The Potential, utilization, and development of Geothermal Energy in Türkiye

Geothermal energy is a natural resource that can be utilized directly or by converting to other types of energy. Considering the diversity of the geological structure of Türkiye, the geothermal systems have developed depending on young tectonic and volcanic active rock. Western and Central Anatolia are especially rich in geothermal resources. The geothermal well with the hottest well-bottom temperature was drilled in Central Anatolia, and the well-bottom temperature was measured as 341°C at a depth of 3845 meters. In 2022, Türkiye's electricity generation capacity and the total installed direct heat use reached 1663 MWe and 5113 MWt, respectively. Considering Anatolia's Curie depth and heat flux, the probable thickness of the batholith can be regarded as 10 km. For example, the total granitoid area of Western Anatolia is 4221 km2, and at least 2% of this granitoid can provide approximately 8x107 MWh of electricity by Enhanced Deep Geothermal Systems (EDGS). When all granites in Türkiye are considered, it is expected that the future capacity of Türkiye will be much higher with drilling research and development studies and the discovery of new fields. This capacity will exceed 100,000 MWt levels in the medium term, especially with the addition of EDGSs

Geothermal resource potential of Nigde and surround

Çalışma sahası Niğde il sınırları içerisinde Türkiye 1/25.000 ölçekli topoğrafik haritalarından L32,33,34 ve M32,33,34 paftaları içerisinde yer almakta olup Alt Senoniyen yaşlı Niğde grubu kayaçları, posttektonik Üç kapılı Granadiyoriti tarafından kesilmiştir.Bölgede geniş bir alan kaplayan Neojen çökelimi Pliyosen yaşlı Melendizdağ Volkanikleri tarafından etkilenmiştir.Niğde il merkezinde bulunan alterasyon zonundan alınan örneklerde yapılan XRD analiz sonuçlarına göre; Korund, Mika, Feldispat, Jarusit, Alurit, Kil mineralleri ve Opal birlikteliklerine saptanmıştır. Kimyasal analiz sonuçlarına göre SiO2 (46.34-69.34), Fe2O3 (1.01-31.48), Al2O3 (9.20-27.81), K2O (0.66-3.95) yüzde değerleri sunmaktadır. Bu sonuçlardan hareketle Niğde il merkezinde potasik ve ileri arjilik bir alterasyon saptanmış olup 120oC-150oClik bir jeotermal ve/veya hidrotermal akışkan etkilerinden söz edilebilir.The study area is located within 1/25.000 topographic maps of L32,33,34 and M32,33,34 the borders of Niğde in Turkey. The Early Senonian rocks of Niğde group are bounded by the posttektonik Üçkapılı Granodiorit.Neogene deposition covering a vast area in the region has been affected by the Volcanics of Melendiz Mountain from the age Pliocene.According to the results of XRD analysis carried on the samples obtained from the alteration zone in Niğde Centrum, on associated with Corundum, Mica, Feldspar, Jarusit, Alurit, clay minerals and opal are specified. The results of chemical analysis give SiO2 (46.34-69.34), Fe2O3 (1.01-31.48), Al2O3 (9.20-27.81), K2O (0.66-3.95). Based on these results, a potassic and further argillic alteration has been observed in Niğde Centrum and effects of geothermal or hydrothermal liquid at 120-150 oC may be subject matter

Geochemical proxies and formation mechanism of Hatay (Baslamis) travertine and relation with Dead Sea Fault Zone (S-Turkey)

