{"id":{"repo_id":"queens","oai_identifier":"oai:queensu.scholaris.ca:1974/6985"},"canonical_url":"https://search.dev.ndltd.org/etd/queens/oai:queensu.scholaris.ca:1974/6985","repository":{"repo_id":"queens","name":"Queens University","base_url":"https://qspace.library.queensu.ca/server/oai/request"},"display":{"title":"Process Sedimentology and Three-Dimensional Facies Architecture of a Fluvially Dominated, Tidally Influenced Point Bar: Middle McMurray Formation, Lower Steepbank River Area, Northeastern Alberta, Canada","abstract":"Within the middle McMurray exposures along the Steepbank River (Steepbank River Outcrops 3 and 4), nine recognized facies can be divided into three genetically related groups: sand-dominated facies, inclined heterolithic stratification (IHS) facies and mixed heterolithic facies. Together, these facies are interpreted to represent a fluvially dominated, tidally influenced point bar that experienced strong seasonal variation in river discharge. Annual fluctuations between river-flood stage and low-flow stage are responsible for the deposition of fluvially dominated sand beds alternating with brackish, tidally influenced mud beds that cover the point-bar surface as members of the various IHS facies. The dichotomy of fluvially dominated sand deposition and brackish-water ichnology of the mud beds represents the annual migration in position of the tidal and salinity nodes caused by fluctuations in fluvial discharge. Recognition of metre-scale cycles (MSCs) of alternating sandier and muddier intervals within the IHS facies imply that decadal climate cycles, likely caused by fluctuations in ocean and/or solar dynamics, influenced point-bar deposition. These MSC packages are defined by an upward decrease in sand-bed thickness, an upward increase in mud-bed frequency, and an upward increase in bioturbation intensity, all occurring on a metre scale. MSCs are an important architectural element of these large-scale tidal-fluvial point bars because they are predictable, repeatable and continuous around the point bar. Analysis of paleocurrents relative to inclined-heterolithic-stratification bedding planes indicates that bend-flow modifications (BFMs) were effective in redistributing flow around the point bar. Furthermore, this suggests that Outcrop 3 is representative of an upstream-to-bend-apex transition within a large-scale point-bar planform. Recognition of multiple channels at Outcrop 4 was based on large-scale erosional truncation, IHS bed-orientation changes, large cumulative thicknesses of the middle McMurray, thick sand-package thicknesses, changes in relative scale of sedimentary structures, and the occurrence of large mud clasts. Similarities in depositional expression between channels suggest autogenic channel stacking (within-valley stacking), rather than the stacking of separate valleys. Finally, discordant paleocurrents within the basal sand-dominated facies are likely representative of amalgamated channel-bottom facies from several generations of channel. This suggests that only the upper intervals of basal sand-dominated facies are genetically linked to the overlying IHS facies.","abstract_html":"Within the middle McMurray exposures along the Steepbank River (Steepbank River Outcrops 3 and 4), nine recognized facies can be divided into three genetically related groups: sand-dominated facies, inclined heterolithic stratification (IHS) facies and mixed heterolithic facies. Together, these facies are interpreted to represent a fluvially dominated, tidally influenced point bar that experienced strong seasonal variation in river discharge. Annual fluctuations between river-flood stage and low-flow stage are responsible for the deposition of fluvially dominated sand beds alternating with brackish, tidally influenced mud beds that cover the point-bar surface as members of the various IHS facies. The dichotomy of fluvially dominated sand deposition and brackish-water ichnology of the mud beds represents the annual migration in position of the tidal and salinity nodes caused by fluctuations in fluvial discharge. Recognition of metre-scale cycles (MSCs) of alternating sandier and muddier intervals within the IHS facies imply that decadal climate cycles, likely caused by fluctuations in ocean and/or solar dynamics, influenced point-bar deposition. These MSC packages are defined by an upward decrease in sand-bed thickness, an upward increase in mud-bed frequency, and an upward increase in bioturbation intensity, all occurring on a metre scale. MSCs are an important architectural element of these large-scale