Refraction microtremor (ReMi (TM))-based investigation of the accumulation of Quaternary sediments on the northern edge of Isparta, Turkey

摘要

Refraction microtremor (ReMi (TM)) technique is one of the most effective techniques to obtain near-subsurface average shear wave velocity structure. This technique was used to delineate the subsurface structure of the Plio-Quaternary sediments deposited on the limestone bedrock. Transect data were collected at 130 points along the N-S profile at the northern part of the Isparta basin with a 20-m interval. The seismic velocity-depth models were produced from these data separately, and then, 2D seismic section was obtained from these models. The subsurface layers and possible fault structures were interpreted according to this cross section. The field observation and the shear wave velocity section showed that this area was controlled by normal fault systems causing a NNW and SSE extensional structure. The formed depression structure had been filled in time by the Plio-Quaternary sediments. This case was interpreted as an evidence of fluvial reworking possibly during flash-flood events. As a result, this study shows that the ReMi (TM) technique may also be used for delineating near-surface bedrock topography and fault structures.