The Geology of the Arabian-Nubian Shield (Regional Geology Reviews)

Preface
	Why This Book?
	Contents
Contents
About the Editors
1 The Arabian–Nubian Shield, an Introduction: Historic Overview, Concepts, Interpretations, and Future Issues
	Abstract
	1.1 Introduction
	1.2 ANS: Plate Tectonic Setting
	1.3 ANS: Geologic Investigations
		1.3.1 Historic Developments
		1.3.2 Mineral Resources and Exploration
		1.3.3 Geologic Mapping, Surveys, and Findings
	1.4 ANS: Nomenclature
	1.5 ANS: External Boundaries
		1.5.1 ANS Northwestern Margin
		1.5.2 ANS Southern Margin
		1.5.3 ANS Eastern Margin
		1.5.4 ANS Margins in the Southwestern Arabian Peninsula
		1.5.5 ANS Margins in the Eastern Arabian Peninsula
		1.5.6 ANS Northern Extent
	1.6 ANS: Internal Divisions
		1.6.1 Volcanic Arcs; Where, How Many, and Origin?
		1.6.2 Mineral Belts: An Aid to Metallogenic Analysis and Exploration Targeting
		1.6.3 Structural or Tectonic Belts and Domains
		1.6.4 Divisions in the Egyptian Eastern Desert
		1.6.5 Tectonostratigraphic Terranes
		1.6.6 Isotopic Domains
		1.6.7 Inherited Zircons
	1.7 Concluding Comments
	Acknowledgements
	References
2 The Boundary Between the Saharan Metacraton and the Arabian Nubian Shield: Insight from Ediacaran Shoshonitic Granites of the Nuba Mountains (Sudan): U–Pb SHRIMP Zircon Dating, Geochemistry and Sr–Nd Isotope Constraints
	Abstract
	2.1 Introduction
	2.2 Granitoids in the ANS and the SmC and Change in Stress Regime
	2.3 The SmC–ANS Boundary in Sudan
	2.4 Geological Setting and Petrography
	2.5 U–Pb SHRIMP Dating of Zircon
		2.5.1 Analytical Techniques
		2.5.2 Results
	2.6 Geochemistry of the Late-Orogenic Granitoids
		2.6.1 Analytical Techniques
		2.6.2 Major and Trace Elements Chemistry
	2.7 Sr and Nd Isotopes
		2.7.1 Analytical Techniques
		2.7.2 Rb–Sr and Sm–Nd Isotopic Results
	2.8 Discussion
		2.8.1 Lithochemistry and Structural Characterization of the Nuba Post-collisional Plutons
		2.8.2 The Source of the Parental Magma of the Nuba Post-collisional Plutons
		2.8.3 Timing of Magmatism, Metamorphism and Regional Correlations
		2.8.4 Implications for the Boundary of the Saharan Metacraton in Southern Sudan
	2.9 Conclusions
	Acknowledgements
	References
3 The Southern Part of the Arabian–Nubian Shield in Kenya and Tanzania
	Abstract
	3.1 Introduction
	3.2 Geological Overview
	3.3 Lithology, Formation Ages and Tectonic Setting
		3.3.1 Sobo Unit
		3.3.2 Galana Unit
		3.3.3 Sagala Unit
		3.3.4 Kinyjki Unit/Kasigau Group
		3.3.5 Kurase Group/Eastern Granulites Metasediments
