Rare earth element-bearing fluorite deposits of Turkey: An overview

Rare Earth Element (REE)-bearing fluorite deposits in Turkey occur in association with Cenozoic post-collisional alkaline-carbonatite systems and can be divided into three groups: (1) carbonatite-associated; (2) those associated with subalkaline to alkaline magmatic rocks of Cretaceous to Cenozoic age; and (3) those in sedimentary successions, typically in areas dominated by limestone. Some of these deposits show significant enrichment in the REE, especially the Kızılcaören deposit which has average REE grades of almost 30,000 ppm; others have very low REE contents but have potential fluorite resources. The homogenization temperature and salinity values of fluid inclusions in these deposits vary between 600 °C and 150 °C, and 10–65 wt% NaCl eq., respectively. The carbonatite-associated deposits have the highest bulk REE contents and are LREE-enriched. As a general feature, the REE contents of the fluorite deposits decrease with decreasing homogenization temperatures and salinity of the fluorite fluid inclusions. Fluorite ore chemistry indicates that a plot of Nb + Ta versus total REE differentiates the carbonatite- hosted from the alkali intrusive- hosted and carbonate- hosted deposits. Beyond the cooling and/or dilution of the fluids, REE and fluorite deposition was driven by changes in pH, instead of change in Eh, according to our geostatistical treatment. The chondrite-normalized rare earth element patterns of each group of deposits show some similar features, indicating that the REE in the fluorite are independent of their host lithology, but reflect the magmatic systems from which they were derived. Overall, the F-REE deposits of the Anatolides-Taurides in Turkey are considered to be largely related to the post-collisional magmatic systems, but with variable contributions of fluids from other sources

Mineralogy and geochemical properties of İspirtepe (Niğde) carbonaceou's lead-zinc deposits

Orta Toroslar'da yer alan Aladağ Bölgesi, Devoniyen-Alt Kretase zaman aralığında çökelmiştir. Bölgeye, uzun süre tektonizma etkin olmuştur. Bu nedenle bölgede nap yapılı allokton Yahyalı, Siyah Aladağ, Minaretepeler, Çataloturan, Beyaz Aladağ napları ve ofiyolitli melanj istifleri meydana gelmiştir. Aladağ bölgesindeki İspirtepe civarında iki türlü cevherleşmeye rastlanmıştır. Birinci cevherleşme, Minaretepeler istifine ait Üst Triyas yaşlı dolomitik kireç taşları ile Kretase yaşlı ofiyolitik melanj dokanağında gözlenmektedir. Cevher K-G doğrultulu kırıklarda kırık dolgusu şeklinde gözlenir. İkinci cevherleşme ise cevherli fay zonlarının çevresinde bölgeye morenlerle taşınarak gelen sülfitli cevher parçaları şeklindedir. Bu cevher parçaları içerisindeki galenit bloklarının boyları bir metreye kadar ulaşmaktadır. Bölgedeki cevherli örneklerde yapılan cevher mikroskopisi çalışmaları ile mineral parajenezi belirlenmiştir. Birincil cevher minerali olarak galenit, sfalerit, pirit, fahlerz (tetrahedrit), kalkoprit ve bunların dönüşüm ürünü olarak simitsonit, anglezit, serüzit, malahit, götit ve lepidokrokit, gang minerali olarak kalsit, dolomit ve kuvars belirlenmiştir.Aladağ region had precipitated in Devonian Alt Creatse time interval in middle Taurus. This region had been tectonic events along with long durations. Because of it contains nappe structured allocton Yahyalı, Siyah Aladağ, Minaretepler, Çataloturan, Beyaz Aladağ nappes and ophiolitic melange stocks in Aladağ region. Around İspirtepe of Aladag region two types of mineralization had been found. First mineralization is seen in Mineratepe's stocks Upper Trias aged dolomitic limestone and Kretase aged ophiolitic melange intersection. Ore is seen by being fault filling through North and South directed faults. Second mineralization is structured as sulphide ore part which has been carried by morens to the area. The galenite blocks have been about one meter. There is a moren cover an ore blocks in northern part of mineralization in the area. Paragenesis has been found in ored-samples with respect to microscopic ore workings it is found that first ore minerals are galenite, sphalerite, pyrite, fahlerz (tetrahedrite), chalcopyrite and their alterational products which are smithsonite, gotite, malachite, seruzite, anglezite, lepidocrosite, gang mineralization of calsit, dolomite and quartz

Mineralogy and geochemical properties of Meydan Yaylası (Nigde) carbonaceou's lead-zinc deposits

