Türkiye Jeoloji Bülteni

Abstract: Miocene units at the north Beypazarı (Ankara) are represented by conglomerate, agglomerate, sandstone,siltstone, clay stone, coal, bituminous shale, limestone and tuffs. Exposures of bituminous horizons just above coal areobsewed in extensive areas in the region. Total organic carbon content obtained from different outcrops of thisbituminous horizon varies from % 0.37 to % 7.07 organic matter, mainly dominated by algal origin, is of type 1 and 2kerogen. Vitrinite reflection measurements vary between % 0.27 - % 0.56 and Tmax values obtained from Rock -Eval pyrolysis are in the range of 407 - 437°C. These data point out that organic matter is immature. Biomarkercharacteristics also verify this results. The Ts/Tm ratio is 1.5 and show immaturity of organic matter. According tothe Pr/n-Cjy and Ph/n-Cjs, Miocene units were generated in reducing environments and their source is shale. 

Abstract: The Kızıldağ (Sivas) Ophiolites, belonging to the Refahiye Ophiolitic Melange, generaly consist of wherlite oftransition zone, gabbros of mafic cumulate sequence and pyroxene gabbros, hornblende gabbros, microgabrointrutions, meta basalts and spilitic basalts. The ophiolitic complex is cut by Neogene magmatics, represented byaplite veins, granite, quartz monzonite and diorite as well as volcanic products such as andesite and basalt.Ni enrichment, up to 4630 ppm took place within the ophiolite bodies. Ore microscopy studies have revealed thatthe source of Ni is linneit, bravogite, gersdorfite, millerite, heazlewoodite and pentlandit e minerals. This studyreveals that Ni, occurring at levels of 0.2 to 0.3 % in primary ultramafic rocks, shows enrichments up to 0.46 %. It isbelived here that with more detailed studies, economical nickel deposits may be found. The ultramafic rocks in the investigation area show variable contents of Pt group elements comparition withprimitive mantle values. Os and Ru show enrichment, Ir, Rh and Pt show depletion, Pd shows both effects but withfew changes. Au, which is treated geochemicaly with Pt group elements, shows enrichment relatieve to primitivemantle values with few amounts. Comparision of Kizildag Ophiolites with N-Type MORE, the normalized values ofREE`s show generaly depletion except U and Ta. The Cl Chondrite normalized values of REE`s show differentpattern; Th, U, Ta, La and Ce show enrichment up to 10 times but Sr, Nd, Zr, Sm, Tb, Y, Yb, Rb and Ba showdepletion with different amounts.

Abstract: The Karamadazı pluton (Yahyalı-Kayseri) constitutes one of the scarcely exposed granitic outcrops in the middleparts of Tor ides in Turkey. It intrudes the Permo-Tr lassie marble belonging to Bolkardağ unit by forming somemagnetite-type skarn occurrences of which some are economically operated. Although there is no any geological andstratigraphical age evidences about the age of the Karamadazı pluton, just covered by Quaternary debris and alluvium, a Late Cretaceous to Early Tertiary emplacement age can be proposed on the basis of regional geologicalcorrelation. The Karamadan pluton is formed by two different types of rocks of quartz dioritic/tonalitic andI e uco granitic in composition which led it to be called a typical bimodal pluton. The mineralogical assemblages of thequartz diontes/tonalites and leucogranites consist of plagioclase(albite + oligoclase) + calcic clinoamphibole +quartz ± biotite ±_ chlorite ± epidote ± apatite ± sphene, and quartz + K-feldspar + plagioclase ± biotite ( ± calcicclinoamphibole instead of biotite in some samples) ± chlorite ± apatite ± sphene, respectively. Mineralogical andgeochemical data, always represent the coexistency of two different magmatic associations composed of quartzdiorites/tonalites and leucogranites which are considered to be derived from different mafic and felsic magmasources, respectively. On the other hand, major and trace element geochemistry data also reveal that both of thequartz diorites/tonalites and leucogranites seem to be the highly differentiated derivatives of their discrete magmasources. The extremely depletion in K, and a considerable enrichment in Na is an important characteristic for thequartz diorite/tonalite type of rocks of bimodal Karamadazi pluton. As to the geodynamics, the calc-alkaline maficand felsic magma sources of the bimodal Karamadazi pluton can be proposed to have been derived from mantle andcrust, respectively, in a post-collisional situation. Some advanced geochemical studies such as REE,geothermobarometry based on mineral chemistry, absolute age dating and isotope geochemistry would beappreciated for better understanding of some processes involving assimilation, assimilation-fractional crystallization,replenishment-fractional crystallization and metasomatism during the evolution/solidification of magma source(s) inthe petrogenesis of bimodal Karamadazi pluton.

