The Geometry And Controls On Basement-Involved Deformation In The Adelaide Fold Belt, South ...

236 Pages·2015·18.95 MB·English

by  Eike Paul

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THE UNIVERSITY OF' ADELAIDE {
Department of Geology and Geophysics
South Australia
The geometry and controls on
basement-¡nvolved deformation in the
Adelaide Fold Belt, South Australia
by
Eike Günther Paul
M.Sc., Karl-Franzens-University Graz, Austria
Submitted in fulfilment required
for the degree of Doctor of Philosophy in the Faculty of Science,
University of Adelaide
November 1998
TABLE OF CONTENTS
Table of contents.. .. I
List of Figures ...... Vl
ListofTables........ IX
Abstract .. X
Disclaimer xll
Acknowledgments xfl1
Dedication
Chapter 1: Introduction. .1
1.1 Project overview 1
1.2 Focus and Aims J
1.3 Outline of thesis presentation...... 4
Part 7 The Proterozoic tectonothermal evolution of crystalline
basement terranes in South Australia
Chapter 2: Basement areas west of the Adelaide Fold Belt 6
2.1 Introduction. 6
2.2The Gawler Craton 6
2.2.I Introduction 6
2.2.2 Sequence of events. 6
2.3'|L'rc Mus grave Block 9
2.3.I Introduction 9
2.3 .2 Mulga Park Subdomain 9
2.3.3 Fregon Subdomain. ... . 9
2.3.4 Structure and metamorphism.. 10
2.4'lhe Peak and Denison Inliers 11
2.4.I Stratigraphy. 11
2.4.2 Structure and metamorphism.. 12
Chapter 3: The pre-Neoproterozoic evolution of the
Mt. Painter Inlier I3
3.1 Introduction. l3
3.2 The geological framework .16
3.3 Stratigraphic and spatial relationships of lithologies in the central
Mt. Painter Inlier 18
3.3.1 Introduction 18
3.3.2 Paralana Composite Gneiss . . . . 18
3.3.3 Yudnamutana Quartzite t9
3.3.4 Yudnamutana Gneiss 19
3.3.5 Freeling Heights Quartzite.. . 20
3.3.6 Mesoproterozoic intrusives. 20
3.3.7 P nalana Granodiorite . 20
3.3.8 British Empire Granite 26
3.4 Structural observations. 26
.
3.4.1 Dl deformation......,... 26
3.4.2 DZ deformation . . . . . 26
3.5 Structural constraints on the stratigraphy of the central Mt. Painter Inlier 27
3.6 Metamorphism 28
3.6.1 Metamorphic mineral associations and their spatial distribution 28
3.7 Discussion and summary 30
Chapter 4 The Olary Block, Willyama Inliers 34
4.1 Introduction.... 34
4.2'1he geological framework 35
4.3 Lithological components and spatial distribution of the V/illyama Supergroup
and associated intrusives in the Plumbago area and the Weekeroo Inliers..... 39
4.3.1 Introduction 39
4.3.2 Plumbago area 39
4.3.3 Weekeroo Inliers 40
.
4.4 Summary of structural observations..... 40
.
4.4.I Dl deformation .. 40
4.4.2 D2-D3 deformations . . ... 43
4. 5 Metamorphic observations . 43
4.6 Discussion and summary 46
Chapter 5: Inliers of the Mt. Lofty Ranges; the Barossa Complex
in the Houghton Inlier.. 49
5.1 Introduction. . . . 49
5.2 Geological framework... ... 50
.
