ARISTOTLE UNIVERSITY OF THESSALONIKI FACULTY OF SCIENCES SCHOOL OF GEOLOGY

203 Pages·2013·18.3 MB·English

ARISTOTLE UNIVERSITY OF THESSALONIKI
FACULTY OF SCIENCES
SCHOOL OF GEOLOGY
ISMAIL ABD EL RASOUAL THABET ISMAIL
Ass. Lecturer, Faculty of Science, Tanta Univ., Egypt
PETRLOGICAL AND MICROSTRUCTURAL EVOLUTION OF
SYN-TECTONIC GRANITOIDS ROCKS, MIGIF-HAFAFIT AREA,
SOUTH EASTERN DESERT, EGYPT
PhD THESIS
THESSALONIKI
2012
ISMAIL ABD EL RASOUAL THABET ISMAIL
MSc Geology, Faculty of Science, Tanta Univ., Egypt
PETRLOGICAL AND MICROSTRUCTURAL EVOLUTION OF SYN-
TECTONIC GRANITOIDS ROCKS, MIGIF-HAFAFIT AREA, SOUTH
EASTERN DESERT, EGYPT
A Thesis Submitted to the Faculty of Sciences – School of Geology in Partial Fulfillment
of the Requirements for the Degree of
DOCTOR OF PHILOSOPHY IN GEOLOGY
(Microstructural Geology)
Supervision Committee
Prof. AD. KILIAS Supervisor
Ass. Prof. AN. KORONEOS member of supervision
Dr. S. KAMH member of supervision
Examining Committee
Prof. AD. KILIAS, Thesis Adviser
Ass. Prof. AN. KORONEOS, Member
Dr. S. KAMH, Member
Prof. G. MIGIROS, Member
Prof. K. CHATZIPANAGIOTOU, Member
Ass. Prof. T. SOLDATOS, Member
O. Prof. D. MOUNTRAKIS, Member
Αριθμός Παραρηήμαηος Επιζηημονικής επεηηρίδας Τμήμαηος Γεωλογίας Ν 158°
© Ismail A. Thabet Ismail, 2013
All right reserved.
PETRLOGICAL AND MICROSTRUCTURAL EVOLUTION OF SYN-TECTONIC
GRANITOIDS ROCKS, MIGIF-HAFAFIT AREA, SOUTH EASTERN DESERT,
EGYPT
ISBN:
«The approval of the present philosophy Doctoral Dissertation from the School of
Geology of Aristotle University of Thessaloniki does not imply obligatory that the school
accepts the opinion of the writer»
CURRICULUM VITE
Name Ismail Abd El Rasoual Thabet Ismail
Date of Birth March 25, 1979
Nationality Egyptian
Qualifications B. Sc. Degree in Geology (2000-Very Good), M. Sc. Degree
Mineralogy (2008), Geology Department, Faculty of Science,
Tanta University, Egypt
Occupation Demonstrator of Geology from December 2001 until November
2008 and then, Assistant Lecturer of Geology from November
2008 until now at Geology Department, Faculty of Science,
Tanta University, Egypt
ACKNOLWLEDGEMENTS
First, utmost gratitude for the State Scholarships Foundation (IKY) for their
funding this research work and their support which making my time a great learning
experience in Greece.
My deep gratitude and appreciation to my head supervisor, Prof. Ad. Kilias
(AUTH, Greece) for his guidance, kindness, expertise and his patient supervision
during the development of this research. Also, I would like to thank Prof. An.
Koroneos (AUTH) for his boundless help and encouragement during the preparation
of this work.
The author is also greatly indebted to Dr. Samir Zaky kamh Geology
Department, Tanta University, Egypt for their kind supervision, continuous guidance,
and great help in both field and office works, and for reading the manuscript with
continuous encouragement and helpful advice.
This work could not have been completed without the help of many people. I am
grateful for Prof. M. Abd El-Wahed (Tanta Univ.) for accompanying me during the
field work and for his advises and ideas that improve the structural part of this thesis.
