Sequence stratigraphy of the Precambrian Rooihoogte–Timeball …research.eas.ualberta.ca/catuneanu/files/Papers_s/2002... · Third-order sequence stratigraphic analysis is performed

Sequence stratigraphy of the Precambrian Rooihoogte–Timeball

Hill rift succession, Transvaal Basin, South Africa

Octavian Catuneanu a,*, Patrick G. Eriksson b

aDepartment of Earth and Atmospheric Sciences, University of Alberta, 1-26 Earth Sciences Building, Edmonton, Alberta, Canada T6G 2E3bDepartment of Earth Sciences, University of Pretoria, Pretoria 0002, South Africa

Received 31 December 2000

Abstract

Third-order sequence stratigraphic analysis is performed on the Rooihoogte–Timeball Hill second-order rift succession of

the Paleoproterozoic Transvaal Basin, South Africa. This provides a case study for systems tract and sequence development

during a time of glacio-eustatic fall, when accommodation was generated by subsidence related to syn-rift and post-rift tectonic

processes. Two third-order depositional sequences have been identified, separated by a basin-wide subaerial unconformity. The

lower third-order sequence includes the complete succession of lowstand, transgressive, and highstand systems tracts (LST,

TST, and HST), whereas the upper third-order sequence only preserves lowstand and transgressive systems tracts. This indicates

that the fall in base level associated with the upper second-order boundary of the Rooihoogte–Timeball Hill sequence was of

higher magnitude relative to the third-order subaerial unconformity, which is in agreement with the principles of boundary

hierarchy based on the magnitude of base-level changes. The position of the lower boundary of the Rooihoogte–Timeball Hill

second-order sequence has been revised from the base of the chert breccias to the contact between the breccias and the overlying

chert conglomerates. This is because a major tilting event occurred between the deposition of the two facies, which are

genetically unrelated, and which are separated by a subaerial unconformity. The lithostratigraphic contact between the

Rooihoogte and Timeball Hill formations is interpreted as a diachronous transgressive surface of erosion. In this interpretation,

the Polo Ground Member of the Rooihoogte Formation may be coeval with the basal black shales of the Timeball Hill

Formation, the two facies (fluvial and marine, respectively) forming together a transgressive systems tract. D 2002 Elsevier

Science B.V. All rights reserved.

Keywords: Precambrian sequence stratigraphy; Second-order rift sequence; Third-order systems tracts; Transvaal Basin

1. Introduction

Sequence stratigraphy, which developed as a meth-

odology for explaining the relationships of allostrati-

graphic units that fill a sedimentary basin, is currently

one of the most actively evolving disciplines in sedi-

mentary geology. Through the recognition of bounding

surfaces, genetically related facies (systems tracts) can

be identified. Lithofacies can then be correlated accord-

ing to where each unit is positioned along an inferred

curve that represents base-level fluctuations. The con-

cepts of sequence stratigraphy have primarily been

perfected from the study of Phanerozoic successions,

which provide better preservation potential and time

control for detailed stratigraphic analyses and correla-

0037-0738/02/$ - see front matter D 2002 Elsevier Science B.V. All rights reserved.

PII: S0037-0738 (01 )00188 -9

* Corresponding author. Tel.: +1-780-492-6569.

E-mail address: octavian@ualberta ca (O. Catuneanu).

www.elsevier.com/locate/sedgeo

Sedimentary Geology 147 (2002) 71–88

tions (Vail, 1987; Posamentier et al., 1988, 1992; Van

Wagoner et al., 1990; Hunt and Tucker, 1992; Miall,

1997; Plint and Nummedal, 2000). More recently, the

principles of sequence stratigraphy have also been

applied to genetic interpretations of Precambrian suc-

cessions (e.g., Christie-Blick et al., 1988; Catuneanu

and Eriksson, 1999; Catuneanu and Biddulph, in

press).

1.1. Concepts of sequence stratigraphy

Comprehensive discussions of sequence strati-

graphic concepts and their application to the Precam-

brian rock record are provided by Christie-Blick et al.

(1988) and Catuneanu and Eriksson (1999). Briefly

summarized below are key concepts relevant to this

study. The various systems tracts and stratigraphic

surfaces are defined relative to the base-level and

transgressive–regressive curves (Fig. 1). The two

curves are offset by a time period equivalent to the

duration of sediment-driven (‘‘normal’’) regressions,

which depends on the ratio between the rates of base-

level rise and the sedimentation rates (see Catuneanu

and Eriksson, 1999 for a more detailed discussion).

Lowstand systems tracts form during early stages

of base-level rise, when the rates of base-level rise are

outpaced by sedimentation rates. As a result, a ‘‘nor-

mal’’ regression of the shoreline occurs. Typical

products for lowstand systems tracts (LST) include

amalgamated channel fills overlying subaerial uncon-

formities, and lowstand deltaic deposits. Protected

from subsequent erosion by the aggradation of over-

lying transgressive and highstand deposits, these LST

deposits have a high preservation potential.

Transgressive systems tracts form during acceler-

ated base-level rise, when rates of base-level rise out-

pace sedimentation rates. As a result, a transgressive

shift of the shoreline occurs, and retrogradation and

vertical aggradation in both fluvial and shallow marine

environments results.

Fig. 1. Types of sequences, bounding surfaces and systems tracts defined in relation to the base-level and transgressive– regressive curves

(modified from Catuneanu et al., 1998). Abbreviations: TST—transgressive systems tract; RST—regressive systems tract; LST—lowstand

systems tract; HST—highstand systems tract; FSST—falling stage systems tract; SU—subaerial unconformity; c.c.—correlative conformity;

MRS—maximum regressive surface; MRS-c—MRS-correlative (i.e., the nonmarine correlative of the marine MRS); MTS—maximum

transgressive surface; (A)—positive accommodation; NR—normal (sediment supply-driven) regression; FR—forced (base-level fall-driven)

regression.

O. Catuneanu, P.G. Eriksson / Sedimentary Geology 147 (2002) 71–8872

Highstand systems tracts form during late stages of

base-level rise, when sedimentation rates outpace

rates of base-level rise. ‘‘Normal’’ regression of the

shoreline occurs, resulting in aggradation and progra-

dation of both fluvial and marine deposits. Highstand

deltaic deposits, bounded above by subaerial uncon-

formities, are typical products. Highstand strata may

have a low preservation potential due to erosion

accompanying subsequent base-level falls.

Subaerial unconformities develop in the nonmarine

portion of the basin due to fluvial or wind degradation

during stages of base-level fall. They may overlie

fluvial or marine strata, but are overlain by nonmarine

deposits.

