2001 catuneanu and elango balfour sedimentary geology
TRANSCRIPT
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
1/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
2/23
0 1500km
SUBDUCTION AND ACCRETION
KarooParana
BeaconBowen
Pan Gondwanianforeland fill
thrust-fold belt
Grahamstown
Beaufort West
Cape TownPort Elizabeth
East London
Queenstown
AliwalNorth
Durban
Bloemfontein
Kimberley
Estcourt
Johannesburg
INDIAN
OCEAN
33S
31S
27S
29S
30E28E26E24E
22E20E18E
CAPE
FOLD BELT
Stormberg Group
Drakensberg Group
Tarkastad SubgroupAdelaide Subgroup
Ecca Group
Dwyka Group
0 100 200 300 km
Study area
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
3/23
200
300
Ma
210
220
240
230
250
260
270
280
290
MoscovianLateCarbonifer.
EarlyPermian
LatePermian
Scythian
MiddleTriassic
EarlyT.
LateTriassic
Carnian
Norian
Lias
Kungurian
Kazanian
Ladinian
earlyAnisian
lateAnisian
190
180
Dogger
EarlyJurassic
Sakmarian
Asselian
Artinskian
Gzelian
Tatarian
MiddleJ.
Ufimian
Dwyka Group:floating icebergs anddeposition in marine
environment
Ecca Group:deep to shallow
marine environment
Stratigraphichiatus
Tarkastad Subgroup(upper Beaufort)
Adelaide Subgroup(lower Beaufort)
BeaufortGroup:
fluvialenvironment
Molteno Formation:fluvial environment
StormbergGroup:
nonmarineenvironment
Elliot Formation:fluvial environment
Clarens Formation:aeolian environment
Drakensberg Group:basalts (Gondwana break-up)
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
4/23
Beaufort
Group
Burgersdorp Formation
Katberg Formation
Balfour Formation
Middleton &Koonap formations
240
250
LatePerm
ian
Triassic
Kazanian
Tatarian
Scythian
Anisian
Ufimian
UpperBeaufort
Lower
Beaufort
Ecca Group
My
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
5/23
B1
Fort Beaufort
B2B3
B4
B5
B6
B7
B8
B9
B10
B11 B12
B13
B14
B15B16
B17
B18
B19 B20
B21 B22
B23
B24
B25
B26
Seymour
0 5Km
Grahamstown63 km
Queenstown65 km
Balfour
N
MdtMdt
Ktb
Ktb
Ktb
Katberg FormationBalfour FormationMiddleton Formationnational roadsBalfour-Katberg contactMiddleton-Balfour contactlocation of studied roadcutsB1-26
Ktb
Mdt
KEY:
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
6/23
0
0
250
250
m
m
0
15m
Vertical scalefor the logged sections
clay + silt
clay + silt
sand
sand
Fine-grained dominated section,
poorly exposed. Undifferentiatedmeandering systems. Thicknessindicated in brackets.
