Türkiye Jeoloji Bülteni

Abstract: The Gördes Dam has been planned for flood-preventing on Gördes River which is one of the important branches ofGediz River. The aim of this study is to investigate the detailed geological characteristics of the dam site and adjacent areas and discoverprobable water-leakages horn the reservoir area.The study region is stituated in the Izmir-Ankara zone and Menderes Massif. The Izmir-Ankara zone consists of ophiolite, flysch andvariouses carbonate rocks mainly of Cretaceous age. The metamorphic rocks of the Menderes Massif, consist of marble, mica-schist andphyllites region. The allochthonous ophiolite bodies are mainly composed of serpantinite, gabbro, and basic volcanics, and overthruston to the Cretaceous carbonates and Menderes Massif`s rocks. The two different flysch units- exposed in this region, are separated carbonate rocks from each other with platform-type Cretaceous. The contact is conformable and transitional between carbonate and flysch unitsin all places. Locally, the lower flysch unit rests unconformably on the metamorphic rocks of the Menderes Massif.The majority of the faults raughly represent a NE-NW trend and are shown in high-dipping systems in this region. The thrust faultsgenerally display N-NW trends in the study area. Hie discharges of the Akpmar springs are controlled by the NE-trending Ahmetler fault,and probably cause to the leakages from the reservoir, due to the karstic and morphological features of this fault

Abstract: In this study, geological and geotechnical properties of the Görmel dam site and its reservoir area have been evaluated.Görmel formation, widely extended at the dam site and the reservoir area, consists of mostly impervious marls. The fractured and jointedmarly levels between 20 and 30 meters at the drillings of the dam site need to be grouted. The slope washes on the slopes of the dam siteshould be removed away before construction of the dam. Çamlıca formation`s ophiolitic rocks, cropping out in the reservoir area, are impervious. Stability and watertightness problems are not common features in the dam site and the reservoir area. As a result, the Görmeldam site is a suitable place for construction of a dam.

Abstract: The tin bearing Sulucadere lead-zinc mineralisation is of hydrothermal-metasomatic origin and occurs in the Bolkar marble. The hydrothermal solutions were brought about by the quartz-prophyry veins of the Horoz granodiorite. The primary ore minerls respectively are sphalerite, galena, pyrite, fahlerz, chalcopyrite, arsenopyrite, marcasite, stannite, bpumonite-seligmanite, pyrrhotite, siderite, ankerite, navite-gold, idaite and Ag-sulpho salts. Surface alteration of these minerals prouced the following secondary minerals.Covellite, chalcocite, limonite, malachite, azurite, anglesite, cerassite, smithsonite, hydrozincite, psilomelane, skorodite, etc. The majorgangue minerals are calcite, dolomite, quartz, epidote, sericite, muscovite and chlorite. Sericite, muscovite, chlorite, rutile and anatasehave been obtained from the limestone wall rocks.

Abstract: The factors, which control the formation of the iron ore deposits in the Divriği Region, have been discussed by the useof rare earth element (REE) analyses.The massive iron - ore and the serpentinized ultramafic rock samples both have low REE values close to the condrite values orslightly higher. The light REE contents are relatively higher than those of the heavy REE (LREE / HREE > 1). Negative Ce - and Eu anomalies are characteristic features giving a similar REE pattern for the iron ore and serpentinite samples.The granitic rocks in the Divriği area have high light REE values and low heavy REE giving fairly steep dipping REE curves. Theintrusion of the granitic rocks have hydrothermally altered some parts of the serpentinite, and caused a stock-work type iron ore occurence. The granitic rocks and the hydrothermally altered serpentinite and the stock-work type iron ore show similar patterns with no negative Ce - and Eu anomalies.The parallelism between the REE patterns for the massive iron ore and the serpentinite, established with the previously publishedgeochemical data, indicates the genetic relationship between the iron ore and the serpentinization. A later hydrothermal phase due to thegranitic intrusion has influenced the REE pattern in the altered serpentinite, and indicates that the stock-work iron ore is hydrothermal inorigin.The present investigation proposes a genetic model for the iron ore, where the iron formation is* connected with the serpentinization process. In earlier investigations, the serpentinization process was determined to be prior to the intrusion of granitic rocks, whichcaused the hydrothermal activity. 

Abstract: The Boyabat basin is one of the important sedimentary zone in oil exploration in the Pontid belt, Presence of source,reservoir rocks, seals, oil and gas seeps at Ekinveren, Üzümlü and Uzunöz localities makes the investigated area an important oil exploration target.The Ekinveren fault is a big thrust fault, advensing from north to south and thrusting the northern sedimentary units on to the Boyabat autochthonous units. Due to these thrust movements, the pay zones of the Boyabat basin series has been stayed buried under the advancing units.During our field work, it has been observed that the thick basal Çağlayan sandstones are continious from Ekinveren to Uzunöz wherethey are overlain by Yemişliçay volcanics. Furthermore, the gas seep which has been observed at Uzunöz, withnesses presence of buriedÇağlayan reservoir sandstones and İnalü limestone under the overlaying Yemişliçay formation.As a general rule, although the volcanic activities are considered as a negative factor for oil exploration, our geologic observation indicate that the Çağlayan sandstones and İnaltı limestones could be pay zones under Yemişliçay volcanics. In summary, the Ekinveren faulthas an important role on the hydrocarbon entrapment in the studied area. The southern and northern zones of the Ekinveren fault zone andextensional area of the Çağlayan and înaltı formations under the Yemişliçay formation can be considered important exploration targets inthe Boyabat basin. 