5.2.I The Houghton Inlier 50
5.2.1.1 Rocktypes 50
5.2.I.2 Structural, Metamorphic and geochronological constraints 50
5.2.7.3 The Warren Inlier... 50
5.2.I.4 The Myponga Inlier...... 51
11
5.2.L5 Rocktypes.... 51
5.2.1.6 Structure and metamorphism 51
5.3 Geological Investigations in the Houghton Inlier 51
5.3.1 Lithological components and their spatial distribution .. 51
5.3.2 Unit 1 . ... .. 52
5.3.3 Unit 2 ....... 52
5.3.4 Unit 3 ....... 53
5.3.5 Unit 4 53
5.3.6 Unit 5 55
5.4 Remarks on the structural and metamorphic evolution... 55
5.5 Discussion and conclusions ...... 59
Chapter 6: Heat flow in South Australia .6t
6.1 Introduction. .61
6.2Heat production-heat flow relationships in the Mt. Painter Province .64
6.3 Heat production-heat flow relationships in the Olary Block 64
6.4 Origin of heat flow 67
Chapter 7: Summary of Part 1 69
7.1 Introduction. . . . .. 69
7 .2 The Proterozoic tectonothermal evolution 69
7.3 Unifying features of the inliers of the Eastern Province. 12
Part 2: Controls on basement re-activatíon and regíonal-scale
variations in deformøtion intensíty ín the Adelaide Fold Belt
Chapter 8: Introduction. ........14
8.l Introduction. ......74
8.2 The Adelaide Geosyncline and its sedimentary successions .........74
8.2.1 Neoproterozoic stratigraphic relationships and thickness distribution in the
northem Flinders Ranges. ........78
8.2.2 Neoproterozoic stratigraphic relationships and thickness distribution in the
central Flinders Ranges 81
8.2.3 Neoproterozoic stratigraphic relationships and thickness distribution in the
Nackara Arc ... 82
8.2.4 Neoproterozoic stratigraphic relationships and thickness distribution in the
vicinity of the Olary Block. 82
8.3 The Delamerian Orogen in South Australia (Adelaide Fold Belt). 85
lU
Chapter 9: Delamerian tectonothermal evolution of basement inliers
in the Adelaide Fold Belt 90
9.1 Introduction. .90
9.2 The Houghton Inlier. 90
9.2.1 Structural geometry of the Houghton Inlier and adjacent cover sediments . 90
9.3 The Mt. Painter Inlier...... 94
9.3.1 Introduction 94
9.3.2 Delamerian structural geometry. . . . 94
9.3.3 Structural cross sections 99
9.3.4 Metamorphic constraints in basement and cover 103
9.3.5 Structural observations along the southwestern basement-cover unconformity 106
9.4'fhe'Weekeroo Inliers. 106
.
9.4.1 Introduction . .. , 106
rcl
9.4.2Structural and metamorphic investigations in the Weekeroo Inliers
9.4.3 Structural cross section acloss the Weekeroo Inliers (sections I, II, III) ...... r07
9.5 Summary....... 115
Chapter 10: The structural geometry of regional-scale variations
in deformation intensity across the northern Flinders Ranges,
central Flinders Ranges and the Nackara Arc.. . 118
10.1 Introduction 118
10.2 Regional structural cross sections across the northern Flinders Ranges. t19
tt9
10.2.I Norwest Fault transects (sections IV, V)
10.2.2 Southern transect (section VI, VII) r22
10.3 Composite structural cross section across Domains 2,3 and 4. '.. 124
10.4 Discussion and summary. t21
t3r
Chapter 1L: Summary..
1 1.1 Introduction 131
1 1.2 Summary of deformation styles associated with the re-activation of basement
inliers... 13l
11.3 Summary of the characteristics of the regional-scale variations in deformation
intensity in the Adelaide Fold Belt.... 133
1 1.4 The thermo-mechanical perspective 135
11.5 Synthesis 140
References ....... . r42
Appendices........... 160
lV
Appendix A: Mt. Painter Inlier
A. 1 Summary of earlier investigations
A. 2 Lithological observations
Figure a Sample location map
Table b Sample mineralogy
Table c Pb-Pb ratios
Table d Mineral analyses used in P-T calculations
Table e P-T- calculations of sample YGl16
Appendix B: Willyama Inliers; Olary Block
8.1: Summary of the geology of the Broken Hill Block
8.2: Lithological observations in the western Olary Block
8.3: Structural and metamorphic observations of Proterozoic features in the
western Olary Block
8.4: Structural and metamorphic observations of Delamerian features in the
vicinity of the'Weekeroo Inliers
Table a Sample locations and mineralogy
Appendix C: Houghton Inlier sample location map
Appendix D: Heat production data of leucogranites in the Olary Block
Appendix E: Controls on the distribution of continental deformation
E.1: Variations in deformation intensity in central Asia
8.2:YaÅations in structural style and the role of basement-involvement
Appendix F: Manuscripts currently in press
Paul, E., Flöttmann, T. & Sandiford, M. (1999). Structural geometry and controls on
basement-involved deformation in the northern Flinders Ranges, Adelaide Fold Belt, South
Australia. Australian Journal of Earth Sciences.
