Join SEPM in the Exhibition Hall for all-day poster sessions. Channels are conduits through which fluids, sediment (suspended and bed-load) and dissolved loads are transported across the Earth surface. Their general geomorphologic expression is comparable similar in terrestrial, submarine and extraterrestrial environments; however, formative sedimentary processes can be fundamentally different. For example, sinuosity and aspect ratio tend to be similar; however, submarine channels tend to be larger than fluvial channels and the stratigraphic records of fluvial and submarine channel deposits can be different. A key research challenge is the link between the geomorphic expression and stratigraphic record of channels. Rivers are more accessible to direct monitoring compared to submarine channels and the link between fluvial geomorphology and stratigraphy is better understood. In the case of submarine channels, we commonly rely on the stratigraphic record to inform insights about formative processes and evolution.

Join SEPM in the Exhibition Hall for all-day poster sessions. Channels are conduits through which fluids, sediment (suspended and bed-load) and dissolved loads are transported across the Earth surface. Their general geomorphologic expression is comparable similar in terrestrial, submarine and extraterrestrial environments; however, formative sedimentary processes can be fundamentally different. For example, sinuosity and aspect ratio tend to be similar; however, submarine channels tend to be larger than fluvial channels and the stratigraphic records of fluvial and submarine channel deposits can be different. A key research challenge is the link between the geomorphic expression and stratigraphic record of channels. Rivers are more accessible to direct monitoring compared to submarine channels and the link between fluvial geomorphology and stratigraphy is better understood. In the case of submarine channels, we commonly rely on the stratigraphic record to inform insights about formative processes and evolution.

Panel_14419 Panel_14419 8:30 AM 5:00 PM

A novel, shallow-investigation, high-resolution 3D (HR3D) seismic acquisition system has been employed, for the first time in the Gulf of Mexico, to characterize storage potential and de-risk targets for CO2 sequestration. HR3D data can image detailed depositional, architectural, and structural features in the shallow subsurface that have previously been below seismic resolution and/or excluded from industry surveys, which are optimized for deeper targets. One HR3D survey is located just offshore from San Luis Pass, TX and covers an area of 31.5 km2. The dataset images the shallow subsurface with an unprecedented level of detail -- peak frequency of approximately 150Hz (8 25m cables, spaced at 12.5m, 6.25m by 6.25m bin size). Imaged within this dataset at ~100ms, is a mappable erosional unconformity that is interpreted to be associated with the Brazos River system during the last glacial-eustatic lowstand and following Holocene transgression. Through the analysis of stratal slices and the geometries of the valley form and its dendritic features, we explore the evolution history of the valley system during a transgressive episode. Observations indicate that the system evolves from a lowstand meandering channel with clear point-bar deposits to a transgressive estuary characterized by dendritic tidal features that is eventually flooded. This is an exceptional 3D example of a lowstand to transgressive transition and the sedimentary processes that dominate in each instance. A novel, shallow-investigation, high-resolution 3D (HR3D) seismic acquisition system has been employed, for the first time in the Gulf of Mexico, to characterize storage potential and de-risk targets for CO₂ sequestration. HR3D data can image detailed depositional, architectural, and structural features in the shallow subsurface that have previously been below seismic resolution and/or excluded from industry surveys, which are optimized for deeper targets. One HR3D survey is located just offshore from San Luis Pass, TX and covers an area of 31.5 km². The dataset images the shallow subsurface with an unprecedented level of detail -- peak frequency of approximately 150Hz (8 25m cables, spaced at 12.5m, 6.25m by 6.25m bin size). Imaged within this dataset at ~100ms, is a mappable erosional unconformity that is interpreted to be associated with the Brazos River system during the last glacial-eustatic lowstand and following Holocene transgression. Through the analysis of stratal slices and the geometries of the valley form and its dendritic features, we explore the evolution history of the valley system during a transgressive episode. Observations indicate that the system evolves from a lowstand meandering channel with clear point-bar deposits to a transgressive estuary characterized by dendritic tidal features that is eventually flooded. This is an exceptional 3D example of a lowstand to transgressive transition and the sedimentary processes that dominate in each instance. Panel_14843 Panel_14843 8:30 AM 5:00 PM

Sediment supply to the Equatorial Guinean continental margin consists predominantly of northbound littoral-drift derived mud and sand from the Ogooue River in Gabon. Locally, sediment is sourced from the Mitemele and Benito rivers, low discharge rivers ending in large estuaries. The sediment flux is low, and delivery of sand to the deep sea is limited to a few locations where canyon heads erode into the shelf edge. These canyons are erosive, sand rich, and terminate in extensive submarine aprons (Type I canyons). The vast majority of submarine canyons along the margin do not indent the shelf edge, are muddy and aggradational, and lack any downslope sediment apron/fan (Type II canyons). Smooth, draping seismic reflections indicate that hemipelagic deposition is the chief depositional process aggrading the Type II canyons. Intra-canyon lateral accretion deposits indicate that canyon concavity is maintained by thick (>150 m), dilute, turbidity currents. This study attempts to reconstruct sediment budgets and routing systems for the Equatorial Guinean continental margin and determine the causal mechanisms for variations in temporal sediment flux. Planktic foraminifera from two cores from the modern seafloor, obtained in water depths of 268 and 497 m, provide radiocarbon ages which indicate an average sedimentation rate of ~30 cm/ky (centimeters per kiloyear) during the last ~40,000 years. This relatively slow accumulation rate does not seem to be influenced by changes in relative sea level, supporting the interpretation that hemipelagic deposition is the dominant process aggrading the Type II canyon system. A long term (8 Ma - Recent) sedimentation rate previously calculated in the study area (3.4 cm/ky) is 10x slower than the short term rate calculated in the present study. This discrepancy in rates may be a manifestation of the Sadler effect, a theory that predicts decreasing sedimentation rate as the measured time interval increases. Although the overall sedimentation rate during the last 40 ka averages ~30 cm/ky, there is an abrupt increase during the 15-10 ka time interval to 80-180 cm/ky. We investigate possible causal mechanisms for this increase using sea surface temperature and salinity proxies derived from foraminiferal trace metal data. Constraining temporal and spatial sediment flux to the study area will aid in understanding the development of low sediment supply continental margins with Type II canyons. Sediment supply to the Equatorial Guinean continental margin consists predominantly of northbound littoral-drift derived mud and sand from the Ogooue River in Gabon. Locally, sediment is sourced from the Mitemele and Benito rivers, low discharge rivers ending in large estuaries. The sediment flux is low, and delivery of sand to the deep sea is limited to a few locations where canyon heads erode into the shelf edge. These canyons are erosive, sand rich, and terminate in extensive submarine aprons (Type I canyons). The vast majority of submarine canyons along the margin do not indent the shelf edge, are muddy and aggradational, and lack any downslope sediment apron/fan (Type II canyons). Smooth, draping seismic reflections indicate that hemipelagic deposition is the chief depositional process aggrading the Type II canyons. Intra-canyon lateral accretion deposits indicate that canyon concavity is maintained by thick (>150 m), dilute, turbidity currents. This study attempts to reconstruct sediment budgets and routing systems for the Equatorial Guinean continental margin and determine the causal mechanisms for variations in temporal sediment flux. Planktic foraminifera from two cores from the modern seafloor, obtained in water depths of 268 and 497 m, provide radiocarbon ages which indicate an average sedimentation rate of ~30 cm/ky (centimeters per kiloyear) during the last ~40,000 years. This relatively slow accumulation rate does not seem to be influenced by changes in relative sea level, supporting the interpretation that hemipelagic deposition is the dominant process aggrading the Type II canyon system. A long term (8 Ma - Recent) sedimentation rate previously calculated in the study area (3.4 cm/ky) is 10x slower than the short term rate calculated in the present study. This discrepancy in rates may be a manifestation of the Sadler effect, a theory that predicts decreasing sedimentation rate as the measured time interval increases. Although the overall sedimentation rate during the last 40 ka averages ~30 cm/ky, there is an abrupt increase during the 15-10 ka time interval to 80-180 cm/ky. We investigate possible causal mechanisms for this increase using sea surface temperature and salinity proxies derived from foraminiferal trace metal data. Constraining temporal and spatial sediment flux to the study area will aid in understanding the development of low sediment supply continental margins with Type II canyons. Panel_14835 Panel_14835 8:30 AM 5:00 PM

