Bulletin of the Mineral research and exploration

1-16

Authors: Volkan ÖZAKSOY, Hasan ELMACI, Selim ÖZALP, Meryem KARA, Tamer Yiğit DUMAN

Orhaneli Fault is 30 km long, right-lateral strike-slip fault with dominant reverse component located in the Biga Peninsula. This fault controls the southern margin of the Quaternary Orhaneli Basin. Additionally, it cuts the metamorphic rocks of the Tavşanlı Zone, Cretaceous ophiolitic units and Neogene/Quaternary sediments, and can be easily recognized on aerial photographs and in the fi eld due to linearity and fault scarps. Elongated ridges, offset valleys and fault saddles observed along the fault are important geomorphological features indicating fault activity. This study presents the results of the fi rst palaeoseismological study on the Orhaneli Fault. Two trenches were excavated along the fault. These trenches, named Serçeler and Kusumlar, exhibited that metamorphic rocks of the Tavşanlı Zone were thrust onto Quaternary sediments by the fault. The study encountered evidences of four large earthquakes accompanied by surface rupture in Quaternary. The results of Serçeler trench indicated the older earthquake occurred between 22,000±3,200 BC and 6,600±800 BC, and the most recent earthquake occurred before 770-415 BC. The Kusumlar trench data showed that the older earthquake occurred between 6,660 BC and 3,085 BC, and the most recent event in the period after 650 AD. Any interpretation could not be made about the recurrence period between palaeoearthquakes. In this study, Holocene activity on the Orhaneli Fault was proven. If this fault, with 30 km total length comprising two segments, ruptured as a single piece, it has the potential to produce an earthquake with Mw=6.9.

41-66

Authors: Şule GÜRBOĞA, Özgür AKTÜRK

Elmalı Basin, which consists of the Elmalı county and some villages, approximately 120 km far from Antalya city, is one of the recent depositional areas in the extensional neotectonic region of southwestern Turkey. The basin provides signifi cant data for the understanding of the geological evolution to record from the basement to recent depositional units. For this reason, these kinds of structures are used to determine the deformations phases for the evolutionary history of basin formation. In the content of the study, following applications have been investigated: (a) mapping of the area and structures in 1/25.000 scale, (b) information about deformation and tectonic activity along the basin margin faults, (c) the distribution of peak ground acceleration (PGA) in case of an earthquake with 6.5 magnitude and (d) morphometric analyzes of the basin to understand the tectonic uplift by using the digital elevation model. The new results combined with existing data imply that the Elmalı Basin has a number of deformation structures and active faults on both western and eastern sites of the basin. Depending on the morphometric indices, western side of the basin created higher uplift ratio compared with the eastern side of the basin. http://dx.doi.org/10.19111/bulletinofmre.399090

87-116

Authors: Engin MERİÇ, İpek F. BARUT, Atike NAZİK, Niyazi AVŞAR, M. Baki YOKEŞ, Mustafa ERYILMAZ, Fulya YÜCESOY- ERYILMAZ, Erol KAM, Bora SONUVAR, Feyza DİNÇER

The aim of this study was to fi gure out the effects of the submarine hot water springs located on the coast of Doğanbey Cape (north of Kuşadası Bay) on various micro- and macrofaunal assemblages living around these springs. Young sediment samples were collected from different depths at 15 stations. The benthic foraminifer, ostracod and mollusc faunas were investigated. 35 genera and 61 species of benthic foraminifers, 16 genera and 20 species of ostracods and 14 genera and 15 species of molluscs were identifi ed. Typical Aeegan foraminifer fauna was found to be dominant. Besides, individuals with colored tests or abnormal morphology, as well as alien species, which are frequently observed on the Aegean coasts were also observed in the study area. The foraminifer, ostracod and mollusc species also constituted typical Aegean fauna. It is known that the ecological conditions experienced of the Amphistegina lobifera Larsen individuals in typical Aegean benthic foraminifer assemblage have an effect on the abundance distribution. Ideal conditions for Amphistegina lobifera Larsen was found to be 18.00-32.00 m depth range and 19-20oC temperatures. CTD conductivity values gradually increased near to the hot water spring but a decrease in the number of individuals were observed. Chemical analyzes in sediment samples were performed with X-Ray Fluorescence Analysis Spectrometer (WDXRF). Heavy metal ingredients (Cr, Mn, Co, Ni, Cu, Zn and Pb) of the sediments were evaluated, concentrations were recorded as Cr>Ni>Mn in samples DB1-DB6 and also in DB15; Mn>Cr>Ni in DB8-DB11 and DB13-DB14; Cr>Mn>Ni in DB7 and in DB12. The radioactive elements U and Th were found to be high in DB9, DB10 and DB11. The chemical and radioactive properties of the sediments were observed to affect the tests of benthic foraminifers, where as no such effect was found on ostracod and mollusc tests. http://dx.doi.org/10.19111/bulletinofmre.363329

