Uludağ'ın güneyinde gelişmiş granitoyidik intrüzyonlarla ilişkili cevherleşmelerin değerlendirilmesi
Interpretation of grantiodic intrusions related mineralizations over southern Uludag
Yazar: HÜSEYİN KOCATÜRK
Danışman: DOÇ. MUSTAFA KUMRAL
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü / Jeoloji Mühendisliği Ana Bilim Dalı
Derece: Yüksek Lisans, 2016
Konu: Jeoloji Mühendisliği = Geological Engineering

Özet:
Plaka tektoniği yer bilimleri açısından yer yüzü ve yer altı en büyük jeodinamik sonuçları olan  ve  en iyi bilinen teorilerden biridir. Tektonik yerleşim, kayaç yapıcı mineraller, stratigrafik form, maden oluşum süreçleri, kristal yapıları ve kayaç dokuları bile aslında plaka tektoniği ile ilişkilidir. Çalışma sahasıda cevher oluşumuna olanak sağlama potansiyeli nedeniyle plaka tektoniğine dayalı olarak seçilmiştir.
Uludağ iki kıta arasında plaka hareketlerine dayalı ağırlıklı olarak orojenik bir oluşumun sonucunda gelişmiştir. Uludağın güneyinde uzun bir hat boyunca dalma-batma zonu yer almaktadır. Bölgede bu zona bağlı olarak ultra bazikden asidiğe yakın derecesine kadar değişen kompozisyonlarda farklı kayaç birimleri yer almaktadır.
Literatür çalışmlarına göre Uludağın güneyinde kalan bu bölge Türkiye'nin en çok araştırırlan bölgelerinden biridir. Bölgedeki litolojik birimler metamorfikler, ofiyolitler, ve genellikle I tipi granitoyidlerden oluşan magmatik intrüzyonlar olarak üç ana başlık altında incelenebilir. 
 Araştırma sahası yaklaşık 400 kilometrekarelik bir alnı kapsamaktadır. Öncelikli olarak sahada yapısal unsurlar tanımlanmıştır. Bu tanımlama sırasında intrüzyonlarla ilişkili kayaçlar yoğun bir hidrotermal aktivete ile şekillenmiş ve altere olmuşlardır. Bu çalışma büyük ve küçük parçaarın birbiri arasında ilişkisinin anlaşılabilmesi amacıyla plaka tektoniği, akışkan patikaları ve litolojik birimleri konu almaktadır.
Her bir cevherleşme süreci yapısal unsurlar ve ekonomik oluşumlar arasında belirgin bir sonucu bize sunmakatadır. İlişkilendirilmiş verileri baz alarak konuyu incelediğimizde mineral gelişim süreçleri ile plakanın nasıl daldığı, yay volkanizması, orojenik oluşumla ilişkili yer altı eriyik sistemlerinin çalışması ve plaka tektoniğine bağlı jeokimyasal etkiler arasında anlamlı sonuçlar çıkmaktadır.
Jeokimyasal analizler nikel, titanyum, nadir toprak elementleri, altın ve gümüş zenginleşmelerine dair önemli anomaliler sunmaktadır. Titanyum değeri tonda yüzde 1,5 toplam nadir toprak elementi değeri zenginleşen örenkler için tonda 200 ile 500 gram arasında, nikel değeri yüzde 0,5 gibi değerleri bulurken en umut verici sonuç altının tonda 2 gramı ve gümüşün ise tonda 4 gramı bulmasıdır. Ayrıca bu sonuçalrı veren örnekler belirli yapılarla ilişkili olarak belirli örneklerde yakın sonuçlar vermektedir.
Ttianyum zenginleşmeleri için yapılan inclemelerde titanyum mineralleri ilmenit, rutil ve sfen olarak tespit edilmiştir. Ne yazık ki ilmenit demir miktarına bağlı olarak zenginleşme süreçleri sırasında manyetik seperatörde doğurduğu ayrıştırma sorunu nedeniyle istenmeyen bir mineraldir. Sfen ise aksesuar mineral olarak tanımlanmıştır. 
Nadir toprak elementlerinin zenginleşmesinin ise ofiyolit şist dokanağında gelişen metamorfizmaya bağlı olarak geliştiği tespit edilmiştir. Zenginleşmenin ilksel kaynağının ofiyolitik kayaçlar olduğu düşünülmektedir.
Deformasyon yapılarındaki düşük sülfürlü kuvars damarları ve bazı büyük kuvars filonları dışında alterasyon zonlarında yapılan önreklemeler ise altın ve gümüş zenginleşmelerinin bu yapılarla ilişkili olduğunu açıklar şekilde ortama bağlı olarak belirgin artış sergilemektedir.