The 3-D reconstruction of meanderbelt deposits from ancient strata can provide significant insight into the long-term (i.e., centuries to millennia) evolution of fluvial systems. A significant challenge to such analyses is limited exposures in outcrop belts and widely spaced or low-resolution perspectives in subsurface datasets. A particularly dense and high quality dataset consisting of 130 km2 of high-quality 3D seismic data and over 350 well penetrations from the Cretaceous McMurray Formation of northeastern Alberta, Canada provides a unique perspective of an immense ancient river system. The high-resolution dataset features large-scale meandering channel elements, associated with paleochannels that were 400-600 m wide and up to 50 m deep. The data reveals evidence for intra-point bar rotation, neck cut-offs, point bar accretion and other morphodynamic processes. The stratigraphic expression of these processes is recognized through creation of a 3-D geocellular model that includes core-calibrated lithologic properties and seismic-constrained surface projections. A specific objective is to characterize the ancient expression of morphodynamic processes that are commonly observed in modern systems, yet rarely described from the rock record. The analysis also provides insight into sandstone and, inherently, reservoir distribution within the ancient meanderbelt. Reconstructed paleochannel migration patterns reveal the evolutionary history of eight individual meanderbelt elements, including point bars, counter point bars, abandoned channel fills, side bars and mid-channel bars, which have been mapped in core, FMI and seismic data and incorporated into the geocellular model. Results of the study show intra-point bar erosion surfaces bound lateral accretion packages characterized by unique accretion directions, internal stratigraphic architecture and lithologic properties. Individual lateral accretion packages fine as they evolve, as do entire point bars. Seismic and FMI characterization also reveals a multi-phase channel abandonment history that includes vertical aggradation, sidebar development and mid-channel bar deposition, which is not typically recognized in ancient meandering river deposits. The 3-D reconstruction of meanderbelt deposits from ancient strata can provide significant insight into the long-term (i.e., centuries to millennia) evolution of fluvial systems. A significant challenge to such analyses is limited exposures in outcrop belts and widely spaced or low-resolution perspectives in subsurface datasets. A particularly dense and high quality dataset consisting of 130 km² of high-quality 3D seismic data and over 350 well penetrations from the Cretaceous McMurray Formation of northeastern Alberta, Canada provides a unique perspective of an immense ancient river system. The high-resolution dataset features large-scale meandering channel elements, associated with paleochannels that were 400-600 m wide and up to 50 m deep. The data reveals evidence for intra-point bar rotation, neck cut-offs, point bar accretion and other morphodynamic processes. The stratigraphic expression of these processes is recognized through creation of a 3-D geocellular model that includes core-calibrated lithologic properties and seismic-constrained surface projections. A specific objective is to characterize the ancient expression of morphodynamic processes that are commonly observed in modern systems, yet rarely described from the rock record. The analysis also provides insight into sandstone and, inherently, reservoir distribution within the ancient meanderbelt. Reconstructed paleochannel migration patterns reveal the evolutionary history of eight individual meanderbelt elements, including point bars, counter point bars, abandoned channel fills, side bars and mid-channel bars, which have been mapped in core, FMI and seismic data and incorporated into the geocellular model. Results of the study show intra-point bar erosion surfaces bound lateral accretion packages characterized by unique accretion directions, internal stratigraphic architecture and lithologic properties. Individual lateral accretion packages fine as they evolve, as do entire point bars. Seismic and FMI characterization also reveals a multi-phase channel abandonment history that includes vertical aggradation, sidebar development and mid-channel bar deposition, which is not typically recognized in ancient meandering river deposits. Panel_14844 Panel_14844 8:30 AM 5:00 PM

