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In Northern Tunisia, geological structuring is very diverse. This diversification is due to its localization, which is situated within the convergence zone between Africa and Eurasia plates. This situation allows to a complicated geodynamic evolution from Permian Tethy’s opening to the quaternary. Our study area is a key zone because we find severa...
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... density is very suitable with the lithology of the outcrops in this region. The complete Bouguer Anomaly map obtained in our study area ( Figure 4) shows values between -10 mGal and -38 mGal. These values correspond to anomalies that reflect the heterogeneous densities in the subsurface, related to sources of different depths. ...
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... density is very suitable with the lithology of the outcrops in this region. The complete Bouguer Anomaly map obtained in our study area ( Figure 4) shows values between -10 mGal and -38 mGal. These values correspond to anomalies that reflect the heterogeneous densities in the subsurface, related to sources of different depths. ...
Citations
... In this study, compared to previous work in Northern Tunisia (Jallouli et al. 2002;Jallouli et al. 2005;Inoubli and Mansouri 2006;Benassi et al. 2006;Hamdi Nasr et al. 2008;Hamdi Nasr et al. 2009;Amiri et al. 2011;Arfaoui et al. 2011;Hachani et al. 2016;Balti et al. 2016;Hicheri et al. 2018), we use the tilt angle method producing a structural map showing the gravity lineaments for the study area. Our main contribution in this study has been to present the effectiveness of the TDR, ED for the interpretation of gravity data. ...
Abstract
To gain insight into the organization of the underlying structures in the northern Tunisia region, detailed gravity data in
combination with geological information have been investigated.
Many techniques have been used, including residual, upward continuations and derivative. Results from the edge detection
technique based on the tilt angle map generated from the frst vertical gradient were discussed and compared with results
obtained by Euler deconvolution. The compilation and comparison of gravity maps and geology maps enable the determination of major structural trends. It validates specifc structural elements acquired from outcrops and specifes new ones.
According to the gravity data interpretation, the area of study is impacted by several underlying structural trends. The main
trend direction is NE–SW, which is closely linked to the J Chehid and Bled Tejra Akseb trends. NW–SE direction is the
second signifcant trend that borders Bled El Ghorfa to the north. Additional determined trends include: the N–S direction,
which is associated with the Lakouat fault. A strong correlation was noted between results from tilt angle method and Euler
deconvolution, showing that they may both be used to delineate the main structural framework of the region.
... This technique is commonly used to highlight near-surface geological features, and to raise the large wavenumber element of spectrum, where zero values of vertical gradient (VG) normally corresponds to the geological boundary [21]. The mathematical equation for vertical gradient can be written as: A horizontal gradient is used to calculate the rate of change in the potential plane in x and y directions [22]. In addition, a horizontal gradient is used to detect the difference in density or susceptibility to potential field model. ...
The province of West Papua in Indonesia is an area crossed by three major faults, including Sorong, Koor, and Ransiki, leading to the collision of Australia, the Pacific, and Eurasia. In the past, there have been strong and damaging earthquakes on these faults, manly Ransiki fault in the South Manokwari regency. Identification of the Ransiki fault segment was conducted by geological subsurface modeling using the earth gravity field of the Global Gravity Map (GGM) based on satellite measurements implicates for earthquake source parameters. The GGM is seen as a solution for the unavailability of direct measurements in the region. The gravity field analysis begins with data reduction using SRTM2gravity as modern terrain correction to obtain a complete Bouguer anomaly. Furthermore, the gravity gradient approach through vertical and horizontal gradients, analytical signal, and the tilt angle are applied to emphasize a contact or fault structures that are not visible using a 2D fast Fourier transform. Overall, the gravity gradient analysis obtained results that were compatible with the alignment of the Ransiki fault segment which direction of the northwest to south. The gravity inversion produces a geological subsurface model that clearly shows the Ransiki fault segment, associated with a low rock density distribution, thought to the Befoor formation and quaternary sediments, located between high-density rocks correlated to Arfak volcanic rocks as a basement.
... The role of diapirism has always been a hot subject of debate. However, the most adopted interpretation is that the Albian diapirism was superimposed by the late Cretaceous-Paleogene compression and then by the Tertiary stage forming the present-day structures (Hicheri et al. 2018). ...
... We used published seismic line in the north of Tunisia (Rigo et al. 1996) and gravity model proposed by numerous authors (Chikhaoui et al. 2002, Jallouli et al. 2005Talbot 2005;Vila et al. 1998;Ayed-Khaled et al., 2012;Gharbi et al. 2013, Hicheri et al. 2018 to further define the morphology of the Triassic bodies in the studied area. The results were compared with published analog model of salt tectonics (Koyi 1988;Jackson and Talbot 1994;Jackson and Hudec 2017;Costa and Vendeville, 2002;Berastegui et al. 1998). ...