İnceleme alanı, Orta Toroslarda, nap tektoniğinin kırık ve faylarının yoğun olduğu bir alan içerisinde yer almaktadır. Devoniyen-Alt Kretase zaman aralığında oluşan çeşitli özelliklerdeki karbonatlı kayaçlar içerisinde, irili ufaklı çok sayıdaki kurşun-çinko. cevherleşmesi, damar ve damarcık şeklinde, fay zonları boyunca genellikle K-G, D-B ve KD-GB yönlerindeki tektonik kırıklarla, karst boşluklarında gözlenmektedir. Söz konusu yataklarda birincil cevher minerali olarak galenit, sfalerit, yanında eser miktarda pirit, kalkopirit, fahlerz (frayberjit), pirotin; İkincil mineral olarak serüzit, anglezit, smitsonit, götit, malakit, azurit, hemimorfit, hidrozinkit, lepidokrosit, gang minerali olarak ise, kalsit, dolomit, kuvars belirlenmiştir. Cevher parejenezlerine ait oluşan bu mineraller ve bunların optik özellikleri ile sfaleritte %5-7 Fe, % 0.13 Cd, 78-210 ppm Mn; galenitte 30-75 ppm Ag, 44.25 ppm Bi ve piritimarkasitte ancak 45 ppm Co ve 87.5 ppm Ni (Co/Ni=0.51 ppm) element oranlarının varlığı bize cevherleşmenin düşük sıcaklıklı epijenetik-hidrotermal olarak oluştuğuna işaret etmektedir. Cevherin kaynağını, levha hareketlerine göre oluşan ve inceleme alanın yakın civarında görülen Paleosen-Alt Eosen yaşlı Yahyalı Granotoidine bağlı metal iyonları bulunduran cevherli çözeltilerin zayıf zonları kat ederek, yankayaçların kırık ve çatlaklarına yerleşmiş olabileceği düşünülmektedir. Söz konusu cevherin yerleşiminden sonra, atmosferik şartlar ve hidrotermal etkileşim sonucu karstlaşma, remobilizasyon ve damarlar içerisinde tekrar çökelim gibi süreçlerle cevherleşme son halini almıştır.The study area is located within a district, which is highly folded and faulted. A great number of lead-zinc mineralizations with varying magnitude are observed in carbonated rocks of Devonian-Lower Cretaceous age. Those mineralizations are mainly in the form of veins and veinlets and they are restricted to the major fault zones that strike N-S, E-W, NE-SW and carstic structures present in the region. Major primary ore minerals are galena and sphalerite with minor pyrite, chalcopyrite, fahlerz (freibergite), pyrrhotity; and secondary minerals are cerisite, anglesite, smithsonite, goethite, malachite, azurite, hemimorphite, hydrozinkite, and lepidocrochite. Gangue minerals observed are calcite, dolomite, and quartz. Analytical data indicated that sphalerite contained 5-7 wt, % Fe, 0.13 wt. % Cd, 78-210 ppm Mn, galena contained 30-75 ppm Ag, 44.25 ppm Bi and pyritelmarcasite included only 45 ppm Co and 87.5 ppm Ni (Co/Ni=0.51). In conjuction with the optical data, this indicates that the ore mineralization took place at relatively lower temperatures, which could be considered under epigenetic-hydrotermal conditions. This investigation is suggest that the Yahyalı Granitoid of Paleocene-Lower Eocene age is genetically related to the ore mineralizations of the district. This geological set up could result in such mineralizations along with previously formed fractures and faults during and shortly after the emplacent of the granitoid body. Later events, such as atmospheric and hydrothermal interactions, should have shaped the mineralizations resulting in the formation of carstic structures, and remobilizations

Rare earth element (REE) resources of Turkey: An overview of their characteristics and origin

The Rare Earth Elements (REE) deposits and mineralization of Turkey can be divided into four types based on their geological setting and origin. First are deposits associated with carbonatite-alkaline magmatic rocks, rich in Light Rare Earth Elements (LREE). The bast known examples are the Kizilcaoren (Eskisehir) and Kuluncak (Malatya) deposits with TREE grades of 2.9% and 0.7% respectively, and typical enrichment of La-Ce. Lower grade REE mineralization at Keban (0.05% TREE) and Divrigi (0.13% TREE) is associated with abundant fluorite and all four occurrences show similar ranges for homogenization temperatures and salinities for fluid inclusions in fluorite and REE profiles. The second type are Triassic shales and the bauxites formed from them in the Bolkardagi region. Enrichment of Heavy REE (HREE) is typical and TREE grades are about 0.15% in bauxites and its protolith. These occurrences are geochemically similar to "ion adsorption type" deposits associated with lateritic clay on the weathered granitic rocks of China. Third is the placer type, represented by the canakli (Burdur) deposit which is enriched in U, Th and HREE and heavy minerals such as; magnetite, zircon and rutile and has an average grade of about 0.08% TREE. The fourth potential source of REE is phosphorites. These rocks host the world's largest resources elsewhere, however the Cretaceous Mazidag deposits in Turkey are very low grade (40ppm TREE) and clearly uneconomic. Consideration of the environmental and health issues associated with exploitation and processing of REE has identified the more favorable outcomes associated with exploitation of the ion adsorption type of deposits and justification for further evaluation of the resources and processing technologies that would enable exploitation of REE-enriched bauxites in the Bolkardagi region