The Berbice Mega canyon in the Cretaceous continental margin of northeastern South
America: A mega-submarine sediment feeder to the Cretaceous deepwater fans of
northeastern South America
Obianuju Ugwu-Oju, 2nd Year Masters
Submarine canyons occur on every modern margin throughout the world’s oceans, however, the Berbice
mega-canyon in the ancient Cretaceous age margin of Guyana may be the largest canyon to have evolved
in earth’s Mesozoic to modern history. Recent giant hydrocarbon discoveries in Exxon Mobil’s Liza-1 well
north and distal to the Berbice Canyon prove the value of these systems as bypass regions for deepwater
fan development. However the complexity of the topography within these canyons may still yield
hydrocarbons trapped in stratigraphic updip locations. The aggradational nature of fill within this
“canyon” leads us to label it a valley rather than a canyon.
This study will examine the nature of the canyon morphology, fill phases and fill architecture within the
Berbice Valley using ~5000 sq km of excellent 3D seismic time and depth data, as well as several wells
drilled closely adjacent to or within the valley fill. The Berbice valley is compared to a compilation of
modern canyons/valleys on both active and passive margins (Harris and Whiteway, 2011) and contrasted
with other known ancient canyons documented in the rock record through outcrop or seismic studies. In
addition, this study intends to document the temporal and spatial relationship between the Berbice
and possible continental or submarine structural influences on the formation of such a large
geomorphic feature.
The Berbice Valley is documented by previous workers as ranging in width from 25 to 100 km. It is
actually composed of five phases of incisions, some as deep as 1250 meters making it an extremely large,
multi-phase valley by world standards. The Berbice would be considered a shelf incised canyon (in the
nomenclature of Harris and Whiteway, 2011). The canyon evolved in the late Cretaceous along a margin
which was separating from the Equatorial Guinea region of the South African margin in response to the
opening of the northern South Atlantic ocean. Large, high volume sediment supplies were shed from the
continents at this time and it is likely that hyperpycnal and high fluvial output flows contributed to the
magnitude of incision in the Berbice Canyon. The fill appears to be composed of more than one period of
reincision and filing and we intend to investigate the variability in these fill using seismic geomorphologic
techniques and ground truthed with well data from the Horseshoe 1, and other wells.