The author would like to acknowledge Dr. Tamer Sabry Zaki Abu Alam
(Geology Department, Tanta University) encouragement and help me during
laboratory to make chemical analysis in Graz, Austria, I would like to acknowledge
Prof. Theodoros Ntaflos for help me in laboratory to make chemical analysis in
Vienna, Austria and also I would like to acknowledge Dr. Lambrini Papadopoulou
(Mineralogy and Petrology Department, Aristotle University) encouragement and
help me during laboratory to make mineral chemistry analysis in Aristotle University,
Greece.
Appreciations go to the secretary of the school of Geology, AUTH for their help
during the completion period of this work and also Acknowledgments are due to all
my staff members in Geology Department, Faculty of Science, Tanta Univ. for their
continuous encouragement and scientific support.
Special thanks should go to the examining committee, Prof. G. MIGIROS, Prof.
K. CHATZIPANAGIOTOU, ASS. Prof. T. SOLDATOS and O. Prof. D.
MOUNTRAKIS, for their reading the manuscript of this thesis and for their kind and
fruitful discussion.
My deepest sense of gratitude is for my parents, brothers and sisters for their
unwavering encouragement and support throughout my life. I want to thank my wife
and children’s (Aya, Abd El-Rahman and Amar) for her never-wave support, her
faith in me and for her patience during the long time to prepare this thesis.
i
TABLE OF CONTENTS
Page no
ACKNOWLEDGEMENTS................................................................................................i
TABLE OF CONTENTS....................................................................................................ii
LIST OF FIGURES.............................................................................................................v
LIST OF TABLES...............................................................................................................x
ABSTRACT..........................................................................................................................xi
ABSTRACT IN GREEK...................................................................................................xiii
CHAPTER ONE: INTRODUCTION..................................................................................1
2.1. General overview.............................................................................................................1
2.2. The Scope of Work……………………………………………………………………..7
2.3. Methodology……………………………………………………………………………8
1- Field Work…………………………………………………………………………….8
2- Laboratory Techniques...................................................................................................8
CHAPTER TWO: GEOLOGICAL SETTING..................................................................10
2.1. The History of Basement.................................................................................................10
2.2. The Northern Portion of Pan-African Belt in Egypt........................................................11
2.3. The Histrory of Hafafit area............................................................................................15
2.3.1.The Norhern Dome A...............................................................................................22
2.3.1.1. Foliated Metagabbros.....................................................................................23
2.3.1.2. Gneissic Tonalites and associated Migmatites.............................................. 23
2.3.1.3. Mylonitic Unit................................................................................................26
2.3.1.4. Deformed Granites.........................................................................................26
2.3.2. The Central Eastern Domes B&C...........................................................................27
2.3.3. The Central Western Dome D.................................................................................31
2.3.4. The Southern Dome E.............................................................................................34
CHAPTER THREE: PETROGRAPHY AND ZIRCON MORPHOLOGY....................37
3.1. Petrography of the Hafafit unit granitoid rocks................................................................37
3.1.1. Tonalites............................................................................................................37
3.1.2. Granodiorites.....................................................................................................39
3.1.3. Quartz diorite.....................................................................................................40
3.2. The Distribution of zircon in rock forming minerals in Hafafit granitoid domes..........43
3.3. Morphological Characters of zircons in granitoids cored Hafafit domes........................46
3.3.1. Colour and Inclusions........................................................................ ...............46
3.3.2. Crystal length, Crystal breadth and Elongation ratio.........................................48
3.3.3. Crystal forms and Habits....................................................................................52
3.3.4. Degree of roundness and corrosion....................................................................53
CHAPTER FOUR: GEOCHMISTRY AND MINERAL CHEMISTRY.........................58
4.1. Introduction.......................................................................................................................58
ii
4.2. Geochemical characteristics of granitoids....................................................................58
4.2.1. Major elements………………………………………………………………..58
4.2.2. Trace elements………………………………………………………………...59
4.3. Magma type..................................................................................................................62
4.4. Tectonic setting.............................................................................................................62
4.5. Mineral chemistry.........................................................................................................73
4.5.1. Plagioclase........................................................................................................73
4.5.2. Amphiboles.......................................................................................................77
4.5.3. Biotite................................................................................................................84
4.5.4. Garnet................................................................................................................84
4.5.5. Ilmenite..............................................................................................................85
4.5.6. Titanite...............................................................................................................85
4.5.7. Zircon.................................................................................................................85