		3.3.6 Eastern Granulites Metamagmatics
	3.4 Isotopic Constraints
	3.5 Tectonics and Metamorphism
	3.6 Interpretation
	3.7 Discussion and Conclusions
	Acknowledgements
	References
4 Tectonic Evolution of the Pan-African Belt in Western Ethiopia, Southern Arabian-Nubian Shield
	Abstract
	4.1 Introduction
	4.2 Regional Geologic Setting
	4.3 Lithology
		4.3.1 Gimbi Terrane
		4.3.2 Nejo Terrane
		4.3.3 Asosa Terrane
		4.3.4 Tulu Dimtu–Baruda Belt
		4.3.5 Intrusive Rocks
		4.3.6 Young Volcano-Sediments
	4.4 Structures
		4.4.1 Gimbi Terrane
		4.4.2 Nejo Terrane
		4.4.3 Asosa Terrane
		4.4.4 Tulu Dimtu–Baruda Belt
		4.4.5 NW-Trending Structures
	4.5 Discussion and Summary
		4.5.1 Structural Evolution
		4.5.2 Tectonic Interpretation and Regional Correlation of Terranes
	Acknowledgements
	References
5 Neoproterozoic Crustal Evolution of the Northernmost Arabian-Nubian Shield, South Jordan
	Abstract
	5.1 Introduction
	5.2 Aqaba Complex
		5.2.1 Metamorphic Suites
			5.2.1.1 Abu Barqa Metamorphic Suite
			5.2.1.2 Janub Metamorphic Suite (JMS)
			5.2.1.3 Abu Saqa Schist
		5.2.2 Gabbroids and Granitoids
			5.2.2.1 Duheila Hornblendic Suite (DHS)
			5.2.2.2 Rahma Foliated Suite (RFS)
			5.2.2.3 Darba Tonalitic Suite
			5.2.2.4 Urf Porphyritic Suite (UPS)
			5.2.2.5 Rumman Suite (RS)
			5.2.2.6 Yutum Suite (YS)
	5.3 Araba Complex
		5.3.1 Safi Group
			5.3.1.1 Saramuj Conglomerate Formation (SCF)
			5.3.1.2 Haiyala Volcaniclastic Formation (HVF)
		5.3.2 The Araba Mafic Suite
		5.3.3 Humrat-Feinan-Mubarak Suite (HFMS)
		5.3.4 Aheimir Volcanic Suite (AVS)
	5.4 Ediacaran Dike Swarms
	5.5 Summary and Conclusions
	Acknowledgements
	References
6 Lithospheric Structure of the Arabian–Nubian Shield Using Satellite Potential Field Data
	Abstract
	6.1 Introduction
	6.2 Data
	6.3 Methodology
		6.3.1 EHGA Method
		6.3.2 Parker–Oldenburg Method
	6.4 Results
		6.4.1 Edge Results
		6.4.2 Moho and LAB Results
	6.5 Discussion
	6.6 Conclusions
	Acknowledgements
	References
7 Evolution of the Arabian Nubian Shield and Snowball Earth
	Abstract
	7.1 Introduction
	7.2 Snowball Earth and Late Neoproterozoic Glaciation
	7.3 Overview of ANS and EAO Development
	7.4 Expected Manifestations of Neoproterozoic Glaciations in the ANS and EAO
	7.5 Evidence for Glaciation in the ANS
		7.5.1 Evidence for Tonian (c. 780–755 Ma) Glaciation
			7.5.1.1 sim780 Ma Diamictite in Eastern Sudan (Meritri Group) and Central Arabian Shield (Mahd Group)
			7.5.1.2 sim750 Ma Ghamr and Amudan Volcanosedimentary Basins, Central Arabian Shield