137-150

Authors: Nursel OKSUZ

The Artova Ophiolitic Complex (AOC), which formed in association with Alpine Ophiolites, is exposed in the NE part of central Anatolia, in the interior of the central Black Sea region and within the borders of Çorum and Yozgat. The Derbent-Eymir manganese- oxide deposit under investigation occurs within this ophiolitic complex. The mineral association in Derbent ore is composed chiefly of pyrolusite, manganite and lesser amounts of ramsdellite, magnetite and goethite. Calcite is the main gangue mineral. The mineral association in Eymir ore is represented by pyrolusite, braunite, neltnerite, jacobsite, psilomelane and trace amount of limonite accompanied by some gangue minerals such as quartz and calcite. Electron microprobe analysis was carried out on pyrolusite, braunite and psilomelane minerals. While pyrolusite from Eymir has higher Si, Al, Mn and Ca, pyrolusite from the Derbent ore has lower Fe, K and Ba contents. Pyrolusite in the Eymir ore has higher Si, Al, Mn and Ca (10.28-7.06; 3.19-1.28; 87.98-81.88; 2.38-1.97 respectively) and lower Fe, K and Ba (0.31-0.16; 0.02-0.00; 0.07-0.00 respectively) contents in comparison to pyrolusite in the Derbent ore. Element variations in core-rim zones of spherical pyrolusites and manganite crystals elongated towards the gangue are quite noticeable. Both Eymir and Derbent ore deposits are low-temperature hydrothermal deposits. Geochemical variations recorded in various manganese minerals are found to be strongly dependent on the changes in pH and temperature of the ore-forming solution and distance to the spreading center. http://dx.doi.org/10.19111/bulletinofmre.334245

167-178

Authors: Marzieh Hosseininasab, Ali Akbar DAYA

In this study, the Inverse Distant Weighting (IDW) and the Concentration –area (C-A) fractal methods were used for identifi cations of geochemical anomalies in Janja region, SE Iran. Eight elements (Au, Cu, Mn, Zn, Fe, As, Mo, and Pb) from 300 stream sediment samples were used. The studied area was gridded by 250 m×250 m cells. Estimation of unsampled locations were carried out by inverse distant squared weighting (IDWS) method. Geochemical maps were generated. Log- log plots of cumulative frequency of elemental concentrations versus related areas were constructed. Threshold values were obtained by fi nding break points in the log-log plots. There were four geochemical populations for As, Fe, Mo, Pb and Zn and fi ve geochemical populations for Au, Cu, and Mn. The resulted geochemical anomaly maps obtained from fractal modelling showed that Anomalies of Zn, Mo, Mn, Fe, Cu and As located in southeastern part of study area. There was a good correlation between faults and elementals anomalies. It can be concluded that mineralization occurred along the faults. There was a correlation between anomalies and sedimentary rocks (alluvium and recent alluvium sediments) in SE part of study area. Gold anomalies were located in the NW parts of the studied area. There was a strong relationship between the location of Au anomalies and fault systems in the NW parts of the studied area. Iron concentrations were sporadic and correspond to the sedimentary volcanic rock and turbidites. http://dx.doi.org/ 10.19076/mta.401236

193-204

Authors: Kamil KAYABALI, Pınar YILMAZ, Mustafa FENER, Ozgür AKTÜRK, Farhad HABİBZADEH

