Sites 243 and 244

Simpson, Edward; Schlich, R.

doi:10.2973/dsdp.proc.25.106.1974

Cited by 4 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Sedimentary core data was previously retrieved from the study area ( Fig. 1B) and indicated mainly a terrigenous origin of the Quaternary sediments (Simpson et al, 1974;Kolla et al, 1980a;Hall et al, 2016).…”

Section: Accepted Manuscriptmentioning

confidence: 77%

“…It resembles to the echo type 3 defined by Damuth and Olson (2015). This facies is dominantly found along the Zambezi and Tsiribihina Valley floors where coarse to very coarse sediments have been recovered during Leg 25 DSDP drillings (site-243, Simpson et al, 1974) and cores VM19-212, VM20-195, VM20-193 and VM34-147 (Kolla et al, 1980a) (see Fig. 16), in the confluence area with the Tsiribihina Valley ( Fig.…”

Section: Accepted Manuscriptmentioning

confidence: 78%

“…Steep slopes or hummocky seafloor or narrow sediment waves (short wavelengths) Table 2 ACCEPTED MANUSCRIPT Mahanjane, 2014; (13) Schematized from Courgeon et al, 2017 andDeville et al, 2018;(14) Ponte, 2018, partly based on Baby, 2017;. Cores from IODP leg 361 (green stars) (Hall et al, 2016), from DSDP leg 25 (white stars) (Simpson et al, 1974) and from Kolla et al (1980a) (after De Ruijter et al, 2002;Schulz et al, 2011;Uenzelmann-Neben et al, 2011;Halo et al, 2014). Bathymetric data used in this study (multibeam bathymetry and sub-bottom seismic tracks).…”

Section: Andmentioning

confidence: 99%

See 2 more Smart Citations

Late Quaternary geomorphology and sedimentary processes in the Zambezi turbidite system (Mozambique Channel)

et al. 2019

View full text Add to dashboard Cite

The morphology and present-day sediment distribution of the Zambezi turbidite system was investigated using new bathymetric and sub-bottom profiler data as part of the PAMELA research project. The Zambezi turbidite system is composed of two depositional systems: a channelized fan (the Zambezi Fan) and a semi-confined fan (in the lntermediate Basin). The Zambezi Fan includes the Zambezi Valley, which is deeply incised in the Mozambique Channel and is more than three times as large and deep as the great Tanzanian and North Atlantic Mid-Ocean channels. The erosion in the Zambezi Valley is evidenced by its V-shaped morphology and the existence of a U-shaped thalweg affected by several generations of incisions. Based on echo facies and cores from literature, sediments of the Zambezi Fan are dominantly coarse-grained and fine-grained overbank deposits are infrequent. The distal portion of the Zambezi Fan is a main depositional area where typical transparent wedged-shape seismic bodies are interpreted as terminal lobes. Seismic facies in the Intermediate Basin are thought to represent mostly fine-grained turbidites intercalated with infrequent coarse-grained sheet-like turbidites. Hydrodynamic circulation (from surface eddies to the deep circulation of NADW) appears to have a great impact on the Mozambique Channel sedimentation and is suggested (1) to be involved in the delivery of the Zambezi River sediments along the Mozambique margin, (2) to entrain the upper suspended load of turbidity currents, contributing to the absence of fine-grained sedimentation and (3) to contribute to the erosion of the valley flanks leading to the exceptionally great dimensions of the valley. Highlights ► The Zambezi turbidite system comprises a channelized fan and a semi-confined fan. ► The Zambezi Valley has an atypical morphology compared to other turbidite systems. ► Erosional processes dominate in the valley. ► From echo facies, deposition appears mainly fine-grained in the semiconfined fan. ► Oceanic and turbidity currents control sediment distribution and erosion.