		7.5.2 Evidence for Sturtian Glaciation (sim717–659 Ma)
			7.5.2.1 Ethiopia/Eritrea—Tambien Group
			7.5.2.2 Banded Iron Formation of Egypt and Arabia
			7.5.2.3 Atud Diamictite (Egypt) and Nuwaybah Formation (Zaam Group) (NW Arabia)
			7.5.2.4 Um Zariq and Zaghara Formations, Sinai Peninsula, Egypt, Northern ANS
			7.5.2.5 Hadiyah Group, NW Arabian Shield
		7.5.3 Evidence for Marinoan (Onset sim650–639, to sim635 Ma) and Ediacaran (sim580–550 Ma) Glaciation
			7.5.3.1 Post-amalgamation (Ediacaran) Basins
			7.5.3.2 Gondwanan Margin Basins
			7.5.3.3 Role of Glaciation in the Formation of the Afro-Arabian Peneplain
	7.6 Conclusions
	Acknowledgements
	References
8 The Arabian–Nubian Shield Within the Neoproterozoic Plate Tectonic Circuit
	Abstract
	8.1 Introduction
	8.2 A Full-Plate Tectonic Reconstruction
	8.3 The ANS Within the Northern ‘East African Orogen’
	8.4 The Mozambique Ocean, Azania and Afif–Abas
	8.5 The Eastern Margin of the EAO (NW India to Oman)
	8.6 The Arabian–Nubian Shield (ANS)
	8.7 The Western Margin of the EAO (the Eastern Saharan Metacraton)
	8.8 Discussion
	8.9 Conclusions
	Acknowledgements
	References
9 Early Ensimatic Stage of the Arabian-Nubian Shield
	Abstract
	9.1 Introduction
	9.2 Rodinia Pre-rifting Configurations
		9.2.1 SWEAT Model
		9.2.2 “Missing-Link” Model
		9.2.3 Other Models
	9.3 Rodinia Rifting
	9.4 Origins and Configurations of the Mozambique Ocean—Rift or Remnant?
	9.5 Remnants of Rodinia Within the ANS
		9.5.1 Rodinia Continental Signatures Within the ANS
		9.5.2 Mozambique Ocean Signatures Within the ANS
			9.5.2.1 Setting and Occurrence
			9.5.2.2 Magma Type
			9.5.2.3 Tectonic Setting
	9.6 Conclusions and Open Questions
	References
10 Terrane Accretion Within the Arabian-Nubian Shield
	Abstract
	10.1 Introduction
	10.2 The Rationale
		10.2.1 Terrane Terminology
		10.2.2 Formation of Terranes
	10.3 Formation and Amalgamation of Gondwana Supercontinent
		10.3.1 Neoproterozoic Pan-African Orogeny
		10.3.2 The East African Orogen (EAO)
	10.4 The Arabian-Nubian Shield (ANS)
		10.4.1 Terrane Analysis, Amalgamation, and Accretion of the ANS
		10.4.2 Assembly of the ANS and Crustal Growth
	10.5 Tectonic Models of the ANS
		10.5.1 Earlier Models of Evolution of ANS
			10.5.1.1 A Single Immature Island Arc Evolution (Island Arc-Accretion Model)
			10.5.1.2 Successive Formation and Accretion of Ensimatic Island Arcs Model
			10.5.1.3 Repeated Rifting of an Older Sialic Crust
			10.5.1.4 Microplate Accretion Model
			10.5.1.5 Reconstruction of the ANS Model
			10.5.1.6 Pan-African Continental Margin Model
		10.5.2 Recent Models of ANS Evolution: Arc-Accretion Model
	10.6 Faults and Shear Zones in the ANS
	10.7 Ophiolite Zones as Evidence for Sutures in the ANS
		10.7.1 Arc–Arc Sutures
		10.7.2 Arc-Continent Sutures
		10.7.3 The Eastern Margin of the ANS
		10.7.4 The Western Margin of the ANS
	10.8 Post-accretionary Structures
	10.9 Post-amalgamation Basins of the NE Arabian Shield
	10.10 Conclusions
	References
11 Tonian/Cryogenian Island Arc Metavolcanics of the Arabian-Nubian Shield
	Abstract
	11.1 Introduction
	11.2 Island Arc Volcanism of the Northern Nubian Shield
		11.2.1 Island Arc Volcanic Rocks of the Eastern Desert of Egypt
			11.2.1.1 Island Arc Volcanic Rocks of North Eastern Desert (NED)
			11.2.1.2 Island Arc Volcanic Rocks of Central Eastern Desert (CED)
			11.2.1.3 Island Arc Volcanic Rocks of South Eastern Desert (SED)
			11.2.1.4 Mineralization Related to Island Arc Volcanism of the Eastern Desert of Egypt
			11.2.1.5 Age of the Younger Metavolcanic Rocks of the Eastern Desert
		11.2.2 Island Arc Volcanic Rocks of Sinai
		11.2.3 Geochemistry and Petrogenesis of Island Arc Volcanics in the Eastern Desert of Egypt
			11.2.3.1 Geochemical Characters of Major, Trace and REEs
			11.2.3.2 Tectonomagmatic Discrimination Plots
			11.2.3.3 Petrogenesis
				(i) Tholeiitic Metavolcanics
				(ii) Calc-Alkaline Metavolcanics
				(iii) Felsic Metavolcanics
			11.2.3.4 Stages of Island Arc Volcanicity in the Eastern Desert
	11.3 Island Arc Volcanism in the Arabian Shield
