ISSN 0016-7029, Geochemistry International, 2016, Vol. 54, No. 6, pp. 559–568. © Pleiades Publishing, Ltd., 2016.

The Geothermal Model of Mersin (Turkey) Region1 Y. Urasa and M. Dagb aKahramanmaras

Sutcu Imam University, Geology Engineering Department, Kahramanmaras, Turkey Milcan Turizm Tarim Sanayi ve Ticaret A.S.Gaziantep Yolu Uzeri 3.km Arikan Mensucat A.S. Binasi Kahramanmaras, Turkey e-mail: [email protected]

b

Received August 26, 2015; in final form, November 6, 2015

Abstract—The purpose of the study is to present the geothermal model of Mersin (Camili) region geothermal area with its geology, hydrogeology, hydrogeochemistry and isotope hydrology. The 1/25000 scale geology map obtained from the literature research is revised. In order to obtain a geothermal model, geological crosssections are extracted in certain points on the revised geology map. There are 3 hot water outlets. There are MC-1, C-1 and Uclu Cesme deep drillings. MC-1 well is 420 m, approximately 43.6°C temperature and 35 L/s flow rate and C-1 is 150 m, 40.3°C and 35 L/s. There is no exact information about the depth of Uclu Cesme well, but its average temperature is 37.5°C and it has a very low flow rate. Isotope analyses of the water samples obtained from these three wells and the Icme Dere are carried out by using the IRMS method with δ18O–δ2H (Deuterium) and IAEA method with 3H (Tritium). Radioactive Alpha-Beta determination and Physico-chemical and Bacteriological analyses of MC-1 well are made by using EPA 900.00. δ18O–δ2H isotope ratios clearly indicate a meteoric origin for the waters. In the light of all this information, the revised 1/25000 scare geology map of Mersin Guneyyolu (Camili) geothermal area is obtained; it is found out that hot waters are of meteoric origin; and the isotope hydrology and hydro-chemical assessment of the area is conducted to shape the geothermal model. Keywords: Mersin, Guneyyolu, Geothermal, Hydrogeology, Isotope, Hydrogeochemistry DOI: 10.1134/S0016702916060070

1. INTRODUCTION The gradual development and improvement of world countries rapidly increase energy needs as well. Accordingly, while counties are looking for ways for more economical utilization of ordinary energy sources, they also investigate ways to make extensive use of renewable energy sources as an alternative. Therefore, geothermal energy, which is one of the renewable energy sources, becomes more and more important as an alternative source. Besides forming own renewable sources for lucky countries like our county, geothermal energy resources, which provide advantages such as being versatile, clean, environmentally friendly and economical, are of great importance in terms of employing the processes in the right way from searching for geothermal resources to operating them, protecting and development of the resource and providing sustainable production. The study area comprises the Mersin-Camili Village and its neighborhood in the Mediterranean Sea coast in the south of Turkey. Camili Village is at 033-a1 and 033-a2 sections of 1/25000 Mersin in the north of Mersin (Fig. 1) The Mediterranean Sea being on its north, Mersin province is separated from the inner parts of Anatolia by the high plateaus and peaks of the West 1 The article is published in the original.

and Middle Toros Mountains. This study aims to present the geothermal model of MC-1, C-1 and Uclu Cesme, which are in (Guneyyolu (Camili) area) with their geothermal resources (Fig. 1) and determine the parameters which enable this formation. In the Guneyyolu (Camili) geothermal area, MC-1 well is inside the Mersin ophiolitic mélange and Uclu Cesme is within the Karaisali formation. 2. GEOLOGY OF THE STUDY AREA The research area in the southeast part of the Toros Mountains formation zone in general carries the explicit geological features of this zone. Mersin ophiolitic mélange (Mom) and Karahamzausagi formation (Pa) of Paleozoic (Permo-Carboniferous) age is observed inside the deep valleys in the northwest of the area and, after these units, the Neogene aged sediments in the area are discordantly present (Durdu et al., 2007). Metamorphic limestone and schist, belonging to the Permo-Carbonfiber aged Karahamzauşağı formation (Pa), which is observed at the Ziyaret Mountain and its neighborhood and described to be having autochthonous position, form the base in the area (Durdu et al., 2007). There is Mersin ophiolitic mélange (Mom) which was dragged over this unit in the Upper Cretaceous period. In the drilling works

