12 research outputs found
Geology, Alteration and Geochemical Characteristics of Inlice (Konya-Turkey) High Sulphidation Epithermal Gold Deposit
Inlice high sulphidation epithermal gold deposit is located in the Erenlerdag-Alacadag Volcanic Complex (EAVC), approximately 40 km southwest of Konya city centre. The volcanic and volcano-sedimentary rocks seen in the study area are andesite, block and ash flow, basaltic andesite lava flow and andesite lava flow, from oldest to youngest. The youngest units unconformably covering the volcanic and volcano-sedimentary rocks are talus and alluvium. Four different alteration zones in the andesites moving from the centre of the alteration toward fresh rock are i) silicified zones (consisting of vuggy-sugary and chalcedonic/opaline quartz veins), ii) advanced argillic alteration, iii) intermediate argillic and iv) propylitic alteration. In addition, a potassic alteration zone consisting of magnetite, quartz, biotite and anhydrite was identified in the deep part of the Merkez Zone. The mineralisation is commonly represented by pyrite, and to a lesser extent enargite, chalcopyrite, covellite, chalcocite, sphalerite and marcasite. Petrographically, the fine-grained gold grains (between 2-6 mu m) are only observed in areas where sulphide minerals are oxidised.
The degree of geochemical variation in the alteration zones decreases from silicified zones to propylitic alteration, and this variation is largely consistent with the mineralogies observed in these zones. Moreover, enrichment in As, Sb, Bi, Ag and Au, and depletion in Zn and Ni are especially notable from fresh/least altered andesites towards advanced argillic alteration and silicified zones. In addition, studies showed that the high Pb value in chalcedonic/opaline textured quartz veins and low Rb/Sr value in advanced argillic alteration and silicified zones can be used as a geochemical guide, at least for the Inlice region.İnlice yüksek sülfidasyon epitermal altın yatağı, Erenlerdağ-Alacadağ Volkanik Kompleksi (EAVK) içerisinde
ve Konya ilinin yaklaşık 40 km güneybatısında yer almaktadır. Çalışma alanında stratigrafik konumlarına göre alttan
üste doğru andezit, blok ve kül akıntısı, bazaltik andezit lav akıntısı ve andezit lav akıntısı olmak üzere dört birime
ayrılan volkanik ve volkano-sedimanter kayaçlar, yamaç molozu ve alüvyonlar tarafından uyumsuz olarak örtülürler.
Andezitler içerisinde gözlenen alterasyonların merkezinden dışa doğru sırasıyla kovuklu-şeker ve kalsedonik/
opalin dokulu kuvars damarlarından oluşan silisleşmeler, ileri arjilik, ortaç arjilik ve piropilitik alterasyon zonları
tanımlanmıştır. Bu alterasyon topluluklarına ek olarak sadece Merkez Zonun derin kesimlerinde gözlenen manyetit,
kuvars, biyotit ve anhidrit içerikli potasik bir alterasyon zonu da tanımlanmıştır. Cevherleşmeler, yaygın olarak
pirit daha az oranda enarjit, kalkopirit, kalkosin, kovellin, sfalerit ve markazit gibi sülfid mineralleri ile temsil
edilmektedir. Petrografik olarak altın taneleri özellikle sülfid minerallerinin oksidasyona maruz kaldığı kesimlerde
saçınımlı olarak 2 ile 6 µm arası boyutlarda gözlenmektedir.
Alterasyon zonlarındaki jeokimyasal değişimin derecesi silisleşmelerden piropilitik alterasyona doğru
azalmakta olup, bu değişim, alterasyon zonlarında gözlenen mineralojik değişimle uyumludur. Bununla birlikte
taze andezitlerden ileri arjilik alterasyon ve silisleşmelere doğru özellikle As, Sb, Bi, Ag ve Au gibi elementler
zenginleşme gösterirken, Zn ve Ni’deki fakirleşmeler belirginleşmektedir. Ayrıca yapılan çalışmalar kalsedonik/
opalin dokulu kuvars damarlarındaki Pb ile ileri arjilik alterasyon ve silisleşmelerdeki düşük Rb/Sr değerlerinin en
azından İnlice bölgesi için jeokimyasal bir kılavuz olarak kullanılabileceğini göstermektedir
Geology, geochemistry and isotope characteristics of Balya (Balikesir) Pb-Zn deposit
Balya Pb-Zn Yatağı Biga Yarımadası'nın güneydoğusunda ve Balıkesir ilinin 50 km KB'sında yer almaktadır. Çalışma alanının temelini Permiyen yaşlı Çamoba formasyonuna ait kireçtaşları ve Triyas yaşlı çok düşük dereceli bölgesel metamorfizma izleri taşıyan çamurtaşı ve fillat (Nilüfer birimi), silttaşı ve kumtaşı (Hodul birimi) ve çakıltaşı ve konglomera (Orhanlar grovakı) ile temsil edilen Karakaya formasyonuna ait kayaç birimleri oluşturmaktadır. Permiyen yaşlı kireçtaşı blokları Karakaya formasyonu içerisinde allokton olarak gözlenmektedir. Temel kayaçlar Oligo-Miyosen yaşlı Doyuran volkanitlerine ait dasidik lav, tüf ve piroklastik kayaçlar ile Üst Miyosen yaşlı Hallaçlar volkanitlerine ait andezitik dayk, lav ve aglomeralar tarafından uyumsuz olarak kesilir ve üzerlenirler. (1) Serizit-kuvars-pirit ve (2) ileri arjilik alterasyonlar cevherleşmeler ile doğrudan ilişkisi gözlenmeyen kil ve serizit bakımından zengin bölgesel alterasyonlar olarak, (1) erken evre (prograd kalk-silikat) alterasyonlar ve (2) geç evre alterasyonlar ise