Damage to structures during earthquakes may be fully or partly caused by soil liquefaction, which has been the subject of extensive research for several decades. Liquefaction susceptibility of a sandy deposit is performed by comparing the resistance of a soil to liquefaction (i.e., capacity) to the load imparted by an earthquake (i.e., demand). In this regard, the stress-based method of liquefaction assessment is by far the most popular. It involves uncertainties mostly related to the computation of the maximum horizontal ground acceleration (amax) at bedrock. A site response analysis or a simplifi ed assumption is necessary to determine the amax on the ground level as well. Developing from the stress-based approach, the strain-based approach has also similar constraints. There exist laboratory techniques such as torsional shear to determine the capacity of a sandy soil in terms of liquefaction energy per unit volume. Likewise, the energy of a strong motion record can be set by employing simple physics principles. For this, a velocity time history and the unit mass of the soil are employed to compute the demand of any strong motion record. The scope of this investigation is to illustrate the usability of the energy-based method for the evaluation of soil liquefaction. The defi ciencies of the stress- and strain-based approaches are outlined and the advantages of the energybased approach are discussed. http://dx.doi.org/10.19111/bulletinofmre.351257

221-236

Authors: Özlem ÖZTEKİN OKAN, Atahan GÜVEN, Bahattin ÇETİNDAĞ

Plajköy spring discharges at the close locations to the SE shore of Lake Hazar. Lake Hazar is a tectonic Lake in Elazığ city. Plajköy spring is a fault spring that is mainly recharging from the volcanites, dikes and blocky volcanosedimentary units of Middle Eocene Maden Complex. These units have gained secondary permeability and porosity related with the active tectonics that is effective in the studied area. The present catchment system of the spring could not collect the springs and leaks discharging from different points around the system. The discharge of the catchment is measured by specifi c volume method while the other springs’ and leaks’ is measured by using triangular weir. Before the discharge measurement of the leaks and the springs, they have been directed to a channel. The discharge of the present catchment system and the leaks have measured twice in a month during one year period beginning from October of 2012 to November of 2013. The discharge coeffi cient of the spring is calculated 1.33*10-3 day-1. Discharge coeffi cient of the spring depends on the geometry and intensity of the active fracture systems in the region. Calculated discharge coeffi cient indicates that the spring discharge is related with the narrow fi ssures, fractures and pores. The total volume of discharged groundwater in the real regime of the Plajköy spring is calculated as 52* 103 m3 during the period from 31st of March, 2013 to the 13rd of October, 2013 by Maillet formula. The spring water is Ca- Mg- HCO3 type water related with the chemical analyses. The chemical and microbiological analyses of the spring water are correlated with the drinking water standarts of Turkey TS 266 (TSE, 2005) and World Health Organization (2004), and it is seen that the spring water is suitable for drinking. The Plajköy spring will be used more effi ciently without exposed to pollution by the new catchment plan and protection zone map that are consequently proposed in the present study. http://dx.doi.org/10.19111/bulletinofmre.376767

247-258

Authors: ERTAN TOKER, EMİN U. ULUGERGERLİ, ALİ R. KILIÇ

The gravity data gathered in and around the Simav Graben in Western Anatolia were reprocessed and reinterpreted by using the standard deviation fi lter and the Euler deconvolution. The joint evaluation of results from the interpretation of gravity data and seismological studies indicates the presence of new intrusive structures in the vicinity of Simav. The intrusion is located in the eastern margin of the graben and has a thickness of 12-15 km at 2.5-3 km depth below the surface. Numerous earthquakes recorded in the eastern part of the graben are associated with this intrusion. Besides, the multidimensional modelling study of the gravity data allowed us to display the Simav Graben, the fold of the Simav Fault, the intrusion named as Naşa, and the epicenters of earthquake within the same tectonic frame. All tectonic structures were marked on the three dimensional relief model. http://dx.doi.org/10.19111/bulletinofmre.410597