Facies and morphostructural enable the recognition of salt–sediment interaction close to the Triassic evaporites of the NE-SW elongated structures of the Kef–Tajerouine area, NW Tunisia. Unconformity-bound growth strata associated with passively rising salt diapirs defined as halokinetic sequences have been recognized within the Debadib-Ben Gasser Triassic salt body (El Kef–Tajerouine area), at the Triassic contact at Guern Halfaya, at J. Slata, and the South of J. Harraba. Salt tectonics was active during the period spanning from the late Albian in the salt province of NW of Tunisia. Facies analyses of Albian sediments revealed that the diapirism appears mainly in the deep facies of the Fahdene Formation. The halokinetic Albian sequences are formed owing to the variations in sediment-accumulation rate versus diapir-rise rate and roof thickness. The halokinetic sequences above and beside the Triassic salt bodies suggest passive diapirism at this time interval. Composite halokinetic sequences bounding unconformities correlate to periods of slower deposition (transgressive system tract).
... It was probably Thompson (1982) who first demonstrated the application of Euler deconvolution technique (EDT) to magnetic anomalies; subsequently, many authors extended the technique in analyzing the potential field data, including gravity; the most recent example is by Hicheri et al. (2018). EDT solutions are particularly successful over geologic structures with strong gravity gradients as expressed by the following expression: ...
The corresponding author did not notice the need to add “International Scientific Partnership Program-0039” in the Acknowledgement section. Given in this article is the corrected statement.
... It was probably Thompson (1982) who first demonstrated the application of Euler deconvolution technique (EDT) to magnetic anomalies; subsequently, many authors extended the technique in analyzing the potential field data, including gravity; the most recent example is by Hicheri et al. (2018). EDT solutions are particularly successful over geologic structures with strong gravity gradients as expressed by the following expression: ...
The Ghawar Anticline (GA) belongs to super-giant Rayn Anticlines in Eastern Saudi Arabia (ESA). The origin of GA is ascribed to basement-uplift, although, its evolution remains obscure due to inadequate knowledge on configuration of deeper crust and role of crust in producing the basement uplift. The nature of deeper crust is comprehended by an integrated crustal model utilizing DEM, Bouguer anomaly (BA) map, and high-pass-filtered residual BA map by using Laplacian operator, tilt derivative, theta maps, and Euler 3D convolution map on BA data. These maps prove helpful in delineating the structural outline of GA and its edge detection of the uplifted basement against the adjoining sub-basins. 2D gravity inversion for a traverse represents a model on subsurface mass anomalies extending from basement to Moho depth, for which, constraints are utilized based on the nature of seismogenic crust in ESA and available results of receiver function for four seismic stations. A 3-layer source on mass anomalies with depths of 3–5, 22.5, and 40 km is inferred. Poisson’ ratio based on Vp/Vs values is high: 0.41–0.42 on its limbs to 0.44 at its median part, where the receiver function data reveals a zone of mantle uplift. Main results derived from Integrated Gravity Model underlying the traverse are as follows: (i) Moho is uplifted by ~ 9 km below GA, for a 220-km width, (ii) the zone of basement uplift in the top crust is ~ 4.5 km over a distance of ~ 75 km, where deep-penetrative faults assist the basement uplift, and (iii) a higher thermal regime probably influenced the crustal configuration below GA.
Abstract A new inversion algorithm of gravity data utilizing the particle swarm optimization (PSO) algorithm is used to interpret dipping faults models. The PSO technique is stochastic in nature; its development was motivated by the common in‐flight performance of birds looking for food. Particles or models represent birds. Individual particles have a location and a velocity vector. The parameter value represents the position vectors. PSO is adjusted by random particles or models and searches for targets by updating generations. This algorithm determines the dipping faults different parameters (amplitude factor, depth to the center of the upper part of the layer, depth to the center of the lower part of the layer, fault dip angle, and the origin of the fault trace). Herein, the PSO algorithm is applied to noise‐free synthetic data, synthetic data contaminated with different random noise levels (5%, 10%, and 15%) and real field gravity data from Egypt. The applicability and efficiency of the PSO inversion algorithm are well demonstrated for synthetic and field gravity data. The errors of the different estimated parameters are calculated for synthetic data, also, the root mean square error is calculated for synthetic and real data. The parameters estimated from real data matches well with that resulted from different published techniques. From the results obtained by using the present technique, we can apply the proposed technique in different applications, like mining and ore exploration.
