Modeling of the principal parameters controlling the evolution of deformation in Atlassic belts: case study of the southern-central Tunisian Atlas

Author(s):  
Mohamed Sadok Bensalem ◽  
Mohamed Hedi Bensalem ◽  
Soulef Amamria ◽  
Mohamed Ghanmi ◽  
Fouad Zargouni
2016 ◽  
Vol 67 (4) ◽  
pp. 391-401 ◽  
Author(s):  
Mohamed Sadok Bensalem ◽  
Soulef Amamria ◽  
Mohamed Ghanmi ◽  
Fouad Zargouni

Abstract The quantification of deformation is one of the main objectives studied by geologists in order to control the evolution of tectonic structures and their kinematics during different tectonic phases. One of the most reliable methods of this theme is the direct calculation of quantity of deformation based on field data, while respecting several parameters such as the notion of tectonic inheritance and reactivation of pre-existing faults, or the relationship between the elongation and shortening axis with major faults. Thus, such a quantification of deformation in an area may explain the relations of thin- and thick-skinned tectonics during this deformation. The study of structural evolution of the Jebel Elkebar domain in the southern-central Tunisian Atlas permits us to quantify the deformation during the extensional phase by a direct calculation of the vertical throw along normal faults. This approach is verified by calculation of thickness of eroded strata in the uplifted compartment and of resedimented series, named the Kebar Formation, in the downthrown compartment. The obtained results confirm the importance of the Aptian-Albian extensional tectonic regime. The extent of deformation during the compressional phase, related to reactivation of pre-existing faults, is less than that of extensional phases; indeed the compressive reactivation did not compensate the vertical throw of normal faults. The geometry of the Elkebar fold is interpreted in terms of the “fault-related fold” model with a décollement level in the Triassic series. This permitted the partition of deformation between the basement and cover, so that the basement was allowed for a limited transport only, and the maximum of observed deformation was concentrated in the thin-skinned tectonics.


2016 ◽  
Vol 8 (1) ◽  
pp. 67-83 ◽  
Author(s):  
Mimi Stith ◽  
Alessandra Giannini ◽  
John del Corral ◽  
Susana Adamo ◽  
Alex de Sherbinin

Abstract A spatial analysis is presented that aims to synthesize the evidence for climate and social dimensions of the “regreening” of the Sahel. Using an independently constructed archival database of donor-funded interventions in Burkina Faso, Mali, Niger, and Senegal in response to the persistence of drought in the 1970s and 1980s, the spatial distribution of these interventions is examined in relation to population density and to trends in precipitation and in greenness. Three categories of environmental change are classified: 1) regions at the northern grassland/shrubland edge of the Sahel where NDVI varies interannually with precipitation, 2) densely populated cropland regions of the Sahel where significant trends in precipitation and NDVI decouple at interannual time scales, and 3) regions at the southern savanna edge of the Sahel where NDVI variation is independent of precipitation. Examination of the spatial distribution of environmental change, number of development projects, and population density brings to the fore the second category, covering the cropland areas where population density and regreening are higher than average. While few, regions in this category coincide with emerging hotspots of regreening in northern Burkina Faso and southern central Niger known from case study literature. In examining the impact of efforts to rejuvenate the Sahelian environment and livelihoods in the aftermath of the droughts of the 1970s and 1980s against the backdrop of a varying and uncertain climate, the transition from desertification to regreening discourses is framed in the context of adaptation to climate change.


2011 ◽  
Vol 6 (6) ◽  
pp. 2081-2087 ◽  
Author(s):  
Soulef Amamria ◽  
Mohamed Sadok Bensalem ◽  
Mohamed Ghanmi ◽  
Fouad Zargouni
Keyword(s):  

2008 ◽  
Vol 173 (1) ◽  
pp. 142-156 ◽  
Author(s):  
Eduardo Contreras-Reyes ◽  
Ingo Grevemeyer ◽  
Ernst R. Flueh ◽  
Martin Scherwath ◽  
Joerg Bialas

2015 ◽  
Vol 03 (01) ◽  
pp. 22-30
Author(s):  
Soulef Amamria ◽  
Mohamed Sadok Bensalem ◽  
Mohamed Ghanmi ◽  
Fouad Zargouni

Geomorphology ◽  
2018 ◽  
Vol 300 ◽  
pp. 77-94 ◽  
Author(s):  
Maryam Jaberi ◽  
Mohammad R. Ghassemi ◽  
Siavosh Shayan ◽  
Mojtaba Yamani ◽  
Seyed Mohammad Zamanzadeh

2019 ◽  
Vol 130 (1) ◽  
pp. 66-75
Author(s):  
Mohamed Sadok Bensalem ◽  
Mohamed Hedi Bensalem ◽  
Amira Ayed Khaled ◽  
Soulef Amamria ◽  
Mohamed Ghanmi ◽  
...  

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