Balya Pb-Zn cevherleşmeleri ile son yıllarda ekonomik hale gelen Cu-Au cevherleşmeleriyle zaman-mekan ilişkisi kurulabilen alterasyonlar olarak tanımlanmıştır. Geç evre alterasyonlar kendi içinde birbirleri ile zaman-mekan ardışık (a) erken retrograd (aktinolit-epidot 1-klorit-kuvars 1), (b) ortaç arijilik ve (c) geç retrograd (epidot 2-kalsit-kuvars 2) alterasyonlar olmak üzere üç alt evreye ayrılmıştır. Balya Yatağı çevresinde yaklaşık 40 km²'lik alandan sistematik olarak alınan toprak numuneleri jeokimyasal analizlerden elde edilen Pb, Zn, Ag, Cu, Au, Sb, Hg ve As elementlerinin birbirleriyle olan korelasyonlarında Pb ile Ag ve Te elementleri, Zn ile S, B, Bi ve Sn elementleri, Ag ile Pb, Te ve W elementleri, Cu ile K, Rb, In, Bi elemetleri, As-Fe arasındaki pozitif korelasyon yatak cevherleşmelerine özgü, bir çok kesitte zamansal ve mekansal birlikteliğe sahip arsenopirit-pirotin-pirit ve hatta manyetit-hematit cevher mineral parajenezinden kaynaklanmalıdır. Galenit, safalerit ve piritlerin δ34S değerleri ‰ 1,5 ile ‰ 3,9 arasında, sıfıra yakın ve dar bir aralıkta dağılım sergilemektedir. Kuvars ve kalsit minerallerinden elde edilen δ18O değerleri ise ‰ 12,7 ile ‰ 16,6 arasında değişim göstermektedir. Cevher-alterasyon-yankayaç ilişkileri, alterasyon zonlarına ait mineral toplulukları, alterasyon zonlarının zamansal-mekânsal dağılımı ve kısıtlı izotop verileri Balya Pb-Zn Yatağı için Pb-Zn skarn tipi bir cevherleşmeden ziyade skarn alterasyonları (kalk-silikat alterasyonları) içeren ortaç sülfidasyonlu bir epitermal sisteme işaret etmektedir
Using an analytic hierarchy process-based index and geographic information system in geochemical exploration of gold
In this study, a gold exploration index (GEI) that reduces financial expenditure and time losses during exploration studies has been developed using the analytical hierarchy process in a region where a high-sulfidation epithermal gold (Au) deposit exists. The GEI can be used to predict the location of the target element by evaluating the maps obtained from related element distributions together with a GEI-based prediction map. The hierarchical structure of the index has been established based on geochemistry of the rock samples. The elements used in the design of the hierarchical structure are arsenic (As), silver (Ag), antimony (Sb), copper (Cu), manganese (Mn), lead (Pb) and zinc (Zn), which are determined by the correlation analysis and experts’ opinions. The efficiency scores of the alternatives are converted into prediction maps called GEI-based anomaly distribution maps. These are compared with the maps derived from both geographic information system-based overlay analysis of the rock samples and spatial gold distribution. The efficiency scores of the alternatives in these maps are categorized into three groups as ‘high’, ‘medium’ and ‘weak’ in terms of gold potential. Comparison of the results with those derived using principal component analysis, weighted sum and weighted product models shows that the produced index yields reliable information that can be used to determine where gold enrichment occurs, especially in high-sulfidation epithermal environments
Geology, geochemistry and isotope characteristics of Darıderesi (Balıkesir,Turkey) Pb-Zn (Au-Ag) mineralization
Metal source and the origin of the Darıderesi Pb-Zn (Ag) veins in the Balya Mining District, NW Türkiye: constraints from ore mineral chemistry, fluid inclusions and S-Pb isotopic signatures
ABSTRACTThe Darıderesi mineralisation was recently discovered in the Balya district, which hosts Pb-Zn (Ag) deposits including Arı Mağara-Balya Main and Hastanetepe-Balya North. Darıderesi is a structurally controlled hydrothermal and associated replacement mineralisation hosted in the shale-mudstone and carbonaceous horizons within the Karakaya Complex. The mineralisation was formed in three main stages as pre-ore calc-silicate alteration, main ore, and supergene alteration. The substages of the sulphide-sulphosalt mineralisation can be summarised as: pyrite-arsenopyrite galena, sphalerite, ferrokesterite, chalcopyrite, fahlore group and geocronite-jordanite solid solution series members, xanthoconite, pyrargyrite and goldfieldite. Fluid inclusion studies indicate that both boiling and fluid mixing were the most effective processes causing the precipitation of sulphides and sulphosalts. Along its pathway, fluid–rock interaction coupled with decreasing temperature evolved the fluid to a lower sulphur and oxygen fugacity and nearly neutral to weakly alkali state which promoted the precipitation of base metal and the following silver-bearing sulphides and sulphosalts. The lead isotope composition of sulphides implies that lead was essentially derived from Oligo-Miocene magmatic rocks in the region with some interaction with basement rocks. The similarity of the lead and sulphur isotopic compositions between Darıderesi and Balya deposits suggests that they may relate to the same magmatic source
