Sequence stratigraphy and facies architecture of fluvio-deltaic depositional systems

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The proposed research program is focused on investigating the sequence stratigraphy and 3D facies architecture of shallow marine, paralic, and fluvial depositional systems. The primary focus is on Cretaceous sedimentary sequences in the Western Interior Seaway of North America. Detailed field and subsurface studies are designed to answer questions about the larger-scale stratigraphic controls on sedimentary basin fills (e.g. eustasy versus tectonics), and equally important questions relating to the formative processes of smaller-scale sedimentary units (e.g. bedforms and bars). **High-resolution outcrop and subsurface stratigraphic analysis, integrated with chronometric and biostratigraphic control, enable the elucidation of the nature and degree of cyclicity in a global Greenhouse. There is evidence of climate-driven Milankovitch-scale cyclicity, suggesting that the Cretaceous was not an ice-free time, as has been hypothesized by some. Comparison of time-stratigraphic analysis within multiple sedimentary basins, including largely completed studies in Utah, Wyoming, and Alberta, with newly proposed analysis of intervening basins in New Mexico, Montana, and the NWT, can help unravel the relative control of tectonic versus eustatic processes, which remains an area of controversy. The research is also focused in quantifying source-to-sink relationships, and in particular using information from the depositional system (especially provenance and paleodischarge studies of the fossilized trunk rivers) to make inferences about paleo-drainage basin size and relief, connectivity of drainage systems within mountain belts, paleoclimate, and plate-tectonic reconstructions.**At the smaller-scale, the research is focused on elucidating the fundamental architectural elements and event-processes that build the sedimentary record of deltaic and shelf sedimentary systems. Facies architectural element analysis is now quite mature in the examination of aeolian, fluvial, and deep-water sedimentary systems, but is not as well documented for paralic and shallow-marine systems. Recent results from my research program have demonstrated that many of the mouth-bars, described in previous studies, are actually composite features. We have discovered the fundamental "unit" bars that scale to the formative physical processes of decelerating river-mouth plumes. This work, however, is preliminary and requires other examples as well as integration with fluid-flow modeling, numerical modeling, and integration with studies of modern systems to present a synthesis of the physical processes and time scales over which deltaic shorelines grow and decay. This is significant, not only for predicting how coastlines evolve in the face of global change, but the 3D stratigraphic organization of sediment bodies is also of fundamental importance to the characterization and modeling of analog reservoirs, such as are common in oil and gas deposits both in Canada and globally.