	11.4 Island Arc Volcanism in the Southern Nubian Shield
		11.4.1 Island Arc Metavolcanics of Sudan
		11.4.2 Island Arc Metavolcanics of Ethiopia
		11.4.3 Island Arc Metavolcanics of Eritrea
	11.5 Conclusions
	References
12 Neoproterozoic Ophiolites of the Arabian-Nubian Shield
	Abstract
	12.1 Introduction
	12.2 Tectonic History of the Arabian-Nubian Shield
	12.3 Components of the ANS Ophiolites
	12.4 Geochronology
	12.5 Protolith and Geodynamic Setting
	12.6 Alteration and Metamorphism
	12.7 Examples of ANS Ophiolites
		12.7.1 Saudi Arabian Ophiolites: Jabal Al-Wask
		12.7.2 Egyptian Ophiolites: Wadi Ghadir
	12.8 Mineralization of the ANS Ophiolites
		12.8.1 Gold
		12.8.2 Chromitite
	12.9 Discussion
	Acknowledgements
	References
13 Ghadir Ophiolites, Eastern Desert, Egypt: A Complete Sequence of Oceanic Crust in the Arabian-Nubian Shield
	Abstract
	13.1 Introduction
	13.2 Geological Setting
		13.2.1 Ghadir Ophiolite Sequence
		13.2.2 Ghadir Ophiolitic Mélange
		13.2.3 Dismembered Ophiolites
	13.3 Geochemistry and Tectonic Setting
		13.3.1 Geochemical Characteristics
		13.3.2 Ophiolitic Affinity and Tectonic Setting
		13.3.3 Comparison with Other Ophiolites
	13.4 Petrogenesis and Tectonic Evolution
	13.5 Concluding Remarks
	References
14 Evidence for Mesoproterozoic Components in the Arabian-Nubian Shield
	Abstract
	14.1 Introduction
	14.2 Early Ideas on the Existence of Pre-Pan-African Crust in the ANS
	14.3 Mesoproterozoic or Older Xenocrystic and Detrital Zircons in the ANS
	14.4 Nature of the Older Cratonic Areas Flanking the ANS
	14.5 Significance of the Mesoproterozoic Rocks in Crustal Evolution of the ANS
	14.6 Conclusions
	References
15 Najd Shear System in the Arabian-Nubian Shield
	Abstract
	15.1 Introduction
	15.2 The Arabian-Nubian Shield Within the East African Orogen
		15.2.1 The Najd Orogeny in the Tectonic Frame of the Arabian Shield
	15.3 The Najd Fault System
		15.3.1 The Main Najd Megashears
			15.3.1.1 Ruwah Fault Zone
			15.3.1.2 Ar Rika Fault Zone
			15.3.1.3 Qazaz Fault Zone
			15.3.1.4 Ajjaj Fault Zone
			15.3.1.5 Halaban-Zarghat Fault Zone
	15.4 Evidence for the Timing of Deformation on the Najd Fault System
	15.5 Kinematic History of the NFS
	15.6 Metamorphic Conditions of Najd Shearing
	15.7 Strain Analysis Across the Najd Shear Zones
	15.8 Remote Sensing and Geophysical Studies of the Najd Fault System
	15.9 Brittle Evolution of the Najd Fault Zone
	15.10 Role of Transpression in the Evolution of the Najd Fault System
	15.11 N-S to NE-SW and Other Trending Dextral Strike-Slip Faults of the Southern Saudi Shield
	15.12 Discussion of Najd as a Regional System
		15.12.1 Along-Strike Trends in NFS Characteristics
		15.12.2 Lithospheric Structure of the NFS
		15.12.3 Najd Shear Corridor in Egyptian Eastern Desert
		15.12.4 Tectonic Models for the NFS
		15.12.5 Brittle Reactivation of the NFS and Seismicity
		15.12.6 Najd-Related Mineralization
		15.12.7 Najd Role in Hydrogeological Systems
	Acknowledgements
	References
16 Low Angle Normal-Sense Shear Zones, Folds and Wrench Faults During the Post-Amalgamation Stage of the Arabian-Nubian Shield
	Abstract
	16.1 Introduction
	16.2 Geologic Setting
	16.3 Post-Amalgamation Events
		16.3.1 Taphrogenic Event
			16.3.1.1 Low Angle Normal Shear Zones (LANSZ)
		16.3.2 Wrenching
		16.3.3 Post-Amalgamation Shortening
			16.3.3.1 Convergence-Related Shortening
			16.3.3.2 Transpression-Related Shortening
				N–S to NNW–SSE Shortening
				E–W to ENE–WSW to NE–SW Shortening
			16.3.3.3 Superposition and Fold Interference Pattern Between Compression- and Transpression-Related Folds
	16.4 Discussion
		16.4.1 Extension: Motives, Evidence, and Deformation vs. Collapse Extension
			16.4.1.1 Extensional Deformation
				Evidence of Extensional Deformation
			16.4.1.2 Possible Models for Extensional Deformation
				Orogen-Normal Shortening and Orogen-Parallel Extension
				Wrench-Related Extension
			16.4.1.3 Non-Tectonic Gravitational Collapse-Related Extension
				Was There a Significant Uplift Throughout the ANS?