This study is the first investigation of the Baslamis(Hatay) travertines formed in the northern part of the left-lateral strike-slip Dead Sea Fault Zone. In this study, Baslamis travertines are examined in terms of structural, mineralogical and formation mechanism by conducting geochemical, hydrogeochemical and facies analysis. The Baslamis travertine occurrences are characterized by successions of terraces and pools developed in slope depositional system, mound depositional system and depression depositional system. The travertines have been classified into five lithotypes, namely: laminated, coated bubble, reed, intraclasts and micritic travertine. According to the thin section, XRD, SEM and EDX analysis, the Baslamis travertines are divided into two groups, the first group contains aragonite and secondary minerals such as silica and clay minerals, while the second group consists only of calcite minerals, therefore, the travertines are morphologically classified as aragonite-bearing travertines and massive calcite bearing travertines. The negative correlation between Ca and Sr abundances in travertine samples indicates that some Ca was replaced by Sr in the calcite lattice. Relatively rich trace element content in the Baslamis travertines is attributed to leaching of the underlying gabbro and limestone. Higher concentrations of some of the elements were probably the result of diagenetic processes and syngenetic mineralization. The Baslamis travertines are defined as meteogene travertine deposits and are fed with meteoric-origin waters along Dead Sea Fault Zone in terms of hydrogeochemical results. The conceptual model of the Baslamis travertine shows that the travertines are formed by precipitation of dissolving the limestone. The heat source of the geothermal fluid forming the travertines is of tectonic origin.Scientific Research Project Coordination Unit of Ni.gde Omer Halisdemir University [FEB2017/15-YULTEP]This study was the funded by the Scientific Research Project Coordination Unit of Ni.gde Omer Halisdemir University within project FEB2017/15-YULTEP. Special thanks go to Dr. Muhammed ZeynelOzturk for his contribution and Mr. Graham H. Lee for proofreading the manuscript