Transgressive surfaces of erosion, also known as

‘‘ravinement surfaces’’, are scours cut by shoreface

waves during the transgression of a shoreline. They

are highly diachronous surfaces, separating fluvial

strata below from shallow marine facies above. In

areas of high preservation potential, ravinement sur-

faces may be entirely developed within transgressive

systems tracts, which is why they are not represented

in Fig. 1 (see Catuneanu and Eriksson, 1999, for

discussion and illustration).

Maximum regressive surfaces represent the boun-

dary between a lowstand systems tract and an over-

lying transgressive systems tract. They are also known

as ‘‘conformable transgressive surfaces’’ (Embry,

1995; Catuneanu et al., 1998).

Maximum transgressive surfaces represent the

boundary between a transgressive systems tract and

an overlying highstand systems tract. A synonymous

term is ‘‘maximum flooding surfaces’’.

1.2. Aim of research

This paper focuses on the Transvaal Basin of South

Africa (Fig. 2), which preserves a � 650-My record

of Late Archaean to Early Proterozoic sedimentation.

Previous work equated the sedimentary fill of the

Transvaal Basin, that is, the Transvaal Supergroup,

with a first-order depositional sequence bounded by

subaerial unconformities generated in relation to

major changes in the tectonic setting (Catuneanu

and Eriksson, 1999; Fig. 3). The inferred curve of

base-level changes for the Transvaal Basin allowed

the further subdivision of the Transvaal first-order

sequence into five second-order depositional sequen-

ces, that is, the Protobasinal, Black Reef, Chunies-

poort, Rooihoogte–Timeball Hill, and Boshoek–

Houtenbek sequences (Fig. 3). The purpose of this

research is to increase the resolution of sequence

stratigraphic analysis to the third-order level of cyclic-

ity, for the case study of the Rooihoogte–Timeball

Hill second-order sequence. The motivation for doing

this work is twofold: (1) no third-order sequence

stratigraphic analyses have been performed so far on

the Transvaal succession, and (2) the accumulation of

the Rooihoogte–Timeball Hill strata took place dur-

ing a time of global glacio-eustatic fall (Young, 1995;

Eriksson et al., 1998; Martin, 1999; Young et al., in

press; Fig. 3), which provides a case study for systems

tract and sequence development with accommodation

generated by tectonic processes. This is particularly

relevant in view of the core debate of sequence

stratigraphy over the eustatic versus tectonic controls

on accommodation and sequence development.

2. Geological background

2.1. Tectonic setting

The Transvaal Supergroup overlies the c. 3.0- to

2.7-Ga Witwatersrand Supergroup in the stratigraphic

record and constitutes the sedimentary floor to the

Bushveld igneous complex (Fig. 3). It should be noted

here, that the c. 2.7-Ga Ventersdorp Supergroup,

which unconformably succeeds the Witwatersrand

strata, is approximately coeval with the lowermost

portion of the Transvaal Supergroup (e.g., Eriksson et

al., in press). The 2714-Ma boundary between the

Witwatersrand and Transvaal (Ventersdorp) Super-

groups marks a significant change in the structural

style of the receiving sedimentary basins. The Witwa-

tersrand succession accumulated within a retroarc

foreland basin developed in relation to the supra-

crustal loading associated with the initial phases of

the Limpopo Orogeny (Winter, 1987; Stanistreet and

McCarthy, 1991; Robb and Meyer, 1995), and prob-

ably also associated with collision of arc systems with

the emerging Kaapvaal craton (Catuneanu, in press).

In contrast, sedimentation within the Transvaal Basin

was controlled by cycles of extensional and/or thermal

subsidence separated by stages of uplift or glacio-

eustatic base-level fall (Catuneanu and Eriksson,

O. Catuneanu, P.G. Eriksson / Sedimentary Geology 147 (2002) 71–88 73

Fig. 2. Outcrop distribution of the Transvaal lithostratigraphic units within the confines of the Transvaal Basin. Modified from Eriksson and Reczko (1995).

O.Catuneanu,P.G.Eriksso

n/Sedimentary

Geology147(2002)71–88

74

1999). The upper boundary of the Transvaal Super-

group, that is, the 2050-Ma contact with the Bushveld

complex, corresponds to another first-order tectonic

event that terminated the evolutionary history of the

Transvaal Basin. Bounded by these two 2050- and

2714-Ma contacts, the Transvaal Supergroup is inter-

preted as a first-order sequence related to the accu-

mulation of sediment within the tectonic setting of the

Transvaal and correlative basins.

The five second-order depositional sequences of

the Transvaal Supergroup correspond to distinct

cycles of extensional and/or thermal subsidence, and

are separated by second-order subaerial unconform-

ities. Important to note is the cyclic repetition of

tectonic settings within the succession of second-order

sequences, indicating no major shifts in structural

styles during the evolution of the Transvaal Basin.

The accumulation of the Rooihoogte–Timeball Hill

second-order sequence took place during a full rifting

cycle, with accommodation provided by syn-rift

extensional subsidence (Rooihoogte time) followed

by post-rift thermal subsidence (Timeball Hill time;

Catuneanu and Eriksson, 1999; Fig. 3).

2.2. Lithostratigraphy

The Transvaal Supergroup comprises four main

lithostratigraphic units, that is, the protobasinal (a

nondescriptive term) rocks, Black Reef Formation,

Chuniespoort Group, and Pretoria Group (Eriksson

and Reczko, 1995; Fig. 3). Our stratigraphic objective

is represented by the two lowermost formations of the

Pretoria Group, that is, the Rooihoogte and Timeball

Hill (Fig. 3).

A generalized lithostratigraphic profile for the

Rooihoogte and Timeball Hill formations is presented

in Fig. 4. The basal contact of the Rooihoogte

Formation, as well as the top contact of the Timeball

Hill Formation, are both marked by major angular

unconformities. These unconformities have been

identified as second-order depositional sequence

boundaries (Catuneanu and Eriksson, 1999), and their

features are described in detail by Eriksson et al. (in

press).

The Rooihoogte Formation consists of three lith-

ostratigraphic members, with a total thickness in

excess of 400 m in the northwestern part of the

Transvaal Basin. The lower Bevets Member includes

coarse products of in situ weathering and alluvial

sedimentation represented by chert breccias and con-

glomerates, respectively. The chert breccias have been

traditionally considered as the basal part of the Pre-

toria Group, but they have been recently reassigned to

the underlying Chuniespoort Group (Eriksson et al., in

press). The revised contact between the Chuniespoort

and Pretoria Groups is now taken at the unconform-

able limit between the Bevets breccias and conglom-

erates (Fig. 4). More details on the reasons for this

suggested change are presented in Section 3 of this

paper. Fig. 4 accommodates both old and new inter-

pretations, preserving at the same time the integrity of

the ‘‘Bevets Member’’ as defined in current literature.

