Türkiye Jeoloji Bülteni

Abstract: This study explains the palaeoecological aspects of the lignite-bearing sediments from the Late OligoceneEarly Miocene Kalkım-Gönen Basin. Studies were carried out in two different areas, Ünsa and Metehan.A core drilling was performed by a private company, Ünsa mining, about 187 m long. Fine grainedlignite bearing deposits alternated with volcanics are dominant along the core. In the Metahan area,lignites with clastic deposits alternation are available as well. Sequence includes primary and secondarygypsum formations in some places. Sediments in the region is densely faulted and folded and orientationsof fold axis is mainly northeast-southwest directed. A section was measured from the open pit minereaching to approximately 30 m thick coniferous plants undifferentiated Pinaceae and Cupressaceae,riparian plant Alnus are in high percentages in the samples from the Ünsa drilling. The main elementsof the mixed mesophytic forest are Engelhardia, Castanea-Castanopsis, Quercus spp., and evergreenQuercus that were recorded in minor quantities. Spores, herbaceous and swamp plants are represented bylowest quantities. Three local pollen zones (Ü/1-3) may be distinguished according to changes on pollenconcentration. Metehan sporomorph associations are rich with respect to elements of coniferous forest(undifferentiated Pinaceae), mixed mesophytic forest (Engelhardia, evergreen Quercus, Quercus spp.,Fagus, Carpinus) and riparian plants (Alnus). Spores are relatively in low amounts. Swamp forest andherbs constitute the lowest percentages. Counting results indicate the existence of two different local pollensub-zones (M/1-2) corresponding to Ü-2 zone of the Ünsa sporormorph associations. Pollen assemblagesidentified in both areas indicate the presence of a dense forest cover during the deposition. Within thisforest, mixed forest plants (evergreen Quercus, Quercus spp., Engelhardia, Castanea-Castanopsis) andconifers (undifferentiated Pinaceae, Cupressaceae, Keteeleria, Cedrus, Cathaya, Picea). Alnus is the mostabundant plant on the edges of the river. In this environment, plants such as Ulmus, Zelkova, Carya,Pterocarya and Liquidambar occur in lesser amounts. Quantitative palaeoclimate results and pollenassemblages in both areas (Kalkım-Gönen Basin) indicate that lignite-bearing sediments were depositedunder humid, hot and rainy conditions.

Abstract: Soğanlı Formation of Early Eocene age in the northeastern of Araç (Kastamonu) has been investigated inorder to determine their paleontology and palaeoecology. The sequence consists of gray, yellowish, clayeylimestone, rich in larger benthic foraminifers. The lower parts of clayey limestone are dominated byporcellaneous foraminifera such as Alveolina and Orbitolites and by dascylad algae. The top of the sectionis characterized by hyaline calcareous foraminifers such as Assilina and Nummulites. Idalina sinjaricaGrimsdale, Glomalveolina lepidula Schwager, A. cemali Sirel & Acar, A. rotundata kazancii Sirel & Acar A. erki Acar, A. ankarensis Sirel, A. pieroi Sirel & Acar, Lockhartia conditi (Nuttall), L. tipperi (Davies),Orbitolites complanatus Lamarck, Cyclopertorbitolites tokerae Özgen-Erdem, Assilina spinosa Davies& Pinfold, Nummulites sp., Cribrobulimina sp., Kathina sp., Neorotalia sp., Triloculina sp. have beendecribed along the section. The distribution of the larger benthic foraminifera indicates Early Eocene age.According to these assemblages, we interpret that deposition of the unit started in a restricted shallowerenvironment and continued in a shallow high energy environment.