Abstract: This research aims to explain the stratigraphic, paleontologic and regional neotectonic characteristics of Late Pleistocene (Tyrrhenian) sediments observed in the Karamürsel area (Kaytazdare, Subaşı and Hersek villages).The unit starts as transgressive on the Eocene and locally on Miocene basement and ends as regressive. The sequence consists ofslightly cemented sand with fossils, silty sand, clayey sand, marl and sandy marl levels on the pebbly levels of the bottom. These sediments »contain Ostrea eduIis(Linne), Venerupis(Aurea) cf.var. calverti (Newton), Thericium(Thericium) vulgatum Bruguiere,Pinna sp., Ammonia beccarii Linne and Lithothamnium sp. most abundantly. According to the characteristics of the sedimentsand fossils, the environment in the Tyrrheinan period is lagunal-marinal.The beds belonging to the Late Pleistocene (Tyrrhenian) marinal sediments dips 10° north. The position of these sediments whichvary up to 60-70 m. heights where they had to be at most 18-20 m. or 25-30 m. according to the present sea-level, show that they wereunder the effect of the North Anatolian Fault(NAF) and went up to 50 m. height at least.In the area, the NAF which has east-west strike, dip of 89° north and has been active since Miocene, is a right-lateral strike-slipfault. The south blok of the fault, moves upwards towards the west in comparison to the north block. Calculated horizontal slip-rate isabout 0.5 cm/year and vertical slip-rate is 0.5 mm/year.The Sea of Marmara and the Gulf of Izmit are in an extentional region between the Hellenic Trench and Caucasian-Crimean Trench.The direction of this extension is NNE-SSW. The extension increases gradually from the east of the Gulf of Izmit where NAF branches, towards the west.The Sea of Marmara and the Gulf of Izmit had been formed by entrance of the Mediterranean waters to the depression area formed bythe extention.in the Tyrrhenian period. Beside a little widening of the sea area of the gulf due to Flandrian transgression, the present position of the gulf has been formed by gradual narrowing. 

Abstract: In the Cambrian of the Western Taurids six species of Hadimopanella has been found, five of them are new. Thesetaxa, Hadimopanella özgüli, H. ataseveri n.sp., H. inurselae n. sp., H. oskayi n. sp., H. saiti n. sp. and H. türkseni n.sp. are described and their startigraphic range determined. According to the startigraphic distribution of these taxa 6 new Hadimopanellabiozones has been established in the Cambrian System: From bottom to the top, these are: Hadimopanella ataseveri Interval-zone,H. ataseveri/H. oskayi Concurent range-zone, H. oskayi Interval - zone, H. türkseni Interval-zone, H. saiti/H. özgüli Assemblage-zone and H. inurselae Acme-zone.In addition, two new genera and species are named and described: Humboldtochaeta anatoliensis n. gen. n. sp. and Konyasphaerullda celali n. gen. n. sp.. The later one has a restricted stratigraphic range and is to be found in abundance in the Middle Cambrianstrata. 

Abstract: The vertebrate fossils of the Alçıtepe surroundings (Gelibolu Penninsula) include Anchitherium sp. from Nebisuyu,Hipparion primigenium Meyer, Chilotherium habereri (Schlosser) and Diceros pachygnathus (Wagner) from Sığındere, andHipparion mediterraneum Hensel from Değirmendere. The Değirmendere fauna has been recognized first in this study, on the basisof correlations with the Eurasian and African fauna, a late Middle Miocene age for the Nebisuyu fauna, an early Late Miocene age for theSığındere fauna and a middle Late Miocene age for the Değirmendere fauna can be established. The paleoecologic characteristics of the faunal assemblages are suggestive of a savannah environment for the Nebisuyu fauna, a forest-savannah for the Sığındere fauna and a steppefor the Değirmendere fauna.

Abstract: Ulukışla Tertiary sequences are located in the southeastern part of the Tuzgölü Basin and geologically bounded to thenortheast by the Niğde massive, to the east by the Ecemiş Fault, to the south by the Bolkar Mountains. The basement of the Tertiary sequences is the Campanian-Lower Maastrihtian aged ophiolitic melange which is tectonically located on the Permian to Upper Cretaceousrocks of the Bolkar Group. The oldest unit of the sequence is the Sansartepe formation consisting of volcanics, dikes and sills. The activity seems Ypresian aged in the south and Paleocene in the north. The Sansartepe unit is covered by the Başmakçı limestone of LowerYpresian in the north, and by Karatepe limestone of Lower Lutetian in the south. The detritics of the following Sereyenkaya formation isthe lateral extinction of the same limestones. These units, which are conformably overlaine by the turbiditic Güney formation, are observed to indicate Ypresian in the north and Lutetian-Bartonian in the south. Zeyvegediği gypsum and anhydrits and the laterally locatedKabaktepe member of the area are deposited in an evaporitic basin following the continental period of Upper Eocene. The sequence isoverlaine conformably by marls and limestones of Kurtulmuştepe formation and sandstones of Kızılöz formation of Lower Miocene. Middle and Upper Miocene are represented by Kızıltepe, Kızılbayır and Katrandedetepe formations. Beştepeler formation in the north, alluvialterraces in the south are the Pliocene sediments of the area studied.The sequence is terminated by the Quaternary alluviums in the studied area.