Abstract: This study is aimed to perform digital geologic mapping and ASTER image analysis around southeasternpart of the Sivas Tertiary Basin. The interest area is located at the intersection of ENE-WSW orientedDeliler Thrust Belt and Tecer Fault Zone. Ophiolithic rocks which were belonging to Inner TaurideOcean Suture belt were outcropped in a vast region. This region also forms the northern boundary of theMenderes-Tauride platform. Tectonostratigraphy of the region is represented by two different sedimentarysequences separated by Deliler Fault Zone. While a thick cover of Oligocene-Miocene continental unit wasobserved on the southern section of Deliler Fault Zone, Lower-Middle Eocene marine, Oligocene gypsumand Lower Miocene marine sediments were outcropped on the northern part of this belt. Late Miocenecontinental deposits were folded while Plio-Quaternary fluvial sediments were observed horizontallyalong the Deliler Thrust Zone. Within the context of this study, interested region was mapped digitallyusing tablet pc and ArcPad software. Using this software, areas of outcropping units, linear geologic mapelements like faults and fold axes were recorded digitally during field studies and some database queriessuch as formation name, age, and lithologies were determined in terms of saving time and digitizationefforts. Additionally, a number of image processing efforts were applied to 14 channels ASTER image ofthe region to highlight geological features such as lithological boundaries and structural components.Thus, a detailed digital geologic map was formed at the end of this search. Furthermore, a number ofimage processing studies were acquired supporting geological mapping at field.