The Role of Deformation in Fault Rock Mineralogy

Abstract

The Igneous and sedimentary rock groups along the East Anatolian Fault have caused formation of fault rocks in different grain sizes from breccia to fault clay due to active fault tectonics. The carbonation, silicification and mineralizations developed along its are the result of tectonism, deformation and geochemical functions. In these rocks have been determined alteration product minerals such as serpentine, carbonate, talc, montmorillonite, illite and chlorite. Furthermore, magnesite minerals shows temperature, reduction and permeability. The progressive alteration of calcite, hematite, limonite and chlorite minerals determined by mineralogical studies. They shows effect of hydrothermal fluids with high CO2 and calcium content on Mg-silicates. The Microscopic studys and geochemical data show that carbonation and accompanying silicification in all brecciated or clay-sized rocks are due to active tectonism, medium temperature and permeability. During siliceous-carbonate development, the medium-high temperature causes acceleration of inter-mineral reaction during deformation.

Keywords

• Silicification
• Alteration
• Pyrite
• East Anatolia Fault.

Fay Kayası Mineralojisinde Deformasyonun Rolü

Öz

Doğu Anadolu Fayı boyunca yeralan magmatik ve sedimanter kayaç grupları, aktif fay tektoniği nedeniyle, breşten fay kilinine kadar farklı tane boyutunda fay kayalarının geliştiği geniş bir zondur. Doğu Anadolu Fay Zonu boyunca; Karbonatlaşma, silisleşme ve cevher oluşumları gelişmiştir. Alterasyon ve farklı cevher oluşumlarının varlığı, tektonizma, deformasyon ve jeokimyasal işlevlerin bir sonucudur. Bu kayaçlarda, yaygın olarak serpantin, karbonat, talk, montmorillonit, illit, klorit gibi alterasyon ürünü minerallerin varlığı, ayrıca manyezit gelişimi, sıcaklığa, redüksiyon ve permeabiliteye işaret eder. Mineralojik incelemelerle belirlenen kalsit, hematit, limonit ve klorit mineralleri progresif alterasyonu, yüksek CO2 ve kalsiyum içeriği ise hidrotermal akışkanların, Mg-silikatlar üzerindeki etkisini gösterir. Mikroskopik incelemeler ve jeokimyasal veriler, breşik veya kil boyutundaki tüm fay kayalarında, karbonatlaşma ve eşlik eden silisleşmenin geliştiğini gösterir. Bu durum, aktif tektoniğin, orta derece sıcaklığın ve kayaç permeabilitesinin sonucu olup, tektonik aktivite silis oluşumunu artırır. Silisli-karbonat gelişimi sırasında, sıcaklığın orta-yüksek derecede olması, deformasyon sırasında mineraller arası reaksiyonun hızlanmasına sebep olur.

Anahtar Kelimeler

• Alterasyon
• Pirit
• Doğu Anadolu Fayı.
• Silisleşme

Kaynakça

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