		16.4.2 Wrenching
		16.4.3 Shortening: Convergence- and Transpression-Related
			16.4.3.1 Active Tectonics-Related Structures
		16.4.4 The Eastern Desert Low Angle to Sub-Horizontal Shear Zone: A Shortening-(Tectonic) versus Extensional Collapse-(Non-Tectonic) Related Fabric!
		16.4.5 Inversion Tectonics and Basins Inversion
		16.4.6 Complications of Tectonic Interpretations: A Regional Single Versus Multi-models
	16.5 Conclusions
	References
17 Arc Accretion and Calc-Alkaline Plutonism Finalizing the Subduction Stage in the Arabian–Nubian Shield, with Emphasis on the Gneissic Core Complexes
	Abstract
	17.1 Introduction
	17.2 Age of Arc Collisions
	17.3 Syn-Collisional (Arc-Related) Older Granitoids
	17.4 Gneissic Domes: Continental Windows (Infrastructure) versus Arc-Related Plutonism and Metamorphism
	17.5 Arc-Related Gneissic Complexes and Metamorphic History in the Sinai Peninsula, with an Emphasis on the Wadi Kid Environ
	17.6 Terrane Accretion in the Arabian Shield
	17.7 Conclusions
	References
18 Origin of the Volcanic-Arc Signature in Late-Orogenic Granitoids from the Arabian–Nubian Shield
	Abstract
	18.1 Introduction
	18.2 Tectono-Magmatic Evolution of the ANS
	18.3 Geochemical Characteristics
	18.4 Discussion and Conclusive Remarks
		18.4.1 Constraints from Zircon Hf Isotope Composition
		18.4.2 Hypothetical Geodynamic Model
	Acknowledgements
	References
19 Post-amalgamation Depositional Basins in the Arabian-Nubian Shield: The Hammamat Basins of Egypt
	Abstract
	19.1 Introduction
	19.2 Geological Setting
	19.3 Stratigraphy
	19.4 Sedimentology, Facies, Environment
	19.5 Provenance
	19.6 Petrography
	19.7 QFL Sedimentary Tectonic Environment
	19.8 Geochemistry
	19.9 Structure of the Basins—the Effects of the Eastern Desert Shear Zone (EDSZ)
	19.10 Strain Studies
	19.11 Basal Unconformity, Boundary Faults, Basin Shape
	19.12 Internal Deformation Structure—Folds and Faults
	19.13 Metamorphism
	19.14 Geochronology
	19.15 Discussion
		19.15.1 Relations of the Hammamat Basins to Each Other
		19.15.2 Information Based on Basin Size, Width and Thickness of Sedimentary Fill
		19.15.3 Relations Between Basin Parameters and Degree of Basin Inversion for a Simple Graben Model
		19.15.4 Subsidence and Inversion of the Larger Hammamat Basins
		19.15.5 Tectonic Setting of the Hammamat Basins
		19.15.6 Future Trends
	19.16 Conclusions
	References
20 Volcanism During the Post-accretionary Stage of the Arabian–Nubian Shield
	Abstract
	20.1 Introduction
	20.2 Geotectonic Evolution of the Arabian–Nubian Shield
	20.3 General Classification of the ANS Volcanic Rocks
	20.4 Post-accretionary Volcanic Sequences in the ANS
		20.4.1 Early Calc-Alkaline Volcanic Sequences
		20.4.2 Late Alkaline/Peralkaline Volcanic Sequences
	20.5 Ages of Post-accretionary Volcanic Sequences in the ANS
	20.6 Collision of East and West Gondwana
	20.7 Existence of Old Continental Crust Beneath the ANS
	20.8 Examples of Post-accretionary Volcanic Sequences in the ANS
		20.8.1 Early Calc-Alkaline Volcanic Sequences
			20.8.1.1 Dokhan Volcanics in the Eastern Desert of Egypt
				Stratigraphic Relation Between the Dokhan Volcanics and the Hammamat Sediments