Recent advances in our understanding of the morpholological evolution of paleovalleys, the composite nature of the associated sequence boundary and its expression in down-dip locations have been largely guided by examples from passive margins, where subsidence increases basinward. This study documents a series of incisional fluvio-deltaic sandbodies from the Pennsylvanian Breathitt Group (central Appalachian Basin, USA), which fulfil the traditional definition of paleovalley fills. The Breathitt Group was deposited in an epicontinental foreland basin setting, in which there was no shelf-slope break, and paleovalleys can be tracked from the high accommodation orogenic margin towards the lower accommodation cratonic margin of the basin, over 100 km down-dip. Thus the upper Breathitt Group provides the opportunity to describe changes in up-dip to down-dip characteristics of paleovalleys from setting that contrasts markedly with continental shelf margins. Sandbody architecture has been captured through a combination of centimetre-scale sedimentary logging and annotation of photomosaics from km-long road-cuts to produce correlation panels. Sandbodies are typically 5-20 m thick, 0.5-30 km wide, and dominated by trough cross-bedded medium-to-coarse grained sandstone deposited as longitudinal bars. Heterolithic strata displaying lateral accretion occur, particularly towards the tops of valley fills, as well as rarer heterolith-filled abandonment plugs, slumps and slides. Characteristic changes between the proximal, high accommodation and the distal, low accommodation sectors of the basin include: (1) the number of stratigraphic levels containing major sandbodies decreases, and the sandbodies become increasingly discontinuous, suggesting an overall distributive morphology; (2) the sandbodies erode into increasingly open-marine facies; (3) the sandbodies contain an increasingly diverse, marine ichnofauna, suggesting increasing marine influence down depositional dip. Up-dip, a basinward facies shift at the bases of the paleovalleys is not evident, whereas down-dip an unambiguous basinward facies shift at the bases of the same sand bodies clearly distinguishes them as paleovalley fills. This contrasts with models for paleovalleys derived from passive margins, where the expression of the paleovalley is lost down-depositional dip, and poses the question “where does a channel complex become a palaeovalley-fill?” in settings where accommodation decreases down-dip. Recent advances in our understanding of the morpholological evolution of paleovalleys, the composite nature of the associated sequence boundary and its expression in down-dip locations have been largely guided by examples from passive margins, where subsidence increases basinward. This study documents a series of incisional fluvio-deltaic sandbodies from the Pennsylvanian Breathitt Group (central Appalachian Basin, USA), which fulfil the traditional definition of paleovalley fills. The Breathitt Group was deposited in an epicontinental foreland basin setting, in which there was no shelf-slope break, and paleovalleys can be tracked from the high accommodation orogenic margin towards the lower accommodation cratonic margin of the basin, over 100 km down-dip. Thus the upper Breathitt Group provides the opportunity to describe changes in up-dip to down-dip characteristics of paleovalleys from setting that contrasts markedly with continental shelf margins. Sandbody architecture has been captured through a combination of centimetre-scale sedimentary logging and annotation of photomosaics from km-long road-cuts to produce correlation panels. Sandbodies are typically 5-20 m thick, 0.5-30 km wide, and dominated by trough cross-bedded medium-to-coarse grained sandstone deposited as longitudinal bars. Heterolithic strata displaying lateral accretion occur, particularly towards the tops of valley fills, as well as rarer heterolith-filled abandonment plugs, slumps and slides. Characteristic changes between the proximal, high accommodation and the distal, low accommodation sectors of the basin include: (1) the number of stratigraphic levels containing major sandbodies decreases, and the sandbodies become increasingly discontinuous, suggesting an overall distributive morphology; (2) the sandbodies erode into increasingly open-marine facies; (3) the sandbodies contain an increasingly diverse, marine ichnofauna, suggesting increasing marine influence down depositional dip. Up-dip, a basinward facies shift at the bases of the paleovalleys is not evident, whereas down-dip an unambiguous basinward facies shift at the bases of the same sand bodies clearly distinguishes them as paleovalley fills. This contrasts with models for paleovalleys derived from passive margins, where the expression of the paleovalley is lost down-depositional dip, and poses the question “where does a channel complex become a palaeovalley-fill?” in settings where accommodation decreases down-dip. Panel_14839 Panel_14839 8:30 AM 5:00 PM

Recent debate has focused on the potential preservation of the signal of seismic events in the sedimentary record via the initiation of large-scale turbidity current flows. It has been postulated that details of seismic activity may be recorded in turbidites. For example, given the long run out time of turbidity currents, secondary turbidity currents events, initiated by seismic aftershocks, are likely to interact with the primary events creating a “pulsing” flow. Such pulsing flow may also be generated if the failure of a seismic fault lies across an interconnected series of submarine channel systems, where a seismic trigger may generate multiple linked flows. With variation in feeder channel length causing variation in the time taken for individual flows to reach channel confluences, the resultant turbidity current is also expected to be pulsed. Thus, cyclical waxing to waning behavior preserved in graded flow deposits may be a key indicator of secondary seismic activity or a seismic trigger acting over an interconnected channel system. Dependent on the ability for signal preservation in pulsing flows, deposit grading may provide a novel means of assessing proximity to source and/or system architecture. Novel experimental research is presented that explores the dynamics of pulsed turbidity currents. The experimental study is used to quantitatively examine controls on the time and length scale of signal preservation. Parameters investigated include volumes of material released, effective flow density and viscosity (as a proxy of flow mud content). Full flow field visualization was made using an array of interlinked HD cameras. Dyeing separate components of the flow different colors enabled detailed analysis of flow dynamic behavior occurring between head and tail. The secondary pulsing flow was seen to rapidly overtake the first flow. Observations of flow velocity and density suggested that due to stratification the secondary flow was travelling along the density interface between the main body of the primary flow and its turbulent wake. As the pulsing flows created in the laboratory experiments rapidly merged, it suggests that it is difficult to preserve pulsing signals of interacting turbidity currents over long run out distance or times. However, these initial experiments have been carried out with solute currents on flat slopes. Particulate currents travelling over a pronounced gradient may have a significantly different signal preservation behavior. Recent debate has focused on the potential preservation of the signal of seismic events in the sedimentary record via the initiation of large-scale turbidity current flows. It has been postulated that details of seismic activity may be recorded in turbidites. For example, given the long run out time of turbidity currents, secondary turbidity currents events, initiated by seismic aftershocks, are likely to interact with the primary events creating a “pulsing” flow. Such pulsing flow may also be generated if the failure of a seismic fault lies across an interconnected series of submarine channel systems, where a seismic trigger may generate multiple linked flows. With variation in feeder channel length causing variation in the time taken for individual flows to reach channel confluences, the resultant turbidity current is also expected to be pulsed. Thus, cyclical waxing to waning behavior preserved in graded flow deposits may be a key indicator of secondary seismic activity or a seismic trigger acting over an interconnected channel system. Dependent on the ability for signal preservation in pulsing flows, deposit grading may provide a novel means of assessing proximity to source and/or system architecture. Novel experimental research is presented that explores the dynamics of pulsed turbidity currents. The experimental study is used to quantitatively examine controls on the time and length scale of signal preservation. Parameters investigated include volumes of material released, effective flow density and viscosity (as a proxy of flow mud content). Full flow field visualization was made using an array of interlinked HD cameras. Dyeing separate components of the flow different colors enabled detailed analysis of flow dynamic behavior occurring between head and tail. The secondary pulsing flow was seen to rapidly overtake the first flow. Observations of flow velocity and density suggested that due to stratification the secondary flow was travelling along the density interface between the main body of the primary flow and its turbulent wake. As the pulsing flows created in the laboratory experiments rapidly merged, it suggests that it is difficult to preserve pulsing signals of interacting turbidity currents over long run out distance or times. However, these initial experiments have been carried out with solute currents on flat slopes. Particulate currents travelling over a pronounced gradient may have a significantly different signal preservation behavior. Panel_14840 Panel_14840 8:30 AM 5:00 PM