559

560

URAS, DAG C

BLACK SEA AEGEAN SEA

Tka Karapinar 20

Karapm ar Strea m

50

Ankara

Türkiye Mersin

Zindan Hill 30

Karaincir (location)

Sk-Pk Tkuk

Yeşilova

Qal

Alluvion

Sk-Pk

Caliche

Tku

Kuzgun formation

Middle

Sk-Pk

am Stre me

Avibeleni Hill

Tertiary

Ic

Explanations

Upper

Cenozoic

Icme Stream

Tgü

Orsü Kalesi (location)

Iğdir

Tkuk

Yassi Hill

Pleistocene Holocene

Uctepeler Yaylagosteren Hill

Miocene

Tku Zeytinli Hill

D

Kuzgun formation Tkuk Member of limostone Tgü

Güvenç formation

Tka

Karaisali formation

Tku

Celtiklialan E (location)

Tkuk

Sk-Pk Tkuk

Lower

Tku Tku

Strike-Slip fault

Qal

Camili

A

Ic

Sk-Pk Sk-Pk

200

Legend Upper system System Series

B

Quaternary

Tka

Tka

0

MEDITERRANEAN SEA

Tgü

Tgü

Camili

me S

N tre am

0

Tku

A

B 20

1 km

Dip-Slip fault Road Sectional lines Direction and slope Residential areas Hot water wells Sample locations

Fig. 1. General geology and location map of Guneyyolu (Camili) geothermal area (Revised from Tekin et al., 1998).

in the Guneyyolu (Camili) geothermal area, the oldest unit in the base was Mersin ophiolitic mélange. Tertiary aged units surfacing in the area are laterally and vertically transitive with each other and are divided as Lower Middle Miocene aged Karaisali formation (Tka) and Guvenc formation (Tgu) Middle Upper Miocene aged Kuzgun formation (Tku) (Demirel, 2005). However, Tertiary aged unit in the stratigraphic section which cannot surface in the research area is Oligocene-Lower Miocene aged Gildirli formation (Tgi). Another formation that cannot surface in the research area is Handere formation. Besides, the youngest units of the area are Quaternary aged Caliche and Alluviums. As a result of the evaluation of the general geothermal map and geology cross-sections on the geothermal area of Mersin Guneyyolu (Camili) in Figs. 1, 2, it can be said that Gildirli and Guvenc formations are in cover positions for the first and second reservoir in the study area due to the clayey and silty levels they contain. Furthermore, the model of hot waters leading to artesian was obtained in the cross-sections (Fig. 2). Waters on the surface of the earth percolate into the underground and leads to a long circulation. The water which gets heated as a result of these circulations again comes to the surface again by cutting faults with deep

drillings. There are two reservoirs determined with drills in the study area. One of them is limestone inside the ophiolitic mélange cut by the MC-1 well and the second reservoir is the Karaisali limestone cut in C-1 and Uclu Cesme wells. There is no young volcanic activity which may lead to heating of waters in Guneyyolu (Camili) geothermal area. As in almost every part of Turkey, the reason why waters get hot in here is tectonic activates. The Guneyyolu (Camili) geothermal area is in the south of the Ecemis Fault, which is one of the important tectonic units in our country. The Guneyyolu (Camili) geothermal area is in the south of the Ecemis Fault Zone, which is one of the important structural units of our country. As they have great importance for the geothermal model, the geology maps, especially for the faults, prepared by Tekin et al. were studied again. As a result of these studies, fault lines in the Guneyyolu (Camili) geothermal area was mapped again (Fig. 1). It was observed that the faults described as a result of the studies cut the surface formations in the study area and that they played important roles in the formation of the geothermal system in the area. Generally NW–SE and NE–SW trending faults were observed in the study area (Fig. 3). The most distinctive one among the NE–SW trending faults extends from the Orsu Kalesi

