Türkiye Jeoloji Bülteni

Abstract: The Sarıyer-Şile thrust, which has been known for many years in the geological literature, caused the northward emplacement of the Istanbul Palaeozoic sequence and the unconformably overlying Permo-Triassic rocks onto Upper Cretaceous volcanic and volcanogenic rocks. During investigations of drill cores and surficial geological observations, carried out with in the scope of route research for a highway tunnel being built between Kilyos and Sarıyer, a cataclastic zone that developed along this thrust was identified. While the thickness of this zone is limited at the base of the overlying Palaeozoic sequence, it probably reaches 200 metres in the underlying volcanic-volcanogenic rocks to the south, and gradually thins and disappears towards the north. This compression altectonic regime, which probably developed during the middle Eocene period, caused different deformations inrheologically different hanging and foot wall blocks along this low angle thrust. Carboniferous gray wackes in the hanging block are shortened and thickened by generally fan-shaped thrusts, and less commonly by duplex thrusts, while the volcanic-volcanogenic sequence in the footwall block was affected by intense cataclasis.

Abstract: The MIS 9, one of the Marine Isotope Stages (MIS) that corresponds to an interglacial period, is considered as an analogue for the present warm period. However, data from terrestrial carbonate sediments for this periodare limited. In this study, records of terrestrial carbonates such as travertine and tufa, which crop out in different locations in Anatolia, were investigated of the MIS 9 interglacial period. For this purpose, the MIS 9 data of terrestrial  carbonates at two locations in SW-Anatolia, (Örtülü/Sarıkavak, Afyon) and (Karahallı, Uşak) were evaluated, and one location from NE-Anatolia (Bahçecik, Gümüşhane). In light of the sedimentological, isotopic and palynological data, the environmental and palaeoclimatic conditions of the MIS 9 interglacial period were revealed. The Örtülü travertines and Sarıkavak tufa, which continued to be precipitated during the MIS 9 period, were accumulated in a depression depositional system and a fluvial system dominated by medium-highly inclined topography, respectively. Karahallı travertines were deposited in a shallow lake margin environment where tectonism was active. Bahçecik travertines were deposited within depression and slope depositional systems. In the MIS 9 period, δ13C stable isotopes values of the Karahallı and Örtülü/Sarıkavak terrestrial carbonates were close to positive (-0.47 to 1.86‰), while δ18O stable isotope values were negative (-9.67 to -8.72‰). However, a significant difference is observed in the stable isotope values of the MIS 9 period in NE-Anatolia. While δ13C isotope values are more positive (4.5 to5.0 ‰), δ18O values are much more negative (–14.67 to –14.6‰). This difference in these carbon and oxygen isotope values is directly related to wetter/drier conditions. According to palynological records, a significant difference was recorded between MIS 9e and MIS 9a, with a changing humidity, relatively. In the light of all data obtained, it can be said that the MIS 9 in Anatolia was generally a milder period, although it showed climatic fluctuations with decreased rainfall within arid conditions.

Abstract: The Mineral Water Producers Association (MASUDER) stated that our country has important resources in terms of mineral water, but consumption rates are quite low. This can be attributed to the fact that the effects ofmineral water are not sufficiently known. So far, studies have shown that mineral waters have positive effects on cardiovascular health, bone structure, digestive system, and metabolism. Increased awareness of health effects willpositively affect consumption. With the increase in consumption, the economic value of mineral water resources will also increase. In this study, the hydrogeochemical and isotopic properties of Ciritdüzü mineral water (CDMS) and some cold-water springs in Şavşat town in Artvin were examined and evaluated in terms of health. The springs have Na-Ca-HCO3, Ca-Mg-Na-HCO3 and Ca-HCO3 water types with temperatures ranging between 8-13 °C, pH values between 6.42-7.97 and EC values between 181-3195 µS/cm. The isotope contents of the waters (O-18, deuteriumand tritium) show that CDMS has deep circulation, and the other springs have shallow circulation. The δ34S values of the waters indicate that the source of sulfate in CDMS is a mixture of marine evaporites, terrestrial evaporitesand atmospheric sulfate; δ13C values indicate that the origin of carbon corresponds to metamorphic CO2. The trace element contents in the waters are generally consistent with the limit values given in the Regulation on Natural Mineral Waters. Antimony and arsenic concentrations are within the limit values and boron concentration is above the limit value for CDMS. When the waters are evaluated medically and climatologically, CDMS has bicarbonate content above the effective dose for drinking cures. When evaluated in terms of sodium, calcium and magnesiumion contents, CDMS can be used for diseases related to the digestive system, prevention of cardiovascular diseases,kidney and urinary tract diseases. The location of the CDMS spring, which has preventive and the rapeutic propertiesfor these disease groups, also offers the opportunity for climatotherapy. 