1-31

Authors: Ali Ekber AKÇAY, Metin BEYAZPİRİNÇ

Sorgun-Yıldızeli basin is an east-west trending asymmetric marginal foreland (peripheral foreland basin) formed as a result of the consumption of oceanic crust of the northern branch of Neotethys due to the collision of Sakarya continent in the north and Kırşehir Block in the south. It provides much information about the geodynamic evolution of the region. The basement of the study area consists of Late Palaeozoic-Mesozoic Akdağmadeni Massif. Akdağmadeni Massif was intruded by Cenomanian-Maastrichtian granitoids and is overlain tectonically by Late Cretaceous Artovaophiolitic melange within the İzmir-Ankara-Erzincan suture zone and by Cenomanian-Maastrichtian Darmik Formation. The volcano-sedimentary sequence deposited in Sorgun-Yıldızeli foreland basin developed on the relicts of the İzmir-Ankara-Erzincan Suture Zone along the northern margin of Kırşehir Block and was named the Boğazköy Formation. The pelitic, clastic and coarse clastic levels of Upper Palaeocene-Middle Eocene Boğazköy Formation including İzmir-Ankara-Erzincan Suture Zone slices and olistostromes are differentiated as the Dolak member. Toward the inner part of the basin, a turbiditic sequence of conglomerate, sandstone, claystone including rare limestone beds was deposited, consisting of conglomerate, sandstone, claystone, rarely limestone and alternations of three different volcanic rocks (acidic, basic and intermediate) related to subduction and/or collision. Calc-alkaline lava and pyroclastics of basaltic and basalt-andesite composition were differentiated as the Pazarcık volcanic member, with lava and pyroclastics of dacitic and rhyolitic composition called the Sarayözü volcanic member and calc-alkaline lava and pyroclastics of andesitic, trachyandesitic and dacitic composition called Kiremitlik volcanic member in Sorgun-Yıldızeli basin. According to the 40Ar/39Ar geochronologic method, the ages of 57.2±2.0 Ma and 56.7±1.8 Ma were obtained for Pazarcık volcanics, 48.8±1.5 Ma for Sarayözü volcanics and 45.1±1.3 Ma and 47.3±0.6 Ma for Kiremitlik volcanics. The reefal limestones which are not thick and occur in higher parts of the Boğazköy Formation were called the Limestone member. The uppermost section of the sequence which consists of generally clastic and coarse clastics is named the Konacı member. When the sedimentation and volcanism continued in the basin, gabbroic intrusions occurred as sills and laccoliths cutting the Boğazköy Formation. These gabbroic rocks were named the Yaycılar Gabbro. The age of 51.0 ± 0.7 Ma was found for the Yaycılar Gabbro with the 40Ar/39Ar geochronologic method. As a result of slab breakoff, the relicts of the consumed oceanic crust and the released massif were uplifted rapidly and the units of Middle-Late Eocene Tokuş Formation were deposited transgressively on the Boğazköy Formation and on outcropping basement rocks in the basin which was controlled by an extensional tectonic regime. Upper Miocene-Pliocene (İncesu Formation), Pliocene and Quaternary terrestrial sediments were deposited unconformably on all older units.

47-71

Authors: Yesim BUYUKMERİC

In the present work, a stratigraphic framework of the early Miocene units of the Kale-Tavas and Acıpayam deposits is proposed.Two stratigraphic sections from the brackish-marine deposits of Aquitanian (Yenidere formation) and three sections from the shallow marine units of late Burdigalian (Kale formation) age have been logged. In total 26 mollusc species are identified similar to those of the areas in the Mediterranean province. The fauna indicates that the Mediterranean Tethys occupied the southwestern part of the Denizli region only during the early Miocene. A tectonic pulse in the basin during the early Miocene may have been very important to understand the limits of marine Tethyan influence in the area.

99-113

Authors: Mohssen MOAZZEN, Roghieh BOZORG SEGHİNSARA, Hossein SHEİKHİ KARİZAKİ, Mohsen POURKERMANİ, Afshin ASHJA ARDALAN

The Late Jurassic aged Lisar granite in North Iran is in tectonic contact of the form of thrust and strike slip faults with Upper Cretaceous sandy limestone and is covered by Paleogene polygenetic conglomerate in the Talesh Mountain at the western continuation of the Alborz range. The rock samples of the granite are pink coloured and coarse-gained with K-feldspar, quartz, plagioclase, biotite and amphibole. The Lisar granite is more likely emplaced in an extensional environment indicated with numerous space filling silica-rich aplitic veins in the rocks. The granite samples are moderately altered and feldspars are changed to sericite and clay minerals and biotite is partially converted to chlorite. The Lisar granite has derived from a high K magma and is A-type in nature, belonging to A2 subgroup. The rock samples of granite are characterized by distinct negative Eu anomaly and a decrease from LREE to HREE contents. The parental melts of the granite were generated from partial melting of a lower continental crustal source with possible contribution from the mantle materials. The Lisar granite represents Cimmerian post-collision magmatism in north Iran following closure of Palaeotethys Ocean and subsequent collision. DOI: 10.19111/bulletinofmre.336499