tidal-fluvial point bars because they are predictable, repeatable and continuous around the point bar. Analysis of paleocurrents relative to inclined-heterolithic-stratification bedding planes indicates that bend-flow modifications (BFMs) were effective in redistributing flow around the point bar. Furthermore, this suggests that Outcrop 3 is representative of an upstream-to-bend-apex transition within a large-scale point-bar planform. Recognition of multiple channels at Outcrop 4 was based on large-scale erosional truncation, IHS bed-orientation changes, large cumulative thicknesses of the middle McMurray, thick sand-package thicknesses, changes in relative scale of sedimentary structures, and the occurrence of large mud clasts. Similarities in depositional expression between channels suggest autogenic channel stacking (within-valley stacking), rather than the stacking of separate valleys. Finally, discordant paleocurrents within the basal sand-dominated facies are likely representative of amalgamated channel-bottom facies from several generations of channel. This suggests that only the upper intervals of basal sand-dominated facies are genetically linked to the overlying IHS facies.","abstract_has_math":false,"creators":["Jablonski, Bryce Vincent John"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Geological Sciences and Geological Engineering","school":null,"contributors":[],"advisors":["Dalrymple, Robert W."],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-01-30","date_published":"2012-01-30","updated_at":"2026-07-27T20:35:35Z","subjects":["Oils Sands","Point Bars","Fluvial-Marine Transition Zone","Process Sedimentology"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1974/6985","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.department","label":"Department","values":["Geological Sciences and Geological Engineering"]},{"key":"dc:contributor.supervisor","label":"Supervisor","values":["Dalrymple, Robert W."]},{"key":"dc:creator","label":"Author","values":["Jablonski, Bryce Vincent John"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-01-30 13:25:32.53"]},{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2012-01-30T22:29:44Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2012-01-30T22:29:44Z"]},{"key":"dc:date.issued","label":"Date","values":["2012-01-30"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Oils Sands","Point Bars","Fluvial-Marine Transition Zone","Process Sedimentology"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1974/6985"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-01-30 13:25:32.53"]},{"key":"dc:description.abstract","label":"Abstract","values":["Within the middle McMurray exposures along the Steepbank River (Steepbank River Outcrops 3 and 4), nine recognized facies can be divided into three genetically related groups: sand-dominated facies, inclined heterolithic stratification (IHS) facies and mixed heterolithic facies. Together, these facies are interpreted to represent a fluvially dominated, tidally influenced point bar that experienced strong seasonal variation in river discharge. Annual fluctuations between river-flood stage and low-flow stage are responsible for the deposition of fluvially dominated sand beds alternating with brackish, tidally influenced mud beds that cover the point-bar surface as members of the various IHS facies. The dichotomy of fluvially dominated sand deposition and brackish-water ichnology of the mud beds represents the annual migration in position of the tidal and salinity nodes caused by fluctuations in fluvial discharge. Recognition of metre-scale cycles (MSCs) of alternating sandier and muddier intervals within the IHS facies imply that decadal climate cycles, likely caused by fluctuations in ocean and/or solar dynamics, influenced point-bar deposition. These MSC packages are defined by an upward decrease in sand-bed thickness, an upward increase in mud-bed frequency, and an upward increase in bioturbation intensity, all occurring on a metre scale. MSCs are an important architectural element of these large-scale tidal-fluvial point bars because they are predictable, repeatable and continuous around the point bar. Analysis of paleocurrents relative to inclined-heterolithic-stratification bedding planes indicates that bend-flow modifications (BFMs) were effective in redistributing flow around the point bar. Furthermore, this suggests that Outcrop 3 is representative of an upstream-to-bend-apex transition within a large-scale point-bar planform. Recognition of multiple channels at Outcrop 4 was based on large-scale erosional truncation, IHS bed-orientation changes, large cumulative thicknesses of the middle McMurray, thick sand-package thicknesses, changes in relative scale of sedimentary structures, and the occurrence of large mud clasts. Similarities in depositional expression between channels suggest autogenic channel stacking (within-valley stacking), rather than the stacking of separate valleys. Finally, discordant paleocurrents within the basal sand-dominated facies are likely representative of amalgamated channel-bottom facies from several generations of channel. This suggests that only the upper intervals of basal sand-dominated facies are genetically linked to the overlying IHS facies."