Structural controls of Özyurt shear-hosted gold deposit, Niğde, central Türkiye

Onat, Kaan
Shear-hosted Özyurt Gold Deposit is located in the Niğde Massif, a metamorphic core complex at the southern tip of Kırşehir Block, in Central Türkiye. The massif is composed of alternations of gneiss, schist, quartzite, marble, and amphibolites. It is tectonically overlain by Neotethyan ophiolites and intruded by Üçkapılı Granite. Gold mineralization is hosted along the foliation surfaces, by oxidized cataclastic breccias formed in schists along a high-angle fault network, as well as the gossans at the contacts of schist and overlying marbles. The pre-existing fault network was cut by syn-tectonic dikes that are coeval with the exhumation. The deposit undergone a supergene stage causing the breakdown of all sulfide minerals and liberating the gold in oxide zones. Two mineralization stage was observed in the polished thin sections. The primary mineralization is composed of disseminated marcasite-pyrrhotitechalcopyrite±pyrite within the foliation surfaces. The secondary mineralization consists of pyrite±carbonate veins and veinlets followed by cross-cutting arsenopyrite-pyrite-chalcopyrite±tetrahedrite in carbonate±chlorite±sericite veins. The low-grade primary mineralization is the hypogene ore while high-grade secondary mineralization is formed due to supergene enrichment. Since schists were less competent than quartzites and marbles between ∼5-13 km depths, they deformedvi intensely during the exhumation of the massif. This deformation along foliation planes of schists provided fluid pathways for hydrothermal fluids. The spatial association of syn-tectonic dikes and gold mineralization within the foliation planes suggests that the intrusion might have played a role in mineralization. The possible age of the hydrothermal activity is interpreted as ∼75 Ma considering the youngest dike age in the massif. The mineralization occurred at ∼11 km depth and the peak temperature was ∼350℃, under brittle-ductile to brittle conditions.


Structural and kinematic analysis of a transpressional basin: Çiçekdağ Basin
Tokay, Bülent (2015-04-12)
The Central Anatolian Crystalline Complex (CACC), which lies within Turkish Alpine orogenic belt, incorporates several basins located either within the complex or at and along its boundaries. Many of the basins developed during extension since Late Cretaceous and then evolved with advancing collision of Anatolide-Tauride with Pontides. With regard to deformation and evolution of the region, recent paleomagnetic study from the central Anatolian intrusives defines three blocks with characteristic rotation, po...
Yurdakul, Emrecan; İmer, Ali; Department of Geological Engineering (2022-6-29)
The Öksüt high-sulfidation epithermal gold-copper deposit is hosted within the late Miocene Develidağ Volcanic Complex (DVC) in south-central Anatolia. Mineralization mainly occurs in two domains, the Keltepe and Güneytepe orebodies, where steeply-dipping and pervasively supergene oxidized breccia zones exploited funnel-shaped diatreme conduits within andesite porphyry. Emplacement of these breccias was largely controlled by sub-vertical faults with dominant normal-slip components. Mineralized breccias comp...
Back arc Setting for the Middle Eocene Çöpler porphyry epithermal gold deposit Turkey
İmer, Ali; Creaser, Robert (null; 2012-11-07)
The Çöpler epithermal Au deposit and related subeconomic porphyry Cu-Au deposit is located in central eastern Turkey, about 120 km west of the city of Erzincan. Porphyry-epithermal Au-Cu mineralization is hosted by the middle Eocene Çöpler-Kabataş magmatic complex which has been emplaced into a succession of Permian–Cretaceous metasedimentary and carbonate rocks within an ENE-trending structural window exposed in the northeastern margin of the Tauride-Anatolide Block. 40Ar/39Ar dating of three samples of ig...
Orta Anadolu Geç Pliyosen İklimi: Pınarbaşı Tufalarından (D Kayseri) Sedimantolojik, Mikroskopik ve İzotopik Bulgular
Ocakoğlu, Faruk; Yılmaz, İsmail Ömer (2015-11-08)
100 km-long, NE-running Pınarbaşı basin (Central Anatolia, E Kayseri) comprises sporadic, km-scale tufa deposits at its uppermost stratigraphic levels in vicinity of basin margin. Tufa deposits are covered by well-dated, extensive Valibaba tepe ignimbrite (2.52 Ma) following several metres thick fluvial sediments. Sedimentological, stable isotopic, microscopic and magnetic susceptibility (MS) data from tufa outcrops in vicinity of Samağır village at the north of basin provide important con...
Kızıltepe low-sulphidation epithermal deposit (Sındırgı, Balıkesir): an example for relay-ramp-hosted epithermal gold mineralization in western Turkey
Uğurlu, Berkin; Bozkurt, Erdin; Department of Geological Engineering (2019)
Kızıltepe, located 50 km southeast of Balıkesir in western Turkey, has a long history of precious metal mining back to 2000 years and hosts numerous low sulfidation epithermal quartz veins. In the modern times, subsequent to 25 years of mineral exploration activities, first gold silver mining operation has started on the vein sector called Arzu South in 2017, and 3 other sectors; Arzu North, Derya and Banu on the line. Kızıltepe low sulfidation epithermal gold mineralization is hosted by early Miocene dacit...
Citation Formats
K. Onat, “Structural controls of Özyurt shear-hosted gold deposit, Niğde, central Türkiye,” M.S. - Master of Science, Middle East Technical University, 2022.