that gold was mined before 1200 B.C. in Astyra (present day Madendag and Kartaldag, near Canakkale) for the Homeric city of Troy (Priam s treasure?). Archaeological records prove that gold was mined from the Pactolus River (present day Gediz) and the Sardis River (present day Sart) in western Turkey (Yiğit, 2006). This gold was refined by Croesus, last king of Lydia, who made the first gold coins in about 700 B.C. (Young, 1972). Midas, King of Phrygia, who was granted the power of turning everything that he touched into gold, lived in the city of Gordion near present day Eskisehir in central Anatolia (Yiğit, 2006). Despite Anatolia s long history of mining, modern concepts of ore geology have not been fuly applied to mineral exploration until the last couple of decades. The Turkish Geological Survey (MTA), founded in 1935, has produced mineral inventories (MTA, 1980) and metallogenic maps (MTA, 1993a) of the country. Changes in the mining law in 1985 resulted in the resuscitation of mineral exploration by multinational companies using modern exploration techniques with successful results; at least 10 gold discoveries have been made in recent years (Yiğit, 2006) The present study is aimed at utilizing classical methods for gold exploration through an approach of establishing a relationship between the known deposit in Efemcukuru region and similiar occurences in the study area which is adjacent to Efemcukuru gold deposit in Izmir. The study area hadn t received any attention in terms of geological research in the past.

4 1.2 Location of the Study Area The Efemcukuru gold deposit currently owned by Eldorado Gold is located 15 km east of Menderes and 12 km south of Izmir in Aegean Region Western Anatolia (Turkey) and bounded by latitudes 26 58' 15" and longitudes 38 17' 30" (Fig 1.1). The study area is adjacent to the Efemcukuru gold deposit. Site access is via approximately 40 km of regional paved and gravel roads from the city of Izmir to the north. Access is gained from the Seferihisar coast road to the west and north or the Izmir-Menderes highway to the east. A two km unimproved public forestry road currently provides access to the mine property from the regional roads. The travel time by road from Izmir is between 45 and 60 minutes.

5 Figure 1.1 Location of the Study Area Physiography Steep hills and narrow valleys characterize the Efemcukuru region with the elevation on site ranging from 580 m. in the valley to 900 m. in the surrounding hills. Vegetation consists of mature pine trees with sparse undergrowth covering the hillsides. The flatter land in the valleys and upper slopes of the hills has been cultivated with grape vines.

6 The mine site is situated within the Aegean climatic zone, which is characterized by hot and dry summers and warm and rainy winters. Temperatures in the region range between 30ºC in summer and 0ºC in winter with an annual average of approximately 17ºC.

7 CHAPTER 2 GEOLOGICAL SETTING 2.1 Regional Geology The Efemcukuru area is located at the western end of the Izmir-Ankara Suture Zone, a major regional structure that extends northeast and then east from Izmir for almost 800 km. The Izmir-Ankara Suture Zone marks the closure point of a subduction zone that separated the Sakarya and Anatolide-Tauride microplates plates during the late Cretaceous and early Paleocene Age. As the subduction zone closed, Neo-Tethyan sea floor between the two microplates was obducted onto the Anatolide-Tauride plate. Lenses of serpentine often associated with thrust faults and large olistoliths of recrystallized limestone were caught up in the melange-like complex (mainly flysch) that formed during the suturing process. Regionally extensive volcanism and intrusive activity were also associated with the subduction process (Oyman, Mineraci & Pişkin, 2003). Gold mineralisation is associated with late pulses of magmatic hydrothermal activity and is present in zones of hydraulic brecciation adjacent to veins or stockwork zones around a domeshaped small intrusion. The veins are hosted by Late Cretaceous Paleogene flysch facies rocks of the Izmir Ankara zone, which were intruded by rhyolites from of Neogene volcanism. Subsequent mid-tertiary dilation in western Turkey resulted in block faulting and the formation of the north-south orientated Seferihisar horst (Oyman, Mineraci & Pişkin, 2003). The Efemcukuru area is situated in the central part of the Seferihisar horst. Younger Neogene sediments and volcanics fill the flanking graben structures (Oyman, Mineraci & Pişkin, 2003) (Figure 2.1).

