Tectonic and crustal structure of the Eastern Pontides using Bouguer gravity data

To study the crustal structure of the Eastern Pontides, gravity data obtained from the World Gravity Map (WGM2012) were analyzed using total horizontal derivative (THD), Parker–Oldenburg (PO) inversion, and normalized full gradient (NFG) techniques. The THD method was applied to the data after bandpass fltering of the Bouguer gravity data in order to image the discontinuities in the basement levels. The maximum amplitude values of the THD were used to reveal the discontinuities caused by the density diference in the Eastern Pontides and its vicinity. In addition, the basement upper surface topography of the region was calculated and mapped with the inverse solution, and the presence of uplift areas in the Eastern Pontides was determined. As a result of the inverse solution, it was found that the depth of the basement in the Eastern Pontides belt reached approximately 5.5 km. An average basement upper surface depth of 3 km was calculated for the area under the Black Sea coastline. Finally, depth values were calculated using the NFG method under the determined profles, and the depth values found by the inverse solution were tested. For the basement upper surface topography, the results obtained from the two depth calculations were found to be compatible, within error limits of ±0.2 km.