Microthermometric and stable isotopic (O and H) characteristics of fluid inclusions in the porphyry related Çöpler (İliç - Erzincan) gold deposit, central eastern Turkey

Abstract

Abstract:The Çöpler gold deposit occurs within the stockwork of quartz hosted by the Çöpler granitoid (Eosen) and by surrounding metasediments of Keban metamorphic (Late Paleozoic -Early Mesozoic) and the Munzur limestones (Late Carboniferous -Early Cretaceous). Native gold accompanied by small amounts of chalcopyrite, pyrite, magnetite, maghemite, hematite, fahlerz, marcasite, bornite, galena, sphalerite, specular hematite, goethite, lepidochrosite and bravoitic pyrite within the stockwork ore veinlets. In addition, epidote (pistazite -zoisite), garnet, scapolite, chlorite, tremolite/actinolite, muscovite and opaque minerals were determined within the veinlets occurred in skarn zones. The study of fluid inclusions in quartz veinlets showed that the hydrothermal fluids contain CaCl 2 , MgCl 2 and NaCl and the salinities of the two phases (L+V) inclusions range from 1.7 to 20.6% NaCl equivalent. Salinity values up to 44% were determined within the halite bearing three phases inclusions. Their homogenization temperature values have a wide range from 145.0 to 380.0 • C, indicative of catathermal/hypothermal to epithermal conditions. The δ 18 O and δD values of the fluid inclusion waters from the Çöpler granitoid correspond to those assigned to Primary Magmatic Water, those from the metasediments of Keban metamorphics fall outside of the Primary Magmatic and are within the Metamorphic Water field. A sample from a quartz vein within the skarn zone hosted by the Munzur limestones has a particularly low δD value. The results suggest that fluids derived from the granitoids were mixed with those derived from the metasediments of Keban metamorphics and the the Munzur limestones and resulting in quartz veinlets in these lithologies and the formation of stockwork ores. In view of the occurrence, the features described and processes envisaged for this study area may be applicable in similar settings.

Hydrogen and 40Ar/39Ar isotope evidence for multiple and protracted paleofluid flow events within the long‐lived North Anatolian Keirogen (Turkey)

“…There is a clear compositional demarcation between fluids from which the end-member illite/mica populations precipitated ( Figure 6). Fluids associated with authigenic mineralization occupy the range of modernday precipitation values [Schemmel et al, 2013], whereas the fluid associated with detrital minerals is in the range of values that are reported from various metamorphic terranes adjacent to the fault zone [Bozkaya et al, 2007;Canbaz and G€ okce, 2014;Satir and Taubald, 2001].…”

“…Meteoric Fluid Regime Figure 6. Comparison of dD fluid values of this study (blue) with fluids of metamorphic origin adjacent the fault (red) and modern-day precipitation (green) [Satir and Taubald, 2001;Bozkaya et al, 2007;Schemmel et al, 2013;Canbaz and G€ okce, 2014]. Measured mineral dD values from referenced sources were converted to fluid values based on temperatures, and were converted to VSMOW for comparison.…”

Fluid and ore sources of the tungsten mineralisation in the Yangbishan iron–tungsten deposit, Heilongjiang Province, North‐eastern China: Constraints from fluid inclusions, sulphide S–Pb isotopes and scheelite C–H–O–Sm–Nd isotopes

“…H and O isotope composition is often used to trace the ore‐forming fluid source of hydrothermal deposits (Canbaz & Gökce, ; Hoefs, ; Pirajno, ). The δ 18 O quartz values are relatively constant in inclusions of quartz from the Yangbishan quartz–sulphide period, indicating the inclusions were formed in an equilibrated fluid system (Ma et al, ).…”

“…Tungsten migrated in the fluid, possibly in the form of tungstic acids, through reaction with wall rocks; decreases in temperature and increases in alkalinity induced the tungsten precipitation. 6.1.2 | Ore-forming fluid source: Evidence from hydrogen and oxygen isotopes H and O isotope composition is often used to trace the ore-forming fluid source of hydrothermal deposits(Canbaz & Gökce, 2014;Hoefs, 1997;Pirajno, 2009). The δ 18 O quartz values are relatively constant in inclusions of quartz from the Yangbishan quartz-sulphide period, indicating the inclusions were formed in an equilibrated fluid system.…”