Abstract: In this study, the effect of the iron deposits, located in Menteş watershed on the ground waters wasinvestigated. The study area is located in the Seyhan river main basin. The Menteş watershed coversan area of 43 km2 with an annual average precipitation of 460 mm/year. The study area comprisesPrecambrian metaclastics, Lower Cambrian quartzite, Middle Cambrian recrystallized limestone,Ordovician metaclastics, Miocene conglomerate and recent alluvium. Recrystallized limestones are mainaquifers within the studied area. To determine aquifer parameters totally 15 groundwater samples weretaken from springs and wells in dry and wet seasons, T, pH and EC values were measured in-situ and themajor anion - cation and trace element analysis were done. Temperature of the waters ranged from 7 oCand 19 oC; pH values ranged from 7,26 and 8,7; EC values ranged from 47,3 μS/cm and 642 μS/cm. Thecation and anion sequencing of the water samples are mostly in rCa> rMg > rNa > rK and r HCO3> rSO4> rCl form, respectively and this sequencing indicate that the groundwater are predominantly locatedwithin the limestone and dolomite. δ18O (‰-10,93 - ‰-8,27) and δ2H (‰-64,18 - ‰-54,58) values showthat waters are meteoric origin. The major anion and cation values of the water samples are below thedrinking water limit values (TS 266 and WHO). Trace element analysis covering 66 parameters wereanalyzed by ICP-MS method and more than 30 elements including Hg, Cd, Th and Ag stayed in belowdetection limits. As, B, Co, Cr, Cu, Mo, Ni, Pb, Sb, Ti, U, V, W, Zn, Se and other elements’ values are lowenough to be ignored. The examined inorganic parameters showed that ground waters located in Menteşwatershed iron mine fields and its close vicinity have drinking water quality. 

Abstract: The beginning of Neogene terrestrial sedimentation in the northeastern coastal part of the Çeşme Peninsulais represented by the Şifne formation, which its lowermost part is not exposed. The age of successionevaluated as Early Miocene stratigraphically and its uppermost observable part consists of lacustrinelimestone bearing fresh water algae. The ignimbrite flows, early products of Armağandağı volcanism,stopped and ended the sedimentation of Şifne formation.The Armağandağı volcanics represents the late Early Miocene-early Middle Miocene calcalkalinevolcanism in the Çeşme Peninsula. The tongues of the volcanism in the study area are mainly composedof volcaniclastics. The volcaniclastic assemblage comprises felsic ignimbrites at the lower part namelyAlaçatı tuff, and andesitic ignimbrite, blocky ash flow deposits and lahars of Reisdere volcaniclastics atthe upper part. Alaçatı tuff is located between Şifne formation and Reisdere volcaniclastics. The Zeytineliformation represents the lavas of the Armağandere group.The Ildır formation overlies the pre-Neogene basement rocks with an angular unconformity and laterallygrades in the upper part of the Armağandağı volcanics. They represent the early Middle Miocenesedimentation and calcalkaline volcanism. The lacustrine Ildır formation is composed of mudstonesandstone alternation in the lower part and clayey limestone at the upper part, and comprises theBelentepe member deposited in a fan-delta environment in the lower part. A synsedimentary lava level inthe Belentepe member dated as 14.6±0.6 Ma by K/Ar method. This lava level is a tongue of the Zeytineliformation, and its age shows that the activity of Armağandağı volcanism continued in the early MiddleMiocene.

