|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Alfred Wegener Institute for Polar and Marine Research, Postfach 120161, 27515 Bremerhaven, Germany
2 Alfred Wegener Institute for Polar and Marine Research, Postfach 120161, 27515 Bremerhaven, Germany
After receiving her diploma in geophysics, geology, mineralogy, and physics at J. W. Goethe University in Frankfurt (1989), Estella Weigelt joined the Alfred Wegener Institute (AWI). After an overwintering campaign in the Antarctic advising a geophysical observatory for 14 months, she worked on her Ph.D. on seismic and gravity investigations of the Eurasian Basin. Since then, she has specialized on climate signals in marine sediments recorded in reflection seismics.After receiving her diploma in geophysics, physical oceanography, geology, and physics at Hamburg University (1985), Gabriele Uenzelmann-Neben went to Kiel University and started working toward her Ph.D. on high-resolution seismic reflection investigations of the Voring Margin. In 1989, Uenzelmann-Neben joined AWI and has since specialized on sediment transport, sediment drifts, and obstacles for oceanic currents such as oceanic plateaus and ridges.
The Benguela Current system, running off southwest Africa, is one of the world's largest upwelling regions. The current has strongly influenced sedimentary features on the continental margin. To unravel its development, seismic stratigraphy, tied to drilling results from Ocean Drilling Program Leg 175 sites 1085–1087, was established. Four units, Southern Cape Basin (SCB)-1 to SCB-4, were defined for the Cenozoic sediments. The upper unit, SCB-1 (<1.5 Ma), characterized by continuous high-amplitude reflectors, represents global cooling and glacial-interglacial cycles. Unit SCB-2 (<14 Ma), distinguished by low-amplitude reflections, is associated with the onset of the upwelling system and establishment of the modern circulation pattern in the Cape Basin. Slump scarps are concentrated along the middle and upper shelf slope, suggesting they are caused by a combination of mass movements triggered by bottom currents and slope instabilities because of increased deposition associated with the upwelling. A westward extension and/or movement of upwelling filaments is interpreted from the observed seaward shift of scarp locations with time. Erosion associated with stronger currents probably thinned unit SCB-2 in the south. The two lower units, SCB-3 and SCB-4 (<56 Ma), probably represent material eroded from the shelf break and deposited during a major Oligocene–early Miocene regression that is consistent with a significant uplift of southern Africa. The basal reflector SCB-D of unit SCB-4 is associated with the prominent reflector D or L described in previous publications.
This article has been cited by other articles:
|
|
 |
|
  D. A. Paton, D. van der Spuy, R. di Primio, and B. Horsfield Tectonically induced adjustment of passive-margin accommodation space; influence on the hydrocarbon potential of the Orange Basin, South Africa AAPG Bulletin, May 1, 2008; 92(5): 589 - 609. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Uenzelmann-Neben, P. Schluter, and E. Weigelt Cenozoic oceanic circulation within the South African gateway: indications from seismic stratigraphy South African Journal of Geology, September 1, 2007; 110(2-3): 275 - 294. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Weigelt and G. Uenzelmann-Neben Early Pliocene change of deposition style in the Cape Basin, southeastern Atlantic Geological Society of America Bulletin, July 1, 2007; 119(7-8): 1004 - 1013. [Abstract] [Full Text] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