131-146

Authors: ABDULBAKİ GÜNAYDIN

Uranium bearing phosphate mineralizations in the tuffs (ignimbrites) of Middle Miocene Arıklı volcanites in the vicinity of Arıklı and Nusratlı villages, Çanakkale have been known since 1977. In the study area, two types of phosphate mineralizations are present in different parts. First type and important one is in the tectonic zones in tuffs and along the contact between tuffs and Çetmi ophiolite and along the contacts of the units of the Küçükkuyu Formation in the Muharremin Tepe, Feyzullah Tepe, Örencik Tepe, Gedikharman Tepe in north and northwest of Arıklı village. Second type is the vein type mineralizations in the tuffs in Çarşılı Tepe, east of Nusratlı village. Both types of mineralizations are hydrothermal origin. Additionally, walnut-sized syngenetic phosphate nodules are also observed in the tuffs in Çarşılı Tepe. XRD and geochemical analysis of samples obtained from mineralizations indicated that the major phosphate bearing mineral is chlorapatite and they have P2O5 contents ranging from 4.5 to 32.4%. The economic potential of the mineralization is not significant due to limited lateral and vertical continuity of the phosphate mineralization. So, in the study area, economically important phosphate deposit is not expected. DOI: 10.19111/bulletinofmre.314197

161-173

Authors: Güllü KIRAT

A study was carried out to identify Cd, Pb and Zn concentrations which exist in the roots and branches of Astragalus pycnocephalus Fischer and Verbascum euphraticum L. plants which grow in the Görgü (Yesilyurt-Malatya-Turkey) Pb-Zn mining area. A total of 60 samples were collected, 30 samples from plants and 30 samples from the soils where the plants grow. Cd concentrations range between 42.2 - 110.2 mg/kg, Pb: 2198 - >10000 mg/kg and Zn: 6088 - >10000 mg/kg in the soil where A. Pycnocephalus plants grow. Cd concentrations range between 4.1 - 544 mg/kg, Pb: 6918 - >10000 mg/kg and Zn: 5020 - >10000 mg/kg in the soil where V. Euphraticum grow. When the anaytical results gained are statistically examined, according to correlation coefficients graphic between the soil and plant, finding positive correlation between (A. Pycnocephalus) soil-root (Cd, r =0.77), soil-branch (Cd, r =0.86) and soil-branch (Pb, r =0.77) could mean that these could be indicator plants and can be used for remediation of the soils polluted by Cd and Pb metals. It is observed that the metallic concentration times values of the plants in this study taken from polluted areas compared to the plants taken from unpolluted areas, are quite high in total 44 samples (Cd, Pb and Zn values are quite high in 7, 30 and 7 samples respectively). Transition factor is >1 in some sample locations and range between 0.13 and 2.07. Enrichment coefficients is >1 for the location of V11 (Cd, root/soil). A. Pycnocephalus and V. Euphraticum, in some locations, according to transition factor, enrichment coefficients, times values and element concentrations could be identified as accumulator/hyperaccumulator for Cd, Pb and Zn elements. DOI: 10.19111/bulletinofmre.306195

187-202

Authors: Mahmut PALUTOĞLU, Ahmet ŞAŞMAZ

Significant tectonic structures observed in the vicinity of Kahramanmaraş are the northern branch of the East Anatolian Fault Zone (EAFZ) (Sürgü segment, Çardak segment, Savrun segment, Çokak segment and Toprakkale segment), the southern branch of EAFZ (Gölbaşı segment and Amanos segment), Engizek Fault Zone, Kahramanmaraş Fault Zone and Narlı segment of the Dead Sea Fault Zone (DSFZ). The manuscript in which the 1795 Kahramanmaraş Earthquake has been mentioned is kept in the work of art called “Divan-ı Hasmi” in the Koyunoğlu Library of the Konya Metropolitan Municipality. From the statements in the work the intensity of the earthquake is 8,0 and due to this fact the magnitude of the earthquake was estimated as 7,0. The estimations made reinforce the probability that the earthquake occurred on Gölbaşı segment of the EAFZ DOI: 10.19111/bulletinofmre.314211