Overlying these basal coarse facies are the shale and

Polo Ground sandstone members (Fig. 4), represent-

ing the products of lacustrine and fluvial sedimenta-

tion, respectively.

The Timeball Hill Formation, with a thickness in

excess of 1100 m in the northern part of the Transvaal

Basin, also comprises three sedimentary members;

these include the lower and upper shale members

separated by a sandstone unit, the Klapperkop quartz-

ite Member (Eriksson et al., 1994a; Fig. 4). Minor

lenses of poorly sorted diamictites and wackes,

ascribed to reworking of periglacial detritus have also

been identified in the upper shale member (Visser,

1971). A variety of genetic facies associations are

recognized in the formation: pelagic suspension

deposits, distal and proximal turbidites, contourites,

and lower and upper tidal flat deposits (Eriksson and

Reczko, 1998). The close association between deeper

marine and coastal facies is explained by a significant

stratigraphic break that separates the lower mudstones

from the overlying Klapperkop quartzite Member

(Fig. 4). Thin stromatolitic carbonate interbeds in

the Timeball Hill mudstones suggest that sedimenta-

tion took place within the photic zone (Eriksson and

Reczko, 1998).

In the southern part of the basin, the contact

between the Rooihoogte and Timeball Hill formations

is marked by a localized occurrence of highly altered

lavas (i.e., the Bushy Bend lava Member, Eriksson et

al., 1994b; Fig. 4). With an average thickness of about

30 m, these lavas are interpreted to reflect the eruption

episode related to the transition from Rooihoogte

rifting, to subsequent post-rift subsidence (Eriksson

et al., in press).



Fig. 4 infers the relative chronologies of the

lithostratigraphic members that build together the

Rooihoogte and Timeball Hill Formations. Although

this generalized vertical profile reflects the true rela-

tionships for individual data points, temporal overlaps

between the timing of sedimentation of the various

facies within the basin are most likely (Catuneanu and

Eriksson, 1999).

2.3. Palaeoclimatic background

The available age constraints of the Rooihoogte

and Timeball Hill formations indicate deposition

within the span of the c. 2.4- to 2.2-Ga global gla-

ciation (Young, 1995; Eriksson et al., 1998; Martin,

1999; Young et al., in press; Fig. 3). As evidence for

extensive ice cover on the Kaapvaal craton is limited,

sea levels were likely low and freeboard high (emer-

gent, glaciated continents; Eriksson et al., in press). In

addition, the cold temperatures would also have

lowered the rates of weathering processes. In view

of the low syn-glacial eustatic levels, subsidence to

accommodate aggradation and epeiric drowning dur-

ing the Rooihoogte–Timeball Hill times must have

been significant. This provides a case study where

accommodation and sequence development were

apparently primarily controlled by tectonic processes.

3. Sedimentary facies

This section presents genetic interpretations for the

sedimentary facies that comprise the Rooihoogte and

Timeball Hill Formations. The outcrop distribution of

the Rooihoogte–Timeball Hill succession is illus-

trated in Fig. 5.

3.1. Rooihoogte Formation

Fig. 6 shows the location of the main data points

and the associated vertical profiles for the Rooihoogte

Formation. Sedimentary facies with regional extent

include chert breccias, chert conglomerates, shales,

and the ‘‘Polo Ground’’ sandstones.

3.1.1. Chert breccias

The chert breccias form a discrete, wedge-shaped

lithological unit that develops at the limit between the

Chuniespoort and Pretoria Groups. This unit was

originally assigned to the Rooihoogte Formation,

and more recently re-interpreted as the time equivalent

of the Duitschland Formation, at the top of the

Chuniespoort Group (Eriksson et al., in press; Fig.

3). The sheet-like nature of the Chuniespoort carbo-

nate and iron-rich units (Malmani Subgroup and

Penge Formation, respectively, in Fig. 3) enables

estimation of the stratigraphic loss related to the basal

Pretoria unconformity, which is shown as a contour

map of denudation in Fig. 7. Preserved thickness of

the chert breccias, when superimposed on Chunies-

poort denudation contours, exhibits a good correlation

(Fig. 7), as expected for such residual products of in

situ weathering. The in situ nature of the breccias, as

borne out by their compositional similarity to varying

underlying chemical sedimentary strata, was first

observed by Button (1973). As shown by Eriksson

et al. (in press), the Duitschland Formation largely

comprises weathered Chuniespoort detritus that has

been transported northwards from the uplifted south-

ern area of the basin, and reworked to produce mainly

fine marly facies. Possibly, formation of the Duitsch-

land basin, presumably restricted to the northeast of

the preserved Transvaal depository, was coeval with

uplift of the southern Chuniespoort rocks. Chert

breccias overlying the Chuniespoort chemical sedi-

ments in the south, and the Duitschland lithologies,

may thus be time equivalents in addition to their

inferred proximal–distal relationship. If the chert

breccias and Duitschland rocks may be correlated,

then these strata represent the entire time gap (possi-

bly up to 80 My; Eriksson and Reczko, 1995; Fig. 3)

between the end of Chuniespoort chemical sedimen-

tation and the onset of Pretoria Group deposition

(beginning with the Rooihoogte conglomerates).

Fig. 3. Lithostratigraphy, chronology, tectonic settings, paleoenvironments and inferred base-level changes for the Transvaal Supergroup. 1) from

Armstrong et al. (1991); 2) from Eriksson and Reczko (1995); 3 – 5) from Walraven and Martini (1995); 6) from Eriksson and Reczko (1995); 7)

from Walraven and Martini (1995); 8) from Harmer and von Gruenewaldt (1991). Wavy lines suggest unconformable contacts. Modified from

Catuneanu and Eriksson (1999).


Fig. 4. Lithostratigraphic profile of the Rooihoogte and Timeball Hill Formations (Pretoria Group). Modified from Eriksson and Reczko (1995).

Wavy lines indicate unconformable contacts.

Fig. 5. Outcrop distribution of the Rooihoogte–Timeball Hill succession in the context of the Transvaal Basin. Modified from Eriksson and

Reczko (1998).