Sandiford, M., Paul, E. & Flöttmann, T. (1998b). Sedimentary thickness variations and
deformation intensity during basin inversion in the Flinders Ranges, South Australia. Journal
of Structural Geology
.
V
LIST OF FIGURES
CHAPTER
1
Figure 1.1: (a) Simplified map of Archaean to early Palaeozoic tectonic provinces in
South Australia, adapted from Drexel et aI. (1993); (b) Location of the
tectonic segments of the Adelaide Fold Belt and basement inliers within..
CHAPTER 2
Figure 2.1: Main Archaean to Phanerozoic tectonic features of the Gawler Craton. 1
.
CHAPTER 3
Figure 3.1: (a) Simplified map shows the main lithological and structural elements
of the Mt. Painter and Mt. Babbage Inliers and surrounding
Neoproterozoic sediments (modified after Coats & Blisset, l9l1 and
Teale, 1993) 15
Figure 3.2: Stratigraphic relationships in the Mt. Painter and Mt. Babbage Inliers after
Coats & Blisset, 1991 and Teale (1979; 1993). t6
Figure 3.3: Simplified rock relationship diagram of mapped lithologies in the
central Mt. Painter Inlier. 19
Figure 3.4: Lithological map of the central Mt. Painter Inlier 2l
Figure 3.5: Main lithologies in the central Mt. Painter Inlier (a-c).. 22
Figure 3.5: Main lithologies in the central Mt. Painter Inlier (d-Ð.. 23
Figure 3.6: Summary of Pb-Pb evaporation data from a granodiorite in the central
part of the southwestern Mt. Painter Inlier. 25
Figure 3.7: Simplified geological profile across the central Mt. Painter Inlier.
Section line crosses the Paralana Plateau and Creek as well as the
Freeling Heights Plateau to Greenhill Hut in the nofihwest 28
Figure 3.8: Photomicrographs and photos a-d showing Proterozoic characteristic
deformation features. 29
Figure 3.9: Order of events recognised in the Mt. Painter Inlier...... 3t
CHAPTER 4
Figure 4.1: Simplified map of the Willyama Inliers showing the main lithological
elements of the Willyama Supergroup in the Olary Block ( modified after
Flint & Parker, 1993; Clarke et aL.,1986) 35
Figure 4.2: Rock relationship diagram/sequence model for the Olary Block,
modified after Ashley et al., (1991)....... 36
Figure 4.3: Simplified solid geology interpretative lithological map of the
VI
Plumbago area derived from airborne, ground magnetic and radiometric
data (courtesy of PIRSA) and regional lithological mapping.. 4I
Figure 4.4: Simplifîed, interpretative structural map of the Plumbago area derived
from airborne, ground magnetic and radiometric data (courtesy of PIRSA)
and regional structural maPPing. 42
Figure 4.5: Lower hemisphere projections of orientation data from the northern
Plumbago area.. 44
Figure 4.6: Simplified geological map of the'Weekeroo Inlier, modified after
unpublished data (courtesy of PIRSA). 44
Figure 4.7 : Photomicrographs showing characteristic structural features. 45
Figure 4.8: Order of events recognised in the western Olary Block. 47
CHAPTER 5
Figure 5.1: Regional map showing the location of inliers in the Mt. Lofty Ranges. . . 49
Figure 5.2: (a) simplified interpretative lithological map of the Houghton
Inlier; (b) simplified lithostratigraphic column of the rocktypes identified
in the Barossa Complex of the Houghton Inlier. 54
Figure 5.3: Main rock units identified in the Houghton Inlier (a-c) . 56
Figure 5.3: Main rock units identified in the Houghton Inlier (d-Ð . 51
Figure 5.4: (a) Simplified structural map of the Houghton Inlier. 58
Figure 5.5: Order of events recognised in the Houghton Inlier' 59
CHAPTER 6
Figure 6. 1: South Australian heat flow data.. 62
Figure 6.3: Colour composite image showing total counts of K (Red), Uranium
(Blue) and Thorium (Green) from airbome radiometric survey. 65
Figure 6.4:Heatproduction data derived from the PIRSA database for the Willyama
Inliers. 66
CHAPTER 7
Figure 7.1: Time-space diagram summarising the geological evolution of the
terranes discussed in the text... 70
CHAPTER 8
Figure 8. 1 : Correlation of Neoproterozoic rock units of the Adelaide
(1993).