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C

Legend

0 –50 50 –100 –150 0 250 Scale, m

1: Üclü Çeşme Well (160–170 m) 2: C-1 Well (150 m) 3: MC-1 Well (420 m)

Pleistocene Holocene gene

1 2 3

Alluvion

Caliche

Upper

300 250 200 150 100

Explanations

Kuzgun formation

Middle

E

S 30° W

Mesozoic

D

Tertiary

0 250 Scale, m

Cenozoic

200

Miocene

12 3

(Member of limostone)

Kuzgun formation

Oligocene Lower

400 200 0 –200

Upper

600 400

Upper system System Series

Quaternary

N 20° E

Neogene

B

N 45° E

Cretaceous Paleo-

A

561

Güvenç formation Karaisali formation Gildirli formation Mersin ophiolitic Mélange Mersin ophiolitic Mélange (Member of limostone)

Fig. 2. Geological cross-sections of Guneyyolu (Camili) geothermal area.

site to the west of Zeytinli Hill and then towards Karapınar district. The fault was described as strike-slip in the previous studies and its vertical component is distinctive. Accordingly, it is thought in this study that the fault mentioned is a diagonal fault with normal components. The fault cuts the Kuzgun and Guvenc formations in the SW and the Karaisali and Guvenc formations in the NE of the study area. Another fault with NE–SW trending was observed in the north of the Ayıbeleni Hill in the study field. This fault, which has the dipslip normal fault characteristics, limits the Kuzgun and Guvenc formations. It is thought that the ones with NW–SE trending are younger. In the SE of the study area, a fault with NW–SE was observed. It was observed that this fault, which has the characteristics of a dip-slip normal fault, bifurcates into two in the SW of the Celtiklialan site. The first one converges with the NE–SW trending normal component diagonal fault in the north of the Orsu Kalesi site. The second one passes by the west of Yassı Hill in parallel with the Icme Dere and converges with the NE–SW trending normal component diagonal fault in the north of Zeytinli Hill. As a result of the field works, it was observed that the region where hot water resources were present due to the faults in the study area had the characteristics of a collapsed reservoir and that Karaisalı limestone created a dome structure and went below the Guvenc formation. The surface water accumulated in this basin as a result of a long circulation due to the geological strucGEOCHEMISTRY INTERNATIONAL

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ture in the study is brought to surface as a result of drills with artesian. MC-1 Well; which is located in Mersin 033a1 area and in the coordinates Y: 644123 X: 4086270, was opened by the General Directorate of Mineral Research and Exploration in 2007. Its depth being 420 m, the well’s flow and temperature were calculated as 45.5°C and 35 L/s shortly after the well was dug. The wellhead pressure was found out to be 18 bar. According to the last measures, the temperature of the MC-1 well was 43.6°C and the flow was 36–37 L/s. The limestone inside the ophiolitic mélange in MC-1 well is used for manufacturing (Fig. 4). C-1 Well; which is located in Mersin 033a1 area and in the coordinates Y: 644063 X: 4086161, was opened by a private company in between 2000 and 2002. The control of the well was lost while drilling, leading to the explosion of the well. According to the unofficial information, the depth of the well is 150 m and it flows uncontrolled. The geology profile and equipment plan of the well is shown in Fig. 5; manufacture from the well is at 39.4°C and 40 L/s (Demirel, 2005). According to the last measures, the temperature of C-1 well was 40.3°C and the flow could not be measured because the head of the well had exploded and there were water outlets from different places. C-1 well produces from Karaisali limestones (Fig. 5). Uclu Cesme; Well; which is located in Mersin 033a1 area and in the coordinates Y: 643919 X: 4086195, was thought to have drilled by a person living in the area in 2009. It is mentioned that there had been natural water outlets before the wells were opened in the Guneyyolu (Camili) geothermal area, which was, in the previous years, known as water 2016