0
27
37
46
61
66
100106
276
280
333
341
361
371
416
430
618
629
666
675
698
705
757762
896
904
930933
1000
1008
1073
1087
1298
1303
1303
1314
13371341
1433
14381444
1479
1491
1562
1570
1706
1715
1875
1880
1888
1943
1951
2007
2019
2134
2150
(m)
(10 m)
(15 m)
(34 m)
(170 m)
(53 m)
(20 m)
(45 m)
(188 m)
(37 m)
(23 m)
(52 m)
(134 m)
(26 m)
(67 m)
(65 m)
(211 m)
(23 m)
(92 m)
(35 m)
(71 m)
(136 m)
(160 m)
(55 m)
(56 m)
(115 m)
B 1 (27 m)
B 2 (9 m)
B 3 (5 m)
B 4 (6 m)
B 5 (4 m)
B 6 (8 m)
B 7 (10 m)
B 8 (14 m)
B 9 (11 m)
B 10 (9 m)
B 11 (7 m)
B 12 (5 m)
B 13 (8 m)
B 14 (3 m)
B 15 (8 m)
B 16 (14 m)
B 17 (16 m)
B 17 (16 m)
B 18 (4 m)
B 19 (11 m)
B 20 (12 m)
B 21 (8 m)
B 22 (9 m)
B 23 (13 m)
B 24 (8 m)
B 25 (12 m)
B 26 (16 m)
A(416 m)
D(135 m)
E(442 m)
F(270 m)
B(282 m)
C(605 m)
SU #1
SU #2
SU #3
SU #4
SU #4
SU #5
SU #6
SU #7
Middleton Formation
Katberg Formation
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
7/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
8/23
0 250m
clay + siltsand
0
27
37
46
61
66
100106
276280
333
341
371
416
(m)
(10 m)
(15 m)
(34 m)
(170 m)
(53 m)
(20 m)
(45 m)
B 1 (27 m)
B 2 (9 m)
B 3 (5 m)
B 4 (6 m)
B 5 (4 m)
B 6 (8 m)
B 7 (10 m)
A(416 m)
SU #1
SU #2
Middleton Formation
Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thicknessindicated in brackets.
Lithofacies Architectural
elementsFluvialstyles
Generalizedvertical profile
Sm, ShSt, Sp
Sh, St, Sp
Sh, St, Sp
Sh, St, Sp
Sh, Sp
Sh, St
SB,CH, DA
LA, SB
LA, SB
CH, SB
CH, SB
LA, SB
B
M1
M1
M1
M1
M1
M2Fm, Fl FF
0 250m
clay + siltsand
Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thicknessindicated in brackets.
Lithofacies Architectural
elementsFluvialstyles
Generalizedvertical profile
Sm, Sh
St, Sp
Sm, Sr
SB,
CH, DA
CH, SB
B
M1
M2Fm, Fl, Sh FF, CS
416
430
618
629
666
675
698
(188 m)
(37 m)
(23 m)
B 8 (14 m)
B 9 (11 m)
B 10 (9 m)
B(282 m)
SU #2
SU #3
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
9/23
698
705
757762
896
904
930933
1000
1008
1073
1087
1298
1303
(52 m)
(134 m)
(26 m)
(67 m)
(65 m)
(211 m)
B 11 (7 m)
B 12 (5 m)
B 13 (8 m)
B 14 (3 m)
B 15 (8 m)
B 16 (14 m)
B 17 (5 m)
C(605 m)
SU #3
SU #4
0 250m
clay + siltsand
Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thicknessindicated in brackets.
Lithofacies Architectural
elementsFluvialstyles
Generalizedvertical profile
Sh, St, Sp
Sh, Sm, St
Fl, Sh, Sr
Sh, Sr
Sh, Sr
Fl, Sh, St
DA, SB
CH, CS
FF, CH
CH, SB
CH, SB
FF, LA, CS
B
M1
M1
M1
M1
M1
M2Fm, Fl FF
0 250m
clay + siltsand
Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thicknessindicated in brackets.
Lithofacies Architectural
elementsFluvialstyles
Generalizedvertical profile
Sh, St, Sp
Fl, Sh
DA, SB
FF, CS
B
M1
M2Fm, Fl FF
1303
1314
13371341
1433
1438
(23 m)
(92 m)
B 17 (11 m)
B 18 (4 m)
B 19 (5 m)
D(135 m)
SU #4
SU #5
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
10/23
0 250m
clay + siltsand
Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thickness
in brackets.
Lithofacies Architectural
elementsFluvialstyles
Generalizedvertical profile
Sh, Sm, St
Sh, St
Sh, St, Sr
CH, CS
CH, SB
LA, CH
M1
M1
M1
M2
M2
Fm, Fl
Fm, Fl
FF
FF
14381444
1479
1491
1562
1570
1706
1715
1875
1880
(35 m)
(71 m)
(136 m)
(160 m)
B 19 (6 m)
B 20 (12 m)
B 21 (8 m)
B 22 (9 m)
B 23 (5 m)
E(442 m)
SU #5
SU #6
0 250m
clay + siltsand
Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thicknessindicated in brackets.