A few key questions inevitably arise while mapping seismically-imaged channel bodies from past landscapes. Where was the shoreline? Can the planform of channel bodies help us predict the reservoir characteristics of the preserved deposits? In this talk, we will discuss how the back-water length scale in rivers defines systematic changes in stratal architecture across the transition from normal flow to the back-water influenced zone. A spatial reduction in bed material flux is observed where rivers transition from normal flow to the back-water influenced zone, as the river flow begins to feel the effect of sea-level in the receiving basin. The back-water length, scaled by characteristic flow depth divided by water surface slope, is a characteristic length scale of all rivers entering a receiving basin and is best distinguished in deep lowland rivers with shallow gradient. Measurements along the Holocene Mississippi Channel Belt from Cairo to Head of Passes show a dramatic reduction in the width of the channel belt from roughly 20 times the channel width upstream of the transition zone to nearly equal to the channel width downstream of the transition zone. This variation in width of the channel belt is tied to the decreased lateral mobility of the channel downstream of the back-water transition. The thickness of bank-attached bar deposits, collected from USACE cores in 110 cross-sections, was used as a proxy for channel depth from Cairo to Head of Passes. Thickness trends reveal that bank-attached bars thicken from approximately 20m upstream of the transition to 45m just above Head of Passes, while decreased lateral migration results in less extensive bar deposits. A comparison of 4 different channel belts from the Rhine-Meuse and Mississippi systems is presented. For these two systems, we present a method that uses the backwater length to non-dimensionalize the geometries of channel belts with disparate scales. We apply this scaling to the Mio-Pliocene Mississippi Delta system, imaged in an industry seismic volume over Breton sound, to estimate distance to the shoreline. Our estimates are tested against independent reconstructions of paleo-geography for the area. Results indicate that this method can be a powerful tool for reconstructing paleo-environment of deposition and characterizing reservoir architecture in ancient seismically-imaged channel belts. A few key questions inevitably arise while mapping seismically-imaged channel bodies from past landscapes. Where was the shoreline? Can the planform of channel bodies help us predict the reservoir characteristics of the preserved deposits? In this talk, we will discuss how the back-water length scale in rivers defines systematic changes in stratal architecture across the transition from normal flow to the back-water influenced zone. A spatial reduction in bed material flux is observed where rivers transition from normal flow to the back-water influenced zone, as the river flow begins to feel the effect of sea-level in the receiving basin. The back-water length, scaled by characteristic flow depth divided by water surface slope, is a characteristic length scale of all rivers entering a receiving basin and is best distinguished in deep lowland rivers with shallow gradient. Measurements along the Holocene Mississippi Channel Belt from Cairo to Head of Passes show a dramatic reduction in the width of the channel belt from roughly 20 times the channel width upstream of the transition zone to nearly equal to the channel width downstream of the transition zone. This variation in width of the channel belt is tied to the decreased lateral mobility of the channel downstream of the back-water transition. The thickness of bank-attached bar deposits, collected from USACE cores in 110 cross-sections, was used as a proxy for channel depth from Cairo to Head of Passes. Thickness trends reveal that bank-attached bars thicken from approximately 20m upstream of the transition to 45m just above Head of Passes, while decreased lateral migration results in less extensive bar deposits. A comparison of 4 different channel belts from the Rhine-Meuse and Mississippi systems is presented. For these two systems, we present a method that uses the backwater length to non-dimensionalize the geometries of channel belts with disparate scales. We apply this scaling to the Mio-Pliocene Mississippi Delta system, imaged in an industry seismic volume over Breton sound, to estimate distance to the shoreline. Our estimates are tested against independent reconstructions of paleo-geography for the area. Results indicate that this method can be a powerful tool for reconstructing paleo-environment of deposition and characterizing reservoir architecture in ancient seismically-imaged channel belts. Panel_14834 Panel_14834 8:30 AM 5:00 PM

The Lower Cretaceous McMurray Formation Type Section is located 5km downstream from the confluence of the Athabasca and Clearwater rivers and extends 2 km along the east bank of the Athabasca River. This outstanding, up to 80 m thick exposure has been visited by many geologists, but remains poorly documented in literature. The outcrop is comprised of four distinct stratigraphic units. The focus of this report is on heterogeneities observed across the large-scale (35m thick) channel deposit. Since oil-saturated, this outcrop also presents an unparalleled portal for reservoir studies. Data was acquired through detailed two-dimensional outcrop mapping recorded on high resolution photographs and scaled photo-montages, line-drawing of various geological contacts interpreted on both outcrops and images, and integrating detailed (cm-dm) bed-by-bed logging along selected outcrop exposures. Mapping and line drawings were further assisted by the collection of paleo-flow indicators. These data were coupled with core descriptions from drill holes behind the outcrop which allowed for 3D visualization. Point bar evolution is interpreted based on nature (geometry) of contacts, geometric relationship of mapped architectural elements, facies changes between architectural elements, and paleo-current indicators. Detailed mapping revealed numerous enigmatic features commonly not associated with point bar processes and architecture that include: (1) five types of breccia not associated with channel lag deposits; (2) a variety of mud occurrences in high-energy bottom-channel deposits; (3) encased channel shaped features within the mid-to-upper point-bar deposits (interpreted as short lived chute and rill channels); and (4) paleo-current reversals. Observations of detailed reservoir architecture from the Type Section provides a basis for characterizing dynamic interplay of deposition and erosion of channel deposits on various time scales; new insights for point-bar facies models; and more fulsome understanding of the impact of facies heterogeneities on reservoir oil-charge and in-reservoir fluid migration. The Lower Cretaceous McMurray Formation Type Section is located 5km downstream from the confluence of the Athabasca and Clearwater rivers and extends 2 km along the east bank of the Athabasca River. This outstanding, up to 80 m thick exposure has been visited by many geologists, but remains poorly documented in literature. The outcrop is comprised of four distinct stratigraphic units. The focus of this report is on heterogeneities observed across the large-scale (35m thick) channel deposit. Since oil-saturated, this outcrop also presents an unparalleled portal for reservoir studies. Data was acquired through detailed two-dimensional outcrop mapping recorded on high resolution photographs and scaled photo-montages, line-drawing of various geological contacts interpreted on both outcrops and images, and integrating detailed (cm-dm) bed-by-bed logging along selected outcrop exposures. Mapping and line drawings were further assisted by the collection of paleo-flow indicators. These data were coupled with core descriptions from drill holes behind the outcrop which allowed for 3D visualization. Point bar evolution is interpreted based on nature (geometry) of contacts, geometric relationship of mapped architectural elements, facies changes between architectural elements, and paleo-current indicators. Detailed mapping revealed numerous enigmatic features commonly not associated with point bar processes and architecture that include: (1) five types of breccia not associated with channel lag deposits; (2) a variety of mud occurrences in high-energy bottom-channel deposits; (3) encased channel shaped features within the mid-to-upper point-bar deposits (interpreted as short lived chute and rill channels); and (4) paleo-current reversals. Observations of detailed reservoir architecture from the Type Section provides a basis for characterizing dynamic interplay of deposition and erosion of channel deposits on various time scales; new insights for point-bar facies models; and more fulsome understanding of the impact of facies heterogeneities on reservoir oil-charge and in-reservoir fluid migration. Panel_14836 Panel_14836 8:30 AM 5:00 PM

