This book presents a significant amount of structural, paleomagnetic and magnetic fabric data in the Central High Atlas (Morocco). The authors thoroughly described and analyzed the present-day structure of this intraplate chain through 22 of cross-sections, potential field data analysis and 3D reconstruction. In addition, the authors propose a palinspastic reconstruction of the structure of the basin at 100 Ma (i.e., post-extension and pre-compression) to finally evaluate its Mesozoic and Cenozoic geodynamic evolution. This books presents (1) a unique three-dimensional model at the chain scale, (2) an analysis of the ca. 100 Ma remagnetization, to perform palinspastic restorations of most representative structures, (3) as well as the interpretation of the magnetic fabrics in order to unravel the tectonic or deformation setting that the rocks underwent in different parts of the basin.
This book is of interest to structural geologists in Northern Africa, the Mediterranean and Iberia, as well as to those interested in inverted intraplate basins and paleomagnetists from around the planet. Also, this book is intended to help students to understand better the geological evolution of the Atlas and therefore Morocco and surrounding areas.
Author(s): Pablo Calvín, Antonio M. Casas-Sainz, Teresa Román-Berdiel, Juan J. Villalaín
Series: Springer Geology
Publisher: Springer
Year: 2023
Language: English
Pages: 665
City: Cham
Foreword
Preface
Acknowledgements
Introduction
Contents
Contributors
The Geological Setting of the Moroccan High Atlas and Its Plate Tectonics Context
1 Geographical and Geological Setting
2 The High Atlas in Its Geological Context: Surrounding Geological Units
2.1 The Sahara Domain
2.2 The Anti-Atlas
2.3 The Meseta Domain
2.4 The Rif Chain
3 Geological Frame of the Moroccan High Atlas
3.1 The Atlantic High Atlas
3.2 The Marrakech High Atlas
3.3 The Central High Atlas (CHA)
3.4 The Eastern High Atlas
4 Geodynamic Frame of the High Atlas and Evolution of the APWP
5 The Main Geodynamic Events in North Africa: Implications in Atlasic Geology
5.1 Permian–Triassic Stage
5.2 First Rifting Event: Late Triassic to Early Jurassic
5.3 Second Rifting Event: Late Liassic to Early Dogger (180 Ma)
5.4 Bajocian–Late Jurassic Stage
5.5 Early Cretaceous
5.6 Late Cretaceous-Cenozoic Inversion
6 Magmatic Events, Hydrothermalism and Mineralization
6.1 Triassic: The CAMP Event
6.2 Jurassic-Cretaceous Event
6.3 Cenozoic Event
6.4 Hydrothermalism and Mineralization
7 Stratigraphic Frame of the Central High Atlas
7.1 Triassic
7.2 Jurassic
7.3 Upper Jurassic-Lower Cretaceous
7.4 Lower Cretaceous
7.5 Post-Turonian Cretaceous Deposits
7.6 Cenozoic Deposits
8 Structuring of the Moroccan High Atlas
8.1 Extensional Structures
8.2 Post-basinal, Pre-inversion Tectonic Structures
8.3 Alpine Compressional Structures
8.4 Crustal Roots for Atlasic Structures: The Geophysical Background
8.5 Recent Evolution of the Atlas Belt: Topographic Features
References
Structure of the Central High Atlas (Morocco). Constraints from Potential Field Data and 3D Models
1 Main Structural Features
1.1 Southern Atlas Fold-and-Thrust Belt (Zone 1)
1.2 Northern Atlas Thrust System (Zone 2)
1.3 Western Sector: The Large Interference Synclines and Basement-Involved Folds (Demnate Area, Zone 3)
1.4 Central Sector (1): Thrusts and Diapiric Anticlines (La Cathédrale Area, Zone 4)
1.5 Central Sector (2): Thrusts, Anticlines and Diapirs (Imilchil Area, Zone 5)
1.6 Eastern Sector (1): Cleavage-Related Linear Structures (Tounfite Area, Zone 6)
1.7 Eastern Sector (2): Vergence-Switching Ridges (Midelt-Rich Area, Ziz River, Zone 7)
2 Seriated Cross Sections