Abstract:
Plate tectonics is one of the most illustrated theory and biggest geo-dynamic incident on earth surface and sub-surface for the earth science. Tectonic settlement, rock forming minerals, form of stratigraphy, ore genesis processes, crystal structures and even rock textures are all related with plate tectonic. Field has been chosed becasuse of important relation between plate tectonic and ore genesis processes.
Uludag is a mountain which is dominantly occurred with main orogenetic plate movements progressed between two crust.  There is a long subduction line at the south of Uludag. Because of these we observe many different type of rocks in the range of ultra-basics to nearly acidics. According to the literature review one of he most investigated region of Turkey is Southern part of Uludag.
On the region it has been defined there is three main lithological unions. These unions can be classified as metamorphics, ophiolites and magmatic intrusions which are generally I-type granodiorites. 
Exploration study includes nearly 400 km square area. First of all characterized structures on the field determined. We obsreved that ıntrusion related rocks has formed and altered by high grade hydrothermal activity. This study approaches to understand bigger to smaller frameworks of these processes which between plate tectonics, ﬂuid pathways and lithological unions.
On the region many place is far away from general structure of ophiolites but locally it is possible to observe characterized lithologic unions and structures. One of these is sheeted dykes which has formed as butterfly structure. İt is possible to observe  pillow lavas. Additionaly pillow lavas not clearly intelligible because of the forest and plant cover. Between the sheted dykes and pillow lavas it is distinct to say gabroic layer exists. Gabroic layer does not exists with the specific structures like gabro but it exists with border of basic chemical compositions.
Age data and determined structure present us schist is metamorphised with the oceanic crust mevoments. Oceanic crust movement not for all of the metamorphism process but singenetically for a period it affected metagranitoid with the schist. 
All the plate movements constituted important faults on the region. Faults and deformation structures seem most important impact factor on alteration and hydrothermal fuid movements. These hydrothermal fluids works pathways which mainly generated on the border of important faults.
  

Each ore genesis story is present us compact conclusion report about structural associations for the economic generations. With the combined informations in one scene we can make sense of mineralization processes about region which occurs in different stages such as subducting slabs, arc volcanism, subsurface ﬂux estimates related orogenic processes, and other geochemical effects of plate movements.
Sampling points and items selected according to each different litology. İnerside of the lithology special structures chosen such as quartz fillons, calcite veins, altered zones, etc.. We got results for Nickel enrichment at the first interactions between ophiolitic rocks and granitic intrusions. It is continued with rare earth elemets enrichment on the border of schists and ultra basics rocks such as peridotites on the region.
Titanium, gold, silver, platinium and pladium enrichments was most realted with granitodic structures. These were not like normally granitioidic sturcture it was mostly like secondary genesis environment. Researched parameters like mafic minerals and enclave ratios on different deformation structures, cross sections of structures and relative existing sequence are all changes with different time periods like geochemical environment and each vein.
Geochemistry analyssises about the nickel, titanium, platinium, paladium, yttrium, lanthanium, cerium, neodmyium, silver and gold demonstarates us important anomalies. Titanium amount is nearly 15000 ppm, Total Rare Element amount is maxiumum 500 minimum 200 ppm for the enriched sapmples, 5000 ppm Nickel is a anomally but not promising result for us, maximum 2 ppm Gold and 4 ppm silver is major encouraging results so much the more with the half ppm platinum plus palladium amounts because these for element enrichments related with the samples from determined one structure. All these results indicate us field has to be investigated in details by researchers.
Determined minerals for titanium enrichments are ilmenite, rutil and sphene. For the economic deposits rutil is the best. Ilmenite is one of the undesirable mineral because of iron content and magnetic separator utilization on enrichment process. Sphene is a accesory mineral which is not usen in ore obtain processes.
Rare elements enrichment is most relevant with schists. Literature investigations shows it is controled by structural factors. Source of elements are mainly ophiolites which contains basic and ultra basic rocks. It enrcihs at the border of ophiolite and schist while plate movements continue.
Gold and silver is related with low-sulphidation quartz veins and lodes. Alteration zones are typically observed in the study field. All the ore types are relavant with intrusions but this type of enrichments are predominant ones. With the altered intrusive rocks there has been many ore occurunces formed. Some of these occurences observed in main body of granitoids but some of them observed along deformation structures.
Deformation structures and ﬂuid pathways which related with plate tectonics progressed on our forearc system and each steps of dynamic movements of subducting mechanism has been seemed affect both hydrothermal stages and mineral variations together. 
Types of each deformation structure and mineral assemblages has characterized for ﬂux estimations and it can be useful for subsurface mapping. Geoanalytical results showed us clear characteristic stories for mutual processes. Determined compression and release directions on our map explains not only hydrothermal stages but also how succesion of intrusions changes. 
It is possible to say region is one of the most important area for the geological studies. There are several important discoveries on the field. These discoveries should be developed with the questions and new research queries.
Existence of plajiogranit is one of these. Another one aplit and pegmatite dykes structure. One another is petrographic determination of different type grantioids. Two gram in a ton is a very important gold discovery but with the several sample results it is not enough.
Fluid inclusion inv0estigations can be usefull to understand crystallization temperature. Sr 87/86 istope analaysises feasible to determine type of granitoids also chlorite carbonat index will support alteration determinations.
Consequently the sudy field consist of many ore genesis environment. It is easy to understand genetic process of lithologies, deformation structures and alterations but it requires long time to study. This long time all related with different captions like undestanding gold reserve, granitoid types, possibiblity to enrich titanium or rare earth elements. Except unsolved questions field has high potential for gold and silver mining operations and encouraging to expolarate rare earth elements, nickel and titanium.