Structural dynamics in northern Atlas of Tunisian, Jendouba area: insights from geologyand gravity data

摘要

This paper presents a new interpretation of the geometry of Triassic alignment of J. Sidi Mahdi –J. Zitoun in Medjerda Valley Plain (Northern Tunisia) based on detailed analysis of gravity and seismic reflection data. The main results of gravity analysis do not show a distinguish gravity anomaly over Triassic evaporites bodies. The positive gravity anomaly seems to be related to the entire structure containing Triassic evaporites and Cretaceous carbonates and marl strata. Horizontal gravity map highlights NE-SW and NW-SE two prominent directions that surround Triassic outcrops and their bordering strata. Specifically, the seismic sections show a structural evolution and halokinesis in our study area. Analysis of seismic lines associated to interval iso-velocity sections highlight Triassic rising structures related to Mesozoic and Cenozoic tectonic control. The resulted structures are interpreted as original Mesozoic diapirs followed by a lateral outpouring above the late Cretaceous to Eocene series.