8 Figure 2.1 Location of Efemcukuru gold deposit, Turkey showing generalised geology, major ore deposits and favourable host rocks (Oyman at al., 2003)

9 2.2 Geology of Efemçukuru Gold Deposit Efemcukuru is a intermediate sulphidation epithermal vein system with peripheral stockwork zones. Existing mineral reserves are restricted to a single vein (the Kestane Beleni vein), and comprise three ore bodies referred to as the South, Middle, and North ore shoots. Mineralization in the Kestane Beleni vein which strikes generally northwest-southeast through the Kokarpinar valley is open at depth (Figure 2.2) Exploration at Efemçukuru will continue to focus on drill testing the Kestani Beleni northwest extension and Kokarpinar vein systems, with 12,000 metres of drilling planned Figure 2.2 Geological map of Efemcukuru (Eldorado, 2011). Gold mineralization is contained in steeply dipping vein structures of quartz and quartz rhodonite hosted by altered hornfels and phyllites (Oyman, Mineraci, Pişkin, 2003). (Figure 2.3)

10 Figure 2.3 Vein structures of quartz and quartz rhodonite hosted by altered hornfels and phyllites. Gold is fine grained, occurring as free grains in quartz and rhodonite gangue and locked in grains of pyrite, chalcopyrite and sphalerite. The Kokarpinar vein system is still under exploration and reserve calculation has not completed. The main vein system extends approximately meters in a northwest direction, dipping between 55 0 and 60 0 to the east (Oyman, Mineraci & Pişkin, 2003) (Figure 2.4).

11 Figure 2.4 Outcrop of Kestanebeleni Vein. The mineralized zone forms three distinct shoots that are currently open at depth. (Figure 2.5) Widths of the mineralized zone vary considerably from less than one meter to as much as 27 meters in stockwork zones (Eldorado, 2007).

12 Figure 2.5. Efemcukuru south, middle and north ore shoots (Kestanebeleni vein) Longitudinal section looking west (Eldorado, 2007) On October 30, 2009 Eldorado Gold announced a 23% increase in Efemcukuru proven and probable mineral reserves to 1.5 million ounces of gold. 2.3 Exploration History of Efemçukuru Gold Deposit Exploration work began in the license area in 1992 with an extensive geological mapping, trenching, rock, soil and stream sediment sampling. The Kestane Beleni vein was identified and sampled along the surface outcrop, where evidence of prior workings was found. HQ core and RC drilling have been carried out on the property. This work has confirmed the continuity of the vein, mineralization and extension of the structure, along strike and down dip (Eldorado, 2007). Drilling on the Efemçukuru property has been carried out in several phases. The first drill program was started in September 1992 and continued in November 1992 after a one month break to await and evaluate assay results. The second phase of drilling was carried out in May/June The third phase of drilling was carried out from August to October 1996 (after a 3-year hiatus during which Eldorado acquired control of Tüprag from Gencor. The

13 fourth and fifth phase of drilling occurred between March and December 1997 and included several breaks for evaluating results (Eldorado, 2007). Limited work completed after the 1999 prefeasibility study as Eldorado was focusing on the development of the Kışladağ Project (Eldorado, 2007). Infill and exploratory drilling commenced again in August 2006 and has continued throughout 2007 (Eldorado, 2007). In 2009 and 2010 exploration program, drilling operations focused on Kokarpinar vein system (Eldorado, 2007). As of december 2010, Proven+Prabable Reserve is 1.506, g/t (Eldorado, 2007). The high grade epithermal gold vein deposit is suited for underground mechanized mining. Ore is being processed through a milling and flotation concentrate circuit on site. The flotation concentrate is then being transported to Kışladağ mine in Uşak, Turkey (Eldorado, 2007). Production was started on June 30, At year-end 2011, 9,100 tonnes of concentrate, containing approximately 25,000 ounces of gold, had been delivered to Kisladag for processing. Capital expenditures for 2012 are estimated at $30 million and will include the completion of the construction program, underground capital development and construction of a road to bypass a local village. You can see Eldoradogold s significant drill hole intersections from drill program below (Figure 2.6).

14 sfigure 2.6. Eldorado Gold s Significant Drill Hole Intersections from Drill Program

15 CHAPTER 3 METHODOLOGIES We ve been focusing in our permit which is east of Efemçukuru Gold Mine. Classical methods were used such as geological mapping, geochemical sampling IP Resistivity survey and drilling at the field (ER ) (Figure 3.1). Figure 3.1. Frontlinegold s Permits and the permit which studies were carried out. 3.1 Geological Mapping and Geochemical Sampling The soil and geochemical sampling has been completed over a 4 km 2 area, with 1351 soil samples including standards and dublicates and 181 rock chip samples including standards collected since March, The highest anomalous soil sample is ppm Au; the highest anomalous rock sample is 2.83 g/t Au. Two old workings were found and detailed sampling around old workings was completed. Geological mapping was completed (Figure 3.2).