Lithofacies Architectural
elementsFluvialstyles
Generalizedvertical profile
St, Sr
St, Sr
LA, CH
LA, CH
M1
M1
M2
M2
Fm, Fl
Fsm, Fl, Sr
FF
FF, CH
1880
1888
1943
1951
2007
2019
2134
2150
(55 m)
(56 m)
(115 m)
B 23 (8 m)
B 24 (8 m)
B 25 (12 m)
B 26 (16 m)
F(270 m)
SU #6
SU #7
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
11/23
2m
1m
CH,
Sm,
Sh
CH,
Sm,
Sh
CH,
Sh
CH,
Sh
DA
Sm
Sm
DA
(Sp,
Sl)
Sh
SB
SB,
Sh
SB
St
DetailfromsectionB
1,showingtheinternalarchitectureofamalgamatedbraidedchannels.Fluvialstyle:deep,perennial,sand-bedbraidedsystem.
Sh
Sp,
Sl
CH,
Sm
CS,
Sm
CS,
Sm
CH
LA
Detailfromsection
B16,showingthestackingpatternsoflow
-energyfluvialarchitecturalelements.
Flu
vialstyle:sand-bedmeanderingsystem.
DetailfromsectionB
7,showingthestackingpatternsoflow-e
nergyfluvialarchitecturalelements.
Fluvialstyle:fine-grainedmeanderingsystem.
St
Sh
St
Sr
F
F,
Fl
FF,
Fl
FF,
Fl
1m
LA
LA
CS,
Sm
CS,
Sm
CS,
Sm
FF,
Fm
FF,
Fm
FF,
Fm
FF,
Fm
FF,
Fm
FF,
Fm
Fl
Sr
Fl
Sr
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
12/23
FF,
Fl
FF,
Fl
FF,
Fl
3m
LA
FF,
Fm
FF,
Fm
FF,
Fm
FF,
Fm
CH
CS,
Fl,S
m
St
St
Sr
Sr
Sh
Sh
Sm
Sm
FF,
Fl
Sm
Fl
Fl
Sm,
Sh
DetailfromsectionB23,showinganabruptchange
inthesedimentaryregimeacrossthesequenceboundary(SU#6)froma
fine-grainedmea
nderingsystem(belowthesequenceboundary)toahigherenergysand-bedmeanderingsystem.
Noverticalexaggeration.
SU#6
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
13/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
14/23
N N
Sequence F
N
N
N
Sequence A Sequence B Sequence C
N
Sequence D Sequence E
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
15/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
16/23
Dynamic subsidence:
Flexural tectonics + dynamic subsidence:
LOAD
LOAD
Forebulge Back-bulgeCRATONFORELAND SYSTEM
datum (original lithospheric profile)mean flexural profilemean dynamic deflectioncomposite lithospheric deflection (flexural + dynamic)
Horizontal scale: 10 - 10 km;Vertical scale: 10 - 10 m.
1 3
1 3
Flexural profile:
Foredeep
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
17/23
1. Underfilled phase:deep marine sedimentation
2. Filled phase:shallow marine sedimentation
3. Overfilled phase:fluvial sedimentation
LOAD
LOAD
LOAD
LOAD
(1)
(1+2)
(1+2)
(1+2)
a. Orogenic unloading:
b. Orogenic loading:
Hf
Hf
flexural subsidence
flexural uplift
Foreslope
Foredeep
Foresag
Forebulge
(3a)
(3a)(3b)
erosional/extensional unloading
compressional loading (thrusting)
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
18/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
19/23
South (proximal) North
A
B
C
D
E
F
1
2
3
4
5
6
7
200 m 10 km
sand-bed braided systemssand-bed meandering systemsfine-grained meandering systemsou
tcrop
sectio
n
(f-u)
Vertical section (c-u)
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
20/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
21/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
22/23
-
8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology
23/23