Crustal structure of the East-African Limpopo Margin, a strike-slip rifted corridor along the continental Mozambique Coastal Plain and North-Natal Valley

Coincident wide-angle and multi-channel seismic data acquired within the scope of the PAMELA Moz3-5 project allow to reconsider the formation mechanism of East-African margins offshore southern Mozambique. This study most specifically focuses on the sedimentary and deep crustal architecture of the Limpopo margin (LM) that fringes the eastern edge of the Mozambique’s Coastal Plain (MCP) and its offshore southern prolongation the North Natal Valley (NNV). It relies primarily on the MZ3 profile that runs obliquely from the northeastern NNV towards the Mozambique basin (MB) with additional inputs from a tectono-stratigraphy analysis of industrial onshore-offshore seismic lines and nearby or crossing velocity models from companion studies. Over its entire N-S extension the LM appears segmented in (1) a western domain that shows the progressive eastward crustal thinning and termination of the MCP/NNV continental crust and its overlying pre-Neocomien volcano-sedimentary basement; and (2) a central corridor of anomalous crust bounded to the east by the Mozambique fracture zone (MFZ) and the oceanic crust of the MB. A prominent basement high marks the boundary between these two domains. Its development was most probably controlled by a steep and deeply rooted fault, i.e. the Limpopo fault. We infer that strike-slip or slightly trans-tensional rifting occurred along the LM and was accommodated along this Limpopo fault. At depth we propose that ductile shearing was responsible for the thinning of the continental crust and an oceanward flow of lower crustal material. This process was accompanied by intense magmatism that extruded to form the volcanic basement and gave to the corridor its peculiar structure and mixed nature. The whole region remained at a relative high level during the rifting period and a shallow marine environment dominated the pre-Neocomien period during the early phase of continent-ocean interaction. It is only some times after break-up in the MB and the initiation of the MFZ that decoupling occurred between the MCP/NNV and the corridor allowing for the latter to subside and being covered by deep marine sediments. A scenario for the early evolution and formation of the LM is proposed taking into account both recent kinematic and geological constraints. It implies that no or little changes in extensional direction occurred between the intra-continental rifting and subsequent phase of continent-ocean interaction.
 
Citation proposal
EVAIN Mikael (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France) - SCHNURLE Philippe (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France) - LEPRETRe Angélique (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France LGO, IUEM, Place Nicolas Copernic, 29280 Plouzané, France) - VERRIER Fanny (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France) - WATREMEZ Louise (Univ. Lille, CNRS, Univ. Littoral Côte d’Opale, UMR 8187 – LOG – Laboratoire d’Océanologie et de Géosciences, F-59000 Lille, France) - THOMPSON Joseph Offei (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France) - DE-CLARENS Philippe (TOTAL, R\&D, avenue Larribau, 64000 Pau, France) - ASLANIAN Daniel (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France) - MOULIN Maryline (IFREMER, Geosciences Marines, REM/GM/LGS, Centre de Brest, 29280 Plouzané, France) (2021) . Crustal structure of the East-African Limpopo Margin, a strike-slip rifted corridor along the continental Mozambique Coastal Plain and North-Natal Valley. https://services.mspdata.eu:/geonetwork/srv/api/records/seanoe:80287

Simple

Date ( Publication )
2021
Date ( Revision )
2022-01-14
Other citation details
Evain Mikael, Schnurle Philippe, Lepretre Angélique, Verrier Fanny, Watremez Louise, Thompson Joseph Offei, De-Clarens Philippe, Aslanian Daniel, Moulin Maryline (2021). Crustal structure of the East-African Limpopo Margin, a strike-slip rifted corridor along the continental Mozambique Coastal Plain and North-Natal Valley. SEANOE. https://doi.org/10.17882/80287

  Author

  Author

  Author

  Author

  Author

  Author

  Author

  Author

  Author

  Publisher

Keywords ( Theme )
  • wide-angle seismic , continental margin , Mozambique , Marine geology
ODATIS aggregation parameters and Essential Variable names ( Theme )
  • Seismic , Geology , Bathymetry
SeaDataNet Parameter Disciplines ( parameter )
  • Marine geology
Type de jeux de donnée ODATIS ( Theme )
  • Observational data
Use constraints
Other restrictions
Other constraints
Date ( Publication )
2021

  Publisher

  Author

  Author

  Author

  Author

  Author

  Author

  Author

  Author

  Author

Association Type
Cross reference
Initiative Type
Study
Association Type
Cross reference
Initiative Type
Platform
Association Type
Cross reference
Initiative Type
Platform
Metadata language
English
Topic category
  • Oceans
N
S
E
W


Distribution format
  • TEXTE ( )

  • PDF ( )

OnLine resource
Processed data  

p-wave velocity model of MZ3 profile in RAYINVR v.in format - 20 KB

OnLine resource
Processed data  

Travel times picked MZ3 OBS records in RAYINVR tx.in format - 3 MB

OnLine resource
Processed data  

Correspondence between seismic phases and travel time picks ids provided in the RAYINR tx.in file (4th column) for MZ3 profile - 42 KB

OnLine resource
DOI of the product  
OnLine resource
Seanoe  
Hierarchy level
Dataset
Statement

Metadata

File identifier
seanoe:80287   XML
Metadata language
English
Character set
UTF8
Hierarchy level
Dataset
Date stamp
2022-01-14
Metadata standard name
ISO 19115:2003/19139
Metadata standard version
1.0

  Point of contact

 
 

  Overviews

Map of PAMELA MOZ3-5 seismic experiment offshore southern Mozambique. MZ3 profile is highlighted in red.

Provided by

Access to the portal

Associated resources

Not available