Comptes rendus de l’Acad´ emie bulgare des Sciences GEOLOGIE Stratigraphie APPLICATION OF 2D RESISTIVITY PROFILING FOR DELINEATION OF SPECIFIC LITHOLOGICAL BODIES Asen Mitev, Marlena Yaneva (Submitted by Academician T. Nikolov on September 14, 2012 ) Abstract The present study aims to demonstrate the potential of 2D resistivity pro- filing in recognizing and determining the sediment successions in areas with lack of outcrops. Neogene Gotse Delchev Basin was chosen for a test area. Ap- plication of this method is a first attempt to delineate the diatomite deposits in SW Bulgaria. Diatomites from Baldevo Formation were clearly delineated ac- cording to their resistivity characteristics. Alluvial successions from Nevrokop Formation were recognized in 2D resistivity profiles and distribution of a Qua- ternary travertine layer was outlined. Key words: resistivity profiling, Neogene, sedimentology Introduction. Various geophysical methods are used for detailed logging of the surface-subsurface geological composition. Electrical surface geophysical methods can be used to detect changes in the electrical properties of the sub- surface. The two-dimensional (2D) resistivity profiling method records a large number of resistivity readings in order to map lateral and vertical changes in ma- terial types along a survey line [ 1, 2 ]. Its advantage is the detail of measurements comparing to other resistivity methods. The aim of the present study is to demonstrate the potential of 2D resistivity profiling in recognizing and determining of a specific sediment body among the sedimentary successions. We applied 2D resistivity profiling on areas built of diatomites and used the obtained data in delineating the diatomite bodies among other sediments. 2D resistivity profiling was applied to 6 sites located in Gotse Delchev Basin: near the villages of Ognyanovo, Kornitsa, Musomishta and north of the town of Gotse Delchev (Fig. 1). For the present study, we chose two sites with diatomite deposits in Gotse Delchev Basin (Ognyanovo and Kornitsa) and two other sites without any (Gotse Delchev–North and Musomishta). The diatomites near the village of Ognyanovo in Gotse Delchev Basin are known since the first half of the last century. The The present study was accomplished under the financial support of NSF – DO 02-139/2008. 231