• Architectural Variation in Confined Channels: Examples from Outcrop and 3D Seismic Data
• Styles of Channel Body from Outcrop as an Indicator of Connectivity in Deep Marine Channel Systems
• Playa Esqueleto and other outcrops - Braided, Conglomeratic Submarine Channels: Upper Cretaceous Rosario Fm., Baja California, Mexico
• Spectral Decomposition of Seismic Forward Modelled Outcrops of Deepwater Channel and Levee Deposits
• Quantification of Slope Channel-Levees, the Rosario Formation, Baja California, Mexico
• Numerical Simulation and Model for Channel Levee Formation
• Collapse of Submarine Channel Levees; Examples from Outcrop and Subsurface, and Reservoir Implications
• Syndepositional Faults in Mass-Transport Deposits: Seals or Conduits to Fluid Flow?
• Sensitivity of Clinoform Geometry to Geological Processes Operating on the Continental Shelf and Slope

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Architectural Variation in Confined Channels: Examples from Outcrop and 3D Seismic Data
Philip Thompson1, Benjamin Kneller1, and Mason Dykstra2. (1) Department of Geology and Petroleum Geology, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, United Kingdom, phone: +441224273439, p.thompson@abdn.ac.uk, (2) Institute for Crustal Studies, University of California, Santa Barbara, CA 93106

We present an integrated approach to the study of confined submarine channels using high-resolution 3D seismic data and outcrop data. Outcrop studies from the San Fernando Channel Levee System, Baja California have shown a systematic trend in submarine channel evolution which is observed at a range of scales from individual channel bodies (m's) through to channel body sequences (100's m). The range of channel architectures observed is related to the degree of confinement within the system. The lowest sections of individual channel bodies and channel body sequences are typically erosionally confined and are dominated by amalgamated channel deposits due to the repeated re-incision of the channel base. The upper parts typically show thinner, more laterally extensive, segregated channel deposits that are less erosive and only amalgamate locally. Seismic data from the Foz do Amazonas Basin and the Nile Cone has been used to study the variation in the cross sectional profile and morphology of confined channels as they evolve through time. A combination of 3D seismic interpretation, iso-proportional slicing, amplitude analysis and attribute analysis has been used to investigate the evolutionary variation of confined channels which have been observed in seismic data and include submarine channels which are entirely erosionally confined, levee confined, levee/slope confined and confined by deformed levees.

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Styles of Channel Body from Outcrop as an Indicator of Connectivity in Deep Marine Channel Systems
Mason Dykstra1, Benjamin Kneller2, Philip Thompson2, and Ian Kane3. (1) Institute for Crustal Studies, University of California, Santa Barbara, CA 93106, phone: 8058938435, dykstra@crustal.ucsb.edu, (2) Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom, (3) School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom

Three main types of channel bodies are examined for the type and degree of relative connectivity in a reservoir context: aggradational, lateral accretion, and amalgamational bodies. While neither type is exclusively a complete end-member, they do display specific geometric properties that make for distinct reservoirs. Aggradational channel bodies tend to be relatively thin, laterally extensive but vertically isolated within packages of fine-grained sediment. Their lateral connectivity is very good but vertical is not. Lateral accretion bodies also tend to be relatively thin, but laterally extensive and multi-lateral. Because of this multi-lateral behavior their lateral connectivity can be good (if the contacts between multi-lateral elements are erosional) or poor (if these same contacts are non-erosive), while their vertical connectivity tends to be low as they also commonly are isolated within packages of fine-grained sediments. Amalgamational channel bodies have the greatest vertical and lateral connectivity, as all bed-scale elements are generally vertically or laterally erosionally truncated. This type of channel body also tends to be the largest in scale. Geometrically similar features to these channel body end-members are recognizable on high-resolution seismic images of deep marine channel systems, although naturally the scale of the individual elements is greater on seismic than in outcrop. We suggest that these are process-driven geometries and that they therefore may be truly scalable across the outcrop/seismic resolution gap.

