Investigating fracture–cracked systems with geophysical methods in Bayburt Kıratlı travertine

Abstract

There are many outcropping masses on the K?ratl? travertine fields where a new or open quarry is planned to be exploited. In this study, ground penetrating radar (GPR) and vertical electrical sounding (VES) have been applied on these fields in order to identify massive or weathered blocks and fracture?cracked systems in a short time and at low cost. GPR data were acquired on two areas, named Ocakustu (Ocakustu 1, Ocakustu 2) and Alarduc (Alarduc 1, Alarduc 2), using a 100?MHz unshielded and 250?MHz shielded antennas on 35 profiles. Generally, radargrams obtained from GPR profiles revealed massive or weathered blocks and fracture?cracked systems of these fields. The quarry operation was stopped in Ocakustu 1 due to the intensely fracture?cracked and weathered structures of the travertine field imaged by GPR. Detailed information was not obtained under the topping layer of 4?m from GPR sections?on Ocakustu 2 area. Therefore, VES was also performed along four profiles which made it possible to define the areal extension and thickness of the lithotype in this site. Electrical resistivity tomography (ERT) sections?have been generated by the inversion of the VES data. The subsurface geometries with resistivity values in the area were determined from these sections. Massive blocks with high resistivity could be seen at depths of 2?10?m and 10?20?m below the surface on these results and it was suggested that the quarry should be extended these parts. In addition, according to the GPR data, fracture?cracked blocks were present in Alarduc where a travertine quarry is thought to be operated. The places that will be started and orientated to quarry can be determined with respect to radargrams on Alarduc 1. Ultimately, the exploitation of a quarry was not recommended due to the extremely fracture?cracked systems found in Alarduc 2.