3.1.2. Chert conglomerates

The chert conglomerates represent alluvial fan and

fan-delta deposits sourced from the north, which pro-

gressively downlap onto the underlying lithologies in a

southward direction. The major occurrence (up to 250

m thick) of the chert conglomerate facies in the west of

the basin is lobate in preserved geometry, and thickens

northwards towards the source (Fig. 8). Amuch thinner

lobe occurs in the northeast, where it overlies both

Duitschland and older rocks. There is also a partial

overlap between the areas of occurrence of chert

breccias and chert conglomerates in the central part

of the Transvaal Basin (Fig. 8). The conglomerates

contain mostly chert pebbles, are matrix- and clast-

supported (thus indicating, respectively, gravity flow

and streamflow transport processes), and with pebbles

that vary in size up to about 10–15 cm, with sizes of 7

cm or less being most common (Fig. 6). The matrix of

the conglomerates is generally sand-sized and sili-

ceous, and the roundness of clasts varies between

poorly rounded, subrounded, and well rounded.

A very significant aspect is the change in topo-

graphic tilt at the boundary between the chert breccias

and the overlying chert conglomerates (Fig. 8). The

direction of tilt during the latest Chuniespoort times

was from south to north, which explains the more

pronounced weathering (thicker chert breccias) in the

south. The progradation of the younger chert con-

glomerates took place on a topographic slope dipping

to the south, which marks a change of approximately

180� in the direction of topographic tilt. This shows

that the second-order sequence boundary that sepa-

rates the Chuniespoort and Pretoria groups is related

to a significant tectonic event that led to the reorgan-

ization of the Transvaal Basin. The chert breccias and

the chert conglomerates preceded and succeeded this

tectonic event, respectively, which indicates that they

belong to sedimentary packages that are unrelated

Fig. 6. Lithological field profiles of the Rooihoogte Formation.


Fig. 7. Contour map showing the correlation between the occurrence of chert breccias and the thickness loss of the underlying Chuniespoort

chemical deposits. Modified from Eriksson et al. (in press).

Fig. 8. Isopach maps of the chert breccias (uppermost Chuniespoort Group) and chert conglomerates (lowermost Pretoria Group), showing the

contrast in the direction of topographic tilt between the timing of deposition of the two facies. Modified from Eriksson et al. (in press).


genetically (i.e., different depositional sequences sep-

arated by a subaerial unconformity).

3.1.3. Rooihoogte shales

The shales of the Rooihoogte Formation exhibit

horizontal stratification, graded laminae, ripple marks

(siltstone interbeds), flaser lamination, and varve

structures (Eriksson, 1988; Eriksson et al., 1991).

This facies is interpreted to represent periglacial la-

custrine sedimentation, with the depocenter in the

western part of the Transvaal Basin (Eriksson and

Reczko, 1995). The Rooihoogte shale Member dis-

plays a variable thickness, ranging from about 18 up

to 250 m (Eriksson, 1988; Fig. 6). The boundary

between the shales and the underlying chert conglom-

erates is a diachronous facies contact, as the two facies

are partly age equivalent (Catuneanu and Eriksson,

1999). The conglomerates and shales together form a

fining-upward genetic package that led to the pene-

planation of the pre-existing karst topography. Paleo-

geographic reconstructions show the progradation of

chert conglomerates via alluvial fans and fan-delta

systems towards the south, into the standing body of

water of the lacustrine environment (Eriksson and

Reczko, 1995). The balance between fan progradation

and lacustrine aggradation gradually shifted in the

favor of the latter, in parallel with the denudation of

the northern sediment source areas, which explains the

overall fining-upward profile of the alluvial–deltaic–

lacustrine systems tract (Catuneanu and Eriksson,

1999).

3.1.4. Polo Ground quartzite Member

This lithofacies is thin, generally varying from 6 to

10 m in thickness (Fig. 6). It comprises fine- to

medium-grained ferruginous quartz wackes, with

locally abundant lenses of very coarse pebbly lithic

wackes, 10–50 cm thick and 1–5 m wide. The

pebbles consist of siltstone and silty, very fine sand-

stone, indicating erosion of the underlying lithofacies

(Eriksson, 1988). These intraformational pebbles may

be interpreted as rip-up clasts preserved at the base of

braided channel fills, generated as the unconfined

fluvial systems shifted laterally across their own over-

bank areas. The high-energy character of the inter-

preted braided systems is also confirmed by the

observed sedimentary structures and textures. The

sandstones exhibit common planar and trough cross-

bedding organized in macroforms up to 8 m wide and

70 cm thick, indicating the manifestation of down-

stream accretion processes, typical for multiple-chan-

nel, low-sinuosity systems. The sandstones are

commonly granular in the far west of the basin, and

contain both chert grains and feldspar. They are

coarsest and most immature in the northwest of the

basin, which was probably where they were most

proximal (Eriksson, 1988). The contact between the

Polo Ground sandstones and the underlying lacustrine

shales appears to be conformable, locally represented

by channel base scours. Taking the top contact of the

underlying alluvial–deltaic–lacustrine systems tract

as a time-line datum, the deposition of the Polo

Ground fluvial sands in the west of the basin appears

to be concomitant with the transgression recorded in

the east by the basal black shales of the Timeball Hill

Formation.

3.2. Timeball Hill Formation

The Timeball Hill Formation is the product of

dominantly marine and marginal marine sedimenta-

tion, being represented by fine-grained sedimentary

strata (lower and upper shale members), and subordi-

nate sandstones (medial Klapperkop Member). The

regional distribution of these facies is illustrated in

Fig. 9. The three members can be recognized around

the preserved basin, and tend to have a sheet-like

geometry (Eriksson and Reczko, 1998). The contact

with the underlying Rooihoogte Formation is sharp,

being represented by the ravinement surface at the

base of the lowermost Timeball Hill transgressive

black shales.

3.2.1. Lower shale Member

The Lower Shale Member consists of a widespread

basal black shale lithofacies, succeeded by rhythmical-

ly interbedded mudstones, siltstones, and fine-grained

sandstones, often termed the ‘‘rhythmite lithofacies’’, or

‘‘lower mudstones’’, by previous researchers (Eriksson

et al., 1994b).

The marine black shales are inferred to have trans-

gressed approximately from east to west (Eriksson

and Reczko, 1998). This facies is typically laminated,

with subordinate lenses of silty material with planar

cross-laminations and current ripples. The black pig-

mentation is due predominantly to pervasive micro-


scopic iron minerals (mainly limonite after pyrite),

with subordinate thin beds and laminae more intensely

pigmented by flakes of carbonaceous material (Eriks-

son et al., 1994b).