4.6. Pressure and temperature conditions.................................................................................90
CHAPTER FIVE: OPTICAL DEFORMATION MICROSTRUCTURES....................92
5.1. Single crystal deformation................................................................................................92
5.1.1. Plagioclase.........................................................................................................92
5.1.1.1. Dislocation gliding (synthetic microstructures).................................92
5.1.1.2. Undulose extinction............................................................................93
5.1.1.3. Deformation Band and Deformation Twin.........................................96
5.1.1.4. Subgrain development........................................................................98
5.1.2. Quartz................................................................................................................98
5.1.2.1. Undulose extinction...........................................................................100
5.1.2.2. Subgrain development.......................................................................101
5.1.3. Biotite...............................................................................................................101
5.1.3.1. Kinking and Kink bands....................................................................101
5.1.3.2. Dislocation gliding (synthetic microstructures)................................104
5.1.2.3. Subgrain development.......................................................................104
5.1.4. Hornblende.......................................................................................................105
5.1.4.1. Dislocation gliding (synthetic microstructures)
and Subgrain development.....................................................................105
CHAPTER SIX: STRAIN AND STRUCTURAL ANALYSIS.......................................109
6.1. Definition and Strain parameter.................................................................................109
6.2. Field investigations and sampling..............................................................................109
6.3. Techniques used in Strain Analysis...........................................................................113
6.3.1. Fry Method..........................................................................................114
6.3.2. Projection Method (Panozzo Method)................................................114
6.4. Results of finite-strain analysis..................................................................................120
6.4.1. Deformation Structures.......................................................................120
6.4.2. Magnitudes of Finite Stretches...........................................................120
CHAPTER SEVEN: STRUCTURAL AND TECTONIC EVOLUTION.....................136
CHAPTER EIGHT: DISCUSION AND CONCLUSIONS............................................150
REFERENCES...................................................................................................................164
LIST OF FIGURES page No
Fig.1.1: Schematic tectonic map of the Arabian Nubian Shield showing ophiolite belts, major
structures and lineaments (Kroner et al., 1992).............................................................4
Fig.1.2: Location map of study area...........................................................................................5
Fig.1.3: Geological map of the Wadi Hafafit area showing major rock types and tectonic
structure after Greiling and El Ramly (1990)...............................................................6
Fig.2.1: Geologic setting of the Northern portion of the pan African belt in the Eastern Desert,
Egypt. (After Greiling et al.1988)...............................................................................12
Fig.2.2: Geological map of Hafafit domes (modified from El Ramly et al., 1993)..................21
Fig.2.3: Geological map of northern part of Hafafit domes (modified after Rashwan,
1991)...........................................................................................................................24
Fig.2.4: Photomicrographs of granitoids dome A....................................................................25
Fig.2.5: Geological map of domes B&C..................................................................................28
Fig.2.6: Photomicrographs of granitoids dome B&C..............................................................29
Fig.2.7: Geological map of dome D........................................................................................32
Fig.2.8: Photomicrographs of granitoids dome D...................................................................33
Fig.2.9: Geological map of dome E........................................................................................35
Fig.2.10: Photomicrographs of granitoids dome E...................................................................36
Fig.3.1: Classification of the granitoids cored Hafafit domes on basis of Q-F vs ANOR
diagrom (Streckeisen and Le Maitre 1979)................................................................38
Fig.3.2: Photomicrographs showing different petrographic features of different minerals
forming gneissic tonalites of Hafafit domes...............................................................41
Fig.3.3: Photomicrographs showing different petrographic features of different minerals
forming gneissic granodiorites& Quartz diorite of Hafafit domes………….............42
Fig.3.4: The distribution of zircon in hosting minerals of Hafafit granitoids domes..............45
Fig.3.5: Histograms showing distribution frequency of morphological characters of zircon in
Hafafit granitoids domes.............................................................................................50
Fig.3.6: Histograms showing distribution frequency of morphological characters of zircon in
Hafafit granitoids domes.............................................................................................56
Fig.3.7: Photomicrographs showing zircon morphololgical characters from granitoid Hafafit
domes...........................................................................................................................57
Fig.4.1: Variation of major elements of studied granitoids......................................................65
Variation of major and trace elements of studied granitoids......................................66
Fig.4.2:
Variation of trace elements of studied granitoids.......................................................67
Fig.4.3:
Plot of the granitoid cored Hafafit domes Na O+K O-CaO vs SiO ( A), AFM (B) and
2 2 2
Fig.4.4:
K O vs SiO (C) diagrams...........................................................................................68
2 2
v
Fig.4.5&4.6: Plot of the granitoid cored Hafafit domes on tectonic discrimination diagrams.