3 Input from Modeling of Potential Field Data
3.1 Petrophysical Properties
3.2 Magnetic Maps Processing
3.3 Results
3.4 The Geophysical Anomalies in Their Relation to Geological Features and Evolution of the CHA
3.5 2.5D Modelling. Configuration and Interpretation of Magnetic and Gravimetric Models
4 Contributions of 3-D Reconstructions to the Geometry of the Central High Atlas
4.1 Methods and Workflow
4.2 3D Structural Model of the Central High Atlas
4.3 Potential and Limitations of the 3D Model
References
Magnetic Properties of the Jurassic Sedimentary Rocks of the Central High Atlas Affected by a Regional Chemical Remagnetization
1 Methodology
2 General Magnetic Fraction in the Atlasic Rocks
2.1 Carbonates
2.2 Red Beds
3 Magnetic Properties of Magnetite-Bearing Remagnetized Carbonates
3.1 SP vs. SSD Grain Size
3.2 ARM vs. IRM Experiments
3.3 Coercivity Spectra
3.4 Discussion and Summary
4 Carriers of the Magnetic Susceptibility
4.1 Magnetic Susceptibility of Carbonates
4.2 Magnetic Susceptibility of Red-Beds
References
Paleomagnetism of the Central High Atlas. The Widespread Cretaceous Remagnetization and Structural Implications
1 Materials, Sampling Strategy and Methods
2 Natural Remanent Magnetization of Mesozoic High Atlas Rocks
2.1 Carbonates
2.2 Red Beds
3 Directional Analysis of the Characteristic Remanent Magnetization
4 Age of the High Atlas Remagnetization
5 Extent of the High Atlas Carbonate Remagnetization
6 Restoration of the Paleomagnetic Directions. Paleo-Dips at the Remagnetization Acquisition Time (100 Ma)
6.1 Method
6.2 Paleo-dip Evolution Diagram (PED)
7 Conclusions
Appendix
References
Geodynamic Evolution During the Mesozoic and Cenozoic in the Central High Atlas of Morocco from Anisotropy of Magnetic Susceptibility
1 Sampling and Methodology
2 Magnetic Fabric (RT-AMS) Results
2.1 Global RT-AMS Results
2.2 RT-AMS by Zones and Types
3 Magnetic Subfabrics (LT-AMS and AARM) Results
3.1 Scalar Parameters
3.2 Orientation Distribution of Grains, Information of the Magnetic Subfabrics (LT-, RT-AMS and AARM)
3.3 Comparison with Petrofabrics
4 Structural Interpretation of the Magnetic Fabrics/Tectonic Implications of the Magnetic Fabric Orientation
4.1 Strain Characterization from Magnetic Fabrics in the Central High Atlas
4.2 Timing of Acquisition of AMS: Information Derived from Magnetic Subfabrics Separation
5 Conclusions
Appendix
References
Kinematics of Structures and Basin Evolution in the Central High Atlas. Constraints from AMS and Paleomagnetic Data
1 Paleodips and Fold Tests. Results and Limitations
2 Origin of Individual Structures According to Paleomagnetism and Magnetic Fabrics Data
3 Restored Cross-Sections
4 Significance and Meaning of Major Structures in the Central High Atlas from the Perspective of Magnetic Techniques
4.1 Deformation of the Paleozoic Basement
4.2 The Asymmetry of the Chain: Compressional Features of the Southern Atlas Fold-and-Thrust Belt
4.3 Compressional Features of the Northern Belt
4.4 Diapirism, Magmatism and Thrusting in the Central High Atlas
4.5 Geophysical Constraints to Large-Scale Structural Features
4.6 Internal Deformation: The Cleavage Domain
4.7 The Structural Style of the Central Zone: Thin-Skinned or Thick Tectonics?
4.8 Geometry of the Overall Extension and Inversion of the Atlasic Basin
5 Conclusions. The Contribution of Magnetic Techniques to the Evolution of the Central High Atlas
5.1 Paleomagnetism and AMS Applied to the Study of the CHA
5.2 The Intermediate Stage in Basin Evolution
5.3 Basin Geometry: Transtension Versus Salt Tectonics?
5.4 Final Considerations: Comparison with Other Basins of the Tethys Domain
5.5 Concluding Remarks
Appendix
References
