A critical review of the Kibyra Fault (Burdur-Fethiye Shear Zone,SW Turkey)

The Kibyra Fault is considered as the most significant evidence about the existence of the NE–SW-striking left-lateral Burdur-Fethiye Fault Zone in the south-western Anatolia in previous studies. However, recent studies show that there is a shear regime, named the Burdur-Fethiye Shear Zone, dominated by normal and left-lateral oblique normal faults in this region. A large number of ancient cities lie on this zone and many of them have been damaged by ancient earthquakes. One of these ancient cities is the ancient city of Kibyra. Most of previous studies suggest the Kibyra Fault depending on the damage in the city. However, the closest fault is located on the western side of the city and the earthquake damage was most likely caused by ground shaking. In this study, the existence of the supposed Kibyra Fault is discussed by integrating field studies, geological maps, trench data, digital elevation model and geomorphological analysis. In conclusion, it is understood that there is no evidence directly indicating a 35-km-long left-lateral fault in this region. The aim of this study is to examine the existence of the Kibyra Fault, take a different approach to the active fault studies and emphasise the importance of active faults for socio-economic conditions.     

Geology and petrology of the Simav Magmatic Complex (NW Anatolia) and its comparison with the Oligo-Miocene granitoids in NW Anatolia: implications on Tertiary tectonic evolution of the region

The Oligo-Miocene granitic plutons and their related volcanic-subvolcanic successions form a NW–SE trending magmatic belt along the northern border of the Menderes Massif. This belt evolved within a nappe package consisting of the Menderes metamorphics, Sakarya Continent, Afyon Zone and Tav?anl? Zone and also intruded this nappe package. The Ezine, Evciler, Eybek, Kozak, Alaçam, Koyunoba, E?rigöz and the Baklan plutons emplaced along this belt and show similarities in their internal structures, emplacement mechanisms, and petrological characteristics. These different granitic plutons cut and stitch various combinations of the nappe package of the above-mentioned tectonic belts, and evolved during and following the Alpine collision. They all show characteristic map patterns of shallow-seated plutons and range from granite to monzogranite. The granitic plutons display calc-alkaline, I-type and post-collisional geochemical characteristics. The E?rigöz, Koyunoba plutons and their subvolcanic–volcanic phases (Simav Magmatic Complex) were studied in detail. The geochemical characteristics and field occurences of the Simav Magmatic Complex were compared to the other magmatic associations in western Anatolia and it was determined that it is of collisional origin and not related to an extensional tectonic regime as suggested in some recent studies.     

Assessment of aquifer vulnerability based on GIS and DRASTIC methods: a case study of the Senirkent-Uluborlu Basin (Isparta, Turkey)

Aquifer vulnerability has been assessed in the Senirkent-Uluborlu Basin within the Egirdir Lake catchment (Turkey) using the DRASTIC method, based on a geographic information system (GIS). There is widespread agriculture in the basin, and fertilizer (nitrate) and pesticide applications have caused groundwater contamination as a result of leaching. According to hydrogeological data from the study area, surface water and groundwater flow are towards Egirdir Lake. Hence, aquifer vulnerability in the basin should be determined by water quality in Egirdir Lake. DRASTIC layers were prepared using data such as rainfall, groundwater level, aquifer type, and hydraulic conductivity. These data were obtained from hydrogeological investigations and literature. A regional-scale aquifer-vulnerability map of the basin was prepared using overlay analysis with the aid of GIS. A DRASTIC vulnerability map, verified by nitrate in groundwater data, shows that the defined areas are compatible with land-use data. It is concluded that 20.8% of the basin area is highly vulnerable and urgent pollution-preventions measures should be taken for every kind of relevant activity within the whole basin.     

Investigation of Crustal Thickness in Eastern Anatolia Using Gravity,Magnetic and Topographic Data

The tectonic regime of Eastern Anatolia is determined by the Arabia-Eurasia continent-continent collision. Several dynamic models have been proposed to characterize the collision zone and its geodynamic structure. In this study, change in crustal thickness has been investigated using gravity, magnetic and topographic data of the region. In the first stage, two-dimensional low-pass filter and upward analytical continuation techniques were applied to the Bouguer gravity data of the region to investigate the behavior of the regional gravity anomalies. Next the moving window power spectrum method was used, and changes in the probable structural depths from 38 to 52 km were determined. The changes in crustal thickness where free air gravity and magnetic data have inversely correlated and the type of the anomaly resources were investigated applying the Euler deconvolution method to Bouguer gravity data. The obtained depth values are consistent with the results obtained using the power spectrum method. It was determined that the types of anomaly resources are different in the west and east of the 40° E longitude. Finally, using the obtained findings from this study and seismic velocity models proposed for this region by previous studies, a probable two-dimensional crust model was constituted.     