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+ –

NE—SW

+ –

NW— SE

C-1

MC-1

+ –

Depth, m

Formation Member

Series

System

Upper system

Fig. 3. A view of the faults in the Guneyyolu (Camili) geothermal area (the view is from south to north).

Well equipment

Marl: Cray, light gray, claystone intermediate level

Limestone: Dirty white in, cream, light gray, fossil shells

Güvenç

150

Pebble: Greenish, blackish color pebbies of the ophiolitic melange Claystone-sandstone-pebble Claystone-sandstone: Brown Sandstone-pebble: Greenish, rich in silica and radiolarite. Pyrite is observed in places

200

Ophiolitic Melange

250

300 Ophiolitic melange: Green, greenish gray, peridotite, dunite, serpantinite, brown radiolarite. Partly crackled and the cracks have calcite filling.

350 Limostone

Upper Cretaceous

Clay: Yellowish and grayish blue

100 Karaisali

Lower–Middle Miocene

Tertiary Cretaceous

Mesozoic

Explanation

Group cover

50

Oligocene– Lower Miocene Gildirli

Cenozoic

0

Lithology

Limestone: Gray, beige, light brown, the cracks have calcite filling.

400

Fig. 4. MC-1 Well log and equipment plan.

springs. It is understood that these natural water outlets dried out after the wells. As there is no official data about the depth of the well, it is consider that the well is 160–170 m and produces from Karaisali lime-

stones. The temperature of the Uclu Cesme Well is 37.5°C and it has a f low rate of 0.16 L/s (İcme Dere; A stream, whose f low rate is seasonally unstable, near the study area.

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Depth, m

Series

Formation

System

Upper system

THE GEOTHERMAL MODEL OF MERSIN (TURKEY) REGION Well equipment

Lithology

0

563

Explanation

Group cover

50

Marl: Cray, light gray, search claystone level

Güvenç

Lower–Middle Miocene

Tertiary

Cenozoic

Clay: Yellowish and grayish blue

100

Karaisali

Sandy limestone: Greenish-gray, gray, karaisali limestones of transition

Limestone: Dirty white in, cream, light gray, fossil shells

150 Fig. 5. C-1 well log and equipment plan.

3. ANALYTICAL TECHNIGUES δ18O–δ2H (Deuterium) isotope analyses of the water samples taken from these three wells and the Icme Dere passing close to these wells was carried out using the Equilibration IRMS method in the British Iso-Analytical Isotope Laboratory. The 3H (Tritium) analyses conducted by using IAEA method in State Hydraulic Works (DSİ) the General Directorate of Technical Research and Quality Control (TAKK) Isotope Laboratory. Moreover, Radioactive Alpha determination of MC-1 well was done by suding EPA 900.00 method in State Hydraulic Works (DSİ) the General Directorate of Technical Research and Quality Control (TAKK) Isotope Laboratory; and Physico-chemical and Bacteriological analyses were done in the Balneology Laboratory in the department of Medical Ecology and Climatology, Istanbul University with the help of Milcan Tourism Agriculture Industry and Commerce INC. 4. RESULTS AND DISCUSSION Hydrogeochemistry Many parameters in order to find out the characteristics of the water samples obtained from the study GEOCHEMISTRY INTERNATIONAL

