A sandy, bed-load dominated fluvial system deposited by lateral-accretion: Permian Karoo Sequence, South Africa

Cadle, A. B.; Cairncross, Bruce

doi:10.1016/0037-0738(93)90097-o

Cited by 21 publications

(7 citation statements)

References 18 publications

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“…In the present case, fining upward trend occurs at individual bed level, a feature generally not observed in channel bar deposits and common in point bars (Boggs 2009). Further trough cross beds that mostly characterize the lower part of the point bar sequence are observed (Massari 1983;Cadle and Cairncross 1993) and planar cross beds occur in the upper part of the lithofacies. However, the convolute bedding and slumping commonly observed in the upper part of channel bars are absent.…”

Section: Channel Belt Sandstone Lithofacies (Cbsl)supporting

confidence: 49%

“…The lithofacies occurs at several stratigraphic levels and shows a wide range of shades, i.e., light grey to dark grey, maroon, red and dark brown. The beds can be traced for few meters and lateral pinching/lenticular bedding (figure 3e) and lateral accretion is observed (Cadle and Cairncross 1993), especially in the lower part of the lithofacies (first occurrence of the lithofacies). Further erosive bedding plans/reactivation surfaces are observed in the beds and trough cross bedding and planar bedding plans (Boggs 2009) are more common in the upper part of the lithofacies.…”

Section: Channel Belt Sandstone Lithofacies (Cbsl)mentioning

confidence: 99%

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Palaeoenvironmental and sequence stratigraphic analyses of the Jurassic Datta Formation, Salt Range, Pakistan

et al. 2015

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The Lower Jurassic Datta Formation, western Salt Range, Pakistan, comprises three facies associations: (1) channel belt facies association (CBFA), (2) channel margin, and overbank facies association (CMOFA), and (3) lagoonal facies association (LFA). A cyclic fining-upward trend in the succession is represented by basal quartzose conglomerate/pebbly sandstone, through coarse to fine quartzose sandstone to siltstone and shales/claystone, which contains some carbonate accumulation. Two prominent depositional sequences are recognized in the Datta Formation with the lower high and upper low magnitude cycles. The Datta Formation thus represents a thick sedimentary succession and in the study area, i.e., western Salt Range, mainly channel belt, flood plain and/or delta top facies are exposed. The palaeocurrent analysis shows that the source area with acidic plutonic rocks laid to S-SE in the Indian shield, aravalies or older sedimentary rocks of the Indus Basin (i.e., Khewra, Tobra and Warchha formations). A tentative stratigraphic correlation of the Datta Formation with the lower Jurassic Lathi Formation, India invites further work in parts of India, which will elaborate the extent of the Datta Formation in the Greater Indian peninsula and develop palaeogeographic setting for this Lower Jurassic deltaic rock unit.

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Section: Channel Belt Sandstone Lithofacies (Cbsl)supporting

confidence: 49%

Section: Channel Belt Sandstone Lithofacies (Cbsl)mentioning

confidence: 99%

Palaeoenvironmental and sequence stratigraphic analyses of the Jurassic Datta Formation, Salt Range, Pakistan

et al. 2015

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“…5) that lateral accretion is more common than downstream accretion (element DA). This trend points, according to Cadle and Cairncross (1993), to a highly sinuous bedload-dominated¯uvial system where rates of lateral channel migration are high.…”

Section: Lateral Accretion Deposits (La)mentioning

confidence: 92%

“…The same pattern was also observed by Cadle and Cairncross (1993) in Permian sandstones, where trough cross-bedding is rare. Cadle and Cairncross (1993) attribute this to strong lateral channel migration, which leads to preferred development of planar cross-bedding in lateral accretion deposits. Further, it is apparent in the Schleenhain strip mine (Fig.…”

Section: Lateral Accretion Deposits (La)mentioning

confidence: 99%

Facies architecture and sedimentology of a meandering fluvial system: a Palaeogene example from the Weisselster Basin, Germany