……………………………………………………………………………………69-70
Fig.4.7: Comparsion of the studied granitoid rocks of Hafafit domes with granitoid rocks from
Jamacia calc alkaline island arc and Chile active contential margin (after Pearce et
al.1984) ……………………………………………………………………………...74
Fig.4.8: Comparsion of the studied granitoid rocks of Hafafit domes with granitoid rocks of
similar chemistry and mineralogy from Sierra Maestra (after Rajas Agramonte et
al.2004) and South west Alaska (Hill et al.1981)…………………………………...75
Fig.4.9: Comparsion of the studied granitoid rocks of Hafafit domes with granitoid rocks of
similar chemistry and mineralogy from Uasilau Yau intrusive complex New Britain
(after Whalen,1984)………………………………………………………………....76
Fig.4.10: Variation diagrams SiO2 in rock vs. An% in plagioclase (A) and CaO in rock
vs. An% in plagioclase (B) for granitoid cored Hafafit domes……………………..78
Composition of the investigated amphiboles (after Leake,1978) (A), variation
Fig.4.11:
diagram (Na+K)A+(Al +Fe *Ti) vs.Al (B) ………………………………….....81
VI tot IV
Fig.4.12:
Variation of SiO2 in rock vs. major elements in hornblende………………….........82
Fig.4.13:
Variation of major oxides in rock vs. major oxides in hornblende……………........83
Fig.4.14:
Classification of biotite (A) after (Deer et al. 1962), plot biotite of granitoid Hafafit
biotite on the Abdel Rahman (1994) (B,C,D)……………………………………....87
Fig.4.15:
Photomicrographs take by microprobe for ilmenite mineral having transformation
rutile-hematite intergrowth……………………………………………………….....89
Fig.5.1: a- Photomicrograph showing synthetic microfractures in plagioclase. It looks-like the
stair-steps slip and make right angle with the twining planes.in dome A C.N. X=12.5.
b and c- Photomicrographs showing some of the microstructures make right angle to
the twinning planes and divided the original plagioclase crystal into subgrains of the
same crystallographic orientation in domes (A,B and C) C.N. X=12.5. d-
Photomicrographs showing microfractures or gliding planes exist fine recrystallized
grains of rarely twinned plagioclase together with epidote grain in domes A and B, C,
C.N. X=12.5. e, f, g, h- Photomicrographs showing plagioclase crystals that are
characterized by the presence of microfractures are bended and exhibit undulose
extinction in domes A, B and C, C.N. X=12.5………………………………….......94
a and b- Photomicrographs showing synthetic microfractures in plagioclase. It looks-
Fig.5.2:
like the stair-steps slip and make right large angle with the twining planes. C.N., in
dome E, C.N. X=12.5. C and d- Photomicrographs showing microfractures or gliding
planes exist fine recrystallized grains of rarely twinned plagioclase together with
epidote grain C.N., in dome E, C.N. X=12.5. e, f and g- Photomicrographs showing
plagioclase crystals that are characterized by the presence of microfractures are
bended and exhibit undulose extinction in dome E, C.N. X=12.5………………......95
Fig.5.3: a- Photomicrograph showing microfractures and undulose extinction in plagioclase in