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Playa Esqueleto and other outcrops - Braided, Conglomeratic Submarine Channels: Upper Cretaceous Rosario Fm., Baja California, Mexico
Ian Kane1, Ben Kneller2, Mason Dykstra3, and William. D. McCaffrey1. (1) School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom, phone: +447932609145, i.kane@earth.leeds.ac.uk, (2) Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom, (3) Institute for Crustal Studies, University of California, Santa Barbara, CA 93106

In the area of Canyon San Vicente there is excellent 3-D exposure of a submarine canyon, canyon-fill including mass transport and channel-levee systems, with a submarine channel-levee system eventually aggrading out of canyon confinement. Channel style varies stratigraphically from thick vertically amalgamated channels to thin laterally accreting channels vertically segregated by inter-channel/overbank facies. Here we document the latter style and report facies architectures from several channels of varying size. Channels are generally incised into structureless sandstone, which may represent frontal splays or channel mouth lobes, cutting down and ‘soling out' at a level associated with older overbank deposits. Channel bases are flat and marked by deposition of a thin sheet-like conglomerate. Channel migration is marked by lateral accretion packages (LAPs) stacking towards the cut bank. The final stages of channel fill are often by the deposits of sandy turbidity flows and debris flows; overlying those and the LAPs is usually another thin sheet-like conglomerate representing a final burst of the system. After the final stages of channel fill and sheet conglomerate deposition there is commonly deposition of laterally extensive debrites possibly reflecting a lack of confinement. Thin bedded heterolithics are found interbedded and are eventually succeeded by another conglomeratic channel. All the evidence suggests active migration of channels within a wider channel belt with flows (especially when unconfined) interacting with topography related to the channel-belt margin (slumps and slides) generating debris flows. We present a detailed facies analysis and suggest methods for reservoir prediction.

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Spectral Decomposition of Seismic Forward Modelled Outcrops of Deepwater Channel and Levee Deposits
Magdalena Szuman, Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom, phone: +441224273439, m.szuman@abdn.ac.uk, Ian Kane, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom, Valerie Charoing, BHP Billiton Petroleum (Americas) Inc, 1360 Post Oak Boulevard Suite 150, Houston, TX 3020, Lars Nielsen, Geological Institute, University of Copenhagen, DK-1350 Kbh, Copenhagen, Denmark, Benjamin Kneller, Department of Geology and Petroleum Geology, University of Aberdeen, Meston Building, Aberdeen, AB24 3UE, United Kingdom, and Mads Huuse, Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom.

The size of many stratigraphic architectural elements, the building blocks of clastic hydrocarbon reservoirs, are typically below the resolution of conventional seismic data, and their interpretability on seismic profiles is restricted. Nevertheless their effect on reservoir connectivity can be profound. Seismic forward modeling of outcrop analogues holds the potential to significantly enhance hydrocarbon recovery by establishing the complex relationships between small scale geometries, physical properties of the rock and the seismic wavelet. We are pursuing this by analysis of frequency-domain representation of a seismic signal generated from forward modelling on outcrop analogues. Time-frequency decomposition has the ability to illustrate features which are difficult to visualize in the time domain. Spectral decomposition results show that geologic lithofacies can be identified even by the incident signals with a wavelength much larger than the dominant bed thickness (Strauss et al., 2003). This technique is applied to two elements of a Cretaceous deepwater continental slope system cropping out in Baja California, Mexico; a deep marine levee complex and a turbidite canyon/channel complex. Forward seismic models were constructed by combining detailed stratigraphic data acquired from outcrop sections together with comprehensive sedimentological logging. Physical properties were adopted from representative subsurface datasets from a variety of settings and burial depths. Elastic mode, finite difference forward modelling was applied to the geological model. We believe this approach will yield the most useful results for comparison between outcrop sections and subsurface datasets.
Strauss, M., Sapir, M., Glinsky, M.E. & and Melick, J.J., 2003. Geologic lithofacies identification using the multiscale character of seismic reflections. Journal of Applied Physics, 94, 5350-5358.

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Quantification of Slope Channel-Levees, the Rosario Formation, Baja California, Mexico
Ian Kane, School of Earth Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom, i.kane@earth.leeds.ac.uk, Ben Kneller, Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom, Mason Dykstra, Institute for Crustal Studies, University of California, Santa Barbara, CA 93106, and William. D. McCaffrey, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom.