Flow process and sediment transport within a channel bend and associated point bar have been studied in modern streams, theoretical models and physical experiments. However, the accuracy of these models are hard to evaluate for long-term evolution of natural rivers. It is also difficult to compare the resulting plan-form bar morphology and facies architecture of modern and modelled systems with what is preserved in the ancient rock record due to the lack of plan-view exposed outcrops. Moreover, compound point bars and scroll bars that are typically found in meandering rivers show different facies architecture, which is essentially the result of different flow processes that have rarely been distinguished. This study examined a point bar complex based on plan-view exposures of channel belts in outcrop of the Ferron Sandstone, south-central Utah. Flow process, sediment transport and bed shear stress show that compound point bars and scroll bars were formed during falling and rising flood stages respectively. The simulation of sine-generated streams showed that channel dimension parameters, such as radius of curvature and sinuosity, have small ranges of 351-205 m and 1.04-1.22 respectively throughout the evolution of the bend. Variation in flow process was interpreted as the main control on facies architecture and bar morphology. In this case, strong helical flow with a maximum strength of 1.05 was developed during the deposition of scroll bars but not the compound bars. The widely used paleocurrent indicator-dip direction of cross beds-was found to be inconsistent with the mean flow direction or the channel margin orientation. Flow process and sediment transport within a channel bend and associated point bar have been studied in modern streams, theoretical models and physical experiments. However, the accuracy of these models are hard to evaluate for long-term evolution of natural rivers. It is also difficult to compare the resulting plan-form bar morphology and facies architecture of modern and modelled systems with what is preserved in the ancient rock record due to the lack of plan-view exposed outcrops. Moreover, compound point bars and scroll bars that are typically found in meandering rivers show different facies architecture, which is essentially the result of different flow processes that have rarely been distinguished. This study examined a point bar complex based on plan-view exposures of channel belts in outcrop of the Ferron Sandstone, south-central Utah. Flow process, sediment transport and bed shear stress show that compound point bars and scroll bars were formed during falling and rising flood stages respectively. The simulation of sine-generated streams showed that channel dimension parameters, such as radius of curvature and sinuosity, have small ranges of 351-205 m and 1.04-1.22 respectively throughout the evolution of the bend. Variation in flow process was interpreted as the main control on facies architecture and bar morphology. In this case, strong helical flow with a maximum strength of 1.05 was developed during the deposition of scroll bars but not the compound bars. The widely used paleocurrent indicator-dip direction of cross beds-was found to be inconsistent with the mean flow direction or the channel margin orientation. Panel_14847 Panel_14847 8:30 AM 5:00 PM

Submarine channels can form important hydrocarbon reservoirs, and modern and ancient siliciclastic channels have been therefore intensively studied in the past. Significantly less is known of channels in carbonate environments. Particularly in non-tropical carbonate settings, information on channel geometries, morphology, architecture and channel-forming processes is limited. This study presents 3D seismic-reflection data of kilometre-scale submarine channels in non-tropical carbonates from different stratigraphic intervals of the European North Sea and the NW Australian Shelf. Though all systems studied developed under non-tropical deepwater conditions, they show distinctly different geometries interpreted to reflect differences in input variables including sediment flux and size, but also differences in the tectonic environment. 3D-seismic analysis of a kilometre-scale channel in the Upper Cretaceous part of the Chalk Group of the North Sea Central Graben documents a rather isolated, sinuous, leveed system that displays many of the architectural elements known from siliciclastic deepwater turbidites. This channel is interpreted to have formed an important conduit for recurrent turbulent flows transporting failed chalk material into the deeper basin depocentres in response to inversion tectonics. Nearby and at the same stratigraphic level, there are other, less extensive, highly asymmetric channels. These systems lack levees and are interpreted to have been eroded by bottom currents and filled laterally by chalk drifts. The channels preserved in the Paleogene section of the Browse Basin, NW-Australian Shelf, in contrast, are much narrower than the North Sea examples and occur in arrays as vertically and laterally-offset stacked multi-storey systems. The repetitive character and restriction to clinoform fronts suggests their development in response to sedimentation-driven clinoform oversteepening and failure under rather stable tectonic conditions. The significant variability in geometry, morphology and architecture of the deep-water carbonate channels presented documents that generalized predictions of deposit type and the associated reservoir properties are difficult. Controlling factors for this variability include active tectonics, differences in sediment type and size, the type of mass-transport system and the superimposed current regime. An understanding of these parameters will be essential for a successful exploration in deepwater carbonates. Submarine channels can form important hydrocarbon reservoirs, and modern and ancient siliciclastic channels have been therefore intensively studied in the past. Significantly less is known of channels in carbonate environments. Particularly in non-tropical carbonate settings, information on channel geometries, morphology, architecture and channel-forming processes is limited. This study presents 3D seismic-reflection data of kilometre-scale submarine channels in non-tropical carbonates from different stratigraphic intervals of the European North Sea and the NW Australian Shelf. Though all systems studied developed under non-tropical deepwater conditions, they show distinctly different geometries interpreted to reflect differences in input variables including sediment flux and size, but also differences in the tectonic environment. 3D-seismic analysis of a kilometre-scale channel in the Upper Cretaceous part of the Chalk Group of the North Sea Central Graben documents a rather isolated, sinuous, leveed system that displays many of the architectural elements known from siliciclastic deepwater turbidites. This channel is interpreted to have formed an important conduit for recurrent turbulent flows transporting failed chalk material into the deeper basin depocentres in response to inversion tectonics. Nearby and at the same stratigraphic level, there are other, less extensive, highly asymmetric channels. These systems lack levees and are interpreted to have been eroded by bottom currents and filled laterally by chalk drifts. The channels preserved in the Paleogene section of the Browse Basin, NW-Australian Shelf, in contrast, are much narrower than the North Sea examples and occur in arrays as vertically and laterally-offset stacked multi-storey systems. The repetitive character and restriction to clinoform fronts suggests their development in response to sedimentation-driven clinoform oversteepening and failure under rather stable tectonic conditions. The significant variability in geometry, morphology and architecture of the deep-water carbonate channels presented documents that generalized predictions of deposit type and the associated reservoir properties are difficult. Controlling factors for this variability include active tectonics, differences in sediment type and size, the type of mass-transport system and the superimposed current regime. An understanding of these parameters will be essential for a successful exploration in deepwater carbonates. Panel_14841 Panel_14841 8:30 AM 5:00 PM

