Search results for "Anticline"
showing 10 items of 16 documents
Influence of pre-existing salt diapirs on 3D folding patterns
2014
Abstract The 3D detachment folding instability gives rise to a wide variety of fold shapes (e.g. from dome shape structures to long en-echelon or straight anticlines) as a result of interactions between growing fold segments. The 3D growth of these folds, as well as the wavelength and lateral propagation of folds, is controlled by the physical parameters of a detachment layer and its overburden. However, the existence of initial heterogeneities, such as pre-existing salt plugs within the sedimentary cover, might affect fold development as well. We use numerical modeling to investigate how the fold pattern is affected by pre-existing salt structures. High-resolution 3D folding simulations (w…
An Integrated Multiscale Method for the Characterisation of Active Faults in Offshore Areas. The Case of Sant’Eufemia Gulf (Offshore Calabria, Italy)
2021
Diagnostic morphological features (e.g., rectilinear seafloor scarps) and lateral offsets of the Upper Quaternary deposits are used to infer active faults in offshore areas. Although they deform a significant seafloor region, the active faults are not necessarily capable of producing large earthquakes as they correspond to shallow structures formed in response to local stresses. We present a multiscale approach to reconstruct the structural pattern in offshore areas and distinguish between shallow, non-seismogenic, active faults, and deep blind faults, potentially associated with large seismic moment release. The approach is based on the interpretation of marine seismic reflection data and …
Evidence of positive tectonic inversion in the north-central sector of the Sicily Channel (Central Mediterranean)
2016
In order to unravel the tectonic evolution of the north-central sector of the Sicily Channel (Central Mediterranean), a seismo-stratigraphic analysis of single- and multi-channel seismic reflection profiles has been carried out. This allowed to identify, between 20 and 50 km offshore the central-southern coast of Sicily, a ~80-km-long deformation belt, characterized by a set of WNW–ESE to NW–SE fault segments showing a poly-phasic activity. Within this belt, we observed: i) Miocene normal faults reactivated during Zanclean–Piacenzian time by dextral strike-slip motion, as a consequence of the Africa–Europe convergence; ii) releasing and restraining bend geometries forming well-developed pul…
Submarine canyon morphologies in the Gulf of Palermo (Southern Tyrrhenian Sea) and possible implications for geo-hazard
2011
12 pages, 12 figures, 1 table.
Influence of surface processes and initial topography on lateral fold growth and fold linkage mode
2015
Elongation of randomly distributed fold segments and their potential linkage are important for hydrocarbon exploration because it can greatly influence the morphology of the reservoir and both migration and accumulation of hydrocarbons in antiformal traps. Here we study the effects of surface processes and the presence of a topographic slope on the different linkage modes that can occur, and how these parameters affect the required horizontal offset for perturbations to link. The proposed numerical model represents a sedimentary cover detached over a much weaker basal decollement layer. The upper surface is modified by mass redistribution, which is achieved by a combination of fluvial and h…
Reverse and normal drag along a fault
2005
An analysis of the theoretical displacement field around a single dip-slip fault at depth reveals that normal and reverse fault drag develop by perturbation flow induced by fault slip. We analytically model the heterogeneous part of the instantaneous displacement field of an isolated two-dimensional mode II fault in an infinite, homogeneous elastic body in response to fault slip. Material on both sides of the fault is displaced and ‘opposing circulation cells’ arise on opposite sides of the fault, with displacement magnitudes increasing towards the center of the fault. Both normal and reverse drag can develop at the fault center depending on the angle between the markers and the fault; norm…
Multi-temporal tectonic evolution of Capo Granitola and Sciacca foreland transcurrent faults (Sicily channel)
2019
Highlights • Seismic reflection profiles evidence tectonic inversion and active strike-slip faults offshore SW Sicily foreland • Pliocene-Quaternary transpressional inversion of Late Miocene extensional basins • Transpressional fold growth rates were high in Latest Miocene-Pliocene and decreased during Quaternary Joint analysis of high-penetration multi-channel and high-resolution single-channel seismic reflection profiles, calibrated by deep well boreholes, allowed a detailed reconstruction of the Late Miocene to Recent tectonic history of the Capo Granitola and Sciacca fault systems offshore southwestern Sicily. These two fault arrays are part of a regional system of transcurrent faults t…
Sedimentological and tectonic context of Paleoproterozoïque Franceville basin (Gabon) : fluid pressure structures, bitumen and uranium mineralization
2016
Metallogenic deposits within paleproterozoic basins depend on generation and migration of fluids. The aim of this study is to provide a better understanding of tectonic, sedimentological and diagenetic setting of the uranium deposits in the Franceville basin and to characterize hydraulic fracturing impact on fluid migration processes in sandstone reservoirs.Tectonic study define the N180-170° transfer faults, associated with Archean tectonic and the N110-120° longitudinal normal faults. These two fault directions split the Franceville basin into small sub-basins. The longitudinal normal faults are associated with footwall anticlines and hanging wall synclines. The uranium deposits of France…
Discussion on Palaeozoic discontinuities in the Kuh-e Surmeh area (Zagros, Iran).
2015
20 pages; International audience; Evidence of several major unconformities in the Lower Palaeozoic succession in Iran lead to question the role of tectonic/eustatism/climate in terms of their formation. The studied Palaeozoic succession in the Kuh-e Surmeh Anticline is characterized by the preservation of two thin Ordovician and Lower Permian Formations separated by a large hiatus encompassing the Upper Ordovician up to the lowermost Permian. The Ordovician sequences were deposited in shallow shoreface to lower offshore environments and the Lower Permian corresponds to a wave-dominated estuarine system evolving to a delta system. These mainly clastic successions represent good reservoirs in…
Fold interaction and wavelength selection in 3D models of multilayer detachment folding
2014
Abstract Many fold-and-thrust belts are dominated by folding and exhibit a fairly regular fold-spacing. Yet, in map-view, the aspect ratio of doubly-plunging anticlines varies considerably from very elongated, and sometimes slightly curved, cylindrical folds to nearly circular, dome-like structures. In addition, the fold spacing often varies significantly around an average value. So far, it remains unclear whether these features are consistent with a folding instability. Therefore, we here study the dynamics of multilayer detachment folding, process by which shortening can be accommodated in thin-skinned fold-and-thrust belts. We start by analysing the physics of this process by using both …