Küplü Dağı (Harmancık) ofiyolit kayalarının incelenmesi ve bu kayalardaki manyezit oluşumunun jenetik etüdü /
Yazar: HALİS MANAV
Danışman: PROF.DR. BEKTAŞ UZ
İstanbul Teknik Üniversitesi / Fen Bilimleri Enstitüsü
Derece: Doktora, 1996
Konu: Jeoloji Mühendisliği = Geological Engineering
Dizin: Kayaçlar = Rocks ; Köplü Dağı = Köplü Mountain ; Kütahya-Harmancık = Kütahya-Harmancık ; Manyezit = Magnesite ; Ofiyolit = Ophiolite

Özet:
ÖZET Kuzey Bati Anadolu'da İzmir-Ankara Zonun'da yeralan çalışma alanının stratigrafîk kesitinde; Tabanda Alt Kretase yaşlı mavi şistler ile bu kayalarla düşey ve yanal ardalanmalı kristalize karbonatlar yer almaktadır. Bu temel kayalar üzerine tektonik bindirme ile gelen ofiyolitik melanj ve yine bu melanj üzerine tektonik bindirme ile gelen peridotitler ve tüm bu birimleri diskordan olarak örten Neojen yaşlı sedimanter topluluk yer almaktadır. Çalışma alam içinde peridotitleri ve ofiyolitik melanjı dayk yada dayk kümeleri halinde kesen doleritleri; plajokoklas ve klinopiroksenden oluşan oldukça basit bir mineral topluluğunun yansıttığı, fakat geçirmiş olduğu ikincil olaylarla (deformasyon+ayrışma) bu doleritierin plajioklaslarımn sösürütleştiği (serisit) ve albitleşme gösterdiği ve klmopirokserderinin (ojit) ise uralitleşmeler gösterdiği anlaşılmıştır. Bu mineraller yanında sfen, opak, klorit, aktinot, epidot (pistaşit) ve zeolitminerallerine rastlanmış olması bu doleritierin etkin bir "sipilitleşme" geçirdiğini göstermektedir. Doleritierin jeokimyasal analizlerinin (majorelement, iz element, nadirtoprak elementleri), diyagramlara yerleştirilip yorumlanması sonunda; bu dayklann 1,5 kb basmç şartlannda oluştuğu ve aynı magmanın ürünü olduğu anlaşılmıştır. Bu kayaların "Ada yayı toleiti" kimyasında oldukları ve bir yitim zonu ile kimyası değişmiş manto kısmının kısmi ergimesi sonucu oluşmuş dayklar olduğu ve günümüzde korunmamış olan okyanusal kabuğun mafik kısmım oluşturan kesimi (okyanus içi ada yaylan), besleyen bacalar olduğu arazi verileri desteği ile de doğrulanmıştır. Peridotitlerden alman krom-spinellerin analizi ile bu peridotitlerin yitim zonu üstündeki manto kesimine ait olabileceğini göstermiştir. Peridotitlerde bol miktarda Mg+2 iyonu olması sabebi ile bu kayalara bağlı manyezit oluşmasında en büyük sorun CCVin nereden ve nasıl geldiğidir. İnceleme alam Küplü Dağı ve civan manyezitleri (peridotitlerde gelişen kriptokristalen manyezitler) için cevherleşmeyi meydana getiren olay, büyük olasılıkla ofîyolitlerin karbonatlar üzerine tektonik bindirmek* olarak gelip yerleşmesidir. (yaklaşık 300°C ve 6-7 kb. basınç şartlan), Bu durumda karbonat kayalar dekompoze olarak ortama CO2 verirler. Peridotitlerden metasomatik olarak Mg+2 iyonlan koparan sıvılar ortamdaki CQ2 ile karşılaştıklarında Mg CO3 (menyezit) oluştururlar. Bu tür iyonlar ihtiva eden sıvılar uygun koşullan buldukça manyezit yataklarını oluşturacaktır. İnceleme Alanında manyezit yataklanmalar Üst Kratese-Paleosen'de ofîyolitlerin karbonatlar üzerine tektonik bindirmesi ile başlayıp yaklaşık 2-3 milyon yılda manyezit yataklanması sona ermiştir. XIV

Abstract:
1.5 1.0 P205 0.5 0.0 Tt-MagntMaANvaaptMl EıtracMon Vı 100** 12 3 4 5 6 7 8 Tİ02 FIGURE: 1. Ti02 Versus P205 Diagram, Used To Determine The Extent Of Fractional Crystallisation And Degree Of melting. (After LATİN. 1990), It is concluded that these dikes show uninterrupted differentiation, and there is Na-bringing in rocks as well as increasing increasing ratio of MgO with increasing solidification according to the "Harker" diagrams established by the relations of dual elements. It is understood that dolerites in a good agreement with the rare soil elements of tholeiitic rocks "front of island arc" have R.E.E. Accarding to geochemical values of dike samples, plotted on abaout 20 diagrams, it is thought that these rocks have a chemistry of island are tholeiite and these dolerites are dikes formed by the partial melting of the mantle section with chenyed chemical composition and a lost zone, and they are chimneys feeding the mafic section (island arcs in ocean) of unprotected oceanic crust at the present. Massive and nodular shaped magnezite deposits has been found at Küplü mountain and its surroundings. Those two types of magnezites differ XVIITHE STUDY OF THE OPHIOLITIC ROCKS IN THE VICINITY OF KÜPLÜ DA?I (BURSA) AND GENETIC INVESTIGATIONS OF THE MAGNEZİTE OCCURANCES RELATED TO THESE ROCKS SUMMARY The study area including Küplü Mountain and its surrounding around Harmancık covers Quadrangles I22CI, I22C2, I22D2 and I22D4. In the stratigraphic column of the study area of which the geological map has been prepared, the lower cretaceous age blue schists at