Abstract: Sedimentary analysis of a well-preserved Miocene area at altitutes as high as 1900 m in the eastern Taurides (NEAladağ mountains) was carried out in this study. A try correlation with the Adana basin that currently situated 40 kmin the south was also aimed.In the light of gravel composition, sedimentary textures and structures, and paleocurrent data, the sedimentsstudied were interpreted to have been deposited in the Dikme basin with a characteristic infill architecture. Althoughit has a prominent unique graben shape of 15 km long with a northeast trend, several intrabasinal fault-controlled relief occured as well The basin was filled from its NW and E margins by debris flow and sheet flow dominatedalluvial fan complexes that gradually pass mud-bearing central gravelly alluvial river system.Within this fluvialsystem, a local coarse pyroclastic level in the north (around Karaköy) and a Langian aged thin marine interval in thevery south (around Taştekne) occurs:The palaeogeographic evaluations rooted from sedimentary environmental interpretations suggest thatsedimentary patterns of the Adana and Dikme basins complete each other forming a larger Adana basin thence, andthis larger basin extends northwards towards the eastern Central Anatolian Volcanic realm.

Abstract: Crustal extension directions trending NNE-SSW and NW-SE to NNW-SSE are documented at the southeasternboundary of the Galatean Volcanic Province (GVP), located at the NW central Anatolia, and at the north of theAegean Region, in Turkey. Extension affects a continental volcano-sedimentary sequence deposited between theEarly Miocene to Pliocene (?) time. Field observations suggest syntectonic volcanism and sedimentation, andextension may begin in the Early-Middle Miocene time. Similar Miocene crustal extension directions are known fromthe Aegean Region. Both zones have also comparable Miocene magmatic evolutions, characterized by production ofLower-Middle Miocene calc-alkalic and Upper Miocene alkalic magmas.The GVP is presently bounded at the north by the North Anatolian fault (NAF), the most important active fracturezone of the Anatolian block. The stress fields associated with the GVP extensions and the NAF movements clearlyare different. This implies that the GVP extensional regime must have ended prior to the NAF initiation at the EarlyPliocene.Based on the structural and magmatic similarities, we propose that the Aegean and GVP zones were parts of thesame block, during possibly much of the Miocene, until the Early Pliocene NAF inception. 

Abstract: In this paper, one new genus {Anatolia) and subgenus (Trabzonella) of Candonidae family are suggested andrepresented from the Araklı section (Trabzon). Both genus and subgenus and their species {Anatolia pontica,Trabzonella turcica) have been found in the thin unconsolidated sandstone horizon which has yellow and abunduntshelly fragments with rich and abundance ostracoda as^Bations. They are Pontian aged and characteristics ofoligohaline environment.

Abstract: Total 125 surface sediment samples were taken from NE Aegean Sea (82 samples), Çanakkale (Dardanelles)Strait (23 samples), Junction of the Marmara Sea with the Dardanelles Strait (DSMJ) (20 samples). Grain size andheavy metals (Fe, Mn, Zn, Ni, Pb, Cu, Co, Cr) the samples were determined by standard methods.N E Aegean Sea, Çanakkale (Dardanelles) Strait, DSMJ surface samples mean mud percentage were found 34.3%,74.1%, 79.9% by mass. The highest mean metal value was calculated in the DSMJ sediment. In the Çanakkale(Dardanelles) Strait sediments some heavy metals concentrations reach same data with DSMJ. Outside Pb all heavymetals show positive correlation with mud in the DSMJ. Heavy metals-mud correlation show positive correlation inthe Dardanelles Strait. But, other parameters for example antropogenic and land-particulate effect to deposition of heavv metal in the DS sediment. In the NE Aegean Sea sediment Ni, Cr, Zn, show high correlation cofficient with mudaccording to Pb, Mn, Fe, Co, Cu. General distribution of Pb, Mn, Co, and Fe decent on different parameters besidesmud size. Cu, Cr, Zn, Ni have high correlation with mud in the studying areas.