Above the transgressive black shale, the ‘‘lower

mudstones’’ consist of a shallowing-upward succes-

sion of pelagic, distal delta-fed turbidites, and con-

tourites, interpreted by Eriksson and Reczko (1998) as

being deposited under highstand conditions. Domi-

nant lithofacies include laminated and graded mud-

stones, and sheets of laminated and cross-laminated

siltstones and fine-grained sandstones. These are

compatible with the Te, Td, and Tc subdivisions of

the low-density turbidity current systems (Eriksson

and Reczko, 1998). Thin interbeds of stromatolitic

carbonates support photic water depths up to about

100 m. Small lenses of coarse siltstone to very fine-

grained sandstone, analogous to modern continental

rise contourite deposits, occur within the suspension

and distal turbidite sediments, and also form local

wedges of inferred contourites at the transition from

suspension to lowermost turbidite deposits (Eriksson

and Reczko, 1998).

3.2.2. Klapperkop quartzite Member

The arenaceous Klapperkop Member (Fig. 9) con-

sists of an erosively based, generally upward-coarsen-

ing succession of tidally reworked braid-delta

deposits, interpreted as lowstand facies by Eriksson

and Reczko (1998). Eriksson and Reczko (1998)

recognized two separate facies within the Klapperkop

Member: (1) mature cross-bedded sandstone sheets,

interpreted as lower tidal flat deposits; and (2) inter-

bedded lenticular immature sandstones and mud-

stones, interpreted as medial to upper tidal flat

deposits.

The lower tidal flat deposits consist of sandstone

beds with lateral extents of tens to hundreds of

meters, and bed thicknesses of up to 5 m. These

rocks are mostly fine- to medium-grained, and com-

prise quartz arenites with subordinate sublithic are-

nites, quartz wackes, and lithic wackes (Schreiber,

1990). Minor, thin mudstone interbeds are also found

(Eriksson and Reczko, 1998). The sandstone sheets

display planar and trough cross-bedding with varying

proportions around the basin (Button, 1973; Key,

1983; Van der Neut, 1990; Schreiber, 1990). A few

Fig. 9. Fence diagram illustrating the distribution, thickness, and sheet-like geometry of the lithofacies identified by previous workers in the

Timeball Hill Formation. Modified from Eriksson et al. (1994b) and Eriksson and Reczko (1998). The position of all localities in the context of

the Transvaal Basin is indicated in Fig. 5.


herringbone cross-bed sets occur, as well as minor

interference and bifurcating ripples, and rare mud-

cracked surfaces and preserved megaripples (Button,

1973; Schreiber, 1990). A relatively shallow water

depositional setting is inferred for these cross-bedded

sandstone sheets, supported by uncommon mudcracks

and ripple marks. The presence of minor herringbone

cross-beds, bifurcating, and interference ripples sug-

gests tidal action. The textural and compositional

maturity of these inferred tidal sandstone sheets

points to a lower tidal flat setting where reworking

would have been more prevalent (Eriksson and

Reczko, 1998).

The medial to upper tidal flat deposits are com-

monly interbedded with stacked lower tidal flat sand-

stone sheet successions up to 30 m thick (Eriksson and

Reczko, 1998). The inferred upper tidal flat deposits

comprise lenticular sandstone bodies, from less than 1

m to about 50 m in lateral extent, and up to about 50 cm

thick, interbedded with finely laminated, micaceous

mudstones. The sandstones are compositionally and

texturally immature, mostly fine to medium grained.

Locally, coarse-grained sandstones and even small

pebble conglomeratic basal lags are observed (Eriksson

and Reczko, 1998). The presence of interbedded sand-

stones and mudstones, ladderback and flat-top ripples,

herringbone cross-strata, and mudcracks supports the

varying energy levels and intermittent exposure typical

of middle to upper tidal flats.

3.2.3. Upper shale Member

The Upper Shale Member consists of a deep-

ening-upward succession of suspension deposits and

delta-fed turbidite fan systems interpreted as trans-

gressive facies (Eriksson and Reczko, 1998). Sub-

ordinate occurrences of black shales and diamictites

are recorded in the south of the basin, and arkosic

sandstones in the north (Fig. 9). Typical for these

‘‘upper mudstones’’ are widespread soft sediment

deformation structures (Eriksson et al., in press).

The zone of disturbed mudstones extends over much

of the eastern part of the basin, thinning to both

north and south of an approximately central max-

imum preserved depth (below the upper contact of

the formation) of deformation of c. 160 m (Button,

1973). The soft sediment deformation of the uncon-

solidated upper Timeball Hill facies is likely related

to the tectonic instability that terminated the evolu-

tion of the Timeball Hill seaway. This tectonic event

was interpreted to reflect conditions of pre-rift uplift

that generated the second-order subaerial unconform-

ity that separates the Rooihoogte–Timeball Hill

from the overlying Boshoek–Houtenbek second-

order depositional sequence (Catuneanu and Eriks-

son, 1999).

4. Sequence stratigraphy

Previous sequence stratigraphic analysis of the

Transvaal Supergroup identified the Rooihoogte–

Timeball Hill succession as a second-order depositio-

nal sequence bounded by major subaerial unconform-

ities (Catuneanu and Eriksson, 1999). This sequence

accumulated during a stage of glacio-eustatic fall,

with accommodation provided by syn-rift extensional

and post-rift thermal subsidence. At a second-order

level of stratigraphic cyclicity, the Rooihoogte–Time-

ball Hill succession conforms with the definition of a

depositional sequence, as it groups together a rela-

tively conformable package of strata that are genet-

ically related to one full tectonic cycle of rifting. As

argued in the previous sections of this paper, the

position of the lower second-order sequence boundary

of the Rooihoogte–Timeball Hill sequence should be

revised from the base of the chert breccias to the

contact of these breccias with the overlying chert

conglomerates (Fig. 10). This is because the chert

breccias are likely age equivalent with the Duitsch-

land Formation of the Chuniespoort Group, and the

major tectonic event leading to the basin inversion and

the change in topographic tilt succeeded the timing of

breccia formation and preceded the progradation of

chert conglomerates. For this reason, the chert brec-

cias and conglomerates are unrelated genetically and

belong to different depositional sequences.

The conformable character of the second-order

Rooihoogte–Timeball Hill succession is disrupted

by the basin-wide erosional surface at the base of

the Klapperkop quartzite Member. This basal Klap-

perkop unconformity has a markedly different char-

acter relative to the second-order sequence boundaries

of the Rooihoogte–Timeball Hill succession. The

basal Rooihoogte and basal Boshoek unconformities

(previously identified as second-order sequence boun-

daries: Catuneanu and Eriksson, 1999) are strongly


angular and erosional, being associated with major

tectonic reorganizations of the basin. The amounts of

downcutting are estimated to up to 800 and 250 m,

respectively (Eriksson et al., in press; Button, 1973).