Abstract: This study aims to reveal the mineralogical characteristics of the carbonate and pelitic rocks in the LowerTriassic Çığlı Group in the Uludere-Uzungeçit (Şırnak) region from Southeast Anatolian Autochthone(SEAA). Çığlı Group is represented by Yoncalı Formation (dolomite-siltstone-shale with limestoneintercalation), Uludere Formation (shale/shale with carbonate-clayey limestone intercalated withdolomite) and Uzungeçit Formation (limestone with chert nodule-dolomitic limestone-shale) from bottomto top. In order of abundances of minerals obtained by XRD investigations as follows; Yoncalı Formationcontains carbonate (calcite, dolomite), feldspar, phyllosilicate (illite, chlorite) and goethite minerals, andUludere Formation is made up of carbonate (calcite, dolomite), quartz, feldspar, phyllosilicate (illite,chlorite, mixed-layered chlorite-vermiculite/C-V, and very minor amount of kaolinite in only a sample)and hematite minerals. Uzungeçit Formation has carbonate (dolomite, calcite), silica (quartz, opalCT, moganite), phyllosilicate (chlorite, illite), and feldspar and hematite minerals. On the basis of illitKübler Index values; Yoncalı Formation reflects the degrees of anchizone; as for Uludere and Uzungeçitformations, they have the degrees of anchizone-high diagenesis, respectively. Similarly, Chlorite ArkaiIndex (AI, °2Ɵ) values indicate the grades of anchizone-diagenesis. Illites exhibit 2M1 ve 2M1 + 1M +1Md polytypes and the values of b unit-cell distances show a composition close to ideal muscovite and lowpressure conditions.The rocks of the Çığlı Group offer differences in terms of rare occurrence of kaolinite, appearanceof moganite and C-V and the dominance of dolomite and hematite in most levels, and diagenesis/metamorphism grades are also high, when compared with the equivalent units in the Diyarbakır-Hazroarea. Lower Triassic series regionally seem to have a deeper depositional environment, and have relativelyhigher maturation because of the volcanic feeding and tectonic burial in the Diyarbakır-Şırnak directionfrom west to east.

Abstract: The East Anatolian fault system (EAFS) of left lateral strike-slip is the second most important neotectonicstructure of Turkey. The travertine occurrence is located on the Sivrice fault zone, which is one thesignificant zone of the EAFS and precipitated on a S to SW-facing slope, 20 km SW of the Sivrice town(Elazığ) in accordance with the slope topography.The Maden Group of Middle Eocene age, on which the travertine occurrence took place, composed mostlyof mudstones with volcanic intercalations, andesite, basalt and diabase dykes that cut them. The PütürgeMetamorfics that play role as a basement rock are represented by calcschist and marble around theirSivrice exposures. Lithology of the Pütürge Metamorfics and the fractured structure of the left lateralstrike-slip Sivrice Fault Zone play an important role on the travertine formation. As the travertineexposures has been precipitated under appropriate conditions that formed by faults and bedrock in frontof a fault along the left lateral strike-slip fault zone with normal component, they have been evaluated as‘fault-front travertines’ depending on the morphological classification.The most abundant element concentrations of the travertine samples are: Ca: 378216-385220 ppm, Mg:5428-8021 ppm, Sr: 2133-6046 ppm. The δ13C values range from +3,5 to +6,7 (‰ PDB), while the δ18Ovalues are between -8.1 and -9.6 (‰ PDB). These geochemical signatures indicate that the travertinesstudied are of thermogene origin. Travertine precipitation began at least 30.86 ± 0.49 ka ago with respectto today in the field based on the U-Th age data. 

Abstract: The study area is located on the eastern part of the North Anatolian Fault Zone (NAFZ) around theKoyulhisar (Sivas) region. The region is represented by a 6-8 km wide and 32 km long deformation belt.This belt is divided in 5 fault segments by Toprak (1988) as North Anatolian Master Fault, KoyulhisarFault Set, Kelkit Fault Set, Şıhlar Fault Set and Kuruçay Fault Set. In this study, a detailed fault kinematicanalysis were carried out along the Şıhkar, Çamlıyaka, Saytepe and Dumanlıca Fault Sets aroundKoyulhisar and its surroundings. The result of kinematc analysis indicates that the region is under the effect of NW-SE compression and NE-SW extension. Morphotectonic structures and microseismic activityreveals the right lateral strike slip activity of the North Anatolian Fault Zone in this region. Intenselandslide activity in the region is seen. One of the severe landslides occurred in Koyulhisar in 2000 is stillaffecting the region. GPS monitoring of this landslide reveals an average of 2.5-7.4 mm/year slip rate.