Sea-Level Changes and Timing of Turbidity-Current Events in Deep-Sea Fan Systems

Kolla, V.; Macurda, Donald B.

doi:10.2110/pec.88.01.0381

Cited by 40 publications

(24 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14, backpocket foldout) indicates that the Amazon Fan contains sheets of sand with high sand to mud ratios that are tens of meters thick and several kilometers to several tens of kilometers in lateral extent. Other large submarine fans like the Indus Fan (Kolla and Macurda, 1988;McHargue, 1991), the Bengal Fan (Droz and Bellaiche, 1991), the Mississippi Fan (Weimer, 1990), and the Rhône Fan (Droz and Bellaiche, 1986;d'Heilly et al, 1988) also contain onlapping units at the base of channel-levee systems, with both high-and low-amplitude seismic character. By analogy with the Amazon Fan, these and other large fans may contain sand-rich units associated with channel bifurcations and with the distal ends of channels.…”

Section: Sand-rich Units and Amazon Fan Sedimentation Processesmentioning

confidence: 99%

Sandy turbidite successions at the base of channel-levee systems of the Amazon Fan revealed by FMS logs and cores: unraveling the facies architecture of large submarine fans

Pirmez¹,

Hiscott²,

Kronen³

1997

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

Continuous bed-by-bed descriptions of thick, sand-rich turbidite successions drilled at five sites on the Amazon Fan have been prepared using a combination of Formation MicroScanner (FMS) and geophysical wireline logs. FMS images enable a complete lithologic section to be derived at Sites 931, 935, 936, 944, and 946 over intervals of poor core recovery up to several tens of meters thick, characterized as high-amplitude reflection packets (HARPs) in the seismic data. On the middle fan, HARP deposition coincides in time with the initiation of a new channel segment after channel bifurcation. Toward the lower fan, HARP units tend to stack directly on top of each other, as overbank deposits thin downfan; these HARP units probably contain deposits formed at the mouths of channels.The turbidite successions within the HARP intervals include sand bodies 5-25 m thick formed of sand beds 0.1-4 m thick. These sand bodies correlate with episodes of channel bifurcation on the middle fan. Most beds thicker than ~1 m contain mud clasts, interpreted to result from upslope levee erosion and channel entrenchment after channel bifurcation. On the lower fan, bed clusters and sets of amalgamated beds form sand bodies as thick as 50 m, with individual beds often exceeding 3 m in thickness and containing abundant mud clasts. Most bed clusters show no apparent trends in bed thickness, although a few clusters show clear thickening-upward trends interpreted to represent channel mouth progradation.Other studies suggest that, for turbidites, the number of beds whose thickness is greater than T is proportional to T -B , where B is a positive exponent. The scaling exponent required to fit the Amazon Fan bed-thickness distributions is different for beds thinner and thicker than about 0.35 m. This difference is attributed to either selective removal, by erosion, of beds thinner thañ 0.35 m, or greater confinement, by seafloor morphology, of flows that deposited such thin beds on the fan surface. The flows that deposited beds thicker than 0.35 m in HARP units were apparently able to freely spread in the interlevee area.The so-called mud-rich Amazon Fan contains thick sheet-like units indistinguishable in facies and sand content from many ancient mud/sand-rich successions described by field geologists. Although it remains true that small fans at convergent and strike-slip plate boundaries are potentially good analogs for such ancient deposits, larger channel-levee-dominated systems that periodically supply sand to interchannel depressions following avulsions also need to be considered.

show abstract

Section: Sand-rich Units and Amazon Fan Sedimentation Processesmentioning

confidence: 99%

Sandy turbidite successions at the base of channel-levee systems of the Amazon Fan revealed by FMS logs and cores: unraveling the facies architecture of large submarine fans

