FIBROUS VEINS AND THEIR STRUCTURAL INTERPRETATIONS IN THE PALEOCENE-EOCENE UNITS OF THE ÇAMARDI (NİGDE) REGION

Abstract

In the Çamardı region, the Nigde Massif consist of Palaeozoic-Mesozoic marble, gneiss, quartzite and amhibolite. The high-grade metamorphic rocks of massif are cut by the Cretaceous Üçkapılı granodiorite. These basement rocks were overlain by the cover rocks of Paleocene-Eocene age that display very low grade metamorphism. The Paleocene-Eocene cover units underwent at least three phases of deformation, as designated D1, D2- and D3 which D1- affected both the basement and cover, polyphase folding and low-grade metamorphism due to closing of the Ulukısla basin. The poly-phase deformation also resulted in the wide spread development extensional vein sets generally in mesoscopic scale. Most of the veins are filled with the fibrous minerals. The fibrous veins are mostly sintaxial, antitaxial and ataxial veins. The mineral fibres have curved shape indicating the rotational progressive deformations. Structural analysis of mineral fibres, shows that the maximum elongation direction (X- axis of deformation elipsoid) has northeast-southwest trend, during the D1- event. With the other structural features, the tectonic transport of cover units most probaply developed from northeast to the southwest. Due to rotational progressive deformation during the D2- event, the maksimum elongation direction appears to rotate to north-northwest – south-southwest direction with an anticlockwise sense.

Keywords

• Çamardı, Genlesme, ilerleyen deformasyon, Lifsi damarlar, Nigde masifi.