213-222

Authors: Fikret DOĞRU, Oya PAMUKÇU, İlkin ÖZSÖZ

In this study, tilt angle method was applied to Western Anatolia gravity data in order to estimate edges of the geological structures. Tilt angle was obtained in two different ways by using gravity and its vertical derivative. In potential field methods, tilt angle technique is expressed as the ratio of vertical derivative to horizontal derivatives of anomaly. In the tilt angle map, 0° contours defines structure edges, half of the distance between ±45° defines depth of upper structure. In the field work of the study, gravity data, which was measured in Western Anatolia, was used to obtain regional anomaly maps and tilt angle and tilt angle of vertical directional derivative were applied to these maps. A significiant difference was observed between western and eastern parts of the N-S striking line, througout 28o longitude, from the results of tilt angle which was obtained by applying upward continuation method (50, 75 and 100 km) to the Bouguer anomaly. Same difference was determined from the results of vertical derivative of tilt angle which was obtained from upward contuniation of Bouguer anomaly. Depth values were obtained from the results of tilt angle and vertical derivative of tilt angle methods between 7 and 43 km in study area. The obtained results were compared with geological structural boundary and possible depths of geological discontinuities were estimated. In addition, obtained results were investigated with seismic activity in the study area and compared with previous geological and geophysical studies. DOI: 10.19111/bulletinofmre.305177

255-260

Authors: Anıl ARDAHANLIOĞLU, Efe DEMİRCİ

The geoscientists have always wondered what evolutionary processes the Early Earth went through until it reached today. The beginning of the plate tectonics poses another matter of debate in these processes. Yet, the debates on when the plate tectonics began have not been resolved. In this sense, especially the lack of records regarding the period of time before the Cambrian Era is considered the biggest obstacle against resolution of these debates. The geoscientists have befitted from various methods to come up with different proposals about the beginning of the plate tectonics. The most notable rock type among the ones produced by the mantle is the komatiites. While the oldest datable komatiite is 3.82 Ga; the youngest is 0.86 Ga. With the high content of magnesium they contain, their special texture and the geological setting, the komatiites are not similar to any other rock groups which can currently be examined. Though they were produced in different geological times, no up - to - date forms of these rocks have been observed. Given the formation conditions of komatiites, recorded time intervals and the content of magnesium they contain, they might indicate when the plate tectonics began. DOI: 10.19111/bulletinofmre.314227

1-14

Authors: Gürol SEYİTOĞLU, Korhan ESAT, Bülent KAYPAK

This paper suggests that the structure known as “Beypazarı flexure / monocline” in the Turkish geology literature should be named as “Beypazarı fault-propagation folds”. Beypazarı, Kilci and Başören blind thrusts together with Erenler back thrust constitute the Beypazarı Blind Thrust Zone which is an active neotectonic structure as indicated by earthquake activity. NW-SE contraction created by the interaction between the North Anatolian Fault Zone, the Kırıkkale-Erbaa Fault Zone and the Eskişehir Fault Zone produced the Eldivan-Elmadağ Pinched Crustal Wedge, the Abdüsselam Pinched Crustal Wedge and the Beypazarı Blind Thrust Zone. These structures take up the internal deformation of the Anatolian Plate.

27-39

Authors: Kamal Haji KARİM, Polla Azad KHANAQA

The Piramagroon anticline (or Pira Magrun Mountain) elongates directly to the northwest of Sulaimani city, Northeast Iraq and its southeastern part contains two other anticlines, named Harmetool and Yakhyian anticlines in addition to their complementary synclines and many other smaller folds. The anticline has experienced intense search for oil in the last few years and a well is drilled to a depth of 3000 meters but, any evidence of oil or gas wasn’t found. In the present study, the southeastern part has been studied stratigraphically and structurally and the previous studies have been critically reviewed which may help to reason about the absence of oil in the area. In this study the stratigraphy of the anticline has been determined and Kometan, Gulneri, Dokan, Balambo and Sarmord formations have been plotted on a geological map and stratigraphic column and the nannofossils have been used for the aging of intervals with undetermined ages. The thickness of the Gulneri Formation is 2-4 m and by the analysis of nannofossils its age was identified as Late Cenomanian-Early Turonian. Lithology and bedding styles of the Dokan and Upper part of the Balambo formations are very similar to Kometan Formation and they can be determined either by fossils or by using Gulneri Formation as marker bed. The outcrop of the Gulneri Formation is helpful for differentiation since it is soft and can be recognized easily in the field by its darker color. The structure of the anticline is relatively complex as it consists of asymmetrical anticlines with southwest plunge mainly in few places while it changes to overturned fold in others and is deformed by reverse fault. The anticlines are shaped by detachments on the Gulneri and Sarmord formations and by the other older soft rocks. The newly formed anticlines have the style of multi-detachment fold or multi-detachment faulted fold.