The ability to directly monitor sediment gravity flows that shape submarine channels on the modern seafloor remains largely elusive. As a result, the sedimentary record is perhaps the most accessible and suitable laboratory from which to consider the dynamic history of channelized sediment transfer and deposition within slope channels. Our analysis features the well-preserved fill of an outcropping submarine channel (“Unit -2”) in the Tres Pasos Fm (Cretaceous), Chile. A spectrum of processes results in fill patterns within channelform bodies 15-25 m thick and 200-400 m wide, including an axial sandstone-dominated zone bound by composite erosional surfaces that define lateral contacts with thin-bedded and finer- grained channel margin units. Channel margin deposits drape or lap onto the composite edge of the channel form. Seventy to eighty percent of the cross-sectional channel fill consists of sandstone-dominated (axis) strata and 20-30% mudstone-prone (margin) strata. A series of 17 stratigraphic sections measured at 0.1 cm resolution through the channel fill, from the channel axis through margin transition, document the number and spatial distribution of sedimentation units, or turbidity current events. Our analysis reveals that >500 individual, distinct sedimentation units are present in the single channel fill. However, <5% of the recorded sedimentation units are preserved in channel axis deposits. Insight into prolonged sediment transfer is preserved in cross-sectionally limited channel margin sedimentation units; many of these fine-grained units overlie erosion surfaces, recording deposition from the dilute tails or fringes of highly erosive, mainly bypassing turbidity currents. The total number of distinct sedimentation units represents the minimum number of turbidity currents that passed through the channel over its lifecycle. Stratigraphic correlation reveals that thinner-bedded, finer-grained margin facies track into thicker-bedded axis facies. At least ten discontinuities form the composite surface that defines the contact between channel axis and margin; a nuanced, time transgressive channel evolution interpretation is required to account for the observations made. A simple, two-step cut and fill model for submarine channels does not represent the prolonged and dynamic nature of evolutionary processes. Thick-bedded, sand-rich channel filling is highly episodic and rare against a background of channel maintenance by bypassing turbidity currents. The ability to directly monitor sediment gravity flows that shape submarine channels on the modern seafloor remains largely elusive. As a result, the sedimentary record is perhaps the most accessible and suitable laboratory from which to consider the dynamic history of channelized sediment transfer and deposition within slope channels. Our analysis features the well-preserved fill of an outcropping submarine channel (“Unit -2”) in the Tres Pasos Fm (Cretaceous), Chile. A spectrum of processes results in fill patterns within channelform bodies 15-25 m thick and 200-400 m wide, including an axial sandstone-dominated zone bound by composite erosional surfaces that define lateral contacts with thin-bedded and finer- grained channel margin units. Channel margin deposits drape or lap onto the composite edge of the channel form. Seventy to eighty percent of the cross-sectional channel fill consists of sandstone-dominated (axis) strata and 20-30% mudstone-prone (margin) strata. A series of 17 stratigraphic sections measured at 0.1 cm resolution through the channel fill, from the channel axis through margin transition, document the number and spatial distribution of sedimentation units, or turbidity current events. Our analysis reveals that >500 individual, distinct sedimentation units are present in the single channel fill. However, <5% of the recorded sedimentation units are preserved in channel axis deposits. Insight into prolonged sediment transfer is preserved in cross-sectionally limited channel margin sedimentation units; many of these fine-grained units overlie erosion surfaces, recording deposition from the dilute tails or fringes of highly erosive, mainly bypassing turbidity currents. The total number of distinct sedimentation units represents the minimum number of turbidity currents that passed through the channel over its lifecycle. Stratigraphic correlation reveals that thinner-bedded, finer-grained margin facies track into thicker-bedded axis facies. At least ten discontinuities form the composite surface that defines the contact between channel axis and margin; a nuanced, time transgressive channel evolution interpretation is required to account for the observations made. A simple, two-step cut and fill model for submarine channels does not represent the prolonged and dynamic nature of evolutionary processes. Thick-bedded, sand-rich channel filling is highly episodic and rare against a background of channel maintenance by bypassing turbidity currents. Panel_14846 Panel_14846 8:30 AM 5:00 PM