The basal Klapperkop unconformity is not associated

with any significant tectonic reorganization within the

basin, and does not display angular relationships. For

these reasons, although it is still uncertain at this stage

how much downcutting took place due to the lack of

angular relationships, we propose that this unconform-

ity has a lower hierarchical order relative to the basal

Rooihoogte and basal Boshoek surfaces. We therefore

suggest that the basal Klapperkop unconformity is a

third-order sequence boundary, which provides the

basis for the sequence stratigraphic subdivision of the

Rooihoogte–Timeball Hill second-order sequence

into two third-order depositional sequences. These

two third-order sequences are marked as (1) and (2)

in Fig. 10.

4.1. Sequence (1)

Sequence (1) includes the entire Rooihoogte

Formation, plus the Lower Shale Member of the

Timeball Hill Formation (Fig. 10). It corresponds to

a period of time of continuous base-level rise, when

a succession of lowstand, transgressive, and high-

stand systems tracts accumulated in the Transvaal

Basin.

The lowstand systems tract (LST) consists of a

fining-upward succession of partly coeval lacustrine,

fan-delta, and alluvial fan sediments, which includes

Fig. 10. Sequence stratigraphic interpretation of the Rooihoogte–Timeball Hill succession. Not to scale. The Rooihoogte and Timeball Hill

Formations build together a second-order depositional sequence. This sequence is split by the basal Klapperkop basin-wide subaerial

unconformity into two third-order depositional sequences, marked as (1) and (2) in this diagram. Abbreviations: LST—lowstand systems tract;

TST—transgressive systems tract; HST—highstand systems tract; (1)—lacustrine facies (mudstone Member) of the Rooihoogte Formation;

(2)—Polo Ground sandstone Member of the Rooihoogte Formation; (3)—Lower Shale Member of the Timeball Hill Formation, excluding the

basal black shales; (4)—Klapperkop Member of the Timeball Hill Formation; (5)—Upper Shale Member of the Timeball Hill Formation.


all the pre-Polo Ground Member lithofacies of the

Rooihoogte Formation. The progradation of alluvial

fans and fan-deltas into the lacustrine environment

took place from north to south, which indicates the

direction of syn-depositional topographic tilt (Fig. 8).

This initial stage of aggradation in the Pretoria Basin

led to the peneplanation of the pre-existing karst

topography that formed during extensive subaerial

exposure at the top of the Chuniespoort Group. The

lower contact of the LST coincides with the second-

order subaerial unconformity that bounds the Rooi-

hoogte–Timeball Hill succession at the base. The

upper contact of the LST is represented by a max-

imum regressive surface (Fig. 10), which is associated

with a tectonic re-organization of the basin and the

debut of the subsequent transgression.

The transgressive systems tract (TST) includes

two lithostratigraphic units that are inferred to be

partly age equivalent: the Polo Ground fluvial sand-

stones of the Rooihoogte Formation, and the trans-

gressive black shales of the Timeball Hill Formation.

There is a noticeable change in the direction of

topographic tilt between the LST and the TST, as

inferred from the chert conglomerate isopachs (Fig.

8), Polo Ground paleocurrents (Eriksson, 1988), and

the direction of initial Timeball Hill transgression

(Eriksson and Reczko, 1998). The transgression of

the Timeball Hill seaway took place from east to

west, which implies an easterly tilt in the basin. This

in agreement with the paleodrainage patterns of the

Polo Ground fluvial systems, with an overall flow

along the strike of the basin in an easterly direction.

The change in topographic tilt from the LST to the

TST (southerly to easterly, respectively) is most likely

related to differential subsidence in the basin. The

bounding surfaces of the TST are represented by a

maximum regressive surface, at the base, and a

maximum transgressive surface, at the top (Fig. 10).

The latter surface marks the contact with the over-

lying shallowing-upward succession of the lower

Timeball Hill shales.

The highstand systems tract (HST) is built by the

shallowing-upward succession of the Timeball Hill

Lower Shale Member (Fig. 10). This succession of

fine-grained pelagic and low-density gravity flow

facies is interpreted to represent aggradation in a

marine environment during the normal regression of

the shoreline. The HST is bounded at the base by the

maximum transgressive surface (contact with the

underlying transgressive black shales), and at the top

by the third-order subaerial unconformity (contact

with the overlying Klapperkop Member).

4.2. Sequence (2)

Sequence (2) includes the Klapperkop and Upper

Shale members of the Timeball Hill Formation. It is

bounded at the base and top by two basin-wide

subaerial unconformities of third- and second-order,

respectively (Fig. 10). This sequence preserves low-

stand and transgressive systems tracts.

The lowstand systems tract is represented by the

tidally reworked braid-delta deposits of the Klapper-

kop Member (Fig. 10). The shallowing upward tran-

sition from lower tidal flat to medial and upper tidal

flat settings suggests gradual normal regression in the

braid-delta environment. This normal regression

resulted in the aggradation of sandy lowstand deposits

with a sheet-like geometry being developed across the

entire Transvaal Basin. The lowstand aggradation

lasted until the debut of the subsequent transgression,

which is marked by an abrupt facies shift from low-

stand sands to transgressive mudstones and shales.

The contact between the lowstand and the overlying

transgressive facies is represented by a wave-cut

ravinement surface (Fig. 10).

The transgressive systems tract is equated with the

Upper Shale Member of the Timeball Hill Formation.

This is a deepening-upward marine succession of

pelagic and gravity flow deposits, topped by the upper

boundary of the Rooihoogte–Timeball Hill second-

order sequence (Fig. 10). The lack of a preserved

maximum transgressive surface, as well as of an

overlying highstand systems tract, indicates signifi-

cant subaerial erosion and truncation associated with

the upper boundary of the Rooihoogte–Timeball Hill

depositional sequence.

The uppermost deep marine facies of the Timeball

Hill Formation are sharply overlain by the high energy

alluvial fan deposits of the Boshoek Formation (Fig.

3), indicating an abrupt change in the sedimentation

regime across the sequence boundary. This second-

order subaerial unconformity may be related to a stage

of pre-rift uplift that preceded the next second-order

cycle of rifting in the Pretoria Basin (Catuneanu and

Eriksson, 1999).


5. Discussion

Precambrian successions are generally character-

ized by a scarce time control, due to the lack of a

usable fossil record and the error margins associated

with the radiometric dating of pre-Phanerozoic rocks.

This impairs sequence stratigraphic analyses at high-

frequency temporal scales. This case study, as well as

the previous lower resolution work in the Transvaal

Basin (Catuneanu and Eriksson, 1999), shows, how-

ever, that sequence stratigraphy can be applied with a

high degree of confidence at second- and third-order

levels of stratigraphic cyclicity. The lack of a high-

resolution time control may be partly compensated by:

(a) careful observations of the facies relationships of

the basin fill, and (b) the study of changes in the

direction of topographic tilt through time. Lateral and

vertical facies changes allow for genetic interpreta-

tions of relative sea-level changes, as well as for the

delineation of systems tracts. In addition, the shifts in

the direction of topographic tilt help to constrain the

age relationships between the various facies in the

absence of other absolute or relative time indicators.

