Conjugate Divergent Margins
The main focus of the book is the geological and geophysical interpretation of sedimentary basins along the South, Central and North Atlantic conjugate margins, but concepts derived from physical models, outcrop analogues and present-day margins are also discussed in some chapters. There is an encompassing description of several conjugate margins worldwide, based on recent geophysical and geological datasets. An overview of important aspects related to the geodynamic development and petroleum geology of Atlantic-type sedimentary basins is also included. Several chapters analyse genetic mechanisms and break-up processes associated with rift-phase structures and salt tectonics, providing a full description of conjugate margin basins based on deep seismic profiles and potential field methods.
Late Cretaceous–Cenozoic sediment and turbidite reservoir supply to South Atlantic margins
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Published:January 01, 2013
Abstract
Maps have been compiled of indicators of uplift, denudation, sedimentation rates, igneous activity and climate over South Atlantic margins in order to develop the most consistent interpretation of the development of topography, climate and sediment supply through time. Continental margin uplifts and associated topography are concentrated in the Late Cretaceous and Oligocene–Recent periods, with the rates of sediment supply from these dependent on the occurrence of wet or rapidly changing climate. An irregular bimodality is seen on several aspects of African and Brazilian margin geology through time, particularly on periods of sediment progradation, high sedimentation rates and turbidite reservoir development, with peaks of "each centred on the Santonian and Miocene. Some regions show only one of these sedimentation rate peaks and the bimodal pattern, in general, is weaker for the Brazil margin, attributed to continuing uplift of southern Brazilian margins in the early Palaeogene.
A crude relationship is observed between sedimentation rate and reserves in turbidite reservoirs. Sedimentary rate mapping can thus be used to identify turbidite fairways of different ages, tied in turn to drainage catchments containing a combination of high topography and wet climate. Additional implications for source rock development and burial history are also explored.
The published papers and electronic sources used for the construction of sedimentation rate profiles (Excel and ArcGIS files of calculated sedimentation rates) are available at http://www.geolsoc.org.uk/gsl/SUP18520.
- ArcGIS
- Atlantic Ocean
- Brazil
- Cenozoic
- continental margin
- Cretaceous
- denudation
- geographic information systems
- information systems
- mapping
- marine sedimentation
- Mesozoic
- Oligocene
- Paleogene
- reservoir rocks
- Santonian
- sediment supply
- sedimentation
- sedimentation rates
- Senonian
- South America
- South Atlantic
- Tertiary
- topography
- turbidite
- Upper Cretaceous