Master of Science / Department of Geology / Allen W. Archer / Abstract This study compares the tidally influenced facies found within the Tonganoxie Sandstone Member (Stranger Formation, Douglas Group) (Upper Pennsylvanian) of northeastern Kansas with similar facies directly observed in the upper intertidal mudflats of Turnagain Arm of Cook Inlet (Alaska, USA). The two settings contain strikingly similar facies that are characteristic of upper macrotidal estuaries with a strong influence of tidal activities. Identical aspects and features found within both settings include rhythmic vertical variation in stratum thicknesses (cyclic tidal rhythmites), high estimated sedimentation and aggradation rates, and biogenic and physical sedimentary structures (e.g., drag marks, raindrop impressions, arthropod traces and tetrapod trackways, zigzag burrows, runoff washouts, and upright trees, among others). Tidal rhythmites are the most important evidence that is indicative of the tidal influence on the depositional processes of these two study areas. Such cyclic tidal rhythmites have been reported and described from several Carboniferous settings in the eastern USA. Modern analogs to these Carboniferous rhythmites are usually found within upper macrotidal estuarine depositional environments, especially within fluvio-estuarine transitional zones. These environments are distributed over a wide range of modern latitudes. Using cyclic tidal rhythmites as modern analogs for interpreting similar ancient facies is a powerful tool for paleogeographic and paleoenvironmental reconstructions, although it is somewhat a new approach.

Northeastern British Columbia was occupied by the Cordilleran (CIS) and the Laurentide (LIS) ice sheets, however, the timing and extent remains contentious. The late Quaternary and Holocene history of this area is examined by exploring geomorphic, stratigraphic, geochemical and geochronologic components of glacial, deglacial, paraglacial and non-glacial landsystems. New tools, such as GIS, LiDAR, and new geochronologic methods, such as optical dating are used to understand the Quaternary geology and geomorphology of the region. Bedrock topography represents the base of the Quaternary section and modelling shows that paleovalleys, common in this region, host extensive Neogene sedimentary records. Stratigraphies from the Murray and Pine valleys indicate glaciation prior to the Mid-Wisconsinan (MIS 3) and during the Late Wiconsinan (MIS 2). Glacial landforms record Late Wisconsinan ice-sheet coalescence and reflect the complex interaction of the LIS and CIS margins. During deglaciation, the LIS and CIS separated and glacial Lake Peace (GLP) formed. Shoreline features enable reconstruction of lake and ice configurations. Four phases of GLP are preserved. Optical ages from Phase II indicate GLP occupied the area some time between ca. 16 – 14 ka yrs ago. The apparent tilt on the shorelines provides a measure of isostatic adjustments and suggests asynchronous retreat of first the LIS, then the CIS. The transition from paraglacial to boreal conditions was driven by climate change and is recorded by vegetation sucession and cessation of paraglacial processes. Optical ages from stabilized dunes and radiocarbon ages from organics date the transition between 12 – 11.5 ka yrs ago with full boreal conditions established by 10 ka yrs ago. The Holocene is dominated by erosional processes, however some systems are aggrading. A case study on a floodplain demonstrates that resistivity (Ohmmapper) surveys provide a grain-size proxy to suppliant GPR studies, which is essential for geophysical fluvial architectural analysis. In the study, the discrepancy between planform style (classic meander model) and subsurface geophysical surveys (indicative of vertical accretion associated with braided and wandering fluvial styles) reiterates cautions that planform may not always be a functions of depositional process and one may not be used to predict the other. / Graduate / 0372 / 0373 / 0368