Integrating Gravity Data With Remotely Sensed Data for Structural Investigation of the Aynak-Logar Valley, Eastern Afghanistan, and the Surrounding Area

This study integrates gravity data with interpreted lineaments from remotely sensed images and geological fault in an effort to understand the geological structure of the Aynak-Logar Valley (ALV) and its surrounding area in eastern Afghanistan. Integrated analysis of Landsat Enhanced Thematic Mapper Plus (ETM+), Shuttle Radar Topography Mission (SRTM), and Digital Elevation Model (DEM) data was applied for lithological mapping and extraction of geological lineaments and landforms. Gravity data were used to delineate a detailed picture of the subsurface structure.

Several gravity interpretation techniques such as horizontal gradient (HG), tilt derivative (TD), and analytic signal (AS) were applied to the gravity data with the objective of making geological features such as faults and contacts more visible, and also a three-dimensional (3-D) inversion model of gravity data was developed to show the density distributions in the study area. The combination of these geoscience data provides information about the subsurface structure of ALV. The interpreted faults from remote sensing are striking NE-SW. The faults and contacts from geological map and gravity data analysis are striking mainly in NNE-SSW, which is the direction of the Kabul block trending fault structure.