For example, both the Polo Ground sandstones and

the basal black shales of the Timeball Hill Formation

accumulated during the same stage of easterly tilt,

which differentiates them from the underlying systems

tract dominated by a southerly topographic tilt.

The value of applying the methods of sequence

stratigraphy also consists in the better understanding

of the nature and significance of the contacts between

lithostratigraphic units. The most important lithostrati-

graphic contact in this case study is the boundary

between the Rooihoogte and Timeball Hill forma-

tions. As inferred from our analysis, this contact is

represented by a ravinement surface cut by waves in

the upper shoreface during the transgression of the

shoreline. This makes the Rooihoogte–Timeball Hill

contact a diachronous surface, with the rate of shore-

line transgression, which develops within a transgres-

sive systems tract.

It is difficult to quantify the absolute and relative

contributions of the different controls on accommo-

dation, due to subsequent denudation and the intru-

sion of the Bushveld Complex (Eriksson et al., in

press). We do know, however, that at the second-order

level of the Rooihoogte–Timeball Hill rifting episode,

extensional and thermal subsidence rates outpaced the

rates of glacio-eustatic fall to generate the necessary

accommodation for sediment accumulation. It is still

uncertain what caused the relative sea-level fall that

resulted in the subaerial unconformity at the base of

the Klapperkop Member. Temporary slowing down of

subsidence, outpaced by the eustatic fall, or a tempo-

rary increase in the rate of eustatic fall, outpacing the

subsidence rates, may both explain the generation of

the third-order sequence boundary identified at the

base of the Klapperkop Member.

6. Conclusions

(1) The Rooihoogte–Timeball Hill second-order

sequence represents the depositional product of a

rifting cycle in the Transvaal Basin, and accumulated

during a stage of glacio-eustatic fall. This provides a

case study for accommodation and sequence develop-

ment controlled by tectonic processes.

(2) Relative to previous research, the position of

the lower boundary of the Rooihoogte–Timeball Hill

sequence is revised from the base of the chert brec-

cias, to the contact between the breccias and the

overlying chert conglomerates. This is because a

major tilting event occurred between the deposition

of the two facies, which are unrelated genetically and

separated by a subaerial unconformity. The chert

breccias formed through in situ weathering on a

northerly dipping topographic slope, whereas the

chert conglomerates represent the product of alluvial

and delta–fan progradation on a southerly dipping

topographic profile.

(3) The Rooihoogte–Timeball Hill second-order

sequence consists of two third-order depositional

sequences separated by the subaerial unconformity

at the base of the Klapperkop quartzite Member. The

lower third-order sequence preserves lowstand, trans-

gressive, and highstand systems tracts. The upper

third-order sequence includes only a lowstand systems

tract and a partially preserved transgressive systems

tract. The missing highstand systems tract indicates

strong erosional processes associated with the upper

boundary of the Rooihoogte–Timeball Hill second-

order sequence.

(4) Secondary tectonic reorganizations within the

basin, including changes in the direction of topo-

graphic tilt and changes in the subsidence rates,


occurred during the Rooihoogte–Timeball Hill sec-

ond-order cycle of rifting. Paleocurrents and stratal

stacking patterns record a change in the direction of

topographic tilt between the lowstand and the trans-

gressive systems tracts of the lower third-order

sequence, likely related to differential subsidence in

the basin. The third-order subaerial unconformity at

the base of the Klapperkop Member also suggests a

shift in the balance between the rates of subsidence

and eustatic fall, leading to a stage of relative sea-level

fall.

(5) The lithostratigraphic contact between the Rooi-

hoogte and Timeball Hill formations is interpreted as a

transgressive surface of erosion (ravinement surface)

in sequence stratigraphic terms. This contact develops

within a third-order transgressive systems tract,

between the inferred coeval Polo Ground fluvial sand-

stones and the transgressive marine black shales, and is

diachronous with the rate of shoreline transgression.

(6) Sequence stratigraphy can be successfully

applied to the analysis of Precambrian successions at

least at the second- and third-order levels of cyclicity.

The scarce time control may be partly compensated by

careful observations of lateral and vertical facies

relationships. Supplementary age constraints may be

added by the changes through time in the direction of

topographic tilt, which may be inferred from paleo-

currents and stratal stacking patterns.

Acknowledgements

O.C. acknowledges financial support from the

University of Alberta and NSERC Canada. P.G.E. is

grateful for generous research support from the

University of Pretoria and the National Research

Foundation, South Africa. We thank Andrew Willis

and John Hancox for their thoughtful reviews of the

manuscript. In addition, we are grateful to the special

issue subeditor, Pradip Bose, for his thorough

handling of the manuscript, guidance, and construc-

tive comments.

References

Armstrong, R.A., Compston, W., Retief, E.A., Williams, I.S.,

Welke, H.J., 1991. Zircon ion microprobe studies bearing on

the age and evolution of the Witwatersrand Triad. Precambrian

Res. 53, 243–266.

Button, A., 1973. A regional study of the stratigraphy and develop-

ment of the Transvaal Basin in the eastern and northeastern

Transvaal. PhD dissertation, University of Witwatersrand, Jo-

hannesburg.

Catuneanu, O., in press. Flexural partitioning of the Late Archaean

Witwatersrand foreland system, South Africa. Sediment. Geol.

Catuneanu, O., Biddulph, M.N., in press. Sequence stratigraphy of

the Vaal Reef facies associations in the Witwatersrand foredeep,

South Africa. Sediment. Geol.

Catuneanu, O., Eriksson, P.G., 1999. The sequence stratigraphic

concept and the Precambrian rock record: an example from

the 2.3–2.1 Ga Pretoria Group, Kaapvaal craton. Precambrian

Res. 97, 215–251.

Catuneanu, O., Willis, A.J., Miall, A.D., 1998. Temporal signifi-

cance of sequence boundaries. Sediment. Geol. 121 (3–4),

157–178.

Christie-Blick, N., Grotzinger, J.P., von der Borch, J.P., 1988. Se-

quence stratigraphy in Proterozoic successions. Geology 16,

100–104.

Embry, A.F., 1995. Sequence boundaries and sequence hierarchies:

problems and proposals. In: Steel, R.J., Felt, V.L., Johannes-

sen, E.P., Mathieu, C. (Eds.), Sequence Stratigraphy on the

Northwest European Margin. Norweg. Petrol. Soc., Spec. Publ.