Pirmez¹,

Hiscott²,

Kronen³

1997

Proceedings of the Ocean Drilling Program

View full text Add to dashboard Cite

show abstract

“…However, unconformities on the New Jersey continental slope document deep-water (Valentine, 1980) erosive processes that may be indirectly linked to sea-level changes. For example, sea-level lowerings may facilitate delivery of large volumes of sediment that can destabilize slopes and eventually lead to slumping (e.g., Coleman et al, 1983;Kolla and Macurda, 1988). Various other mechanisms of slope incision not necessarily associated with sea-level changes are reviewed in Mountain (1987) and Mountain et al (1994b).…”

Section: Discussionmentioning

confidence: 99%

Seismic-to-Well Correlation of Seismic Unconformities at Leg 150 Continental Slope Sites

Lorenzo¹,

Hesselbo²

1996

Proceedings of the Ocean Drilling Program, 150 Scientific Results

View full text Add to dashboard Cite

Seismic-to-well correlation at Ocean Drilling Program (ODP) continental slope Sites 902, 903, 904, and 906 identifies 19 Pleistocene-Eocene unconformable surfaces and reflectors. Seismic features on 120-channel, tuned, air-gun seismic data are tied to borehole depths via one-dimensional synthetic seismogram models. Reprocessed migrated seismic profiles along Maurice Ewing Lines 1005 and 1027 reveal clear images of two middle Miocene canyon-cutting surfaces and Pleistocene slumpbounding unconformities. At Site 904, good-quality compressional-wave velocity and density values allow models to match seismic facies. A high-amplitude continuous seismic facies between Miocene unconformities q and w can be attributed to distal toe-of-delta clinoforms containing alternating glauconite-rich and -poor sedimentary facies. A seaward-thinning Oligocene interval downlaps the upper Oligocene/upper Eocene, producing reflectors resolvable only through ties to biostratigraphic and lithologic borehole data. A silica-indurated diagenetic front within the middle Eocene produces reflectors that do not have chronostratigraphic significance and can mislead sequence stratigraphic interpretations.

show abstract

“…Some modern fans are very large indeed and took much longer than the period of a single glacial-eustatic lowstand to form. Furthermore, the fan-building process is not confined to lowstands, and other factors, including sediment supply, tectonic setting, and the uplift of source areas, can also affect the process (Kolla and Macurda 1988). Some of the larger Millstone Grit turbidite-fronted deltas may likewise represent more than one lowstand.…”

Section: Discussionmentioning

confidence: 99%

The Millstone Grit (namurian) of the southern pennines viewed in the light of eustatically controlled sequence stratigraphy

Read

1991

Geological Journal

View full text Add to dashboard Cite

The overall lithological succession in the Millstone Grit of the southern Pennines was most probably controlled by glacial-eustatic sea-level oscillations and may be interpreted in terms of the systems tracts of sequence stratigraphy. Bands containing thick-shelled goniatites represent 'condensed sections' formed at times of maximum flooding. Turbidite-fronted deltas, marking major basin-filling episodes, resemble 'lowstand systems tracts'. However all sand influxes did not necessarily occur during lowstands. Millstone Grit sheet deltas and elongate deltas resemble lobate and birdfoot deltas in Recent 'highstand systems tracts'. The prograding fluviodeltaic complexes at the tops of some major turbiditefronted deltas were braid deltas. So was the sheet-like channel complex of the Rough Rock at the top of the Millstone Grit, but this was probably part of a 'highstand systems tract'. KEY WORDS EPR Sequence stratigraphy Systems tracts Eustasy Allocycles Braid deltas Northern England

show abstract

Sea-Level Changes and Timing of Turbidity-Current Events in Deep-Sea Fan Systems

Cited by 40 publications

References 7 publications

Sandy turbidite successions at the base of channel-levee systems of the Amazon Fan revealed by FMS logs and cores: unraveling the facies architecture of large submarine fans

Sandy turbidite successions at the base of channel-levee systems of the Amazon Fan revealed by FMS logs and cores: unraveling the facies architecture of large submarine fans

Seismic-to-Well Correlation of Seismic Unconformities at Leg 150 Continental Slope Sites

The Millstone Grit (namurian) of the southern pennines viewed in the light of eustatically controlled sequence stratigraphy

Contact Info

Product

Resources

About