Geothermal resource potential of Cappadocia geothermal province

Bu çalışmaya FEB2013/07 numaralı proje ile finansal destek sağlayan Niğde Üniversitesi Bilimsel Araştırma Projeleri Birimine ve yurt dışı araştırmalarımı gerçekleştirmemde finansal destek sağlayan TÜBİTAK Bilim İnsanı Destekleme Daire BaşkanlığıBu tez çalışması kapsamında Orta Anadolu Bölgesi’nin güneyinde yer alan ve Kapadokya Jeotermal Provensi olarak adlandırılan çalışma alanının jeolojik, jeokimyasal ve hidrojeokimyasal araştırmaları yapılarak, sistemin jeotermal enerji potansiyelinin ortaya konulmasına ve kavramsal modelinin oluşturulmasına yönelik değerlendirmelerde bulunulmuştur. İnceleme alanı içerisinde Dertalan, Balcı, Çömlekçi, Ziga, Şahinkalesi, Acıgöl ve Derinkuyu jeotermal sahaları yer almaktadır. Bu sahalar, Tuzgölü Fay Zonu ile Keçiboyduran-Melendiz Fayları tarafından kontrol edilen jeotermal sistemlere sahiptir. Çalışma alanı Tuzgölü Fay Zonu ile Keçiboyduran-Melendiz Fayı arasında kalan sahalar ve Keçiboyduran-Melendiz Fayının kuzeyinde kalan sahalar olmak üzere iki farklı sistem halinde incelenmiştir. Altere kayaç örneklerinden yapılan mineralojik incelemelerde albitleşme, alünitleşme ve silisleşme gibi hidrotermal alterasyon tipleri yaygın olarak görülmektedir. Bu numunelerde illit, smektit, kalsit, jarosit ve alunit gibi hidrotermal alterasyon minerallerine kuvars, plajiyoklas, biyotit ve vermikülit gibi birincil mineraller eşlik etmektedir. v İnceleme alanından derlenen altere kayaçların ve aynı alana ait su numunelerinin NTE (Nadir Toprak Elementleri) ve İtriyum jeokimyası incelemelerine göre birinci sisteme ait numuneler pozitif Ce anomalisi sergilerken ikinci sisteme ait numuneler düze yakın ve/veya negatif Ce anomalisi sergilemektedirler. Analiz edilen numunelerin neredeyse tümü pozitif Eu anomalisi sunmaktadır. Derinkuyu sahası dışında ikinci sisteme ait numuneler pozitif Y anomalisi sergilerken birinci sisteme ait numuneler negatif Y anomalisi sergilemektedirler. Çalışma alanına ait su örneklerinin kimyasal ve izotop analiz sonuçlarına göre, her iki alandaki soğuk sular Ca-Mg-HCO3 ve Ca-HCO3 tipinde mineralce fakir sulardır. Ancak sıcak sulardan birinci alan içerisindeki sıcak sular Ca-Na-SO4 ve Ca-Mg-SO4 iken ikinci alanda bulunan sıcak sular ise Na-Cl-HCO3 ve Ca-Na-HCO3 tipinde mineralce fakir sıcak sulardır. İzotop hidrolojisi çalışmalarına göre çalışma alanındaki sular meteorik sulardan beslenmektedirler. Silis jeotermometre sonuçlarına göre Dertalan, Melendizdağ, Keçiboyduran Dağı, Hasandağ (Keçikalesi), Ziga, Acıgöl ve Derinkuyu sahaları sırasıyla 150-173 o C, 88-117 o C, 91-120 o C, 94-122 o C, 131-156 o C, 157-179 o C; 152-174 o C ve 102-130 o C arasında değişmektedir. Jeolojik, jeokimyasal ve jeofizik verilerin birlikte değerlendirilmesi ile oluşturulan Kapadokya Jeotermal Provensine ait kavramsal jeotermal modele göre; alandaki jeotermal kaynaklar birincil ve ikincil tektonik kuşaklar tarafından kontrol edilmektedir. Ayrıca, Paleozoyik-Mesozoyik yaşlı mermer ve gnayslar sistemin hazne kayasını, Geç Kretase yaşlı gabro/granodiyorit sokulumları ile bölgesel tektonik sonucu gelişen muhtemel bir kabuk incelmesi ile yüzeye yaklaşan ısı akıları sistemin ısı kaynağını ve Kapadokya volkanitlerine ait tüf ile ignimbiritlerde sistemin örtü kayasını oluşturmaktadır. Tüm bu çalışmalara göre, alanda önemli bir jeotermal potansiyel bulunduğu görülmektedir. Çalışma alanında bulunan jeotermal sistemin rezervuar veya hazne kayası ile örtü kayasında herhangi bir sorun bulunmamakta, sistemde jeotermal akışkan problemi bulunmaktadır.Within the scope of this thesis, the geothermal potential of the system has been introduced and conceptual model has been established with geological, geochemical and hydrogeochemical research in the area named as Cappadocia Geothermal Province in the south of Central Anatolia. Dertalan, Balcı, Çömlekçi, Ziga, Şahinkalesi, Acıgöl and Derinkuyu geothermal fields are located in the field area. These areas, which are controlled by KeçiboyduranMelendiz fault and Tuzgölü Fault Zone have geothermal systems. These areas, which are controlled by Keçiboyduran-Melendiz fault and Tuzgölü Fault Zone have geothermal systems. Hydrothermal alteration types such as albitization, alunitization and silicification are widely observed in mineralogical investigation of altered samples. Beside this, primary minerals such as quartz, plagioclase, biotite and vermiculite are accompanied to hydrothermal alteration minerals such as illite, smectite, calcite, jarosite and alunite in petrographic examinations. vii According to REY (Rare Earth Elements and Yttrium) geochemistry of altered rock samples and water samples which are belonging to the same location, the first system of rocks exhibit positive Ce anomaly, as the second group of rocks show negative and/or close to the flat Ce anomaly. Almost all of examined altered samples offer positive Eu anomalies. While the second system of rocks except Derinkuyu exhibit positive Y anomaly, the first group of rocks exhibit negative Y anomaly. According to water chemistry and isotope analysis, the cold waters of both area groups are Ca-Mg-HCO3 ve Ca-HCO3 type mineral poor waters but the hot waters of first group are Ca-Na-SO4 and Ca-Mg-SO4 type and the hot waters of second group are NaCl-HCO3 and Ca-Na-HCO3 type of mineral poor hot waters. According to isotope hydrology studies, the geothermal waters are fed from meteoric waters and according to the results of silica geothermometer, the reservoir temperature of Dertalan, Melendiz Mount, Keçiboyduran Mount, Hasan Mount (Keçikalesi), Ziga, Acıgöl, and Derinkuyu geothermal waters are 88-150-173 o C, 88-117 o C, 91-120 o C, 94-122 o C, 131-156 o C, 157-179 o C; 152-174 o C and 102-130 o C, respectively. According to the conceptual geothermal model of Cappadocia Geothermal Province which is generated after geological, geochemical and geophysical data; the geothermal resources in the field area are controlled by primary and secondary tectonic belts. Also, according to this conceptual geothermal model, Paleozoic-Mesozoic marble and gneiss constitutes the reservoir rock. Late Cretaceous intrusions of granodiorite/gabbro and impending heat fluxes to the surface with a possible crustal thinning which developed after regional tectonism results constitutes the heat sources. Miocene-Pliocene and tuff and ignimbrites of Quaternary Cappadocia Volcanics also constitute the seal rock of the geothermal system. As a result of all these studies, Cappadocia has a significant geothermal potential. There are no problems of reservoir or seal rock in the study area, but geothermal fluid of the system is problemati