Abstract: This study aims to investigate the geochemistry and sulfur isotope ratios, as well as the origin of Pb-Zn-Cu mineralization, between Karadoru (Biga, Çanakkale) and Karaköy (Yenice, Çanakkale) in the Biga Peninsula (NWTurkey). Mineralization was observed at four locations: Karadoru, Peynirderesi, Madençeşme (Biga, Çanakkale) and Karaköy (Yenice, Çanakkale). The lowest tectonostratigraphic unit in the region is the Karakaya Complex. The Nilüfer unit, which is part of the Karakaya Complex and mainly consists of metabasic rocks, is overlain by the Hodul unit. The Hodul unit comprises limestones, spilitic basalt, diabase, and arkosic sandstones. The Karadoru, Sarıçayır, and Soğucak granitoids, which are Oligocene-Miocene in age, cut through units of the Karakaya Complex. Skarn zones developed in locations where many plutonic masses intersect with the units of the Karakaya Complex (Nilüferand Hodul). The Çan volcanics, which date back to the Miocene era, are found on top of the Karadoru, Sarıçayır, and Soğucak granitoid rocks. The Pb-Zn-Cu mineralizations were deposited as veins in the Nilüfer unit (epimetamorphics) in the Karadoru and Madençeşme locations within the Karakaya Complex, and in the Hodul unit (metadiabase and crystallized limestone) in the Peynirderesi and Karaköy (Arapuçandere) locations. The paragenesis includes galena, chalcopyrite, sphalerite, pyrite, limonite, hematite, malachite, manganese, quartz, calcite, and chlorite. The δ34S values of galena and pyrite samples taken from the ore zones in the study area are as follows: Karadoru -3.4‰ and-3.9‰, Karaköy -1.7‰ and -1.6‰, and Peynirderesi -1.7‰ and -4.0‰. The examined Pb-Zn-Cu mineralizations had Sb/Bi ratio in galena ranging from 0.06-0.34 ppm, and Co/Ni ratio in pyrites ranging from 1-10 ppm. The sulfur isotope ratios are negative, indicating that the mineralization has magmatic hydrothermal origin and is due toI-type magmatic activity. The mineralization contains vein-shaped epigenetic deposits of Pb-Zn-Cu mineralization, high trace element contents (Pb, Zn, Cu, Bi, Sb, Ag, Au, W, As), and silicification, sericitization, argillization, and limonitization are observed. These characteristics support the view that the mineralization has hydrothermal origin. 

Abstract: The study area consists of Palaeozoic-aged Kırşehir Block Metasedimentaries, which are represented by Kalkanlıdağ Metamorphite and the Bozçaldağ Formation. The Upper Cretaceous-aged Artova Ophiolitic Melange overlies these basement units tectonically. The Yozgat Batholith cuts these metasedimentaries and the Artova Ophiolitic Melange with a hot contact. However, in the study area, the Artova Ophiolitic Mix is observed tectonicallyon the units belonging to the Yozgat Batholith. The members of Yozgat Batholith in the study area are Karga Quartz Monzonite Porphyry, Karaveli Quartz Monzonite, Kodallı K-feldspar Megacrystalline Quartz Monzonite and Alci Monzogranite. Upper Cretaceous - Palaeocene aged Kötüdağ Volcanite overlies these units. The sedimentary coverrocks in the study area are the Lower – Middle Eocene-aged Baraklı Formation; Upper Miocene – Pliocene-agedKızılırmak Formation and Quaternary-aged Alluvium. Plutonic units belonging to Yozgat Batholith are subalkaline (calcalkaline), generally I-type, metallumino granitoids formed from a hybrid magma which is the product of homogeneous (magma mixing) and sometimes heterogeneous (magma migration) mingling of coeval mafic and felsic magmas. Although these plutonic units were formed in close time intervals, when analyzing the field relations, the formation pattern in the alteration diagramsand the age analysis data (40Ar - 39Ar) geochronological age range 81.48 ± 0.82 Ma – 89.35 ± 0.92 Ma obtained fromhornblende and biotite minerals, it is seen that they were formed in the order of Karga Quartz Monzonite Porphyry, Karaveli Quartz Monzonite, Kodallı K-feldspar Megacrystalline Quartz Monzonite, and Alcı Monzogranite.The plutonic units are within plate granitoids (WPG); which were settled in the region during collisional andpost-collisional uplift (Coniacian – Campanian).