CLASTIC SEQUENCE STRATIGRAPHIC FRAMEWORK OF CAMBRIAN AND PERMIAN AGES IN MISSA KESWAL AREA, POTWAR SUB BASIN, PAKISTAN

Abstract

Seismic sequence stratigraphy has completely revolutionized the field of stratigraphy as it has led to the introduction of new ways for the purposes of correlation and mapping of sedimentary rocks. The area under study is Missa Keswal oil field which is located ten kilometres from Gujar Khan in Rawalpindi District of Punjab and it is about 70 kilometers SSE of Islamabad. This area has undergone compression and pop up anticlinal structure was interpreted. Stratigraphically this area lies in Potwar sub basin Pakistan which is very well known for its complex geological features. A tentative model explaining Sequence stratigraphic framework of area was developed using wireline logs and seismic lines. Focus of research was on Permian and Cambrian aged Formations. Depositional model 3 and Genetic model were used as base. Both the Cambrian and Permian aged Formations fall in second order of cyclicity. Trends of Gamma ray log aided in identification of depositional environments of Formations. Two Type 1 Sequence boundaries have been identified and marked on top of Khewra Sandstone and top of Tobra Formation respectively. Three MFS were identified in Kussak Formation, one MFS in Dandot Formation and three clinoformal geometries in Jutana Dolomite were observed. Owing to the poor quality and resolution of data, truncations and geometries were merged in reflections and therefore limited translation of sequential model was possible. Downlap in Khewra Sandstone, incision in Baghanwala Formation in Rajian-01 well and thinning of data towards Eastern Salt Range in Missa Keswal-01 and 03 was observed.