TY - JOUR
T1 - Crustal Structure and Stratigraphy of the South Mozambique Margin to South Mozambique Ridge From Combined Wide-Angle and Reflection Seismic and Drill Hole Data
AU - Schnürle, P.
AU - Leprêtre, A.
AU - Evain, M.
AU - Verrier, F.
AU - De-Clarens, P.
AU - Thompson, Joseph
AU - Dias, N.
AU - Afilhado, A.
AU - Loureiro, A.
AU - Leroy, S.
AU - d'Acremont, E.
AU - Aslanian, D.
AU - Moulin, M.
N1 - Publisher Copyright:
© 2023 The Authors. Earth and Space Science published by Wiley Periodicals LLC on behalf of American Geophysical Union.
PY - 2023/10
Y1 - 2023/10
N2 - We have analyzed the MZ6 onshore-offshore wide-angle seismic profile of the MOZ3-5 survey to investigate the crustal structure of the South Mozambique passive margin. The NNW-SSE, 625 km-long profile runs across the Mozambique coastal plain (MCP), the Continental Shelf and Slope, the Almirante Leite Ridge (ALR), the North Natal Valley (NNV), the Ariel Graben and the Dana Plateau of the Mozambique Ridge. Forward modeling through combined interpretation of the multichannel seismic, the main reflected and refracted phases of the wide-angle, drill hole data and bathymetric data reveal: (a) a sedimentary cover poorly compacted up to 3 km-thick, intruded by magmatic dykes that reach the seafloor at the ALR forming 0.5 to 5 km-wide corrugated mounts, (b) between 2 and 7 km, thick magmatic or volcano-clastic deposits are observed both at the MCP and NNV, forming a 40 km-wide terrace at the center of MZ6 and southward-dipping reflectors in the southern part interpreted as the Pre-Neocomian Formation contemporary of the Karroo and/or Bombeni-Movene magmatic events reached in several wells, (c) onshore, the 3-layered crust reaches 39 km thickness, gradually thinning to ∼27 km at the southern end of MZ6. In the deepest layer, velocities exceed 7.15 km/s, reaching at its base 7.55 km/s at the vertical of the ALR. (d) the seismic Moho is marked by a strong reflection on the wide-angle data. These results suggests that the basement is composed of slightly thinned and altered continental crust, most likely intruded by several phases of intense magmatism.
AB - We have analyzed the MZ6 onshore-offshore wide-angle seismic profile of the MOZ3-5 survey to investigate the crustal structure of the South Mozambique passive margin. The NNW-SSE, 625 km-long profile runs across the Mozambique coastal plain (MCP), the Continental Shelf and Slope, the Almirante Leite Ridge (ALR), the North Natal Valley (NNV), the Ariel Graben and the Dana Plateau of the Mozambique Ridge. Forward modeling through combined interpretation of the multichannel seismic, the main reflected and refracted phases of the wide-angle, drill hole data and bathymetric data reveal: (a) a sedimentary cover poorly compacted up to 3 km-thick, intruded by magmatic dykes that reach the seafloor at the ALR forming 0.5 to 5 km-wide corrugated mounts, (b) between 2 and 7 km, thick magmatic or volcano-clastic deposits are observed both at the MCP and NNV, forming a 40 km-wide terrace at the center of MZ6 and southward-dipping reflectors in the southern part interpreted as the Pre-Neocomian Formation contemporary of the Karroo and/or Bombeni-Movene magmatic events reached in several wells, (c) onshore, the 3-layered crust reaches 39 km thickness, gradually thinning to ∼27 km at the southern end of MZ6. In the deepest layer, velocities exceed 7.15 km/s, reaching at its base 7.55 km/s at the vertical of the ALR. (d) the seismic Moho is marked by a strong reflection on the wide-angle data. These results suggests that the basement is composed of slightly thinned and altered continental crust, most likely intruded by several phases of intense magmatism.
KW - East Gondwana breakup
KW - North Natal Valley
KW - South Mozambique
KW - continental margin
KW - crustal structure
KW - wide-angle seismic
UR - http://www.scopus.com/inward/record.url?scp=85151686267&partnerID=8YFLogxK
U2 - 10.1029/2021EA001902
DO - 10.1029/2021EA001902
M3 - Article
AN - SCOPUS:85151686267
SN - 2333-5084
VL - 10
JO - Earth and Space Science
JF - Earth and Space Science
IS - 10
M1 - e2021EA001902
ER -