2D Seismic interpretation of strike-slip faulting, salt tectonics, and Cretaceous unconformities, Atlas Mountains, central Tunisia

A field structural analysis has been carried out in the High Atlas Mountains of Morocco. Paleostress solutions provide information on the successive orientations of major stress patterns during Mesozoic and Cenozoic time. An initial rift stage in the Early Jurassic is characterized by normal–oblique faults bounding tilted blocks, which are associated with tensional paleostress patterns whose minimum component trends west-northwest–east-southeast. Faults parallel to this direction are interpreted as paleotransfer faults. We assume that the divergent motion responsible for the opening of the rift system in the Early Jurassic was oriented west-northwest–east-southeast, subparallel to the paleotransfer faults and the trend of the minimum component (σ3) of the paleostress field. The east–west-trending Jurassic central–eastern High Atlas rift opened obliquely, and not in a pure strike-slip stress regime along east–west-striking faults as previously proposed. A later stage of rifting (Middle Jurassic) is characterized by large normal faults and is supposed to accompany local movements, probably due to gravity. The uplift of the High Atlas belt occurred mainly during the Cenozoic period as a consequence of a north–south- to northwest–southeast-directed compression related to collision between Europe and Africa.

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Salt Tectonics Offshore Morocco - New Insights from Numerical Modelling and 2D Seismic Interpretation

78th EAGE Conference and Exhibition 2016 - Workshops ◽

10.3997/2214-4609.201601648 ◽

2016 ◽

Author(s):

L. M. Pichel ◽

M. Huuse ◽

E. Finch ◽

J. Redfern

Keyword(s):

Numerical Modelling ◽

Seismic Interpretation ◽

Salt Tectonics

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Mechanical relationship between strike-slip faulting and salt tectonics in the Northern Tunisian Atlas: The Bir-El-Afou salt structure

Journal of Structural Geology ◽

10.1016/j.jsg.2021.104501 ◽

2021 ◽

pp. 104501

Author(s):

Zayneb Amri ◽

Amara Masrouhi ◽

Chahreddine Naji ◽

Olivier Bellier ◽

Hemin Koyi

Keyword(s):

Strike Slip ◽

Salt Tectonics ◽

Salt Structure ◽

Tunisian Atlas

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The Fault Analysis Projection System (FAPS) - A new seismic interpretation and structural geological interpretation tool.

Exploration Geophysics ◽

10.1071/eg989001 ◽

1989 ◽

Vol 20 (2) ◽

pp. 1

Author(s):

B. Freeman ◽

M. Badley ◽

G. Yielding

Keyword(s):

Seismic Interpretation ◽

Strike Slip ◽

Fault Analysis ◽

Normal Faults ◽

Simple Task ◽

Projection System ◽

Geological Interpretation

Recent research has demonstrated that the displacement on faults varies in a systematic manner, both vertically and laterally. Contours of displacement on strike projections display ordered patterns for isolated normal faults, strike-slip faults and syn-sedimentary faults. Recognition of these ordered patterns forms the basis for a new seismic interpretation and structural/geological interpretation tool, enabling objective verification of fault correlation, identification of bad fault or horizon picks, and a better understanding of the overall kinematic framework. The Fault Analysis Projection System (FAPS) is a computerized implementation of this technique designed to run on UNIX-based workstations. The FAPS uses the X-windows graphics system which permits different elements of the interpretation/analysis to be viewed at the same time and is designed to make adjustments to interpretations a simple task. For example, an interpreter may work on a map in one window, a set of sections in another window, perform a graphics screen-edit on data in a third window and view the results of an analysis in a separate, fourth window.

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Halokinetic analysis of the Frade field area, Campos Basin, Brazil: Salt tectonics within an offshore strike-slip setting

Interpretation ◽

10.1190/int-2018-0201.1 ◽

2020 ◽

Vol 8 (4) ◽

pp. T869-T883

Author(s):

Stephanie Wischer ◽

Webster Mohriak

Keyword(s):

Strike Slip ◽

Oil Field ◽

Salt Diapir ◽

Salt Tectonics ◽

Tectonic Structures ◽

Complex Deformation ◽

Pull Apart Basin ◽

Campos Basin ◽

Salt Structure ◽

3D Volume

The Frade field, located within the Campos Basin in the southeastern Brazilian margin, is a key oil field that produces from Oligo-Miocene turbidite reservoirs that derived their structural positioning due to the presence of an underlying salt diapir. The evolution of the Frade salt structure was examined using well data, selected 2D lines, and a 3D volume that were interpreted in detail focusing on the Aptian evaporite interval and its influence on the overburden. Analysis of the salt-sediment interaction indicated a complex deformation history that included five main stages of deformation, some assisted by tectonic reactivation episodes. (1) Post-Albian reactivation of a nearby north–northwest-south–southeast basement fault caused the Albian carbonate interval to fault, forming a west–northwest-east–southeast shear zone with a dextral strike-slip component. This movement initiated thin-skinned tectonics that offset the Albian carbonates and formed a pull-apart basin that accommodated a thick Late Cretaceous interval, which weakened the overburden and allowed for the initial formation of the Frade salt diapir. (2) Renewed diapir growth thickened and redistributed the Cenomanian-Maastrichtian sedimentary package proximal to the Frade salt anticline. (3) An initial and localized collapse of the Frade salt anticline occurred during early Paleogene extension. (4) Paleogene shortening caused the salt to flow, resulting in salt withdrawal in the southeast and diapir rejuvenation near its present-day apex, forming several inversion structures. In addition, the Paleogene shortening resulted in a low-relief anticlinal structure that rotated the turbidites into geometries favoring hydrocarbon accumulation. (5) A return to an extensional regime occurred during the late Oligocene/early Miocene. The results of this study provide a new insight into the development of strike-slip salt tectonic structures and show for the first time within the Campos Basin an Albian-level pull-apart basin that formed in association with salt tectonics.

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