2001 Catuneanu and Elango Balfour Sedimentary Geology

8/11/2019 2001 Catuneanu and Elango Balfour Sedimentary Geology

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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


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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)


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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


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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:


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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


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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





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


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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





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





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


10/23

0 250m

clay + siltsand

Fine-grained dominated section, poorly exposed.Undifferentiated meandering systems. Thickness

in brackets.




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





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


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


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


13/23


14/23

N N

Sequence F

N

N

N

Sequence A Sequence B Sequence C

N

Sequence D Sequence E


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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


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)


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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)


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Documents

2001 Catuneanu and Elango Balfour Sedimentary Geology