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area were found out. It is hard to compare these parameters both in hot and cold waters. Therefore, the comparison is made according to water’s areas of use. Piper and Schoeller diagrams were prepared. in order to do the isotope and chemical analyses of the water samples (MC-1, C-1, Uclu Cesme and İcme Dere), to find out their origins and to come up with a model (Figs. 6, 7). According to the Piper classification of the hot and cold water samples obtained from the Guneyyolu (Camili) area; the results of the analyses of the samples from MC-1, C-1 and Uclu Cesme (Hot water sources) wells fall into the area numbered as 7 in the Piper diagram. As the waters whose non-carbonate alkalinities are more than %50, NaCl, KCl, Na2SO4 alkalies and strong acids are dominant. Moreover, they are also rich in Ca-HCO3. The theme of the samples obtained from MC-1, C-1 and Uclu Cesme wells are shown with waters with Ca-HCO3 and limestones. The existence of Na+, Cl and SO4 ions may arise from waters’ contact with halite (NaCl) and gypsum (CaSO4 ⋅ 2H2O) type evaporitical rocks. MC-1, C-1 and Uclu Cesme are rich in Cl and Na + K and poor in Ca, Mg and Cl. (Fig. 6). 2016

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80

+C l

80 60

60

+ Ca

Explanations MC-1 C-1 Uclu Cesme Icme Deresi

SO

4

Mg

40

20

20

20 40 60 80

80

60

60

40

60

40

80

80

20

80

60

40

3

60

CO

40

Ca

80

20

SO 4

40

K

60

40

SO4

3

20

+ Na

Mg

80

20

+H CO

Mg

40

HCO3 + CO3 20

20 Na + K

Ca

Cations

20

40

Cl

60

80

Cl

Anions

Fig. 6. The Piper Diagram of the water samples obtained from the Guneyyolu (Camili) area.

100 90 80

mEq/L

70 60

MC-1 C-1 Uclu Cesme Icme Deresi

50 40 30 20 10 0

SO4 HCO3 + CO3

Cl

Mg

Ca

Na + K

Fig. 7. The Schoeller Diagram of the water samples obtained from the Guneyyolu (Camili) area.

It is seen that the water samples, which were analyzed according to the semi-logarithmic graphic presented in Fig. 7, have 2 different origins. The electrical

conductivand temperature values of the samples also show that the system has two different circulations and mixtures. MC-1, C-1 and Uclu Cesme hot water sam-

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Table 1. Geochemistry of the hot and cold water sources of Guneyyolu (Camili) area (March 2012) MC-1

C-1

Uclu Cesme

Icme Dere

Na+(ppb)

43 7.02 1048 2245

40 7.03 1026 2160

37 7.24 1460 2063

19 7.35 793 22

K+(ppb)

47

67

78

5

Ca+2(ppb)

1431

110

127

78

Mg+2(ppb)

49

51

52

38

Cl–(ppm)

3480

2734

3247

27

HCO3− (ppm)

234

347

184

374

CO3−2 (ppm)

9

9

9

0.00

SO 4−2(ppm)

447

4.00

3.50

4.50

Temperature (°C) pH EC (μS/cm)

ples forms the first group while Icme Dere forms the second group. The following conclusions were made according to Schoeller’s chemical classification (Fig. 7): The MC-1, C-1 and Uclu Cesme sample (hot waters): The waters belong to the medium chloride water group according to their chloride concentration. The waters belong the oligosulfate water group according to their sulfate concentration. The waters belong to the normal carbonate water group according to their Carbonate + Bicarbonate concentrations. Icme Dere sample (cold waters): The waters belong to the normal chloride water group according to their chloride concentration. The waters belong the normal sulfate water group according to their sulfate concentration. In the sulfate classification, these waters are below the sulphate saturation. The waters belong to the normal carbonate water group according to their Carbonate+Bicarbonate concentrations. Results of pH, °C, salinity and EC analysis of water, taken from Mersin Guneyyolu (Camili) geothermal area are given in Table 1. According to the results, the samples which have the highest temperature are MC-1, C-1 and Uclu Cesme hot water sources. The temperatures of these wells range from 37.5°C to 43.6°C. The water sample obtained from Icme Dere has the normal value in terms of temperature. The pH value of the MC-1 hot water sample is lower than the other samples. However; its electrical conductivity is high. This shows us that the water possesses acidic features. Anion-Cation values of the water obtained from Mersin Guneyyolu (Camili) geothermal area are given in mg/L in Table 1. According to this graph, anion– cation values are shown in the form of graphs. The total values in terms of anion-cation content, the highest values are measured MC-1, Uclu Cesme, and C-1 hot water sources, respectively. If these analyzed samples are compared with physical and chemical features GEOCHEMISTRY INTERNATIONAL

