Türkiye Jeoloji Bülteni

Abstract: Koru (Çanakkale) barite bearing lead-zinc deposits are typical examples of the lead-zinc deposits occurred in theTertiary volcanic rocks outcropped in the Biga Peninsula. Volcanic rocks around the investigated deposits aredistinguished as; Eocene Akçaalan andesite, Oligocene Adadağı pyroclastics, Miocene Dededağ dacite and PlioQ ucite rnary Karaöm e der basalt.The investigated deposits hosted by Adadağı pyroclastics and show two different mineralization styles such asstock work ore veinlets in the upper parts and ore veins along the fault zones in WNW-ESE direction, in the lowerparts. Galena, sphalerite and barite are the main minerals and accompanied by minor amounts of py rite, chalcopyrite,fahlerz (tennantite), marcasite, chalcosine, covellite, bornite, tenorite and quartz.TFM, T m ICE and TH values measured during the fluid inclusion studies indicate the presence of CaCl2 and MgCl2 inthe mineralizing hy d rothermal fluids, salinity of the hydrothermal solutions is rather relatively high during baritecrystalisation in the early episode of mineralization, while decrased during the sulfide dominated later episode. Thetemperatures of fluids is low (< 80 °C) during the early stage and increased up to 270 °C during the later stage.Sulfide minerals seem to be formed in a temperature range of 120-160 °C.Major element results show that the volcanic rocks in the study area have high potassic calcalcaline composition inthe early stage, while they have medium potassic calcalcaline compositon similar to within plate basalts in the laterstage (Karaöm erler basalt).Trace elements contents of the various rock units show that the lead and zinc in the ore deposits may be drivedfrom Akçaalan andesite, while copper from Dededağ dacite. REE studies show that normalised REE values ofbaritesresemble to sea water. The dispersion of the galena, sphalerite and barite values among those of volcanic rocks andseawater on the CeN/YbN ~ YbN diagram was assumed to be ore forming elements were derived from the surroundingvolcanic rocks by deep circulated sea. water

Abstract: This study includes examination and evaluation of Karababa C Formation`s reservoir caharacteristics, porosity andhydrocarbon saturation values which is one of the reservoir rocks of Adıyaman region by using geostatisticalsimulation methods. The data which were obtained from the 11 drillholes drilled in the study area were evaluated bydetermining the parameters geostatistically. By using geostatistical simulation softwares three dimensional evaluationof the study area was done and variogram functions were calculated. Variogram s which were obtained from porosityand hydrocarbon saturation values were modelled spherically, model parameters with C0=0.0003,C=0.0020, a=400for porosity values and CO=O.OJ, C=0.04, a=450 for hydrocarbon values were determined. The suitability of modelparameters were validated with back-kriging technique.The study area was seperated in blocks for x direction 300x10 m, for y direction 120 xlO m and for z direction15x10 m and evaluated conditional simulation was done by using "annealing simulation method". 40 different results which were obtained from simulation the simulation result giving the best senario which means to he compatible ofexistance production area and covers the most wide area is examinated. Some statistical parameters such as mean,varince, histogram and variogram were calculated and evaluated of 540000 simulated data values which wereobtained for porosity and hydrocarbon saturation. Simulation results were evaluated on cross-sections which isdetermined x,y,z directions and the best areas where petroleum production could be done were detennined.

Abstract: The Fe-oxide-Cu-Au deposits are characterized by large masses of Ti-poor Fe oxides related to petvasivealteration processes such as magnetite or hematite. Besides, they are characterized by pervasive sodic and potassicalteration, and higher abundances of REE compared to porphyry and skam types. This study deals with thecomparison of the Fe-oxide-Cu-Au deposits with those of Fe-oxide mineralizations in Divriği region. In doing so,well-known alkaline metasomatism, mineralogy, late stage sulfide mineralization, tectonic setting of plutonic rocksand structural control characteristics unique to Fe-oxide-Cu-Au deposits were used.The authors of this paper initiated the studies in recognition of Fe-oxide-Cu-Au deposit type in Turkey. This studyshows that A -B-kafa mineralizations at Divriği (Sivas) occur in metasomatic plutonic rocks that were experienced anextensive and pervasive alkaline metasomatism. The early stage of metasomatism is related to sodic-calcic alteration.This stage is followed by a late and/or shallower potassic alteration. Products of potassic alteration superimpose theproducts of sodic-calcic alteration. Therefore, the alteration products and style of mineralization suggest-that thedeposits long known as pyrometasomatic, felst calc-skarn and skam might be of Fe-oxide-Cu-Au type. The A-kafamineralizations occur as massive magnetite mineralizations hosted by a K-feldspar and phlogopite-rich zonesuperimposing scapolite-garnet zone. B-kafa mineralizations consist of martitized magnetite, limonitizcıtion,silicification, and sulfide mineralizations, and are regarded as late-stage alteration products. These are observed in astructurally controlled and funnel shaped settings that might be regarded as breccia pipes or diatremes. The granitoidsclose to brecciated zone is characterized by extensive serialization. Colloform barite formations develop particularlyalong contacts between brecciated limestone and sericitized rocks.Although, the examples of the similar deposit types have not been recognized yet in Turkey, pervasive alkalinemetasomatism and relationships between mineralizing events and alkaline metasomatism, the oxide and sulfidemineralogy, morphology and distribution of the iron oxide deposits in and around the Divriği (Sivas) suggest that itshows characteristics similar to Fe-oxide-Cu-Au deposits. Therefore, they could be re-defined as Fe-oxide-Cu-Autype mineralizations on the basis of alteration pattern and mineralization styles. It is also proposed that these depositshave gold and copper potential, and the exploration programs should be re-designed so as to investigate this potential. 

Abstract: The Sultandağı-Çay (Afyon) and surrounding regions were affected by two destructive earthquakes occured onFebruary 3, 2002 at 9.11 and 11.26 respectively. These events caused 45 deaths and damaged hundreds of buildings.These earthquakes are called as Çay earthquakes with respect to surface ruptures, epicenters and damagedistributions. USGS data indicate that first destructive main shock which was located near Çay town. 080° trendingobserved surface rupture of this first event represents at least 2 km length and have a vertical displacement of 35 cm.The epicenter of latter, which was happened two hours later, locates around Kadıköy village. Focal mechanismsolution and field evidences indicate that presence of a 020° normal faulting with a vertical displacement of 10 cm.We assume that the first event (Mw=6.2) probably have a role of triggering on the 020° trending fault movementbecause of the forming of two ruptures normal to the each other.