Hydrothermal alterations and relationship with thermal waters at Aliağa (İzmir) geothermal field

Aliağa ve çevresinde yer alan kayaçlarda gözlenen hidrotermal alterasyonların özelliklerinin belirlenmesi ve termal sularla olan ilişkilerini saptamaya yönelik yapılan bu çalışmada, alınan kayaç örneklerinin alterasyon mineralleri ve jeokimyasal özellikleri ile su örneklerinin hidrojeokimyasal özellikleri birlikte ele alınarak, jeotermal sistemin oluşum sıcaklığı saptanmaya çalışılmıştır. Batı Anadolu’da Çandarlı Körfezi’nin güneyinde Aliağa ve yakın çevresini içine alan inceleme alanı, volkanik ve çökel kayalardan oluşan bir topluluk sunmaktadır. Miyosen yaşlı volkanik kayalar; andezit, latit andezit, bazaltik andezit, riyolit lavları ve bunlarla ilişkili piroklastiklerden oluşur. Miyosen yaşlı çökel kayalar ise, karasal ve gölsel çökellerden meydana gelir. Bölgede, jeotermal akışkan akımını kontrol eden KD-KB doğrultulu aktif fay sistemleri bulunmaktadır. Alterasyon zonlarındaki kayaçlarda genel olarak bir silisleşme gözlenmektedir. Silisleşmenin yanı sıra killeşme, kloritleşme gibi alterasyon izleri de saptanmıştır. Jeotermal alandaki kaynak ve sondajlara ait suların kimyasal karakteri, bunları besleyen kaynağın meteorik ve deniz suyu kökenli olduğunu göstermektedir. Hidrotermal alterasyonu oluşturan bikarbonatlı ve klorürlü olmak üzere iki tip jeotermal akışkan bulunmaktadır. İnceleme alanından derlenen kayaç örneklerinde saptanan alterasyon ürünü minerallerden yararlanılarak hidrotermal alterasyon türleri, su örneklerine uygulanan bazı jeotermometre teknikleri ile de hazne kaya sıcaklığı belirlenmeye çalışılmıştır. Kayaç analizlerinden elde edilen bulgulara göre, yöredeki alterasyon türleri ileri arjilik, arjilik ve dış-pirofillitik alterasyon olmak üzere üçe ayrılarak incelenmiştir. Bu alterasyon türlerinde gözlenen karakteristik minerallerin ortaya çıkış veya kayboluş sıcaklıklarından, daha önceleri sistemde 175°C’ye kadar ulaşan bir akışkanın bulunduğu, aktif jeotermal sistemin şu andaki hazne kaya sıcaklığının ise yaklaşık 100-130°C arasında değişebileceği düşünülmektedir.In this study, the alteration zones and geothermal geology of Aliağa area and surroundings have been investigated. The alteration zones and reservoir temperature have been determined via the use of the alteration minerals and geochemical properties of waters issuing in the area. The study area, which is lying between Çandarlı Bay and Menemen in western Anatolia has a rock association consisting of volcanic and sedimentary rocks. Miocene aged volcanic rocks are composed of andesitic, latitic andesitic, basaltic andesitic, rhyolitic lavas and associated pyroclastics. Miocene aged sedimentary rocks are terrestrial and lacustrine type. There are several fault systems trending NE-NW, which control the movement of geothermal fluids in the region. As a result of microscopical investigations of the rock samples collected from the alteration zones, silicification is observed in most of the rocks. Additionally, chloritisation and clay minerals are also seen. The chemical character of hot spring and well water in the geothermal area indicate that the source watersfeeding these springs and wells are meteoric and sea water in origin. There are two types of geothermal fluids causing the hydrothermal alteration in the area. These are bicarbonate and chloride type waters. Hydrothermal alteration types have been determinated by using the alteration minerals recognized in the rock samples of study area. The reservoir temperature of the present day geothermal system has been determined by applying chemical geothermometer techniques to water samples. According to the data obtained from rock analyses, the alteration types in the region are advanced argillic, argillic and outer-sub propylitic alteration. The characteristic alteration mineral assemblages indicate a fluid temperature reaching up to 175 oC in the paleogeothermal system of the area. However, it is estimated that the reservoir rock temperatures of the active geothermal system may be around 100-130 oC