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of drinking waters and the drinking water standards of the World Health Organization, it is seen that the hot waters include more anion-cation than drinking water standards. According to the results from the analyses, the samples are put in order in cations as Na + K > Ca > Mg and as Cl > SO4 > HCO3 in anions (Table 2). The highest value measured in Uclu Cesme sample is Cl; 3234 mg/L. The highes rate of Na values in hot waters is because the units they pass by are salty and gypsumbearing units. MC-1, C-1 and Uclu Cesme sources are mostly Na–Cl–SO4 types. This shows that the underground water flows of hot waters after the solution of substances occur in great depths and they include a high rate of Na–Cl–SO4 during the ion exchange. The order of anions and cations in Icme Dere is Ca > Mg> Na + K and HCO3 > SO4 > Cl (Table 3). Icme Dere is clearly different from other hot water sources with this anion-cation order. This change is totally because of the differences of the lithologies the water pass by. The dominance of CaCO3 units in this area provided the water an identity which is dominant in Ca and HCO3. Efforts were made to determine the hydrochemistry of the water samples obtained from the Mersin Guneyyolu (Camili) geothermal area. Na, Ca, Mg, K, Cl, HCO3 and SO4 ions, which form more than 90% Table 2. The major ion order of the water samples obtained from the study area

Sample No.

Cation Order

Anion Order

MC-1

Na + K > Ca > Mg

Cl > SO4 > HCO3

C-1

Na + K > Ca > Mg Cl > SO4 > HCO3

Uclu Cesme

Na + K > Ca > Mg

Icme Dere

Ca > Mg > Na + K HCO3 > SO4 > Cl

2016

Cl > SO4 > HCO3

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Table 3. Results of the oxygen-18, deuterium, and tritium analyses Hot and Cold Water Sources of the Guneyyolu (Camili) area

Date

δ18O (‰)

δ2H (‰)

Trityum (TU)

MC-1

20.06.2013 –9.46

–66.68

0.59

C-1

20.06.2013 –9.45

–67.83

0.26

Uclu Cesme

20.06.2013 –9.41

–67.10

0.85

Icme Dere

20.06.2013 –6.01

–35.82

2.70

of the ionic content of the water samples are called major ions. Substances which are found in trace amounts in the water samples apart from the major ions are called minor components. The major ion contents of the water samples obtained from the study area are given in order in Table 3. The Anion and Cation orders of the hot waters are the same and the cold water, namely the sample from Icme Dere, is different. The reasons can be the high amount of dissolved substances in hot waters and the low amount of solution of substances in cold waters. The fact that the Ca and Mg ions are in equal concentrations in Mersin Guneyyolu (Camili) geothermal area is because the field generally consists of high-carbonate rocks. In the Guneyyolu (Camili) geothermal area, the main rock generally consists carbonate rocks. The concentrations of Ca, Mg, and HCO3 ions are the evidences for this conclusion. It can be noticed when the compositions of the waters in which ophiolitic mélange and gypsum are in fact are examined. In the chemical characteristics of all the waters, Ca, Mg and HCO3 are dominant ions. This is a natural result of the fact that carbonate rocks are common in the catchment of both the aquifers. The similarity of the chemical characters is the result of similar mineralogical components of aquifers. However, the chemical character of the underground water flowing in the alluvial aquifer is generally Mg–Ca–HCO3. Besides the carbonates in the Karaisalı limestones as a source of Ca and Mg ions, biotite and chloride minerals are also sufficiently present. Gypsum series in the Kuzgun formation are the source of SO4 in the underground water. As the hot water sources we are studying pass by the Mersin ophiolitic mélange, Karaisalı, Güvenç and Kuzgun formations, the traces of these units are found