Geosyncline and Cambrian sequences, adapted from Preiss .....16
Figure 8.2: Isopach map for the Neoproterozoic sequences in the northem Flinders
Ranges, central flinders Ranges and Nackarra Arc region, after data from
7l
Preiss (1986, 1981, 1993)..
Figure 8.3: Generalised geological map of the northern Flinders Ranges, showing
components....
the main stratigraphic and tectonic ....79
Figure 8.4: North-south oriented standard lithostratigraphic column of
the Neoproterozoic and Cambrian sediments through the northern Flinders
Ranges.. ... 19
Figure 8.5: Isopach map of the spatial distribution of the thickness
variation of Neoproterozoic sequences in the northern Flinders Ranges. 80
Figure 8.6: Standard lithostratigraphic columns of Neoproterozoic sediments across
the Olary Block and the northeastern Nackara Arc. .. 83
Figure 8.7: Spatial distribution of Delamerian structural and metamorphic features
in the Adelaide Fold Belt, adapted from Preiss (1993). 86
Figure 8.8: Strain domains in the Adelaide Fold Belt. 89
CHAPTER 9
Figure 9.1: Simplified structural map of the Houghton Inlier and adjacent
Neoproterozoic sequences showing the main Palaeozoic deformation
features. 92
Figure 9.2: Photomicrographs and photos a-d showing the main Delamerian
deformation features. 93
Figure 9.3: Simplified structural map and lower hemisphere projections of
Proterozoic and major Delamerian structural features in domains I to 4.........96
Figure 9.4: Photos and Photomicrographs showing the main Delamerian
metamorphic and deformation features (a-c) 97
Figure 9.4: Photos and Photomicrographs showing the main Delamerian
metamorphic and deformation features (d-Ð. .98
Figure 9.5: Mt. Painter section (Section I-I'). 101
.
Figure 9.6: Balcanoona section (section II-II'). to2
Figure 9.7: Schematic cross section across the Terrapinna Coridor (Section III-III')..... 103
Figure 9.8: Delamerian deformation features (a-c). 108
Figure 9.9: Simplified cartoon showing the orientation of the principal stress
direction during the Delamerian contractional evolution. ..109
Figure 9. 10 : Weekeroo-McDonald Fault transect.. 110
Figure 9. 1 1 : Plumbago-Anabama transect 111
Figure 9.12: Sequence of cartoons showing the interpreted Neoproterozoic to
Delamerian evolution of the northeastern margin of the Adelaide
Geosyncline. .. 113
Figure 9.13: Relative timing of Neoproterozoic to Delamerian events recognised in
rt6
the Mt. Painter Inlier
CHAPTER 10
v111
Figure 10.1: Copley Section (Section IV'-IV).
Figure t0.2: Norwest-Mundy fault section (Section V-V')..
Figure 10.3: Paralana-Narina Faults Section (Section VI-VI')..
Figure t0.4: Composite section through the northern Flinders Ranges
(section VII-V[').. r23
Figure 10.5: Composite section across the northern Flinders Ranges, central
Flinders Ranges and the Nackara Arc... t26
Figure 10.6: Sequence of cartoons showing the interpreted Neoproterozoic and
Delamerian geodynamic evolution of the northern Flinders Ranges..... t29
CHAPTER
1 1
Figure 11.1: Summary of structural and metamorphic Delamerian features, and
the styles of basement re-activation of inliers in the Adelaide Fold Belt. .. . . 132
Figure 11.2: The strength of the lithosphere in compression expressed as a function
.
of Moho temperature and strain rate. . . ..... . 136
Figure 11.3: Variation in Moho temperature resulting from the progressive
basement.....
burial of a radioactive .. 138
Figure 11.4: Rheological effects of progressive burial of a radioactive basement. .. .. ..... 139
LIST OF TABLES
CHAPTER 6
Table 6.2: Location (latitude and longitude) of south Australian heat flow data. . .. .63
IX