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Integrated microstructural, quartz petrofabric and flow vorticity analyses on mylonitic rocks in the lower plate of the Neybaz Chatak Detachment Shear Zone provide significant information regarding the kinematic characteristics coeval with the Chapedony metamorphic core complex development within the Central East Iranian Microcontinent. Several kinematic shear sense indicators including quartz c-axis fabrics, S–C fabrics, rotated feldspar and mica fish reveal that the detachment shear zone has experienced a consistent top-to-the NE-directed progressive shear deformation. Detailed investigations on recrystallization types of quartz and feldspar in the mylonites demonstrate that the deformation occurred under the amphibolite facies condition corresponding to mid-crustal levels. A combination of investigations on mineral assemblages, microstructures of quartz and feldspar, and quartz lattice preferred orientations (LPOs) show that deformation temperatures ranged from 400 to 645 °C that were varied across a distance of ~21 km in the extension direction (NE-SW). The western and eastern parts of the study area experienced lower temperatures compared to the central parts. The gneissic mylonite record sub simple shear deformation (Wm = 0.56–0.85, 64–36%) associated with an increasing of pure shear component. These data highlight that the metamorphic rocks of the study underwent a non-coaxial shear with ductile low-angle normal faulting, resulting in subvertical thinning in the extensional deformation regime responsible for formation of the core complex. • This study provided information regarding the kinematics of the shear zone. • The detachment shear zone has experienced a consistent top-to-the NE shear. • Recrystallization types of quartz and feldspar highlighted the amphibolite facies. • The gneissic mylonite was recorded sub simple shear deformation. [ABSTRACT FROM AUTHOR]

DRASTIC is a model used to reliably assess the pollution potential of aquifers at global location. Despite various criticisms of this model or its optimization, sometimes the territorial or geological conditions still must rely on this model approach based on its simplicity. The existence of sinkholes in the alluvial aquifer with an underlying karst aquifer is a clear example of the need to change or optimize the DRASTIC model to improve accuracy of prediction. In this study, the DRASTIC model was changed by adding two factors, the distance to a sinkhole and the sinkhole catchment factors. The modified DRASTIC model was then used to evaluate the pollution potential of Abarkouh aquifer in Yazd province, Central Iran. The intrinsic vulnerability index of Abarkouh aquifer was calculated by the weighted sum method in GIS. The resulting numerical values ranged between 62 and 176 for full study area. Without adding the two layers related to Sin-DRASTIC, the generic DRASTIC Index map showed summed values ranging between 54 and 130. The final Sin-DRASTIC map was divided it into 4 orders very low (<106; 722 km2, 78%), low (107-133; 186 km2, 20%), low to moderate (133-160; 15.3 km2, 1.7%), and moderate vulnerability (161-176; 1.7 km2, 0.3%) vulnerability. Both of the created maps showed high Area Under the Curve values at 76% and 78% for the generic DRASTIC and Sin-DRASTIC respectively. However, the area of the aquifer containing the sinkholes showed low and very low zones of contamination vulnerability on the generic DRASTIC map. The sensitivity analysis showed that the aquifer vulnerability to pollution is mainly controlled by the vadose zone impacts and the sinkhole catchment factor. Therefore, it is concluded that for geologic settings containing sinkholes that are open or contain higher vertical hydraulic conductivity sediment compared to the general matrix of the unconfined aquifer, the Sin-DRASTIC model method yields a superior prediction. Sin-DRASTIC is a modified version of the generic DRASTIC method that used in regions wherein sinkholes occur The Sin-DRASTIC models was applied to intrinsic vulnerability of Abarkouh aquifer, Central Iran. The high AUC values at 76% and 78% for the generic DRASTIC and Sin-DRASTIC respectively, show the accuracy of the results. In the Sin-DRASTIC map the sinkhole areas showed a high potential for groundwater contamination [ABSTRACT FROM AUTHOR]