Active Tectonics in the Guelma Basin (Eastern Algeria)

In the Guelma intra-mountainous basin, the neotectonic activity is concentrated around the NE-SW and E-W oriented folds and faults. The Djebel Debbagh fold structure and the Roknia fault, which are the northern and western borders of the basin respectively, shows witnesses of Quaternary tectonics. Southward, the Debbagh fold is limited by a typical east-west right lateral strike slip that was reactivated during the post-Miocene period and, which shows recent tectonic activity affecting the Pliocene deposits. Other structures, such as the Roknia fault (or Hammam Debbagh-Roknia fault), which is the western boundary of the Guelma basin is a normal fault with right lateral component that plays a role in the placement of travertine deposits. The tectonic stress inferred from field measurements shows NNW-SSE directions that are at the origin of the Guelma basin development in a pull-apart system. Field investigations and satellite image analysis show that the recent tectonic activity in the Hammam Debbagh zone is marked by deformations affecting recent Pliocene and Quaternary series.