59-82

Authors: Barbaros ŞİMŞEK, Mustafa ERGİN, Murat EVREN, Özgür TÜRKMEN, Serkan PALAS, Hakan PEHLİVAN, Bahri Serkan AYDEMİR, Füsun ÖCAL

This paper presents research results for Holocene sedimentary processes and controlling factors in Datça and Hisarönü Bays located in south west Turkey. For this purpose, we collected seafloor grab samples (upper 30 cm) from 71 stations and seismic profiles (only one sample is used to explain sedimentary process) from Hisarönü and Datça Bays with the MTA-SELEN research ship. According to the seismic profile, the continental self edge or threshold is found at depths of -90/-120 m and displays seismic facies parameters showing sea level variations from the Quaternary period. According to radiocarbon dating calculations, the sediment samples began to be deposited 2694-14700 years before present. The seafloor sediments comprise 1-18% gravel, 7-85% sand, 2-30% silt and 6-69% clay size clastic material. Although mud of mixed silt and sand composition is the most common sediment type, there are significant sand and gravel amounts. As well as discussing regional differences in grain size distribution, the presence of residual (relict) sediments is noted. The total amount of heavy mineral-rich black sand is mostly below 2%, reaching 13% in ophiolite- and chromite-rich central and eastern regions. Inorganic geochemistry of sediments includes relatively significant amounts of ophiolitic sourced Mg, Cu, Ni and Fe. Regional variations in river drainage system, bay morphology, terrestrial source rock lithology and marine waves and currents affect not only sediment grain size distribution, but also total heavy mineral content and the main element composition.

109-133

Authors: Saad Zeki ABDULKADİR Aİ-MASHAIKI

Magnesite mineralization of high purity was discovered and described herein for the first time from metamorphosed folded belt from Al-Thanyiah locality in Rub’Al-Khali sector, 360 km east of Sana’a City, northwest Yemen. The magnesite-metamorphic belt, belonging to the Precambrian/Neoproterozoic age? comprises thrust belt, which trends generally N-S direction. Magnesite mineralization was identified in an extended carbonate-metamorphic belt for several tens of kilometers cf. 31 km and occurred in association with 8 stratigraphic units. The thicknesses of pure magnesite bearing units are variable and ranges from 20 to 60 m, associated with dark green chlorite-schist with intersecting huge ultrabasic intrusions. Geochemical, mineralogical and petrographic analyses show that the magnesite concentrations in the stratigraphic units are ranging from 78% up to high purity of 99.6% cf. 35 to 48.9% MgO, with minor dolomite and calcite respectively. Little to rare content of talc and brucite were also recognized. Two thick, productive and high purity magnesite beds, the first is of 40 m thick and the second is 60 m in thickness, which reveals more than 95% MgCO3 and considered to be economic. The suggested origin of the magnesite mineralization is coming from high stress of regional metamorphism associated with ultramafic intrusions cf. amphibolite and harzburgite associated with diagenetic solutions rich in Mg2+, associated with the heat of magma. The alteration of dolomite to magnesite was formed by multiple phases to transform calcite and/or dolomite to magnesite.

157-168

Authors: Mustafa Can CANOĞLU, Bedri KURTULUŞ

This study comprise the design of the planned grout curtain in Savcıbey Dam (Söğüt/Bilecik) in order to provide impermeability along the dam axis. Within the context of field studies, engineering geology map was generated, ground investigation drilling was realized and permeability tests were performed. Within the field studies, the joint conditions of the geological units (Triassic aged Bozüyük Metamorphic schists) under the dam axis and its effect on permeability was observed considering the positions of the discontinuities with regard to the dam axis location. Orientation of discontinuities generally have strikes changing between N – S and NNE – SSW. 5 boreholes on dam axis, 2 boreholes on cofferdam, 3 boreholes on diversion tunnel and 2 boreholes on spillway total 245 m ground investigation borehole were drilled. In order to determine the permeability profile of dam axis and design the grout curtain, Lugeon tests in Bozüyük Metamorphic units observed in dam axis, falling head permeability tests in alluviums observed in thalveg and slope debris observed in right abutment were performed. Lugeon tests realized in Bozüyük Metamorphic units show that the unit is generally permeable and partly low permeable. Alluvium and slope debris are highly permeable. In addition, drilling works realized in dam axis shows that the augmentation of the weathering degree cause an increase of permeability in Triassic aged Bozüyük Metamorphic schists. As a result of these studies information about the permeability of Savcıbey Dam was collected and the grout curtain hole was designed. Accordingly, it is predicted that approximately 40 m depth of grout curtain from the stripping excavation with the depth of 1.50 m would prevent the possible leakages