5, pp. 1–11.

Eriksson, P.G., 1988. Sedimentology of the Rooihoogte Formation,

Transvaal Sequence. S. Afr. J. Geol. 91, 477–489.

Eriksson, P.G., Reczko, B.F.F., 1995. The sedimentary and tectonic

setting of the Transvaal Supergroup floor rocks to the Bushveld

Complex. J. Afr. Earth Sci. 21, 487–504.

Eriksson, P.G., Reczko, B.F.F., 1998. Contourites associated with

pelagic mudrocks and distal delta-fed turbidites in the Lower

Proterozoic Timeball Hill Formation epeiric basin (Transvaal

Supergroup), South Africa. Sediment. Geol. 120, 319–335.

Eriksson, P.G., Schreiber, U.M., Van der Neut, M., 1991. A review

of the sedimentology of the Early Proterozoic Pretoria Group,

Transvaal Sequence, South Africa: implications for tectonic set-

ting. J. Afr. Earth Sci. 13, 107–119.

Eriksson, P.G., Engelbrecht, J.P., Res, M., Harmer, R.E., 1994a. The

Bushy Bend lavas, a new volcanic member of the Pretoria

Group, Transvaal Sequence. S. Afr. J. Geol. 97, 1–7.

Eriksson, P.G., Reczko, B.F.F., Merkle, R.K.W., Schreiber, U.M.,

Engelbrecht, J.P., Res, M., Snyman, C.P., 1994b. Early Proter-

ozoic black shales of the Timeball Hill Formation, South Africa:

volcanogenic and palaeoenvironmental influences. J. Afr. Earth

Sci. 18, 325–337.

Eriksson, P.G., Condie, K.C., Tirsgaard, H., Mueller, W.U., Alter-

mann, W., Miall, A.D., Aspler, L.B., Catuneanu, O., Chiaren-

zelli, J.R., 1998. Precambrian clastic sedimentation systems.

Sediment. Geol. 120, 5–53.

Eriksson, P.G., Altermann, W., Catuneanu, O., van der Merwe, R.,

Bumby, A.J., in press. Major influences on the evolution of the c.

2.67–2.1 Ga Transvaal basin, Kaapvaal craton. Sediment. Geol.

Harmer, R.E., von Gruenewaldt, G., 1991. A review of magmatism

associated with the Transvaal Basin—implications for its tec-

tonic setting. S. Afr. J. Geol. 94, 104–122.


Hunt, D., Tucker, M.E., 1992. Stranded parasequences and the

forced regressive wedge systems tract: deposition during base-

level fall. Sediment. Geol. 81, 1–9.

Key, R.M., 1983. The geology of the area around Gaborone and

Lobatse, Kweneng, Kgatleng, Southern and South East Districts.

Dist. Mem. -Geol. Surv. Botswana (Gaborone, Botswana) 5.

Martin, D.McB., 1999. Depositional setting and implications of

Paleoproterozoic glaciomarine sedimentation in the Hamersley

Province, Western Australia. Geol. Soc. Am. Bull. 111, 189–

203.

Miall, A.D., 1997.TheGeologyof StratigraphicSequences. Springer-

Verlag, Berlin, Heidelberg.

Plint, A.G., Nummedal, D., 2000. The falling stage systems tract:

recognition and importance in sequence stratigraphic analysis.

In: Hunt, D., Gawthorpe, R.L. (Eds.), Sedimentary Response to

Forced Regression. Geol. Soc. London, Spec. Publ. 172, pp.

1–17.

Posamentier, H.W., Jervey, M.T., Vail, P.R., 1988. Eustatic controls

on clastic deposition: I. Conceptual framework. In: Wilgus,

C.K., et al., (Eds.), Sea-Level Changes: An Integrated Ap-

proach. American Association of Petroleum Geologists, SEPM

Spec. Publ. (Tulsa) 42, 109–124.

Posamentier, H.W., Allen, G.P., James, D.P., Tesson, M., 1992.

Forced regressions in a sequence stratigraphic framework: con-

cepts, examples and exploration significance. Am. Assoc. Pet.

Geol. Bull. 76, 1687–1709.

Robb, L.J., Meyer, F.M., 1995. The Witwatersrand Basin, South

Africa: geological framework and mineralization processes.

Econ. Geol. Research Unit, Information Circular, vol. 293. Uni-

versity of Witwatersrand, Johannesburg, South Africa.

Schreiber, U.M., 1990. A palaeoenvironmental study of the Pretoria

Group in the Eastern Transvaal. PhD thesis, University of Pre-

toria, unpublished.

Stanistreet, I.G., McCarthy, T.S., 1991. Changing tectono-sedimen-

tary scenarios relevant to the development of the Late Archaean

Witwatersrand Basin. J. Afr. Earth Sci. 13, 65–81.

Vail, P.R., 1987. Seismic stratigraphy interpretation using sequence

stratigraphy. In: Bally, A.W. (Ed.), Atlas of Seismic Strati-

graphy, vol. 1. Am. Assoc. Pet. Geol., Stud. Geol., vol. 27,

pp. 1–10.

Van der Neut, M., 1990. Afsettingstoestande van die Pretoria Groep

gesteentes in die Pretoria-Bronkhorstspruit-Delmas gebied. MSc

thesis, University of Pretoria, Pretoria.

Van Wagoner, J.C., Mitchum, R.M., Campion, K.M., Rahmanian,

V.D., 1990. Siliciclastic sequence stratigraphy in well logs,

cores, and outcrops: concepts for high-resolution correlation of

time and facies. AAPG Methods Explor. Ser. 7.

Visser, J.N.J., 1971. The deposition of the Griquatown Glacial

Member in the Transvaal Supergroup. Trans. Geol. Soc. S.

Afr. 74, 187–199.

Walraven, F., Martini, J., 1995. Zircon Pb-evaporation age determi-

nations of the Oak Tree Formation, Chuniespoort Group, Trans-

vaal Sequence: implications for Transvaal –Griqualand West

basin correlations. S. Afr. J. Geol. 98, 58–67.

Winter, H. de la R., 1987. A cratonic foreland model for Witwa-

tersrand Basin development in a continental back-arc, plate-tec-

tonic setting. S. Afr. J. Geol. 90, 409–427.

Young, G.M., 1995. Are Neoproterozoic glacial deposits preserved

on the margins of Laurentia related to the fragmentation of two

supercontinents? Geology 23, 153–156.

Young, G.M., Long, D.G.F., Fedo, C.M., Nesbitt, H.W., in press.

Paleoproterozoic Huronian Basin: product of a Wilson cycle

punctuated by glaciations and a meteorite impact. Sediment.

Geol.


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