Equatorial spread-F initiation: Post-sunset vortex, thermospheric winds, gravity waves

We present experimental evidence and modeling results which indicate that eastward thermospheric wind is the primary controlling factor of equatorial spread-F initiation in the post-sunset ionosphere. Eastward wind-driven Pedersen currents are able to polarize F-region density perturbations with westward tilting wavefronts into rapidly growing modes to trigger the formation of spread-F bubbles. The described process is so rapid that seeding requirements of spread-F initiation by external factors such as gravity waves are effectively eliminated.     

Bedrock bedding,landsliding and erosional budgets in the Central European Alps

We explore the controls of the litho‐tectonic architecture on the erosional flux in the 370‐km² Glogn basin (European Alps). In this basin, the bedding and schistosity of the bedrock dip parallel to the topographic slope on the NW valley flank, leading to a non‐dip slope situation on the opposite SE valley side. While the dip slope condition has promoted the occurrence of landslides (e.g. the c. 30‐km² deep‐seated Lumnezia landslide), the opposite non‐dip slope side of the valley hosts >100‐m‐deeply incised tributary streams. ¹⁰Be concentrations of stream sediments yield catchment‐averaged denudation rates that vary between 0.27 ± 0.03 and 2.19 ± 0.37 mm a^?1, while the spatially averaged denudation rate of the entire basin is 1.99 ± 0.34 mm a^?1. Our ¹⁰Be‐based approach reveals that the Lumnezia landslide front contributes c. 30–65% of the entire sediment budget, although it covers <5% of the Glogn basin. This suggests a primary control of the bedrock bedding on erosion rates and processes.     

Possible climatic controls on the accumulation of Peru's most prominent alluvial fan: The Lima Conglomerate

Sediment accumulation can occur in response to a change in either tectonic or climatic driving forces. Here, we explore these controls on the deposition of the Lima Conglomerate, Peru. We use a combination of quantitative methods to explore the age of sediment accumulation, the provenance of the material and the paleo-erosion rates recorded by these deposits. Isochron burial dating with cosmogenic ¹⁰Be and ²⁶Al yield an age of c. 500 ka for the base (490 ± 70 ka) and the uppermost sample situated c. 30 m higher upsection (490 ± 80 ka). Results of paleo-erosion rate estimates with concentrations of in situ ¹⁰Be show a c. 60% increase from 105 ± 10 mm ka^-1 for the base to 169 ± 14 mm ka^-1 for the uppermost sample. Finally, provenance tracing with in situ U/Pb ages on detrital zircon implies that the material has been derived from the entire drainage basin. The combination of results suggests that sediment accumulation occurred in response to an erosional pulse, which affected the entire basin within a short time interval. Because ¹⁰Be data represents a large spatial record of erosion, we exclude the possibility where a breakout of a lake or a focused release of material in response to earthquakes, were responsible for the large material flux. Instead, the erosional pulse was likely to have occurred at the scale of the entire basin, supporting the idea of a larger-scale, most likely climate driven control. In this context, the accumulation age of c. 500 ka falls into an orbital cycle fostering the emerging picture in the literature that sediment routing in the Andes have most likely been driven by climate and cyclic changes. We suggest that the Andean mountain range offers an ideal laboratory to explore the erosional history in relation to climate patterns, at least in Peru. © 2018 John Wiley & Sons, Ltd.     

CCD <Emphasis Type="Italic">UBV</Emphasis> photometric study of five open clusters—Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1

In this study, we present CCD UBV photometry of poorly studied open star clusters, Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1, located in the first and second Galactic quadrants. Observations were obtained with T100, the 1-m telescope of the TÜB?TAK National Observatory. Using photometric data, we determined several astrophysical parameters such as reddening, distance, metallicity and ages and from them, initial mass functions, integrated magnitudes and colours. We took into account the proper motions of the observed stars to calculate the membership probabilities. The colour excesses and metallicities were determined independently using two-colour diagrams. After obtaining the colour excesses of the clusters Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1 as \(0.19\pm0.06\), \(0.15\pm0.05\), \(0.32\pm0.05\), \(0.12\pm 0.04\), and \(0.43\pm0.06\) mag, respectively, the metallicities are found to be \(0.00\pm0.09\), \(0.02\pm0.11\), \(0.03\pm0.07\), \(0.01\pm0.08\), and \(0.01\pm0.08\) dex, respectively. Furthermore, using these parameters, distance moduli and age of the clusters were also calculated from colour-magnitude diagrams simultaneously using PARSEC theoretical models. The distances to the clusters Dolidze 36, NGC 6728, NGC 6800, NGC 7209, and Platais 1 are \(1050\pm90\), \(1610\pm190\), \(1210\pm150\), \(1060\pm90\), and \(1710\pm250\) pc, respectively, while corresponding ages are \(400\pm100\), \(750\pm150\), \(400\pm100\), \(600\pm100\), and \(175\pm50\) Myr, respectively. Our results are compatible with those found in previous studies. The mass function of each cluster is derived. The slopes of the mass functions of the open clusters range from 1.31 to 1.58, which are in agreement with Salpeter’s initial mass function. We also found integrated absolute magnitudes varying from ?4.08 to ?3.40 for the clusters.