				Tectonic Setting of the Dokhan Volcanics
				Compositional Gaps
				Metamorphism
				Geochemical Characteristics
				Evolution Models for the Dokhan Volcanics
			20.8.1.2 Rutig and Ferani Volcanics in Sinai
				Rutig Volcanics
				Ferani Volcanics
			20.8.1.3 Murdama and Bani Ghayy Groups in Saudi Arabia
				Murdama Volcano-Sedimentary Succession
				Bani Ghayy Group
			20.8.1.4 Saramuj Conglomerate in Jordan
			20.8.1.5 Elat Conglomerate
		20.8.2 Late Alkaline/Peralkaline Volcanic Sequences
			20.8.2.1 Attala Felsite in the Eastern Desert of Egypt
			20.8.2.2 Katharina Volcanics in Sinai
			20.8.2.3 Biq’at Hayareah Volcanics in Sinai
			20.8.2.4 Elat Volcanics
			20.8.2.5 The Aheimir Volcanic Suite in Jordan
	20.9 Geodynamic Significance of ANS Post-accretionary Volcano-Sedimentary Successions
	20.10 Conclusions
	Acknowledgements
	References
21 An Overview Study of Zircon Geochronology from Sinai Precambrian Basement: Implications for Crustal Evolution of Northern Arabian-Nubian Shield
	Abstract
	21.1 Introduction
	21.2 Regional Geology of the Sinai Precambrian Basement
	21.3 Data Compilation
		21.3.1 Magmatic Crystallization Ages
		21.3.2 Maximum Depositional Age
		21.3.3 Metamorphic Age
		21.3.4 Inherited Zircon
	21.4 Discussion
		21.4.1 Comparison of Zircon Ages from the Sinai Peninsula and Arabian-Nubian Shield
		21.4.2 Implications for the Evolution of the ANS
	21.5 Conclusion
	Acknowledgments
	Appendix 2: U–Pb and Pb–Pb Single Zircon Age Data from the Sinai Peninsula, Egypt
	References
22 Spectral Characteristics of Listvenites and Serpentineites Along Ophiolite-Decorated Megashears (Suture Zones) in the Arabian Shield Using ASD Fieldspec and Satellite Data
	Abstract
	22.1 Introduction
	22.2 Geologic Setting
		22.2.1 Jabal Ess Area
		22.2.2 The Bir Umq Ophiolite Complex
		22.2.3 Jabal Jizah
		22.2.4 Jabal Tays—Al Amar Area
	22.3 Materials and Methods
		22.3.1 Portable ASD FieldSpec Data Collection
	22.4 Results
		22.4.1 Description of ASD Fieldspec Profiles
			22.4.1.1 Jabal Ess Area
			22.4.1.2 Bir Umq Area
			22.4.1.3 Jizah Area
			22.4.1.4 Jabal Tays—Al Amar Area
		22.4.2 Listvenites Discrimination Using Band Ratio Technique
			22.4.2.1 Jabal Ess Area
			22.4.2.2 Bir Umq Area
			22.4.2.3 Jabal Tays—Al Amar Area
			22.4.2.4 Discrimination of Listvenites Exposures at Jizah Area Using SPOT 5 Data
	22.5 Discussion
		22.5.1 Jabal Ess Area
		22.5.2 Bir Umq Area
		22.5.3 Jizah Area
		22.5.4 Jabal Tays—Al Amar Area
	22.6 Conclusions
	Acknowledgements
	References
23 Ore Deposits in the Arabian-Nubian Shield
	Abstract
	23.1 Introduction
	23.2 Tectonomagmatic Evolutions of the ANS
	23.3 Petrological Assemblages Characteristic for Mineral Deposits in the ANS
		23.3.1 Relicts of Oceanic Crust
		23.3.2 Island Arc Assemblages
		23.3.3 Mafic–Ultramafic Rocks
			23.3.3.1 The Dismembered Ophiolitic Ultramafic Rocks
			23.3.3.2 Arc-Related Metagabbros
			23.3.3.3 Concentrically Zoned Mafic–Ultramafic Complexes
			23.3.3.4 Unmetamorphosed Layered Younger Gabbros
		23.3.4 Felsic Plutonic Rocks
	23.4 Mineral Deposits in the ANS
		23.4.1 Mineral Deposits Associated with Mafic–Ultramafic Assemblages
			23.4.1.1 Ophiolitic Sequences