out through chemical analyses and diagrams (Piper and Schoeller diagrams). Environmental Isotope Hydrology Waters samples are obtained from MC-1, C-1, Uclu Cesme wells and Icme Dere in the Guneyyolu (Camili) geothermal area in a way that they can present the system. The results of the analyses are given in Table 3. Although the waters belonging to the study area have the high salinity and EC values, they are among the type of waters which have not reached the balance (have partial balance) according to dominant ions. Durative isotopes are observed to center around or between the Eastern Mediterranean Region local meteoric water line (Craig, 1961) and World meteoric water line (Fig. 8a). When Fig. 8A is examined, it is seen that the waters which are hot and have high concentration of minerals are fed from high elevations when compares to the cold water, namely the water from Icme Dere. It is observed that the hot waters are together while the cold water is another area on the graphic. As a result, it is seen that the hot waters have high circulation durations in deep circulations and have nothing to do with sea water. The tritium contents also support this idea. However, the fact that the waters are not balanced and have similar contents to meteoric waters shows that they have a high rate of cold water mixture. While the values of the hot waters are between 0–1, the tritium value of the Icme Dere is close to 3. Therefore, it can be said that the hot waters represent deep circulation. It is understood that Icme Dere water, on the other hand, is fed from the current precipitation and from waters which do not have much circulation (Fig. 8b) In the graphics, it is seen that the hot waters are very similar in terms of chloride values. Tritium values of the hot waters are different from the Icme Dere water in terms of circulation and the age (Fig. 8c). The relationship between Tritium and Deuterium is presented in Fig. 11d. The locations which have low tritium values for each of the deuterium values in the samples are the waters going into deep circulations. While the hot waters with meteoric origin are together, the Icme Dere water is in a different position in the graphic. It was understood that the hot water samples obtained from MC-1, C-1 and Uclu Cesme had high electrical conductivity and have low levels of tritium. Again, the conclusion here is that the hot waters have similar formations (Fig. 11e). Oxygene-18 among durative isotopes and temperature readings show that the hot waters are similar in their origins.

Fig. 8. (a) The relationship between the hot and cold waters sources of Guneyyolu (Camili) area and the Global Meteoric Water Line, the Mediterranean Water Line, and oxygen-18 (δ18O), (% SMOW = Standard Mean Ocean Water) (b) δ18O-tritium (3H; TU) relationship of Guneyyolu (Camili) area sources, (c) Cl-TU relationship of Guneyyolu (Camili) area water sources, (d) deuterium (δ2H)–TU relationship of Guneyyolu (Camili) area water sources, (e) The electric conductivity (EC; lS/cm)–TU relationship of the Guneyyolu (Camili) area water sources. GEOCHEMISTRY INTERNATIONAL

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–12 0

–10

(a) δ18O, ‰ SMOW –8 –6 –4

–2

567

0

–10 δ deuterium, ‰ SMOW

Explanations Global meteoric water line Mediterranean water line

–20 –30

MC-1 C-1 Uclu Cesme Icme Deresi

–40 –50 –60 –70

(b)

(c)

12

5

10

4

8 Tritium, TU

Tritium, TU

Young water

3

6 Mix line

4

2

Mix cycle

2

1

Deep circulation

0 –10

–9

–8 –7 –6 –5 δ18O, ‰ SMOW (d)

–4

0

–3

100

12

5

10

4

8

Old water

200 300 Cl, ppm (e)

