The sedimentological and ichnological characteristics of inclined heterolithic stratification (IHS) of modern and ancient fluvio-tidal systems

Abstract

Modern and ancient fluvio-tidal sedimentary successions are studied in order to enhance understanding of sedimentological, ichnological, and, if possible, stratigraphic relations in the rock record. Modern sedimentary environments investigated include the inner estuary to fluvial reach (inclusive of the fluvio-tidal transition zone) of the mud-dominated, macrotidal Petitcodiac River estuary, New Brunswick, Canada, and the sand-dominated, micro- to mesotidal Ogeechee River estuary, Georgia, USA. The ancient paleoestuarine environment, namely, the early Cretaceous middle McMurray Formation, Alberta, Canada, has been examined by applying process ichnological framework in order to refine the paleogeographic interpretations and distinguish between the tidally influenced fluvial and tidally influenced estuarine settings. The macrotidal Petitcodiac River estuary has also been used as a laboratory to test the significance of flocculation as a crucial process in the rapid removal of large amounts of sediments from suspension. Mud floccule ripples poorly known from the rock record and barely documented in the modern sedimentary environments, are reported from the intertidal flats of the upper Petitcodiac River estuary. The presented floccule ripples are current-generated, non-episodic in nature, are characterized by morphometric and grain-size data, and constrained by the observed physical processes. Moreover, this thesis explores the advantages of using the high-resolution SWIR hyperspectral imagery to enhance the visibility of physical and biological sedimentary structures, especially within coarse-grained, bitumen-saturated sediments. One well within the middle McMurray Formation (Kearl Oil Sands area) has been analyzed to ascertain the usefulness of this technique, make new observations, support previously made environmental interpretations, and, in some cases, change the paleoenvironmental interpretations. Finally, a new removable-cap suction corer, developed within the course of this thesis work, that is inexpensive to construct, light in weight, highly portable, and designed to extract any core diameter, is presented.