INVESTIGADORES
MILANA Juan Pablo
artículos
Título:
Mass-transport and slope accommodation: Implications for turbidite sandstone reservoirs
Autor/es:
KNELLER, B., DYKSTRA, M; LUKE FAIRWEATHER; JUAN PABLO MILANA
Revista:
AAPG BULLETIN
Editorial:
AMER ASSOC PETROLEUM GEOLOGIST
Referencias:
Lugar: Tulsa; Año: 2015 vol. 100 p. 213 - 235
ISSN:
0149-1423
Resumen:
Mass-transport events are virtually ubiquitous on the moderncontinental slope and are also frequent in the stratigraphic record,but the potential they create for stratigraphic trapping within thesea-floor topography is not generally appreciated. Given theabundance of mass-transport deposits (MTDs), we should expectthat many turbidite systems are so affected. The MTDs may bevery large (volumes > 103 km3 [~250 mi3], areas > 104 km2[~6250 mi2], thicknesses > 102 m [~330 ft]), and they extensivelyremold sea-floor topography on the continental slope and rise.Turbidity currents are highly sensitive to topography; thus, turbiditereservoir distribution and geometry on the slope and rise are oftensignificantly affected by subjacent MTDs or their slide scars. Turbiditesmay be captured within slide scars and on the trailing edges,margins, and rugose upper surfaces of MTDs; developed in accommodationwhen the mass movement comes to rest; or subsequentlyresulting from compaction or creep. The filling of suchaccommodation depends on the properties of the turbidity currents,their depositional gradient, and how they interact with basin floortopography. The scale of accommodation on top of MTDs is determinedlargely by the dynamics of the initial mass flow and internalstructure of the final deposit, and it typically has a limited range oflength scales. We present interpretations of a range of previouslypublished and original case studies to illustrate the range of accommodationstyles associated with MTD-related topography withinthe evacuated space of the slide scar, around and on top of thedeposits themselves. In fact, several well-known deep-water outcropsprobably represent examples of sedimentation influenced byMTDs.Hydrocarbon reservoirs in many slope settings may be controlledby the accommodation related to MTD topography. Atthe exploration scale, entire shelf margin and slope depositionalsystemsmay be contained within the scars evacuated on the upper slope by mass failure, whereas at the production scale, the rugosityon the top of MTDs creates widespread potential for stratigraphictrapping. The location, geometry, and property distribution of suchreservoirs are closely controlled by the interaction of turbidity currentswith the topography; thus, an understanding of these processesand their impact on slope stratigraphy is vital to reservoir prediction.