Abstract
This study covers concession 6 in Sirt basin. It's located approximately between latitudes 28° 50' to 30° and longitudes 19°30' to 20°. The study involves interpreting gravity to delineate structures and faults. It also helps locate major structures within the study area. Gravity is very important for studying the subsurface structures. The Libyan Petroleum Institute (LPI) assembled a total of 8871 gravity values. These values cover an area that is 186km long and 96km wide. We gathered the gravity data on spaced irregular grids. The smallest grid spacing was 500m. The largest was approximately 1km. The high gravity anomaly shows up on the Bouguer gravity map. It is not always limited to the platform structures. For example, low gravity expression represents the Zaltan Platform. Also, the low gravity anomaly isn't always limited to the trough structures. A high gravity anomaly represents the Ajdabiya Trough, for example. The Bouguer gravity map shows prominent NW-SE and N-NW trends. The residual gravity map exhibits a dominant NW-SE trend. The application of the total horizontal gradient methods used to analyze gravity data. This clarified the subsurface structures of the study area. High gradient values delineate NNE-SSW and NW-SE trends. A strong N-S lineament occurs over the southern part of the study area. It is well indicated by the horizontal derivative. This study's horizontal derivative provides valuable information about the rift structures