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["M.A.Sc."]},{"key":"dc:title","label":"Title","values":["Process Sedimentology and Three-Dimensional Facies Architecture of a Fluvially Dominated, Tidally Influenced Point Bar: Middle McMurray Formation, Lower Steepbank River Area, Northeastern Alberta, Canada"]}]}],"canonical_facts":{"dc:contributor.department":["Geological Sciences and Geological Engineering"],"dc:contributor.supervisor":["Dalrymple, Robert W."],"dc:creator":["Jablonski, Bryce Vincent John"],"dc:date":["2012-01-30 13:25:32.53"],"dc:date.accessioned":["2012-01-30T22:29:44Z"],"dc:date.available":["2012-01-30T22:29:44Z"],"dc:date.issued":["2012-01-30"],"dc:description":["Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-01-30 13:25:32.53"],"dc:description.abstract":["Within the middle McMurray exposures along the Steepbank River (Steepbank River Outcrops 3 and 4), nine recognized facies can be divided into three genetically related groups: sand-dominated facies, inclined heterolithic stratification (IHS) facies and mixed heterolithic facies. Together, these facies are interpreted to represent a fluvially dominated, tidally influenced point bar that experienced strong seasonal variation in river discharge. Annual fluctuations between river-flood stage and low-flow stage are responsible for the deposition of fluvially dominated sand beds alternating with brackish, tidally influenced mud beds that cover the point-bar surface as members of the various IHS facies. The dichotomy of fluvially dominated sand deposition and brackish-water ichnology of the mud beds represents the annual migration in position of the tidal and salinity nodes caused by fluctuations in fluvial discharge. Recognition of metre-scale cycles (MSCs) of alternating sandier and muddier intervals within the IHS facies imply that decadal climate cycles, likely caused by fluctuations in ocean and/or solar dynamics, influenced point-bar deposition. These MSC packages are defined by an upward decrease in sand-bed thickness, an upward increase in mud-bed frequency, and an upward increase in bioturbation intensity, all occurring on a metre scale. MSCs are an important architectural element of these large-scale tidal-fluvial point bars because they are predictable, repeatable and continuous around the point bar. Analysis of paleocurrents relative to inclined-heterolithic-stratification bedding planes indicates that bend-flow modifications (BFMs) were effective in redistributing flow around the point bar. Furthermore, this suggests that Outcrop 3 is representative of an upstream-to-bend-apex transition within a large-scale point-bar planform. Recognition of multiple channels at Outcrop 4 was based on large-scale erosional truncation, IHS bed-orientation changes, large cumulative thicknesses of the middle McMurray, thick sand-package thicknesses, changes in relative scale of sedimentary structures, and the occurrence of large mud clasts. Similarities in depositional expression between channels suggest autogenic channel stacking (within-valley stacking), rather than the stacking of separate valleys. Finally, discordant paleocurrents within the basal sand-dominated facies are likely representative of amalgamated channel-bottom facies from several generations of channel. This suggests that only the upper intervals of basal sand-dominated facies are genetically linked to the overlying IHS facies."],"dc:description.degree":["M.A.Sc."],"dc:identifier.uri":["http://hdl.handle.net/1974/6985"],"dc:language.iso":["eng"],"dc:subject":["Oils Sands","Point Bars","Fluvial-Marine Transition Zone","Process Sedimentology"],"dc:title":["Process Sedimentology and Three-Dimensional Facies Architecture of a Fluvially Dominated, Tidally Influenced Point Bar: Middle McMurray Formation, Lower Steepbank River Area, Northeastern Alberta, Canada"],"dc:type":["thesis"]},"updated_at":"2026-07-27T20:35:35Z"}