As exploration pushes towards deeper water and increasingly complex reservoirs it becomes imperative to have detailed facies models. In the case of submarine channel-levees, an often ambiguous context coupled with poor preservation potential leads to a paucity of detailed outcrop studies. Here we document the ‘master bounding levees' of a large, coarse grained channel-levee complex within the Upper Cretaceous Rosario Formation of Baja California, Mexico. Levee facies consist of thinly interbedded non-amalgamated, sharp based sandstones and siltstones, often highly bioturbated, with variable palaeocurrents and often containing slide blocks and slumps. Tractional structures in channel-proximal levee facies consist of ripples, including climbing, and overturned ripples, and parallel lamination. Structureless sandstones are also common in channel-proximal localities. In channel-distal levee outcrops starved ripples are abundant. Levee sandstones thin according to a power-law, with standard deviation in thickness decreasing linearly. The levee crest is identified based upon moving averages of bed thickness, which show thinning upwards of inner- and thickening upwards of outer-levee deposits. These data are used to present a model for levee growth and migration of the crest. Additionally, spatial variation of grain size within the levee sandstones will be presented. The field data will be compared to modern, ancient, subsurface and experimental studies.

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Numerical Simulation and Model for Channel Levee Formation
Vineet Birman1, Brendon Hall1, Nicolas Guillaume2, Eckart Meiburg3, and Ben Kneller4. (1) Department of Mechanical Engineering, University of California at Santa Barbara, Santa Barbara, CA 93106, phone: (805) 893-2430, birman@engineering.ucsb.edu, (2) Ecole Nationale Superieure d'Arts et Metiers, 151 Boulevard de l'Hôpital, 75013 Paris, France, (3) Department of Mechanical Engineering, University of California at Santa Barbara, Santa Barbara, 93106, (4) Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom

Submarine channel levees are formed by deposition of sediment from channel overflows. The shapes of the levees vary, but thickness decay away from the channel can be approximated by power law (for channels on higher gradients) or exponential decay (low gradients). We provide a simple analytical model to describe the levee shape as determined by the flow parameters. In our model we assume that levees form due to a steady continuous overflow of a suspension of mono-disperse particles. We derive the conservation equations for particles, fluid and momentum. These equations can be solved analytically for some simple cases and valuable insight into more complex cases can be obtained. We find that entrainment has an important effect on the shape of the levee. We consider a channel cross-section and perform two-dimensional numerical simulations of the Navier-Stokes equations to examine the formation of levee in more detail. The interstitial fluid in the turbidity current is assumed to have same density as the ambient. The density difference is entirely due to particle concentration in the turbidity current. Particle concentration is kept constant at the channel center. A proportion of the particles transported by the flow are deposited on the levee. This flow attains a steady state as it loses particles due to deposition and the steady state deposit profile determines the shapes of the levee. We discuss the entrainment in the numerical simulations and the deposit profiles thus obtained for different grain sizes. We compare the steady state results with our analytical model.

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Collapse of Submarine Channel Levees; Examples from Outcrop and Subsurface, and Reservoir Implications
Ben Kneller1, Mason Dykstra2, and Philip Thompson1. (1) Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom, phone: +44 1224 273453, b.kneller@abdn.ac.uk, (2) Institute for Crustal Studies, University of California, Santa Barbara, CA 93106

Submarine channels in mixed or muddy turbidite systems frequently build levees that can be tens to hundreds of metres thick. Often they form geometrically regular features whose thickness is greatest close to the channel and decays smoothly with increasing distance. Small scale surficial deformation is common in the form of minor slumps and debris flows, but generally high bed continuity makes these potentially excellent reservoirs. However, in many cases considerable portions of the levee show extreme and pervasive deformation, with disruption at all scales; large rotated blocks, slide sheets, slump folds and thick debris flows all occur. In extreme cases the entire levee has collapsed. The collapse process reduces gradients on the levee, and is presumably driven by gravitational instability as the depositional relief grows; this is borne out by the observation that the highest parts of the levee, close to the crest, tend to collapse first, and principally (though not exclusively) collapse inwards towards the channel. Also the higher levee (the right hand in the northern hemisphere) tends to collapse more frequently than the lower. Collapse may occur repeatedly during growth of a levee, producing internal unconformities related to each collapse event. Similar phenomena have been observed at outcrop and in the subsurface, and the frequency of occurrence of wholesale collapse observed in high-resolution seismic data suggests that this is a very common phenomenon. The effect of such collapse on bed continuity and reservoir predictability may be significant.