Depositional environment characteristics of UlukA +/- AYla Evaporites, Central Anatolia, Turkey

Ozturk, Muhammed Zeynel/0000-0002-9834-7680WOS: 000400272000010This paper examines evaporated deposits of gypsum known as the UlukA +/- AYla Evaporites located in the UlukA +/- AYla Basin, central Anatolia, Turkey. The Late Eocene compression between the Eurasian and Afro-Arabian plates formed numerous shallow epicontinental basins in SE central Anatolia. During this period, the UlukA +/- AYla Basin was a shallow marine environment. The composition of the UlukA +/- AYla Basin indicates that gypsum and stromatolite were deposited due to an arid climate and sea level oscillation between 37.25 and 38.52 Ma. Oxygen, sulfur, and strontium isotopes and the geochemistry of the evaporated rocks were measured to understand the paleoenvironment of this formation. Trace element analyses of Fe, K, Mg, Na, Mn, Sr, Ni, and Cu from the gypsum samples showed very high variability. The average K/Na, Sr/Ca, and Mg/Na were measured to be 0.4, 2.35, and 2.9 %, respectively, which indicates that the UlukA +/- AYla gypsum lies in a formerly hypersaline environment. Sr-87/Sr-86, O-18, and S-34 isotope ratios indicate that the gypsum was deposited in marine water then mixed with fresh continental water.Nigde University Research Found (NUAF) [FEB 2008/22]Financial support for this study by Nigde University Research Found (NUAF) (Project No: FEB 2008/22) is gratefully acknowledged

The evolution of the Cappadocia Geothermal Province, Anatolia (Turkey): geochemical and geochronological evidence (土耳其)卡帕多西亚地热区的演化:地球化学和地质年代学证据 Evolution de la province géothermale de Cappadoce, Anatolie (Turquie): Evidences géochimiques et géochronologiques Evolução da Província Geotérmica de Capadócia, Anatólia (Turquia): evidências geoquímicas e geocronológicas La evolución de la Cappadocia Geothermal Province, Anatolia (Turquía): pruebas geoquímicas y geocronológicas