Abstract: The principal component analysis, one of the methods in factor analyses was used to evaluate thegeochemical composition of Karamadazi and Çelebi granitoids. Based on this method, the factorscontrolling the geochemical characteristics of the Karamadazi Granite are TiO2+MnO+Zr/SiO2 andCaO+Na2O+Sr/Rb+Ba+K2O ratios, and for the Çelebi Granitoids the (Fe0(T)+Ca0+Mg0+Y)/(K20+Rb)and (Na2O+Ba+Al2Oj)/(SiO2) ratios. These two granitoids are clearly distinguished from the sterile/nonproductive Central Anatolian Granitoids (CAG) on Harker diagrams based on these controlling factors,(parameters). CAG plutons such as Yozgat batholith, Terlemez quartzmonzonite, Kerkenez granite,Ekecikdağ quartzmonzonite ve Ağaçören intrusive suite are different from the productive ÇelebiGranitoids in their higher silica content and generally higher total alkali values. This study suggests thatfertile (iron producing) plutons are less differentiated and have very little contribution from continentalcrust compared to the sterile (non-productive) plutons. Higher apatite and zircon abundances in the ÇelebiGranitoid suggest that the Çelebi Granitoid have more I-type characteristics compared to non-productiveplutons of CAG. The Karamadazi Granite is the most striking example for the granitoids in CAG plutonsabove having the least contribution from the continental crust, evidenced by the lowest mean Rb, Ba, Th,the highest mean Sc, V, and mean Zr, Y, Ni contents. Based on the factor analysis, it is proposed that theKaramadazi Granite display geochemical characteristics similar to the Terlemez and Ağaçören granitoidsof CAG.

Abstarct: Hercynian basement of Eastern Pontide orogenic belt, NE-Turkey, is made up of the metamorphics andcrosscutting granitoids outcropping mainly in the Bayburt and Gümüşhane areas. Mesozoic basins are examplified bytwo rifting phases, sepereted by a calm tectonic period. First rifting phase occured in Early Liassic, resulting in thebreak-up of the Hercynian basement. Sedimentary rocks of period show sudden fades- and thickness variations. Firstrifting phase ended in the Early Dogger, is succeeded by carbonate platform formation from the Dogger to LowerCretaceous in Gümüşhane, in Dogger-Malm in Bayburt area. Cesseation of the calm tectonic period is recognised bya syn-sedimentary discontinuity. This event is called as second rifting phase, which starten during the middleCretaceous in the vicinity of Gümüşhane, and late Malm in Bayburt. Similar facies sedimentary prisms are developedin both areas, notwithstanding in different periods.

Abstract: This study has been carried out in 20 km. east of Kahta-Adıyaman in the southern Anatolia region. The log dataof some wells in Tokaris field are investigated in order to achive the petrophysical properties under the software ofElan Plus (Schlumberger) using the Elan Plus software the well log data were interpreted to find reservoir levels. Asa result, the effective porosity, total porosity, shale volume, formation water saturation, movable and residual oilvolumes are found in the selected zone. Reservoir rock in the field is Karaboğaz formation and Mardin group carbonates. Production in theinvestigated field were done from Mardin group craked dolomites and limestones. The most important parameter thateffect reservuar quality and production is the permeability, Karaboğaz formation in Tokaris field shows 5-6 %porosity limestones. The field is usually not productive. Karababa-C which is the first 10-13 meters from the groundhas avarege porosity of 5.2-8.4 % limestones. It has a permeability of 0.01 md. which is very low. In the wells, theproduction can only be done by acidizing in these zones. Lower level of Karababa-C is made of dense limestones.Karababa-B is dense limestones and Karababa-A is shaly limestone. D erde re formation is made of limestones whichhas 1.4-5 % porosity from the first 15-28 meters. In some part we can find 10 % porosity. However, production canbe done only by acidizing. High permeability dolomites under limestones has 5.1-9 % porosity values. Because ofmany crack in the N-9 well porosity calculated as 16 %. The main production zone is in the Derde re formationdolomites.