16 Figure 3.2. Geological map of the study area.

17 Assays of rock and soil samples yielded some significant anomalous Ag, As, Cd, and Mn values. It suggests that the working area is located in an upper part of the standard epithermal model and that vein-type structures with higher Au values may be found at m. depth in this part of the system rather than at surface. A soil anomaly map for Au, Ag and As was preapared respectively (Figure 3.3, Figure 3.4, Figure 3.5).

18 Figure 3.3. Soil anomaly map for Au of the study area.

19 Figure 3.4. Soil anomaly map for Ag of the study area.

20 Figure 3.5. Soil anomaly map for As of the study area.

21 Figure 3.6. Ag results from the samples which were collected from the trench.

22 3.2. IP Resistivity Survey IP/Resistivity survey was completed by Enerson Engineering Company. The program started on July, The program consisted of four north-south lines at 200 m spacing totally kilometers. JVX LTD. was retained to review the data from the IP/Resistivity survey completed by Enerson Engineering. JVX identified two IP anomalies. The southern anomaly located in the middle of the grid is medium in strength and associated with a weak resistivity high on its southern flank. The anomaly correlates with anomalous soil geochemical Au values and a 2.83 g/t Au grab sample was taken within the anomaly. In addition an adit is located on the northern flank of the IP anomaly. A second IP anomaly is located on the northern part of the grid, is described as very strong and covers an area 400 m wide by 300 m long. The IP anomaly is associated with a moderate resistivity low and is open to the east and west. Two sources of the anomaly have been interpreted. The IP anomaly correlates with anomalous geochemical Au values, while an adit driven into the southern anomaly. On the southern part of the grid there are several narrow resistivity highs with very week chargeabilities. In this area on the south-western part of the grid several resistivity highs correlate with the highest soil geochemical Au values located on the grid. JVX in its review of the IP/Resistivity survey has recommended seven drill holes totaling m which it has proposed for drilling (Figure 3.7).

23 Figure 3.7. The map showing chargeability. Drill locations were proposed by JVX.

24 Based on the survey there is a low IP anomaly associated with high resistivity around the central area. This anomaly is a deep sitting anomaly and unfortunately, it was not wholly identified by this survey. It is necessary to make a new deep looking survey to wholly identify this anomaly. This survey could only reach to the top of this anomaly and relatively low IP values together with high resistivity suggest a stock work type mineralization. 3.3 Drilling Drilling was carried out by Ortadogu Drilling Company Figure 3.8. Drilling Rig Model used at the field is CHRISTENSEN CS1000 P6. HQ core drilling carried out at the field. We have permissions for 20 drill locations from the Forestry Department. P9 and P12 drill locations have been completed so far. You have the information of P9 and P12 in a DVD. Our rock and soil analyses had been done by ALS Chemex Laboratory ( We use Au-AA24 for Au analyse and ME- ICP 41 for multielement analyse.

25 Figure 3.9 P9 and P12 Drill Locations.

26 Figure Cross Section of P9 and P12

27 CHAPTER FOUR Stream sediment samples were taken from the yellow licenses. Soil samples have been collected from the license which is at the west side of Eldorado (ER ). Figure 4.1 The licenses which were studied.

28 Figure 4.2 Thematic Map for Au Anomalies from the Stream Sediment Samples.

29 CHAPTER FIVE The study area hadn t received any attention in terms of geological research in the past. We will start working at the field soon. Figure 5.1 The licenses which weren t studied before.

30 CHAPTER FIVE RESULTS AND INTERPRETATIONS 4.1. General We ve been focusing in our permit which is east of Efemçukuru Gold Mine. Eldorado gold s drill holes are very close to our boundary as you see on the maps above. The closest drill hole is about 10 meters away from our boundary. Based on Eldoradogold s web site; all of the 2011 drillholes at Kokarpinar have intersected mineralized veins at projected levels, and assay results received from the first three were positive ( Assays of rock and soil samples yielded some significant anomalous Ag, As, Cd, and Mn values. It suggests that the study area is located in an upper part of the standard epithermal model and that vein-type structures with higher Au values may be found at m. depth in this part of the system rather than at surface. In addition the study area is located approximately m higher elevation than the vein also. IP Anomaly supports this theory. The IP anomaly correlates with anomalous geochemical Au values. Based on the survey there is a low IP anomaly associated with high resistivity around the central area. This anomaly is a deep sitting anomaly and unfortunately, it was not wholly identified by this survey. It is necessary to make a new deep looking survey to wholly identify this anomaly. This survey could only reach to the top of this anomaly and relatively low IP values together with high resistivity suggest a stock work type mineralization.