Cappadocia Geothermal Province (CGP), central Turkey, consists of nine individual geothermal regions controlled by active regional fault systems. This paper examines the age dating of alteration minerals and the geochemistry (trace elements and isotopes) of the alteration minerals and geothermal waters, to assess the evolution of CGP in relation to regional tectonics. Ar–Ar age data of jarosite and alunite show that the host rocks were exposed to oxidizing conditions near the Earth’s surface at about 5.30 Ma. Based on the δO–δD relationhip, water samples had a high altitude meteoric origin. The δS values of jarosite and alunite indicate that water samples from the southern part of the study area reached the surface after circulation through volcanic rocks, while northern samples had traveled to the surface after interacting with evaporates at greater depths. REY (rare earth elements and yttrium) diagrams of alteration minerals (especially illite, jarosite and alunite) from rock samples, taken from the same locations as the water samples, display a similar REY pattern to water samples. This suggests that thermal fluids, which reached the surface along a fault zone and caused the mineral alteration in the past, had similar chemical composition to the current geothermal water. The geothermal conceptual model, which defines a volcanically heated reservoir and cap rocks, suggests there are no structural drawbacks to the use of the CGP geothermal system as a resource. However, fluid is insufficient to drive the geothermal system as a result of scanty supply of meteoric water due to evaporation significantly exceeding rainfall

Karstic depressions on Bolkar Mountain plateau, Central Taurus (Turkey): distribution characteristics and tectonic effect on orientation

This study investigates the spatial distribution characteristics of karstic depressions that developed on a 2558 km 2 plateau with gently sloping in neritic (reef ) limestones in the western section of the Bolkar Mountains. The 30,132 karstic depressions identified are located at elevations between 1315 and 2525 m, while 31°/km 2 slope and 5.6 km/km 2 drainage density are limited to the spatial distribution of depressions. In the central section of the study area at the anticlinal surface, maximum density (99 depressions/km 2 ) is reached between elevations of 1930 and 2080 m. The orientation of depressions is predominantly NE–SW. However, in the same area, the orientation of depressions also varies from ENE–WSW toward NE–SW from west to east. The left-lateral strike–slip Ecemiş Fault was effective in the formation of these orientations, with a NE–SW orientation close to the fault and ENE–WSW orientation farther away from the fault.This study investigates the spatial distribution characteristics of karstic depressions that developed on a 2558 km 2 plateau with gently sloping in neritic (reef ) limestones in the western section of the Bolkar Mountains. The 30,132 karstic depressions identified are located at elevations between 1315 and 2525 m, while 31°/km 2 slope and 5.6 km/km 2 drainage density are limited to the spatial distribution of depressions. In the central section of the study area at the anticlinal surface, maximum density (99 depressions/km 2 ) is reached between elevations of 1930 and 2080 m. The orientation of depressions is predominantly NE–SW. However, in the same area, the orientation of depressions also varies from ENE–WSW toward NE–SW from west to east. The left-lateral strike–slip Ecemiş Fault was effective in the formation of these orientations, with a NE–SW orientation close to the fault and ENE–WSW orientation farther away from the fault

Mapping investigation based on engineering geology of a developing urban area (Nigde, Turkey)

Definitions of urban geological environments are usually required to provide information about an engineering basis for planners and design engineers to prepare a rational land use planning and developing urban areas. Therefore, the geological mapping investigation method can be a beneficial way of defining urban geological environments visually. In this study, the Engineering Geological Mapping Method (EGMM) was used to investigate and present the geotechnical and geological data obtained from Nigde city of Turkey. Around forty-five unpublished reports that were obtained from the construction work done around the study area were evaluated as detail. Then, the study area was divided into five different regions which were considered their geological characteristics. In each region, nine unpublished reports were selected and analyzed for interpreting the data and plotting the geotechnical and geological maps. The main indispensable parameters for geotechnical design engineers were drawn by using the data obtained from the different boreholes for Nigde city. These drawn maps by GIS technic: (1) groundwater table, (2) liquefaction zone, (3) plasticity index, (4) bearing capacity, (5) soil classification, and (6) SPT results. For preparing the maps, two types of interpolation methods were used (minimum curvature and Voronoi polygons methods). The Geographic Information System (GIS) was used to rearrange and control all this information and to prepare engineering geotechnical and geological maps. As a result, the Engineering Geological Mapping Method applied for this study is to show more crucial for preventing mistakes making in practical works during preparing urban extension planning for developing cities in the future