Halfar¹,

Riegel²,

Walther³

1998

Sedimentology

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The Schleenhain open pit coal mine, located 30 km south of Leipzig, Germany, exposes Upper Eocene and Oligocene non‐marine strata representing fluvial deposition in the centre of the Weisselster Basin. Active mining and successive cuts provided the rare opportunity to obtain a three‐dimensional perspective of laterally extensive surface outcrops. These were used to construct a detailed fence diagram, which provided the basis for recognition of key architectural elements in the weakly consolidated meandering stream deposits. In addition to the eight basic architectural elements of Miall (1985), the element SL (shallow lake deposits) was newly defined and the element CH (channel) was subdivided into CHg (palaeo‐river system) and CHk (small channel). The profiles contain parts of two fining‐upward cycles, which are separated by an unconformity spanning the Early Oligocene. Deposits of the first cycle begin with transverse sand bars (downstream accretion deposits‐DA) and point bars (lateral accretion deposits‐LA). The upper part of the cycle is represented by overbank fines (OF) and the element SL, which consists of laterally discontinuous lenses of dark, plant‐bearing, kaolinite‐rich clays, that were deposited in shallow lakes adjacent to the active channel. Coal seams interlayered with palaeosols are the main constituents of element OF. Sheetlike bodies of medium to fine gravels (gravel bars and bedforms‐GB) on an erosive coal surface mark the beginning of the second cycle. Dissolution of underlying Permian salts and sulphates prior to, during, and after the deposition of the Palaeogene strata caused the development of two synclines within the outcrop. Coal seams and clay horizons which thicken and dip towards the centre of the synclines, provide evidence for their chronological development.

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“…Similar arguments have been presented for sand dunes (McCabe & Jones, 1977;Ditchfield & Best, 1992), but in the present context there is no evidence for secondary bedforms preserved on the smooth backs of the Siberian bedforms. Consequently, the mechanism would have to be driven by the thin bedload pulses which have low preservation potential (Cadle & Cairncross, 1993) and which have left no topographic expression on the stoss slopes. An alternative and more likely explanation is that the turbulence and shear stress maximum for developed by Flemming (1988) and proposed by Ashley (1990) to define the maximum height of equilibrium dunes developed in sand.…”

Section: Palaeohydraulic Significancementioning

confidence: 99%

Morphology, sedimentology and palaeohydraulic significance of large gravel dunes, Altai Mountains, Siberia

Carling

1996

Sedimentology

115

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Coarse‐gravel bedforms which resulted from Pleistocene glacial outburst floods are identified as subaqueous dunes. Comparison of the morphology of these ‘fossil’ structures with modern dunes shows that the form of two‐dimensional (2‐D) transverse dunes and 3‐D cuspate and lunate dunes developed in coarse gravels is comparable with sand‐dune morphology within lesser‐scale geophysical flows. The similarity of the steepest gravel dunes with equilibrium dunes in sand indicates that grain size is not a major factor in constraining primary duneform. Internal structure indicates that flow over 2‐D dunes was relatively uniform but over 3‐D bedforms flow was locally variable. Flow separation and complex streaming of flow occurred over the steepest 3‐D dunes. Cross‐beds are thin and few approach the angle of repose; consequently most dunes did not migrate primarily by avalanching but by stoss‐entrained gravel transported over the crests rolling‐down and depositing on the lee slopes. Lee‐side sediments are often finer than the stoss‐slope sediments, which indicates the lee formed when flood power was waning. Some dunes were slightly planed‐down during falling stage because lee‐side cross‐beds tend to be steeper than the angle of the preserved lee slope. However, silt‐rich caps indicate that any height reduction was contemporary with the final deposition of foresets. Post‐flood modification has been negligible although the modern topography is subdued by loess deposits within the dune troughs.

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A sandy, bed-load dominated fluvial system deposited by lateral-accretion: Permian Karoo Sequence, South Africa

Cited by 21 publications

References 18 publications

Palaeoenvironmental and sequence stratigraphic analyses of the Jurassic Datta Formation, Salt Range, Pakistan

Palaeoenvironmental and sequence stratigraphic analyses of the Jurassic Datta Formation, Salt Range, Pakistan

Facies architecture and sedimentology of a meandering fluvial system: a Palaeogene example from the Weisselster Basin, Germany

Morphology, sedimentology and palaeohydraulic significance of large gravel dunes, Altai Mountains, Siberia

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