It is generally believed that various exploration failures in the offshore areas of Pakistan are due to the absence of a mature petroleum system. However, a few recent gas shows and shales with 0.55–3.24% TOC suggest that a Middle-Upper Miocene lowstand systems tract (LST) exists that possesses organic, paleo-environmental, and sequence stratigraphic characteristics of a potential source rock. The objective of this work was to highlight and delineate the slope and basin facies through seismic sequence stratigraphy and seismic attribute analysis as a new approach to the interpretation of the southwestern Lower Indus Basin of Pakistan. Working within a sequence stratigraphic framework, four sequences have been delineated on the basis of reflection termination patterns. A sea-level curve was constructed from the reflection patterns representing coastal onlap. This sea-level curve was compared to a hypothetical sea-level curve generated by a spectral analysis Fourier transform function on the density logs.