show abstract

Section: Accepted Manuscriptmentioning

confidence: 77%

Section: Accepted Manuscriptmentioning

confidence: 78%

Section: Andmentioning

confidence: 99%

See 1 more Smart Citation

Late Quaternary geomorphology and sedimentary processes in the Zambezi turbidite system (Mozambique Channel)

et al. 2019

View full text Add to dashboard Cite

show abstract

“…700 m; Fierens et al, 2019) Zambezi Valley may be the reason why turbidites are rarely identified. Moreover, the very coarse material present both on the deep submarine valley floors (see DSDP drilling sites 243-244;Simpson et al, 1974) and in the distal depositional part of the Zambezi sedimentary system (Robin and Droz, 2014) evidence s some 're cent' activity. Since this study is based on only 11 cores taken at specific regions of the turbidite systems, it might be anticipated that the turbidite activity may have been significantly higher than recorde d i n the present study.6.2.…”

mentioning

confidence: 99%

Quaternary sediment dispersal in the Zambezi turbidite system (SW Indian Ocean)

et al. 2020

View full text Add to dashboard Cite

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

show abstract

“…Sediment mixing and homogenization on submarine valley floors occur through repeated episodes of erosion and reworking by turbidity currents and contour currents, as suggested by a variety of bedforms indicative of seabed transport (e.g., sand waves, ripples, scours, knickpoints; Mitchell 2006;Rodrigues et al 2022). Very coarse sand contains small pebbles in the Lower Valley (Simpson et al 1974) and is transported to as far as the Lower Fan, indicating that coarse sediment travels as bedload in the dense basal part of the current. This implies that sand is not necessarily carried all the way to the fan in one shot, but it is mainly dragged stepwise along the thalweg by recurrent deposition and reworking, leading to progressive compositional homogenization.…”

Section: Mineralogical and Geochemical Variability In Spacementioning

confidence: 99%

The Zambezi deep-sea fan: mineralogical, REE, Zr/Hf, Nd-isotope, and zircon-age variability in feldspar-rich passive-margin turbidites

Garzanti

Bayon

Vermeesch

et al. 2022

Journal of Sedimentary Research

View full text Add to dashboard Cite

We here present the first comprehensive provenance study of the Zambezi deep-sea fan, based on integrated petrographic, heavy-mineral, elemental-geochemistry, isotope-geochemistry, and detrital-zircon-geochronology analyses of middle Pleistocene to Holocene turbidites. The Zambezi Valley and Fan represent the submarine part of an ∼ 5000-km-long sediment-routing system, extending from the heart of the South African Plateau to the abyssal depths of the Indian Ocean. Sediment is derived not only from the African side, but also from Madagascar Island mostly via the Tsiribihina Valley. Being shed by two dissected rifted margins, detritus supplied from opposite sides of the Mozambique Channel shares similar feldspar-rich feldspatho-quartzose composition, although with significant differences in heavy-mineral and geochemical signatures. The εNd values of Madagascar sand are markedly more negative and TNd model ages notably older. Zircon grains yield mostly Irumide (late Stenian) U-Pb ages in African-derived sand and mostly Pan-African (Ediacaran–Cryogenian) U-Pb ages in Madagascar-derived sand, which also yields a few grains as old as Paleoarchean and many discordant ages reflecting Pan-African reworking of Archean cratonic rocks. Lower Valley and Lower Fan deposits have intermediate fingerprints, indicating that sediment supply from Madagascar is not much less than from Africa despite a much smaller catchment area, which can be explained by deposition of a conspicuous part of Africa-derived sediment in the Intermediate Basin confined between the Zambezi Shelf, the Beira High, and the Îles Éparses. By assuming that compositional differences between Quaternary submarine deposits and modern Zambezi River sands primarily resulted from sediment impoundment by large dams, we could evaluate the anthropogenic impact on natural sediment fluxes. Quaternary turbidites are somewhat higher in quartz and poorer in heavy minerals with higher relative amounts of durable ZTR species, and yield more Ediacaran, Neoarchean, and Carboniferous detrital-zircon ages than modern river sands. The Orosirian peak characterizing the Intermediate Basin sample points to prominent supply from the middle and upper parts of the Zambezi catchment in the middle Pleistocene. Rough calculations suggest that pre-dam Zambezi sediments were generated ≤ 10% in the upper catchment, ∼ 60% in the middle catchment, and only ≥ 30% in the lower catchment that provides the totality of sediment reaching the Indian Ocean today.

show abstract

Sites 243 and 244

Cited by 4 publications

References 12 publications

Late Quaternary geomorphology and sedimentary processes in the Zambezi turbidite system (Mozambique Channel)

Late Quaternary geomorphology and sedimentary processes in the Zambezi turbidite system (Mozambique Channel)

Quaternary sediment dispersal in the Zambezi turbidite system (SW Indian Ocean)

The Zambezi deep-sea fan: mineralogical, REE, Zr/Hf, Nd-isotope, and zircon-age variability in feldspar-rich passive-margin turbidites

Contact Info

Product

Resources

About