The Austrian Deformation Event in Algeria

Alan F. Chambers, Maria Baena, Jose Maria Jauregui, Eduardo Figari, and Candido Gomez
Repsol-YPF Exploracion SA, 28046 Madrid, Spain

An early Cretaceous deformation event of Barremian-Aptian age has long been recognised in Algeria. Commonly termed the “Austrian” event, this tectonic event was defined in the western Berkine region where it played a major role in the definition of giant hydrocarbon accumulations and where it can be precisely-dated due to the preservation of the Mesozoic sedimentary succession. Farther south, where the preservation of the Mesozoic series is incomplete the event is not so readily distinguished from older tectonic events, it has also been described.
In this paper the regional extent and expression of the Austrian event is presented and its role in the definition of hydrocarbon traps in the Berkine and Reggane-Ahnet basins described. Recently-acquired well and 3D seismic data permit the definition of the structural style associated with the event in the Gassi Touil area of the western Berkine basin. These data are integrated with geological outcrop data from the Fadnoun and Bled el Mass areas to define the event towards the south. Recently-published palaeomagnetic data acquired by Spanish and French teams from the 200Ma dolerite intrusions are presented to demonstrate the distinction between the early Hercynian and Austrian structural styles in southwestern Algeria.
Finally the observations at a local scale will be integrated to illustrate the significance of the Austrian event in Algeria at a regional scale.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece