A Sequence Stratigraphic Analysis of the Lower Miocene, West and East Cameron Areas, Gulf of Mexico

Abstract

A sequence stratigraphic analysis of the nearshore West Cameron and East Cameron blocks, central Gulf of Mexico, was developed for Lower Miocene age strata. Interpretation of each depositional sequence included delineation of paleoshelf/slope breaks, isopach, seismic facies, and paleogeography maps. Sequence development and sedimentation patterns were influenced by two prominent structural styles, growth faulting and salt/shale deformation. Two depositional sequences A and B, were identified and interpreted to consist of depositional environments ranging from submarine fan to coastal and shallow marine deltaics. Sequence A is the oldest Lower Miocene sequence and is divided into two depositional packages, a lowstand portion and a condensed interval. Because the paleo-shelf break was landward of our study area, there is an absence of well-developed shelfal facies in this sequence, and the condensed interval represents the distal transgressive and highstand portion of the sequence. The lowstand portion suggests a north to northwest source direction and has a maximum thickness of 2200 feet. The axis of maximum thickness, derived from isochron mapping, integrated with paleogeographic interpretation, indicates that the thickness or aggradation is related to mass-wasting processes and channel systems characteristic of submarine fan environments. The influence of pre-existing topography and basin configuration on sequence development and stratal architecture is evident where the axes of maximum thickness are separated by thin intervals of little to no deposition, related to a paleostructural high. Sequence B is better developed than Sequence A because of its location within the axis of the depocenter and can be subdivided into the following depositional environments: well-developed prograding submarine fan and slope deposits (associated primarily with falling sea-level) that are capped updip by an erosional surface associated with a marine transgression; an overall transgressive unit composed of localized regressive deltaic deposits; and aggradational fluvial/deltaic and shallow marine sediments associated with a continued rise in sea-level. Sequence B has a maximum thickness of 3200 feet and, like Sequence A, this aggradation within the basin is attributed to mass-wasting and channel development within a slope envronment. The variation in location of thickness trends, combined with evidence of erosional channels from different source directions, indicates the migration of sediment supply through time from a more westerly to a more northerly direction.

Geometry and architectural associations of co-genetic debrite–turbidite beds in basin-margin strata, Carboniferous Ross Sandstone (Ireland): Applications to reservoirs located on the margins of structurally confined submarine fans

“…While there are several published examples where this wedge is resolvable, there are a number of published seismic profiles in northern Gulf of Mexico minibasins where the transition zone cannot be discerned (e.g. Weimer et al, 1998) as the quality of the data are not adequate, or salt interfered with the seismic acquisition process. This problem is especially true for subsalt minibasins and minibasins with steep salt margins.…”

Sequence stratigraphy and its application in marine shale gas exploration: A case study of the Lower Silurian Longmaxi Formation in the Jiaoshiba shale gas field and its adjacent area in southeast Sichuan Basin, SW China

“…As an integrated approach, sequence stratigraphy, after nearly forty years development, has been applied to siliciclastic and carbonate deposits in depositional settings from lacustrine to deep water settings and led to great success in conventional clastic and carbonate petroleum exploration (Vail et al, 1977;Van Wagoner et al, 1990;Miall, 1991;Schlager, 1992;Weimer et al, 1998;Posamentier and Allen, 1999;Catuneanu, 2002;Catuneanu et al, 2009;Jiang et al, 2013;Hemmesch et al, 2014). However, little research has been done to study the sequence stratigraphy of shale strata deposited in deep water environment (Slatt and Rodriguez, 2012).…”

The role of deformation processes on the geometry of mud-dominated turbiditic systems, Oligocene and Lower–Middle Miocene of the Lower Congo basin (West African Margin)

“…Only a few studies investigate the influence of a deforming seafloor on turbiditic sedimentation at large spatial (10 -100 km in length) and time scales (0.5 -10 My) (Cronin, 1995;Haughton, 2001;Normark, 1985;Sinclair & Tomasso, 2002). However, at basin-scale, extensive deep-water petroleum exploration highlights the effect of an irregular seafloor topography on depositional processes during a short period ( £ 100 ky scale) of deposition (Beaubouef & Friedmann, 2000;Nelson, Karabanov, Coleman, & Escutia, 1999;Pirmez, Beaubouef, Friedmann, & Mohrig, 2000;Prather, 2000;Prather, Booth, Steffens, & Craig, 1998;Weimer et al, 1998). This aspect remains fundamental for a better understanding of architectures and facies variations within turbidity currents deposits because seafloor deformation will act on gravitydriven currents through two parameters: change in slope gradient and in flow constriction (Kneller, 1995).…”