Article Details
STRUCTURAL FEATURES OF THE NİĞDE MASSİF İN THE ÇAMARDI (NİĞDE) DİSTRİCT
Indexed In
Volume 154 / 2017Authors:
Ramazan DEMİRCİOĞLU, Yaşar ERENKeywords:
Çamardı, Niğde Massif, poly-phase deformation, cuspate-lobate folds.Abstract:
In the Çamardı (Niğde) region, Niğde Massif is composed of Palaeozoic-Mesozoic marble, gneiss and quartzite. The high-grade metamorphic rocks of the Massif are cut by Cretaceous granodiorites. These rocks are unconformably overlain by Paleocene-Eocene low-grade metamorphic rocks. Upper Cretaceous-Eocene flysch and island-arc type volcanic rocks tectonically overlie the above mentioned units. The youngest rocks in the area are Oligocene-Quaternary continental sedimentary and volcanic rocks. The rocks of the massif have been subjected to at least four ductile deformational events, that are designated as D1, D2, D3 and D4. The first phase of deformation produced recumbent isoclinal folds (F1-F2 folding) which are often intrafolial and rootless, and pervasive axial-planar foliation. Bedding in the metasedimentary rocks of the massif is almost completely transposed into S1-foliation. D2 event generated northeast-southwest trending and variably plunging folds (F3 folding) on the map scale. The superposition of F3 folds over the F1-F2 folds generated Type-2 mushroom fold interference patterns. The second generation inclined folds (F2) are very tight to isoclinal and generally asymmetric. D3- event formed a large dome structure, possibly related to the granodioritic intrusions in the studied area. D4-event is characterised by northwest-southeast trending and southeast plunging map scale synformal and antiformal folds. During the D4-event both the rocks of massif and its Paleocene-Eocene cover rocks are folded (F5- folding). High competency contrast of the lithologies existing across the boundary between the massif and the cover during F5- folding has led to the formation of map scale cuspate-lobate folds. Microscopic observations have shown that the cover rocks of the massif are metamorphosed under the very low grade metamorphic conditions and gained cleaved structures, during the D4-event.
