Architecture and Evolution of A Regressive, Tide-Influenced Marginal Marine Succession, Drumheller, Alberta, Canada

Abstract

Tide-dominated and tide-influenced clastic depositional environments are typically interpreted to be associated with landward-stepping or transgressive systems. Here, we present an example of an overall regressive succession dominated by high-frequency sequences that exhibit abundant sedimentary and ichnological evidence of tidal processes. These strata comprise the Campanian Bearpaw-Horseshoe Canyon Formation transition exposed near Drumheller, Alberta, Canada. The clastic marine to marginal-marine sediments were deposited in mixed-process (wave-, tide-, and fluvial-influenced) depositional environments along the western margin of a foreland basin. The deposits are subdivided into six relatively thin (10 m on average), high-frequency (, 140,000 years), transgressive-regressive (T-R) sequences (A to F).Outcrop sedimentary logs and hand-held gamma-ray profiles were correlated to subsurface data (4 cored wells and 75 wells with wireline logs) within an area of 22 km 3 16 km in order to generate a 3D geocellular computer model. This model along with paleocurrent data from outcrop were used to analyze the stratigraphic architecture and evolution of the succession.The evolution of the successive T-R sequences was mapped on a subregional scale using the 3D geocellular model. The orientations of the paleoshorelines rotate in a predictable manner during transgression and regression. Transgressive shorelines are oriented approximately S-N and rotate clockwise during regression to approximately SW-NE. The rotations are attributed to the paleogeography of the region, with the study area interpreted to sit on the western flank of a large structurally controlled embayment.The progradational high-frequency sequence set is dominated by tide-influenced strata and clearly demonstrates that tidal deposits can be preserved in both regressive as well as transgressive successions. Tidal influence in this regressive setting is attributed to shallow water depths on a wide shelf, which resulted in amplification of the tidal wave as it moved across the shelf. The embayed character of the coastline may also have augmented this effect. Tidal range is estimated to have been mesotidal to macrotidal. A modern partial analogue for the Horseshoe Canyon systems is identified from the tropical Mitchell River Delta in the Gulf of Carpentaria, Queensland, Australia. This delta system is analogous in terms of its tideinfluenced facies, mesotidal range, low-gradient shelf with accompanying shallow water depths, the mixed-process character of its shoreline systems, and its horizontal to falling shoreline trajectory.

Controls on tidal sedimentation and preservation: Insights from numerical tidal modelling in the Late Oligocene–Miocene South China Sea, Southeast Asia

“…For example, current‐rippled heterolithics may indicate fluvial, tidal or mixed fluvial–tidal deposition (Gugliotta et al ., ; Collins et al ., ) and mud and/or carbonaceous drapes are only conclusive tidal indicators if statistical analysis proves an ordered cyclicity of layer thickness and grain size at tidal frequencies (Kvale, ). Predicting palaeotidal range from vertical facies successions is compromised by assumptions regarding the preservational completeness of interpreted foreshore and intertidal deposits (Vakarelov et al ., ; Ainsworth et al ., ). Similar preservation problems also affect the interpretation of ancient, regional‐scale and local‐scale geomorphology based on predominantly one‐dimensional (for example, stratigraphic logs) and more‐limited two‐dimensional (for example exposure panels) stratigraphic data (Ainsworth et al ., ), and comparison with modern analogues (Wells et al ., ).…”

“…Olariu et al ., ); (iii) along various types of coastline adjacent to wide (>75 km) shelves (e.g. Ainsworth et al ., ); and (iv) shoreline–shelf embayments in association with wide shelves (or seaways) (e.g. Steel et al ., ; Chen et al ., ).…”

Recognition criteria, characteristics and implications of the fluvial to marine transition zone in ancient deltaic deposits (Lajas Formation, Argentina)

“…Following an increase in understanding of facies along the FMTZ (van den Berg et al, 2007;Dalrymple & Choi, 2007;Martinius & Gowland, 2011), the establishment of detailed recognition criteria (Pont en & Plink-Bj€ orklund, 2007;T€ anavsuu-Milkeviciene & Plink-Bj€ orklund, 2009) and refined classification schemes for deltas and other coastal systems (Ainsworth et al, 2011;Vakarelov & Ainsworth, 2013), several other regressive successions with evidence of tidal process have been interpreted in large part as fluvial-dominated, tide-influenced rather than tide-dominated. These include the Middle Devonian Gauja Formation, in the Baltic Basin (Pont en & Plink-Bj€ orklund, 2007), the Jurassic Tilje Formation of the Norwegian shelf (Ichaso & Dalrymple, 2009, 2014, the Upper Cretaceous Dorotea Formation, Magallanes-Austral Basin, Patagonia (Schwartz & Graham, 2015), the Neslen Formation of Utah (Shiers et al, 2014), the Schrader Bluff-Prince Creek formations, Alaska, USA (van der Kolk et al, 2015), and the Campanian Horseshoe Canyon Formation, Alberta, Canada (Ainsworth et al, 2015).…”

Evolution of an ancient (Lower Cretaceous) marginal‐marine system from tide‐dominated to wave‐dominated deposition, McMurray Formation

“…There are a significant number of published examples showcasing variation in depositional architectures based on the relative dominance of wave, tides and fluvial processes (Bhattacharya & Giosan, ; Fielding et al ., 2006a; Dalrymple et al ., ; Nanson et al ., ; La Croix & Dashtgard, ). However, ancient examples demonstrating changes in process dominance are significantly less common (Ainsworth et al ., , ) and evolution of systems from tide to wave‐dominance is rarely reported (Buatois et al ., ; Barton, ).…”