				Chromite Deposits
				Cu–Ni–Co Sulfide Deposits
				Asbestos, Magnesite, and Talc Deposits
			23.4.1.2 Non-ophiolitic Mafic–ultramafic Intrusions
				Ti-Fe Oxide Deposits
				Cu–Ni–Co Sulfide Deposits
		23.4.2 Mineral Deposits Associated with Metamorphosed Arc Volcanic-Volcaniclastic Rocks and Associated Arc-Related TTG Assemblages
			23.4.2.1 Orogenic Gold Deposits (OGDs)
			23.4.2.2 Stratiform Volcanogenic Massive Sulfide Deposits (VMSDs)
			23.4.2.3 VMS–Oxide Gold Deposits
			23.4.2.4 Cogenetic VMS-Epithermal Gold Deposits
			23.4.2.5 Epithermal Gold and Polymetallic Deposits
			23.4.2.6 Porphyry Cu–Au Deposits
			23.4.2.7 Algoma-Type Banded Iron Formation (BIF)
		23.4.3 Mineral Deposits Associated with Felsic Association
			23.4.3.1 Carbonatite Mineralization
			23.4.3.2 Deposits Related to Granites
				General Statement
				Intrusion-Related Gold Deposits (IRGDs)
				Tin-Tungsten Mineralization
				Tantalum–Niobium Deposits
				Molybdenum Mineralization
				Fluorite Mineralization
				Beryllium Mineralization
				Uranium Mineralization
	23.5 Discussion and Conclusions
	Acknowledgements
	References
24 Evolution and Mineralization of the Precambrian Basement of Yemen
	Abstract
	24.1 Introduction
		24.1.1 General Regional Setting
		24.1.2 History of Geological Investigations
			24.1.2.1 Geological Studies in Northern Yemen Prior to 1990
			24.1.2.2 Geological Studies in Southern Yemen Prior to 1990
			24.1.2.3 Post-unification Geological Studies
	24.2 Precambrian Basement Distribution and Terrane Interpretation
		24.2.1 Basement Distribution
		24.2.2 Terrane Definitions
		24.2.3 Proposed Wider Terrane Correlations
	24.3 Mineralization of the Precambrian Basement of Yemen
		24.3.1 Metallic Mineralization
			24.3.1.1 Gold Mineralization
			24.3.1.2 Copper and Copper-Nickel (PGE) Mineralization
			24.3.1.3 Iron (BIF) and Fe–Ti Oxide Mineralization
			24.3.1.4 Tin–Tungsten Mineralization
			24.3.1.5 Radioactive and REE-Nb-Ta Mineralization
		24.3.2 Non-metallic Mineralization
			24.3.2.1 Magnesite
			24.3.2.2 Feldspar and Quartz
				Talc
			24.3.2.3 Fluorite
	24.4 Conclusions
	Acknowledgements
	References
25 Applications of Remote Sensing and GIS in Geological Mapping, Mineral Prospecting and Groundwater Investigations in the Arabian-Nubian Shield: Cases from the Red Sea Hills of NE Sudan
	Abstract
	25.1 Introduction
	25.2 Geological Mapping
		25.2.1 Preamble
		25.2.2 Office Work Phase
		25.2.3 Field Work Phase
		25.2.4 Post-field Phase
			25.2.4.1 Petrographic Investigations
			25.2.4.2 GIS Manipulations
		25.2.5 Geological Mapping of Kadaweib Area, Red Sea Hills, NE Sudan
			25.2.5.1 Digital Image Processing of Landsat Image
				Colour Composites
				Principal Component Analysis
				Sultan’s Band Ratio Colour Composite
				Decorrelation Stretching
			25.2.5.2 GIS Manipulation
	25.3 Mineral Prospecting
		25.3.1 Background
		25.3.2 Mineral Resource of the Red Sea Hills of Sudan
			25.3.2.1 Gold
			25.3.2.2 Base Metals
			25.3.2.3 Copper
			25.3.2.4 Gypsum
			25.3.2.5 Iron
			25.3.2.6 Chromite
			25.3.2.7 Manganese
		25.3.3 RS and GIS Prospecting in the Red Sea Hills of NE Sudan
			25.3.3.1 History of Gold Mining in the Red Sea Hills of Sudan
