Geomorphological features and weathering of the Southern Submassif of the Menderes Massif (SW Turkey)
- PDF / 12,904,494 Bytes
- 16 Pages / 595.276 x 790.866 pts Page_size
- 28 Downloads / 197 Views
ORIGINAL PAPER
Geomorphological features and weathering of the Southern Submassif of the Menderes Massif (SW Turkey) Murat Gül 1 & Göksu Uslular 1
Received: 10 December 2015 / Accepted: 12 October 2016 # Saudi Society for Geosciences 2016
Abstract The Southern Submassif crops out in the SW of Turkey. This submassif consists of mostly large feldsparbearing orthogneisses and to a lesser extent tourmaline-orthoclase-plagioclase-, quartz-, muscovite-, and biotite-bearing leucogranites. The orthogneiss forms domed bald hills. The leucogranites crop out (approximately 2 km2) in the southeastern lowland of the hill. Those units show various geomorphological features that are typically reported in granitoids. Many studies about the Menderes Massif are related with petrography and metamorphic history. The geomorphological features are not taken into consideration. Field observation, thin section analysis, joint set-foliation measurements, and Schmidt Hammer value determination were done in this study. The pillar structures (castellated and domed types) are among larger structures observed on flanks of the domed bald hill. Geomorphological features such as weathering pits, tafoni, honeycomb structures, polygonal cracks, flared slopes, exfoliation, and boulders are observed. The metamorphism causes mineral alignments that affect the strength of the rock. The studied rocks have high strength in perpendicular direction to foliation. The complex tectonic history caused developments of several joint sets. Differences in mineral strength (e.g., high in quartz, low in biotite and feldspar) increase weathering effect. Underground water percolation through the fractures weakens the rock and causes subsurface weathering. After exhumation, disintegrated materials are stripped off, and then flared slopes, polygonal cracks, and pillar structures are exposed. Surface weathering by
* Murat Gül [email protected]
1
Department of Geological Engineering, Muğla Sıtkı Koçman University, 48000 Kötekli, Muğla, Turkey
wind and water increases the weathering effects and gives rise to a formation of rounded rock edges called spheroidal weathering. Contrary to other granitoid areas, the metamorphism promotes the formation of geomorphological features in the study area. Keywords Pillar structure . Weathering pit . Orthogneiss . Leucogranite . Southern Submassif of Menderes Massif . SW Turkey
Introduction Geological factors control the geomorphology of the terrains (Migoń and Vieira 2014). Especially, lithological properties of rocks led to the formation of different types and various sizes of landforms. For example, weathering of granitoids may form peculiar landforms owing to chemical and physical processes (Twidale 1986; Migoń 2006). Inselbergs, domes, bornhardts, and tors are significant topographical rises in plain areas, and major geomorphological features are observed in granitoids from different countries (Twidale 1986, 1995; Migoń 2006; Twidale and Bourne 2008). Weathering pits, tafoni, honeycomb weathering, polygonal cracks, spheroida
Data Loading...
