Deepwater Depositional Systems and Evolving Salt-related Topography: Miocene, Offshore Angola

UoM administered thesis: Phd

  • Authors:
  • Ayodeji Oluboyo

Abstract

This thesis examines the interaction of pre-existing and evolving salt-related topography on the temporal and spatial evolution of depositional systems in deepwater. To achieve this, the thesis integrates stratigraphic and structural analysis of 3D seismic data from the Miocene record of the salt-influenced Lower Congo Basin, Offshore Angola. Observations at multiple scales ranging from the semi-regional (> 50 km) to local, kilometre-scale and covering timescales ranging from the entire Miocene (~ 18 Myr) to > 2 Myr are presented.At the semi-regional scale, results from this study shows that the progressive along-strike linkage of short (<10 km) fault segments and salt diapirs into through-going large scale (> 30 km) faults and elongated saltwalls results in long lived diversion and/or confinement of depositional system fairways. Axial confinement of fairways occurs where structural strike is parallel to sediment input, contrasting with ponding or diversion of deposits oriented at a high angle to structural strike. The orientation of the structures remains relatively static, which in combination with the fixed sediment entry points of the fairways results in recurrence of the major styles of interaction, and long term pinning of fairways throughout the Miocene. The development of large (10's of km) "sediment shadow" zones devoid of coarse clastics downdip of diverted and or confined sediment gravity flows is also observed through the Miocene.At the intraslope basin (10's of km) and sub-basin scale (

Details

Original languageEnglish
Awarding Institution
Supervisors/Advisors
  • Robert Gawthorpe (Supervisor)
Award date1 Aug 2013