Salt Tectonics and Sedimentation in the Offshore Majunga Basin, Madagascar

Tari, Gábor; Coterill, Katrina; Molnar, Jim; Valasek, Dave; Walters, G. M.; Álvarez, y Julio

doi:10.5724/gcs.04.24.0614

Cited by 5 publications

(6 citation statements)

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“…The Majunga basin is one of the two major sedimentary basins of Madagascar (with the Morondava basin). This basin partly covers onshore and offshore areas (Tari et al, 2004). In this paper, we only discuss data from the offshore Majunga basin.…”

Section: Regional Settingmentioning

confidence: 99%

Modern sedimentation and geochemical imprints in sediments from the NW Madagascar margin

et al. 2020

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Highlights► The NW continental slope of Madagascar presents moderate sediment accumulation rates, with sediment transport mainly during the wet season ► Recent episodic sedimentation events are due to temporary reconnection of the Mahavavy River with its canyon head during extreme events ► These episodic events carry sediment rich in organic carbon and iron oxides, which influence geochemical processes in the sedimentary column ► The large inputs of iron oxides in this area enhance pyritization efficiency ► Past and present methane outputs influence geochemical signatures in the sediment (sulfur minerals and δ 13 C of bulk organic carbon)

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Section: Regional Settingmentioning

confidence: 99%

Modern sedimentation and geochemical imprints in sediments from the NW Madagascar margin

et al. 2020

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“…The relief from shelf to basin floor, however, appears to be significant (e.g. Tari et al ., ; Fig. ).…”

Section: Observations and Resultsmentioning

confidence: 97%

“…The sedimentary fill appears to have been deposited in small grabens and half grabens surrounded by rotated basement blocks and horsts (e.g. Luger et al ., ; Geiger et al ., ; Tari et al ., ; Giese et al ., ; Figs and 8). The sedimentary fill is interpreted to be age equivalent to the Late Triassic to Early Jurassic fluvial and lacustrine deposits that accumulated in grabens and half grabens as rifting between Africa and Madagascar began (Besairie, ).…”

Section: Observations and Resultsmentioning

confidence: 99%

“…As progradation continued, the Middle Jurassic paleoshelf was bypassed and a significant amount of sediment was deposited rapidly in the deep basin. This rapid loading of sediments likely triggered halokinetic movement in the basin, forming large allochthonous and autochthonous salt structures (Tari et al ., ; Fig. ).…”

Section: Discussionmentioning

confidence: 95%

“…This would suggest that sediment bypass and slope failure continued for a significant amount of time until the margin was flooded during Turonian times. The increase in sediment bypass and resulting MTCs, deposited in the deep basin, would have resulted in rapid sediment deposition in the basin, possibly triggering salt movement (Tari et al ., ; Fig. ).…”

Section: Discussionmentioning

confidence: 99%

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A prograding margin during global sea‐level maxima: an example from Mahajanga Basin, northwest Madagascar

et al. 2017

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The Mesozoic shelf margin in the Mahajanga Basin, northwest Madagascar, provides an example where inherited palaeobathymetry, coupled with sea‐level changes, high sediment supply and fluctuations in accommodation influenced the stacking patterns and geometry of clinoforms that accreted onto a passive rifted margin. Two‐dimensional (2D) seismic profiles are integrated with existing field data and geological maps to study the evolution of the margin. The basin contains complete records of transgression, highstand, regression and lowstand phases that took place from Jurassic to Cretaceous. Of particular interest is the Cretaceous, Albian to Turonian (ca. 113‐93 Ma), siliciclastic shelf margin that prograded above a drowned Middle Jurassic carbonate platform. The siliciclastic phase of the shelf margin advanced ca. 70 km within ca. 20 My, and contains 10 distinct clinoforms mapped along a 2D seismic reflection data set. The clinoforms show a progressive decrease in height and slope length, and a fairly constant slope gradient through time. The successive shelf edges begin with a persistent flat to slightly downward‐directed shelf‐edge trajectory that changes to an ascending trajectory at the end of clinoform progradation. The progressive decrease in clinoform height and slope length is attributed to a decrease in accommodation. The prograding margin is interpreted to have formed when siliciclastic input increased as eastern Madagascar was uplifted. This work highlights the importance of sediment supply and inherited palaeobathymetry as controls on the evolution of shelf margins and it provides a new understanding of the evolution of the Mahajanga Basin during the Mesozoic.

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The formation of vein-type barite (± base metal, gold) deposits in northern Madagascar and its link with Mesozoic Pangean rifting

Heijlen,

Vos,

Kartalis

et al. 2023

Miner Deposita

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Salt Tectonics and Sedimentation in the Offshore Majunga Basin, Madagascar

Cited by 5 publications

References 0 publications

Modern sedimentation and geochemical imprints in sediments from the NW Madagascar margin

Modern sedimentation and geochemical imprints in sediments from the NW Madagascar margin

A prograding margin during global sea‐level maxima: an example from Mahajanga Basin, northwest Madagascar

The formation of vein-type barite (± base metal, gold) deposits in northern Madagascar and its link with Mesozoic Pangean rifting

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