the bottom and recrystallized carbonates laterally and vertically interbedded with these rocks take place. Over these basement rocks, ophiolitic melange pushed by a thrust fault and over this ophiolitic melange peridotites pushed by another thrust fault and neogen age sediment groups overlaying these units as discordant are observed. The study area in the north-western Anatolia takes place in the Akhisar and Tavşanlı Groups according to the studies of KAYA (1981) and by accepting as a continuation of the Îzmir-Ankara Zone in the Îzmir-Ankara- Akhisar and Tavşanlı Groups (İzmir-Ankara Zone). Some part of minerologic, petrographic and lithologic properties of rocks taking place in the study area was determined in this research and given below with rock names. Schists ; Although they are formed by quartz, muscovite (fuchsite), glaucophane and sodic pyroxene minerals, epidote, aragonite, albite and small amount of opaques are other minerals taking place in blue schists. Recrystallized Carbonates : As observed in thin sections they include crystallized calcite minerals with deformation lamella were recrystallized due to tectonism. Ophiolitic Melange : They are formed by pelagic sediments (chert, shale, limestone), basic rocks (dolerites), serpentinite and talc schists. These talc schists are different than regionally metamorphic schists and cataclastic schistose and autoclastic rocks. Peridotite : They are formed by dunite and harzburgite (Dunits take place in harzburgite as lenses and bards). Other than these, serpentinites derived from dunite and harzburgite by the process of alteration more than 90 XV1.5 1.0 P205 0.5 0.0 Tt-MagntMaANvaaptMl EıtracMon Vı 100** 12 3 4 5 6 7 8 Tİ02 FIGURE: 1. Ti02 Versus P205 Diagram, Used To Determine The Extent Of Fractional Crystallisation And Degree Of melting. (After LATİN. 1990), It is concluded that these dikes show uninterrupted differentiation, and there is Na-bringing in rocks as well as increasing increasing ratio of MgO with increasing solidification according to the "Harker" diagrams established by the relations of dual elements. It is understood that dolerites in a good agreement with the rare soil elements of tholeiitic rocks "front of island arc" have R.E.E. Accarding to geochemical values of dike samples, plotted on abaout 20 diagrams, it is thought that these rocks have a chemistry of island are tholeiite and these dolerites are dikes formed by the partial melting of the mantle section with chenyed chemical composition and a lost zone, and they are chimneys feeding the mafic section (island arcs in ocean) of unprotected oceanic crust at the present. Massive and nodular shaped magnezite deposits has been found at Küplü mountain and its surroundings. Those two types of magnezites differ XVII1.5 1.0 P205 0.5 0.0 Tt-MagntMaANvaaptMl EıtracMon Vı 100** 12 3 4 5 6 7 8 Tİ02 FIGURE: 1. Ti02 Versus P205 Diagram, Used To Determine The Extent Of Fractional Crystallisation And Degree Of melting. (After LATİN. 1990), It is concluded that these dikes show uninterrupted differentiation, and there is Na-bringing in rocks as well as increasing increasing ratio of MgO with increasing solidification according to the "Harker" diagrams established by the relations of dual elements. It is understood that dolerites in a good agreement with the rare soil elements of tholeiitic rocks "front of island arc" have R.E.E. Accarding to geochemical values of dike samples, plotted on abaout 20 diagrams, it is thought that these rocks have a chemistry of island are tholeiite and these dolerites are dikes formed by the partial melting of the mantle section with chenyed chemical composition and a lost zone, and they are chimneys feeding the mafic section (island arcs in ocean) of unprotected oceanic crust at the present. Massive and nodular shaped magnezite deposits has been found at Küplü mountain and its surroundings. Those two types of magnezites differ XVIIThe ore formation of the magnezites developed related to ophiolites in the investigation region in Turkey is probably the tectonic placement of ophiolites on to the carbonates (300° C temperature and 6-7 kB pressure conditions). This is enough for the carbonate rocks to decompose and produce CO2. When C02 in this medium mixes to the fluids containing Mg+2 ions produced metamorphic by the alteration of the peridotites, forms MgCC>3 (Magnezite) and in case finds appropriate conditions turns out to be magnezite ore. It is predicted that in the region of interest, the bed formation started by the formation of ophiolites at the Upper Cretaceous-Pliocene period range and after 2-3 million of years ended by the completion of magnezite beds.