400

Tritium, TU

Tritium, TU

Contact time with the aquifer

3

6

2

4

1

2

0 –70 –65 –60 –55 –50 –45 –40 –35 δ deuterium, ‰ SMOW

0

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250

500

1000 EC

2016

1250

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CONCLUSIONS This study has taken place in Guneyyolu (Camili) site within the provincial border of Mersin. Hot waters and Icme Dere waters taken from there have been analyzed with regards to hydrogeology, hydrochemistry and isotope hydrology. The 1/25000 scaled geological map of the study site has been revised from Tekin et al. 1998 and prepared again. Faults in Guneyyolu (Camili) geothermal site have been mapped one more time. Due to the effect of these faults all the formations in the site were broken and formed geothermal system. Karaisalı formation shaped by limestones creates common and fertile aquifer karst. C-1 well and Uclu Cesme well drilled in Guneyyolu (Camili) geothermal site produce from this unit. The reason why Ca and Mg ions in Guneyyolu (Camili) geothermal site are at almost equal concentration Mersin is that the terrain composes of carbonated rocks. Concentration of Ca, Mg and HCO3 ions reflects that. Based on the analysis results of the samples taken from MC-1, C-1 and Uclu Cesmehot water wells, according to Piper diagram; waters with more than %50 non-carbonated alkalinity are NaCl, KCl, Na2SO4 alkaline and strong acids are dominant. Electrical conductivity and temperature values belonging to the samples show that system has two different circulation and mixture. MC-1, C-1 and Uclu Cesme hot water samples are at first group and Icme Dere composes second group. MC-1, C-1 and Uclu Cesmehot waters contain sodium chloride and according to Schoeller diagram these waters medium chloride and in oligosulphate group. On the other hand Icme Dere water is, according to Carbonate+Bicarbanote concentration, mediocre water with carbonate and in waters with sulfate group. For many years it has been thought geothermal waters are magmatic or metamorphic-magmatic waters. However, recently lots of isotopic studies conducted in geothermal sites has shown that geothermal waters have meteoric origin and they get hot during

the process of long and deep underground circulation. Despite high salt level and EC values, waters belonging to study site, according to dominant ions, are at the partly balanced state group. It is seen that stable isotopes are intense between or near the Eastern Mediterranean Region local meteoric water line and World meteoric water line. As a result, it is understood that hot waters have deep and long circulation and they have nothing to do with sea waters. Tritium contents support this fact, as well. However, the fact that waters are not balanced and they have isotope content similar to meteoric waters show that there is cold water mixture at high level. The geology map of our study site where hot water sources are located has been revised and prepared again. Faults determined by these studies have placed to the map. With crosscuts taken from between two certain points, model of hot waters that form artesian has been created. ACKNOWLEDGMENTS This study was funded and supported by Scientific Research Support Fund of Kahramanmaras Sutcu Imam University. REFERENCES H. Craig, “Isotopic variations in meteoric waters,” Science, 13, 1702–1703(1961). Z. Demirel, “Accessible energy amount and the environmental pollution from a clean energy resource; a case study from Guneyyolu geothermal area, Turkey” in Proceedings World Geothermal Congress 2005 Antalya, Turkey, 2005 (Antalya, 2005), pp. 24–29. M. Durdu, Z. Arıgun, H. Yıldız and S. Uslu, “MTA Camili MC-1 Kuyusu, Kuyu Bitirme Raporu” (2007). M. Senol, S. Sahin and T.Y. Duman, “Adana–Mersin dolayının jeoloji etüd raporu”, (MTA, Ankara, 1998). Z. Tekin, I. Kara, and N. Yıldırım, “Mersin Guneyyolu (Camili Köyü İçme Kaynağı) Jeotermal Enerji Araması Etüt Raporu”, (MTA Ankara, Aralık, 1998).

GEOCHEMISTRY INTERNATIONAL

Vol. 54

No. 6

2016