181-191

Authors: Melis A. SOMAY

Wetlands play an important role in the hydrologic cycle. This investigation was completed to determine the origin of waters and recharge-discharge areas using stable isotopes (δ18O and δD) which are fingerprints of the water in Güllük (Muğla) wetland. This area is important both economically and in terms of aquaculture environment in Turkey. Sample locations were selected from not only wetlands but also the possible recharge area that consists of karstic springs and streams. EC (Electrical Conductivity) of the waters range between 5080-41000 µS/cm, except streams. δ18O and δD contents of the samples ranged from -6.00‰ to 0.50‰ and from -29.1‰ to 2.1‰, respectively. In general, samples plotted between Global and Local Meteoric Water line with waters also plotted on the seawater mixing line. The sources of salinity were evaluated by δ18O-Cl in and around the wetland. Streams are under the influence of “Evaporation”; samples from Avşar and Koruköy are under the influence of “Both Evaporation and Seawater Mixing”; İçme and Ekinambarı springs, and Limni Lake are under the influence of “Seawater Mixing”; and Savran spring and Tuzla Lake are under the influence of “Dissolution of Salts-Leaching” processes. The fact that Savran source plotted in this area raises the question of whether the current sea water is the source of salinity. The recharge area of the wetland consists of karstic formations, sea water, streams and precipitation in the Güllük area.

207-213

Authors: Ömürden GENÇ

Impact breakage functions for a gold ore from Bergama region (Turkey) was estimated based on the single-particle impact breakage distributions of particles obtained from drop weight tests. For this purpose, a modified manual version of a JK Tech drop-weight test device was used. Effect of specific comminution energy (Ecs) on impact breakage distributions were investigated. Relationship between specific comminution energy and impact breakage product fineness (t10) parameter was established. Ecs-t10 model given in the literature was successfully fitted to the breakage test results. Ecs-t10 impact breakage model for the gold ore was proposed to be used in breakage function estimation. t-family curve approach was applied to estimate single particle breakage functions of the gold ore. For this purpose, t-family curves were modelled and variations of empirical breakage functions for the gold ore were estimated on different impact energy levels for comminution process modelling.

219-220

Authors: Uğur AKIN

There is not any filter such as the “apparent gravity linear filter”, which is mentioned by the criticizer, in the literature of geophysical potential methods. The “apparent density filter” was used in the study. As the name implies; the crustal structure of Turkey was investigated in the article of “Investigation of the Seismic Velocity Distribution and the Crustal Structure of Turkey” (Akın, 2016). So; the article had different findings. The “Conrad discontinuity” has been one of the findings of this article. Or else; the distribution related to the Conrad discontinuity has not been the main topic of the article as it had been understood by the criticizer. In this study, the density and seismic velocity took their highest values within first 20 km’s of the continental crust as; 2.74 gr/cm³ and 5.86 km/s, respectively. This zone was considered at the same time as the Conrad discontinuity between the lower and upper crusts, and it had an approximate depth of 16 km. The statement of “Although their densities are 2-2.2 gr/cm3 , the velocities are very high (4.5-5 km/s). That is; the response given to the parameter transformation by these formations, which is the subject of the article, is false” made by the criticizer is rather thought-provoking. Therefore; the article was reviewed. However; the density of 2-2.2 gr/cm3 and the corresponding velocity of 4,5-5 km/s mentioned by the criticizer were not encountered in the article. The article has not been carefully read by the criticizer. Density and velocity maps in this publication were prepared for depths of 20 m as emphasized in figure captions. The apparent density map of Turkey for depth of 20 m in figure 4 in the article showed variation within intervals of 2.55-2.98 gr/cm3 . Also; the seismic velocity values of Turkey for 20 km depth in Figure 6 were estimated within intervals of 4.91- 6,78 km/s. Basins mentioned by the criticizer by giving examples for Çankırı and Lake Salt is considered as very shallow structures. Apart from the example basins, which the criticizer mentions about, there are many basins in many places of Turkey. The investigations regarding these basins can surely be carried out by me or by other investigators in the future. However; it can never anticipated personally to answer for some basins in this article.