Deformation of stibnites and pyrites in the Madsan antimony deposit (Niğde, Turkey): Implications for pressure-temperature conditions of local deformation
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Tarih
1999
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info:eu-repo/semantics/openAccess
Özet
Mermerler ve gnayslar içerisindeki epitermal damarlardan oluşan Madsan antimuan yatağı Niğde ilinin (orta-güney Türkiye) güneydoğusunda yer alır. Damarlar ana bileşenler olarak kuvars, kalsit, stibnit ve pirit içeren basit bir mineralojiye sahiptir; zinober iz miktarlarda bulunur. Özellikle stibnit ve piritte gelişen bir dizi dokunun işaret ettiği ilerleyen bir deformasyon yatağı etkilemiştir. Ana dokular basınç lamelleri ve kaynaklanma olup, eğilme, basınç lamellerinin ötelenmesi ve çatlak dolguları ikinci derecede önemli dokulardır. Bu dokular birbirini izleyen üç deformasyon evresinde gelişmişlerdir. Basınç lamelleri bölgedeki deformasyonun ilk evresini temsil ederler; ikinci deformasyon evresinin temsilcileri eğilmiş basınç lamelleri ve kaynaklanma dokularıdır; üçüncü deformasyon evresi basınç lamellerinin kesilmesi ve ötelenmesi ile belirginleşir. Deformasyonlar olasılıkla 180 °Cye kadar ulaşan sıcaklıklarda ve 0.2 MPa dolayında basınç altında gelişmiştir. Jeolojik veriler, Niğde Masifinin güneye doğru Ulukışla Havzasına bindirmesi ile deformasyonun birinci evresinin açıklanmasını desteklemektedir. Deformasyonun ikinci evresinin nedeni ilk deformasyonun bitiminden sonra stibnitlerdeki iç sıkışma kuvvetlerinin artmasıdır. Deformasyonun üçüncü evresi, yatağa yakın genç normal faylanmaların sonucudur.
The Madsan antimony deposit at the southeastern part of the Niğde province (south-central Turkey) includes a series of epithermal veins hosted by marbles and gneisses. The veins have a simple mineralogy of quartz, calcite, stibnite and pyrite as major constituents, and cinnabar occurs in trace amounts. The deposit experienced a progressive deformation evidenced by a set of textures developed especially in stibnite and pyrite. These are pressure lamellae and annealing as the main textures, and curvature, off-set of pressure lamellae and fracture filling as the textures of minor importance. These were developed in three successive deformation phases. Pressure lamellae represent the first stage of deformation in the region, while the second stage of deformation is represented by curved pressure lamellae and annealing texture, and the third stage of deformation is characterised by truncation and offset of pressure lamellae. The deformations probably occurred at temperatures reaching 180°C and at pressures about 0.2 MPa. Geological evidence supports that the first phase of deformation is explained by the southward thrusting of the Niğde Massif over the Ulukışla Basin. The second phase of deformation is due to an increase in internal compression within the stibnites after the first deformation ended. The third phase of deformation is the direct result of younger normal faulting close to the deposit.
The Madsan antimony deposit at the southeastern part of the Niğde province (south-central Turkey) includes a series of epithermal veins hosted by marbles and gneisses. The veins have a simple mineralogy of quartz, calcite, stibnite and pyrite as major constituents, and cinnabar occurs in trace amounts. The deposit experienced a progressive deformation evidenced by a set of textures developed especially in stibnite and pyrite. These are pressure lamellae and annealing as the main textures, and curvature, off-set of pressure lamellae and fracture filling as the textures of minor importance. These were developed in three successive deformation phases. Pressure lamellae represent the first stage of deformation in the region, while the second stage of deformation is represented by curved pressure lamellae and annealing texture, and the third stage of deformation is characterised by truncation and offset of pressure lamellae. The deformations probably occurred at temperatures reaching 180°C and at pressures about 0.2 MPa. Geological evidence supports that the first phase of deformation is explained by the southward thrusting of the Niğde Massif over the Ulukışla Basin. The second phase of deformation is due to an increase in internal compression within the stibnites after the first deformation ended. The third phase of deformation is the direct result of younger normal faulting close to the deposit.
Açıklama
Anahtar Kelimeler
Jeoloji, Yerbilimleri, Ortak Disiplinler
Kaynak
Turkish Journal of Earth Sciences
WoS Q Değeri
Scopus Q Değeri
Cilt
8
Sayı
1