			25.3.3.2 Mining Activity in the Red Sea Hills
				Ariab Mining Company (AMC)
				Orshab VMS
				Oheir Porphyry Copper
	25.4 Groundwater Investigations
		25.4.1 Preamble
		25.4.2 Rainwater Harvesting
		25.4.3 Investigations for Groundwater in Fractured and Weathered Basement Rocks
			25.4.3.1 Digital Processing of Satellite Images
			25.4.3.2 Lineament Mapping
			25.4.3.3 Structural Analysis
			25.4.3.4 Watershed Mapping
			25.4.3.5 Geophysical Investigations
	25.5 Conclusions
	References
26 Phanerozoic Minor Volcanics and Intrusives of the Arabian-Nubian Shield
	Abstract
	26.1 Introduction
		26.1.1 Alkaline Ring Complexes Including Associated Volcanics
		26.1.2 Gabal Elba and Gabal Shendeib Tertiary Alkaline Ring Complexes, Egypt (Case Study)
			26.1.2.1 Geologic Setting
			26.1.2.2 Geochemistry
			26.1.2.3 Radioelements Distribution in the Different Rock Types
		26.1.3 Geological Tertiary Basaltic Rocks of the Arabian-Nubian Shield
	26.2 Wadi Natash, South-Eastern Desert, Egypt of the Arabian-Nubian Shield
		26.2.1 Introduction
		26.2.2 Geological Setting of Wadi Natash Rocks
		26.2.3 Geology of the Rings
		26.2.4 Geochemistry
			26.2.4.1 Volcanic Rocks
		26.2.5 Radioelements Distributions
			26.2.5.1 Cretaceous Volcanic Rocks
	26.3 Felsite Dykes and Plugs of the Arabian-Nubian Shield
		26.3.1 Introduction
		26.3.2 Felsites at Um Safi Area, CED, Egypt
		26.3.3 Felsites at Wadi Ranga
		26.3.4 Felsites at Wadi El-Miyah
		26.3.5 Felsites at Wadi Shait
		26.3.6 Felsites at Gabal Atalla
		26.3.7 Geochemistry of Felsites Rock from the Eastern Desert, Egypt
		26.3.8 Radioelements Distributions
	26.4 Trachyte and Bostonite Dykes and Concordant Sheets
		26.4.1 Introduction
		26.4.2 El Atshan Area, CED, Egypt
			26.4.2.1 Geologic Setting
			26.4.2.2 Radioelements Distributions
		26.4.3 Wadi Kareem Volcanic Rocks, CED, Egypt
		26.4.4 Nasb El Qash Volcanic Rocks, CED, Egypt
		26.4.5 Um El Khors Area, CED, Egypt
		26.4.6 Geochemistry
		26.4.7 Um Doweila Bostonite, SED, Egypt
		26.4.8 Gabal Um Domi, SED, Egypt
		26.4.9 Gabal Umm Salatit Area, CED, Egypt
		26.4.10 Origin of Radioactivity at Bostonites and Trachytes Dykes, Eastern Desert of the Arabian-Nubian Shield
		26.4.11 Mineralogical Features
	26.5 Conclusions
	Acknowledgements
	References
27 Relationship of the Pan-African Tectonic Structures with the Opening of the Afar Triple Junction
	Abstract
	27.1 Introduction
	27.2 The Afar Triple Junction and Plume
		27.2.1 The Afar Depression
		27.2.2 The Surrounding Ethiopian Plateaus
			27.2.2.1 The Nubian Plateau
			27.2.2.2 The Somalian Plateau (also called Eastern Etiopian Plateau)
		27.2.3 Pre-rift Sequences Along Afar Margins
			27.2.3.1 Northern Afar
			27.2.3.2 Central Afar
			27.2.3.3 Southern Afar
	27.3 The Process of Development of the Continental Break-up in Afar
		27.3.1 Nature of the Main Ethiopian Rift: The Continental Rifting
		27.3.2 Mantle Plume(s) and Development Steps
		27.3.3 Determinant Tectonic Structures of the Pan-African Orogeny
		27.3.4 Axial Ranges, Present Oceanic Axis of Spreading
	27.4 Transverse Volcanic Ranges and Marginal Central Volcanoes
	27.5 Conclusions
	Acknowledgements
	References