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Syndepositional Faults in Mass-Transport Deposits: Seals or Conduits to Fluid Flow?
Mason Dykstra1, Benjamin Kneller2, and Katerina Garyfalou2. (1) Institute for Crustal Studies, University of California, Santa Barbara, CA 93106, phone: 8058938435, dykstra@crustal.ucsb.edu, (2) Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom

Mass-transport deposits are typically thought of as fairly homogenous deposits with a consistency similar to wet cement, and are often thought of as seals. Extensive research on mass-transport processes demonstrates, however, that many mass-transport deposits are composed of internally undeformed coherent blocks as well as homogeneous zones, and everything in between (e.g. Locat and Mienert, 2003; Kneller and Dykstra, 2004). Within mass-transport deposits therefore, strain is accommodated in numerous ways, including by penetrative deformation of the sediment involved, as well as the development of discrete ‘faults' (semi-brittle to brittle discontinuities). The purpose of this contribution is to examine the properties of faults in mass-transport deposits, and how these properties determine the behavior of fluids in the system. Mass-transport related faults include normal, reverse, and strike-slip type faults, many of which often accommodate multiple phases and polarities of motion along them. They fall into three categories with regards to conducting fluids: coarse-sediment filled, fine-sediment filled, and welded faults. The eventual behavior of any given fault as regards fluid flow depends on the type of fill of the fault zone, and any diagenetic overprint that may result in a loss of permeability in the fault fill. We present here end-member examples of fault fills from outcrop data collected in numerous locations, and discuss the implications of these fills to fluid flow and sealing.

Locat, J. and J. Mienert, Eds. (2003). Submarine Mass Movements and Their Consequences. Boston, Kluwer Academic Publishers.
Kneller, B. and M. Dykstra (2004). The Internal Structure and External Morphology of Submarine Landslides: A Causative Link. In: AGU Annual Meeting, San Francisco, California, U.S.A.

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Sensitivity of Clinoform Geometry to Geological Processes Operating on the Continental Shelf and Slope
Vanessa Kertznus1, Ben Kneller1, and Mason Dykstra2. (1) Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, AB24 3UE, United Kingdom, v.kertznus@abdn.ac.uk, (2) Institute for Crustal Studies, University of California, Santa Barbara, CA 93106

Conventional 3D seismic reflection data acquired by BG on the Ebro continental margin (northwestern Mediterranean), together with wire-line log data from previously drilled wells, allow us to present a morphological analysis of the Plio-Pleistocene shelf-to-slope depositional system of the Ebro, by examining the geomorphic response of clinoform slopes to changing sedimentary and geological conditions. The seismic data displays a complex pattern of highly prograding and aggrading clinoforms with variable geometry. Two major periods characterize the evolution of this post-Messinian margin in terms of clinoform geometry and slope morphology. Following the Messinian salinity crisis, the first period is characterized by dominantly oblique clinoforms developed as the new Pliocene margin prograded. Rapid progradation resulted in the filling of the underlying Messinian topographic lows. During this period the continental slope is highly incised by closely spaced submarine canyons. The second period is characterized by highly progradational and aggradational, dominantly sigmoidal, and progressively steeper clinoforms, and by an increase in the shelf-to-basin relief. The degree of incision of the continental slope decreases, however submarine canyons are wider and incise deeper. Mapping of the stratigraphy and quantification of the slope curvature throughout the succession, reveal both along-strike and vertical variations in the morphology and curvature of the continental-margin clinoforms, as the depocenters migrated towards the southwest. Documentation of these morphologies is essential for understanding mechanisms of progradation and sediment distribution, and the interplay between proximity to the sediment source, rate of sediment supply, shelf-to-basin relief, character of oceanographic regime, and sea-level change.