By simultaneously examining halokinetics and channel evolution of a deepwater area it is possible to unravel the interactions between the two dynamic bodies. The study area is located in the Mississippi Canyon, Gulf of Mexico, and is situated directly off the continental slope in a prominent salt dome region. While there is a plethora of study on submarine channels in the Gulf of Mexico, their interactions with salt domes are poorly documented. Utilizing 3D seismic data and seismic geomorphology techniques, a long-lived Plio-Pleistocene submarine channel system has been investigated to understand the interaction between channel evolution and changing seascape driven by rising salt domes. In the study area, salt diapirism began to affect the seafloor topography during the late Pliocene. This shifting topography has exerted a first order control on the evolution of the meandering submarine channel, as seen in the seismic data. When investigating the channel evolution and halokinetics concurrently, a relationship becomes apparent. The study results reveal a mechanism to determine variable phases of salt movement based on plan-form morphology of preserved channels. For example, highly sinuous channels developed during periods of slow salt movement whereas straighter channels formed when salt moved upward more rapidly. Furthermore, the channels display a feedback mechanism that illustrates how areas of lower topography on the seafloor were created as the salt was reaching its diapiric state, and the channels adjusted by migrating towards these structural lows. As the channels avulsed and migrated, they were subject to an increase in slope. This increase in slope corresponds to and is directly related to a decrease in meander intensity. Thus, this study reveals how salt movement has acted as a structural control on both the location and morphology of the meandering channel complex. By simultaneously examining halokinetics and channel evolution of a deepwater area it is possible to unravel the interactions between the two dynamic bodies. The study area is located in the Mississippi Canyon, Gulf of Mexico, and is situated directly off the continental slope in a prominent salt dome region. While there is a plethora of study on submarine channels in the Gulf of Mexico, their interactions with salt domes are poorly documented. Utilizing 3D seismic data and seismic geomorphology techniques, a long-lived Plio-Pleistocene submarine channel system has been investigated to understand the interaction between channel evolution and changing seascape driven by rising salt domes. In the study area, salt diapirism began to affect the seafloor topography during the late Pliocene. This shifting topography has exerted a first order control on the evolution of the meandering submarine channel, as seen in the seismic data. When investigating the channel evolution and halokinetics concurrently, a relationship becomes apparent. The study results reveal a mechanism to determine variable phases of salt movement based on plan-form morphology of preserved channels. For example, highly sinuous channels developed during periods of slow salt movement whereas straighter channels formed when salt moved upward more rapidly. Furthermore, the channels display a feedback mechanism that illustrates how areas of lower topography on the seafloor were created as the salt was reaching its diapiric state, and the channels adjusted by migrating towards these structural lows. As the channels avulsed and migrated, they were subject to an increase in slope. This increase in slope corresponds to and is directly related to a decrease in meander intensity. Thus, this study reveals how salt movement has acted as a structural control on both the location and morphology of the meandering channel complex. Panel_14838 Panel_14838 8:30 AM 5:00 PM

Submarine channels occur in many physiographic domains of the deep-sea environment. They have a large spectrum of planforms, dimensions, internal elements and hierarchic significance. This paper focuses on a type of submarine channel found in different environmental settings of the modern seafloor in the Tyrrhenian Sea. The channels are straight or very gently curving and vary in width from 100 to 500 m, with a maximum relief in the order of 10-15 m. Their main feature is a noticeable asymmetry resulting from a steep, abrupt margin and a gentler, more gradual one. Channels are never isolated, but are rather part of extensive channelized areas. Within the channelized areas, elevated longitudinal areas separate the channels. The elevated areas have sediment waves and scours indicative of flows that from their crests point toward the adjacent channels. Sidescan sonar data show that along the gentle channel margin a clear passage between the channels and the bars cannot be picked up. On the contrary, an abrupt limit is observed in coincidence with the steep channel side. Subbottom profiles indicate that the elevated areas are depositional, with deposits that continue along the gentle channel side and, although often with a different seismic facies, also represent the channel infill. Thus, the elevated areas are not erosional remnants between fully erosional channels. Upslope from the channelized areas the seafloor is flat indicating that it is the site of laterally widespread flows. Therefore, we also infer that the elevated areas are not levees, since they are not formed by flows which overbank the channels. They are rather formed from flows that occupy the whole channelized areas and behave differently in the channels and in the elevated areas. We conclude that the elevated areas are better interpreted as bars. As a whole, we explain the channel as being migrating elements with an erosional cut bank and a depositional one where lateral accretion is occurring from the longitudinal bars. The channels and longitudinal bars are located downslope from slope channel mouths in transient fans, or compose channel belts confined within slope channels. They develop on seafloor with a gradient in excess of 1° and where sampled, they consist of sandy or gravelly sediments. The Tyrrhenian sea data, suggest therefore that laterally migrating channels and longitudinal bars are components of channelized, high-gradient, coarse grained systems connected to deeper base levels. Submarine channels occur in many physiographic domains of the deep-sea environment. They have a large spectrum of planforms, dimensions, internal elements and hierarchic significance. This paper focuses on a type of submarine channel found in different environmental settings of the modern seafloor in the Tyrrhenian Sea. The channels are straight or very gently curving and vary in width from 100 to 500 m, with a maximum relief in the order of 10-15 m. Their main feature is a noticeable asymmetry resulting from a steep, abrupt margin and a gentler, more gradual one. Channels are never isolated, but are rather part of extensive channelized areas. Within the channelized areas, elevated longitudinal areas separate the channels. The elevated areas have sediment waves and scours indicative of flows that from their crests point toward the adjacent channels. Sidescan sonar data show that along the gentle channel margin a clear passage between the channels and the bars cannot be picked up. On the contrary, an abrupt limit is observed in coincidence with the steep channel side. Subbottom profiles indicate that the elevated areas are depositional, with deposits that continue along the gentle channel side and, although often with a different seismic facies, also represent the channel infill. Thus, the elevated areas are not erosional remnants between fully erosional channels. Upslope from the channelized areas the seafloor is flat indicating that it is the site of laterally widespread flows. Therefore, we also infer that the elevated areas are not levees, since they are not formed by flows which overbank the channels. They are rather formed from flows that occupy the whole channelized areas and behave differently in the channels and in the elevated areas. We conclude that the elevated areas are better interpreted as bars. As a whole, we explain the channel as being migrating elements with an erosional cut bank and a depositional one where lateral accretion is occurring from the longitudinal bars. The channels and longitudinal bars are located downslope from slope channel mouths in transient fans, or compose channel belts confined within slope channels. They develop on seafloor with a gradient in excess of 1° and where sampled, they consist of sandy or gravelly sediments. The Tyrrhenian sea data, suggest therefore that laterally migrating channels and longitudinal bars are components of channelized, high-gradient, coarse grained systems connected to deeper base levels. Panel_14837 Panel_14837 8:30 AM 5:00 PM

