Structural features of the NIGDE massif in the Çamardi (NIGDE) district
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Tarih
2017
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
General Directorate of Mineral Research and Exploration (MTA)
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Çamardı (Niğde) yöresinde, Niğde Masifi mermer, gnays, kuvarsit ve amfibolitlerden oluşmuştur. Masife ait bu kayaçlar Kretase yaşlı granodiyoritler tarafından kesilmiştir. Paleosen-Eosen düşük dereceli başkalaşım kayaçları masifin otokton örtüsünü oluşturur. Bu birimler, Üst Kretase-Paleosen yaşlı flişoyid ve ada yayı özelliğindeki kayaçlar tarafından tektonik olarak üstlenir. Yörenin en genç birimlerini ise Oligosen-Kuvaterner yaşlı karasal ve volkanik kayaçlar oluşturur. Niğde masifi metamorfitleri en az dört evreli (D1, D2, D3ve D4) sünek deformasyona ve kıvrımlanmaya uğramıştır. D1 evre deformasyonla, masifin kayaçları yatık-izoklinal olarak kıvrımlanmış (F1-F2 evre kıvrımlanma) ve eksen düzlemlerine paralel foliasyonlu (S1) bir yapı kazanmıştır. Kayaçların tabaka (So) düzlemlerinin izoklinal ve şiddetli kıvrımlanması nedeniyle tabaka transpozisyonu gelişmiş ve yalınmış kıvrım yapıları oluşmuştur. D2 evre deformasyonla, harita ölçeğinde kuzeydoğu-güneybatı yönelimli ve hem kuzeydoğuya, hem de güneybatıya dalımlı kıvrımlar (F3 evre kıvrımlanma) gelişmiştir. F1-F2 ve F3 evre kıvrımların girişimi sonucu yörede Tip-2 türü (mantar kıvrımı) kıvrımlanmış kıvrımlar oluşmuştur. İkinci evre mesoskopik kıvrımlar sıkışık-izoklinal geometrili olup, asimetrik ve eğik kıvrım özelliği sunarlar. İnceleme alanında D3 evre kıvrımlanma sonucu bölgede büyük bir dom yapısı gelişmiştir. D4 evre kıvrımlar ise harita ölçeğinde D2 evreye yaklaşık dik yönelimli ve kuzeybatı-güneydoğu gidişli ve güneydoğuya dalımlı sinform ve antiform yapıları oluşturmuştur. D4 evre deformasyonla temel ve örtü kayaçları ile birlikte deforme olmuştur (F5-evre). Mikroskopik analizler, Kretase-Eosen yaşlı kayaçların, bu evre deformasyonla düşük dereceli yeşilşist fasiyesinde başkalaşıma uğradığını göstermektedir F5 evre kıvrımların geometrisi, temel ve örtü kayaçlarının beraberce deforme olduğu yörelere özgü kıvrım şeklini (kasp–lob yapısı) yansıtmaktadır.
In the Çamardi (Nigde) district, the Nigde Massif is composed of marbles, gneisses, quartzites and amphibolites. These rocks of the Massif have been cut by Cretaceous aged granodiorites. The Paleocene-Eocene aged low-grade metamorphic rocks constitute the autochthonous cover of the Massif. These units are tectonically overlain by the Upper Cretaceous-Paleocene aged flyschoid and island arc type rocks. The Oligocene-Quaternary aged terrestrial and volcanic rocks constitute the youngest units of the district. The metamorphites of the Nigde Massif have been subjected to at least four phase ductile deformation (D1, D2, D3, and D4) and folding. Through the D1 phase deformation, the rocks of the Massif have been folded as recumbent-isoclinal folds (F1-F2 phase folding) and have gained a structure with a foliation (S1) which is parallel to the axial planes. Owing to the isoclinal and intense folding of the bedding planes (S0) of the rocks, bedding transposition have developed and transposed folding structures have formed. Through the D2 phase deformation, northeast-southwest trending and both northeast and southwest dipping map scale folds (F3 phase folding) have developed. As a result of the interference of F1-F2 and F3 phase folds, in the district, folds, generated by Type-2 folding, have formed (mushroom folds). Second phase mesoscopic folds are of tight-isoclinal geometry and display asymmetrical and inclined fold feature. In the study area, as a result of D3 phase folding a large dome structure has developed in the district. And D4 phase folds have formed map scale synformal and antiformal structures that are trending approximately perpendicular to D2 phase, plunging southeast and trending northwest-southeast. Through D4 phase deformation, the cover rocks have been deformed together with the basement rocks (F5 phase) that they overlie. The microscopic observations show that Cretaceous-Eocene aged rocks have been subjected to low-grade metamorphism in the greenschist facies through D4 phase deformation. The geometry of the F5 phase folds reflects cuspate-lobate structure which is the folding type peculiar to the districts where basement rocks and cover rocks have been deformed together.
In the Çamardi (Nigde) district, the Nigde Massif is composed of marbles, gneisses, quartzites and amphibolites. These rocks of the Massif have been cut by Cretaceous aged granodiorites. The Paleocene-Eocene aged low-grade metamorphic rocks constitute the autochthonous cover of the Massif. These units are tectonically overlain by the Upper Cretaceous-Paleocene aged flyschoid and island arc type rocks. The Oligocene-Quaternary aged terrestrial and volcanic rocks constitute the youngest units of the district. The metamorphites of the Nigde Massif have been subjected to at least four phase ductile deformation (D1, D2, D3, and D4) and folding. Through the D1 phase deformation, the rocks of the Massif have been folded as recumbent-isoclinal folds (F1-F2 phase folding) and have gained a structure with a foliation (S1) which is parallel to the axial planes. Owing to the isoclinal and intense folding of the bedding planes (S0) of the rocks, bedding transposition have developed and transposed folding structures have formed. Through the D2 phase deformation, northeast-southwest trending and both northeast and southwest dipping map scale folds (F3 phase folding) have developed. As a result of the interference of F1-F2 and F3 phase folds, in the district, folds, generated by Type-2 folding, have formed (mushroom folds). Second phase mesoscopic folds are of tight-isoclinal geometry and display asymmetrical and inclined fold feature. In the study area, as a result of D3 phase folding a large dome structure has developed in the district. And D4 phase folds have formed map scale synformal and antiformal structures that are trending approximately perpendicular to D2 phase, plunging southeast and trending northwest-southeast. Through D4 phase deformation, the cover rocks have been deformed together with the basement rocks (F5 phase) that they overlie. The microscopic observations show that Cretaceous-Eocene aged rocks have been subjected to low-grade metamorphism in the greenschist facies through D4 phase deformation. The geometry of the F5 phase folds reflects cuspate-lobate structure which is the folding type peculiar to the districts where basement rocks and cover rocks have been deformed together.
Açıklama
Anahtar Kelimeler
Çamardı, Niğde Masifi, Çok Evreli Deformasyon Yapısı, Cuspatelobate Structure, Polyphase Deformation, The Nigde Massif, Çamardi
Kaynak
Bulletin of the Mineral Research and Exploration
WoS Q Değeri
Scopus Q Değeri
Q3
Cilt
2017
Sayı
154