Mineralogy, fluid inclusion and stable isotope characteristics of the Inlice (Konya, Turkey) high sulfidation epithermal gold deposit: Implications for hydrothermal evolution and ore genesis
The Inlice high sulfidation epithermal gold deposit with 262,300 oz of gold ore is located in the Erenlerdağ-Alacadağ Volcanic Complex (EAVC) at the northern part of central Taurides. The volcanic succession of the study area is stratigraphically represented by andesite, block and ash flow, basaltic andesite lava flow and andesite lava flow. The deposit consists of seven neighboring mineralized veins termed Ana East, Ana West, West, Discovery, Güllü, Merkez and North Zone and is associated with an andesite (ca 8–9 Ma). Hydrothermal alteration from the innermost to the outermost parts of the deposit includes silicification, advanced argillic, intermediate argillic and propylitic. At the surface, quartz veins related to silicification are exposed as linear topographic relief trending mainly northwest-southeast and secondarily northeast-southwest and east-west. Deep drill core samples, including magnetite, quartz, biotite and anhydrite, imply the presence of potassic alteration in depth (50 to 970 m) possibly related to a porphyry Cu system. Ore assemblages are described as hypogene and supergene. The hypogene ore mainly includes pyrite (Py-I and Py-II) and enargite, and to a lesser extent chalcopyrite, sphalerite and marcasite. The supergene ore incorporates hematite and goethite, and minor covellite, chalcocite, malachite and native copper. Hypogene gold precipitation is associated with the mineral association of Py-II, chalcopyrite and enargite, while enargite mineral is a major host for gold (up to 600 ppm). Supergene oxidation resulted in the development of a secondary enrichment zone for gold (up to 14 g/t) extending to a depth of about 45 m. Microthermometric measurements show that the silicification associated with the mineralization was formed at homogenization temperatures ranging between 147 and 360 °C and salinities up to 6.5 wt% NaCl. This suggests that the fluid mixing and/or fluid dilution processes were important factors controlling the precipitation of gold. δ34S isotope compositions are between −0.9 and − 9 ‰, and further indicate a significant involvement of magmatic components into the hydrothermal fluids. Thus, it is concluded that at Inlice the hydrothermal fluids responsible for the alteration and mineralization processes were derived by relatively dilute fluids formed by the mixing of magmatic fluids with meteoric waters
Effects of turbinoplasty versus outfracture and bipolar cautery on the compensatory inferior turbinate hypertrophy in septoplasty patients
DIZDAR, DENIZHAN/0000-0002-0991-2706; Tasdelen, Bahar/0000-0001-8146-4912; DIZDAR, DENIZHAN/0000-0002-0991-2706; bozan, aykut/0000-0002-3455-4955WOS: 000489065400005PubMed: 29891422Introduction: the most common cause of septoplasty failure is inferior turbinate that is not treated properly. Several techniques have been described to date: total or partial turbinectomy, submucosal resection (surgical or with a microdebrider), with turbinate outfracture being some of those. Objective: in this study, we compared the pre- and postoperative lower turbinate volumes using computed tomography in patients who had undergone septoplasty and compensatory lower turbinate turbinoplasty with those treated with outfracture and bipolar cauterization. Methods: This retrospective study enrolled 66 patients (37 men, 29 women) who were admitted to our otorhinolaryngotogy clinic between 2010 and 2017 because of nasal obstruction and who were operated on for nasal septum deviation. the patients who underwent turbinoplasty due to compensatory lower turbinate hypertrophy were the turbinoplasty group; Outfracture and bipolar cauterization were separated as the out fracture group. Compensatory lower turbinate volumes of all patients participating in the study (mean age 34.0 +/- 12.4 years, range 17-61 years) were assessed by preoperative and postoperative 2 month coronal and axial plane paranasal computed tomography. Results: the transverse and longitudinal dimensions of the postoperative turbinoplasty group were significantly lower than those of the out-fracture group (p = 0.004). in both groups the lower turbinate volumes were significantly decreased (p = 0.002, p < 0.001 in order). the postoperative volume of the turbinate on the deviated side of the patients was significantly increased: tubinoplasty group (p = 0.033). Conclusion: Both turbinoplasty and outfracture are effective volume-reduction techniques. However, the turbinoplasty method results in more reduction of the lower turbinate volume than outfracture and bipolar cauterization. (C) 2018 Associacao Brasileira de Otorrinolaringologia e Cirurgia Cervico-Facial. Published by Elsevier Editora Ltda