Non-marine sequence stratigraphic models for incised valleys predict systematic changes in fluvial style from lowstand through transgressive to highstand system tracts, assuming a constant rate of marine transgression. Downstream base-level influence on fluvial style however, can be highly variable, and may produce less predictable pattern. The main purpose of this paper is to evaluate the change in plan-view style of rivers from their upstream to downstream versus extent of the effects of backwater length recorded within a Cretaceous compound incised-valley fill in the Ferron Notom Delta, Henry Mountain region, southeast Utah. It was hypothesized that the backwater length, which is proportional to river flow depth and inversely correlated to river slope theoretically controls the effects of base-level change to propagate upstream. Previous studies on modern Mississippi river valley demonstrated that channel, channel-belts in a coastal-plain valley experience predictable morphological and sedimentological changes as they enter their backwater length, and characterized by rivers that are aggradational, avulsive and distributive in nature. This paper, for the first time, attempts to test these hypotheses in an ancient compound valley fill by detailed facies architectural analysis of channel and bar deposits from vertical measured sections and estimation of backwater limits from paleo-flow depth measurements in combination with measured changes in base level, tidal range and fluvial slope along an extensively exposed fluvial long profile. Three major erosional surfaces partitioned the compound valley fill into three sequences that have noticeable morphological and sedimentological differences from the upstream to downstream area. All three incised-valley fills in the downstream area shows a vertical translation from fluvial to tidal facies at the top of the valley. This suggests the rivers entered into their backwater length at the later phase of valley filling causing a systematic vertical decrease in overall grain size as well as an upward increase in preserved dune height and bar thickness. The valley fill deposits at the upstream area, which is roughly 15 km southwest, however, lie beyond the reach of the backwater effect and hence do not show any tidal influence, but consist of much coarser facies within channel bodies of relatively low width-thickness ratio. Non-marine sequence stratigraphic models for incised valleys predict systematic changes in fluvial style from lowstand through transgressive to highstand system tracts, assuming a constant rate of marine transgression. Downstream base-level influence on fluvial style however, can be highly variable, and may produce less predictable pattern. The main purpose of this paper is to evaluate the change in plan-view style of rivers from their upstream to downstream versus extent of the effects of backwater length recorded within a Cretaceous compound incised-valley fill in the Ferron Notom Delta, Henry Mountain region, southeast Utah. It was hypothesized that the backwater length, which is proportional to river flow depth and inversely correlated to river slope theoretically controls the effects of base-level change to propagate upstream. Previous studies on modern Mississippi river valley demonstrated that channel, channel-belts in a coastal-plain valley experience predictable morphological and sedimentological changes as they enter their backwater length, and characterized by rivers that are aggradational, avulsive and distributive in nature. This paper, for the first time, attempts to test these hypotheses in an ancient compound valley fill by detailed facies architectural analysis of channel and bar deposits from vertical measured sections and estimation of backwater limits from paleo-flow depth measurements in combination with measured changes in base level, tidal range and fluvial slope along an extensively exposed fluvial long profile. Three major erosional surfaces partitioned the compound valley fill into three sequences that have noticeable morphological and sedimentological differences from the upstream to downstream area. All three incised-valley fills in the downstream area shows a vertical translation from fluvial to tidal facies at the top of the valley. This suggests the rivers entered into their backwater length at the later phase of valley filling causing a systematic vertical decrease in overall grain size as well as an upward increase in preserved dune height and bar thickness. The valley fill deposits at the upstream area, which is roughly 15 km southwest, however, lie beyond the reach of the backwater effect and hence do not show any tidal influence, but consist of much coarser facies within channel bodies of relatively low width-thickness ratio. Panel_14842 Panel_14842 8:30 AM 5:00 PM

The emerging deepwater gas province offshore East Africa presents great opportunities and also dilemmas in high-grading a vast region for petroleum potential. Known hydrocarbon play elements are Cretaceous and Early Tertiary deepwater fan systems, structurally-enhanced stratigraphic traps, and a functioning gas petroleum system with unknown liquids potential. The fan/channel reservoirs contain remarkable reservoir properties and a high degree of connectivity; however, their distribution is more problematic. The ability to map reservoir spatial and temporal distribution is a critical undeveloped play element. We outline a workflow that enables this mapping by generating high-resolution horizon interpretations of a coarse regional 2D seismic grid over a 400,000 square kilometer area. Regional mapping of time-correlative stratal packages outlines the broader depositional and tectonic-stratigraphic framework. Detailed mapping of various architectural elements within these stratal packages reveals systematic variation both within and between stratal intervals. Channel morphology and related geo-body types and dimensions vary both up- and down- depositional gradient, but also according to stratigraphic position. Geo-body dimensions and distribution are dictated by the geomorphic gradient and profile controlling sediment deposition. Steeper profiles have greater potential energy and thus higher incision in up-dip positions, with little levee development and more aggradational frontal splays and lobes occurring down-dip. Sediment partitioning favors down-profile deposition and channel concentration in fewer channels. The resulting stratigraphic record favors single-story channel systems and smaller, multi-storied lobes. Lower-gradient profiles generate more low-energy density flows, resulting in less up-dip incision and significant, symmetric levee development and shingled or progradational frontal splays in down dip positions. The resulting stratigraphic record favors multiple, along-strike channel development creating laterally persistent, single-storied sands and aerially larger, shingled fan lobes. Understanding the distribution and stacking of these different architectural elements through time has significant implications for trapping, reservoir distribution and connectivity. Application of this work provides enhanced predictability to exploration efforts, including distribution of reservoir properties in a regional basin context. The emerging deepwater gas province offshore East Africa presents great opportunities and also dilemmas in high-grading a vast region for petroleum potential. Known hydrocarbon play elements are Cretaceous and Early Tertiary deepwater fan systems, structurally-enhanced stratigraphic traps, and a functioning gas petroleum system with unknown liquids potential. The fan/channel reservoirs contain remarkable reservoir properties and a high degree of connectivity; however, their distribution is more problematic. The ability to map reservoir spatial and temporal distribution is a critical undeveloped play element. We outline a workflow that enables this mapping by generating high-resolution horizon interpretations of a coarse regional 2D seismic grid over a 400,000 square kilometer area. Regional mapping of time-correlative stratal packages outlines the broader depositional and tectonic-stratigraphic framework. Detailed mapping of various architectural elements within these stratal packages reveals systematic variation both within and between stratal intervals. Channel morphology and related geo-body types and dimensions vary both up- and down- depositional gradient, but also according to stratigraphic position. Geo-body dimensions and distribution are dictated by the geomorphic gradient and profile controlling sediment deposition. Steeper profiles have greater potential energy and thus higher incision in up-dip positions, with little levee development and more aggradational frontal splays and lobes occurring down-dip. Sediment partitioning favors down-profile deposition and channel concentration in fewer channels. The resulting stratigraphic record favors single-story channel systems and smaller, multi-storied lobes. Lower-gradient profiles generate more low-energy density flows, resulting in less up-dip incision and significant, symmetric levee development and shingled or progradational frontal splays in down dip positions. The resulting stratigraphic record favors multiple, along-strike channel development creating laterally persistent, single-storied sands and aerially larger, shingled fan lobes. Understanding the distribution and stacking of these different architectural elements through time has significant implications for trapping, reservoir distribution and connectivity. Application of this work provides enhanced predictability to exploration efforts, including distribution of reservoir properties in a regional basin context. Panel_14845 Panel_14845 8:30 AM 5:00 PM