Sedimentation in the Tide-Wave and Tide-River Transition Zones

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The interface between the land and the sea is one of the most complex areas on earth. The deposits formed here are extremely important because they host a significant fraction of the hydrocarbon reserves in Canada and the world, including the world-famous McMurray Oil Sands of northern Alberta. I propose to investigate the deposits of this crucial interface, using an approach that breaks out of the "end-member syndrome" that has characterized much of the previous work on coastal environments, to investigate the complex interactions between the three fundamental processes that control the dynamics these environments and the nature of the facies and their architectural organization within ancient sedimentary successions. Rather than focusing on tide-dominated environments as my past work has done, I propose to explore the interactions between tidal currents and waves on the one hand, and river flow on the other. These transitional zones are widespread on the present-day world, and their deposits should be equally abundant in ancient sedimentary basins, and yet they are incompletely documented because of the scarcity of models for what these deposits look like. The proposed work consists of a set of modern and ancient deposits that have been selected because they are either known or believed to illustrate the process transitions that are the focus of this study, and because they have served as important reference point for interpretations and/or are superbly exposed, thereby allowing unparalleled opportunities for the study of the 3-dimensional architecture of the deposits. Study areas where the river-tide transition will be studied are: the Rio Guayas and its tributaries, Ecuador; the Lajas Fm., Neuquén Basin, Argentina; the Neslen Fm., Utah; and as yet to be chosen deposit in the Spanish Pyrenees. This work will be supplemented by ongoing work on the McMurray Fm., Alberta. The wave-tide transition will be investigated in the Lajas Fm., Argentina; the Sego Sandstone, Utah; and the Haystack Mtns. Fm., Wyoming. This research program will significantly improve the ability to create sophisticated paleoenvironmental and paleoclimatic reconstructions, and to extract hydrocarbons more efficiently.