Physical Sciences and Mathematics Commons^™

Cycles Or Repetitions: A Quantitative Analysis Of Alluvial Bed Thicknesses, Kristopher D. Phillips

WWU Graduate School Collection

Sedimentary strata display a range of repetitive patterns from interbedded lithofacies through recurring sequence stratigraphic systems tracts. Highly structured, large-scale patterns are commonly ascribed to cyclic allogenic forcings such as eustasy and climate. In contrast, autogenic processes are typically thought to impart stochastic noise or limited small-scale structure on stratigraphy. Recent studies indicate some autogenic processes in fluvial and fluvio-deltaic systems such as the large-scale compensational deposition (i.e., the tendency for a channel to occupy and fill topographic lows in a basin), can occur on spatiotemporal scales that may overlap with some allogenic forcings. These autogenic processes could impart deterministic, …

Evaluating Thresholds In Fluvial Response To The Eocene Thermal Maximum 2 In The Bighorn Basin (Wyoming, U.S.A), Grace Marie Sutherland

WWU Graduate School Collection

Earth's climate experienced a set of hyperthermal events during the greenhouse climate state of the early Paleogene. The Paleocene-Eocene Thermal Maximum (PETM) was the largest of these abrupt global warming events, occurring at ~56 Ma and lasting for ~200,000 years. The PETM is identifiable by a large negative carbon isotope excursion and associated with significant changes in global temperature, hydrology, ocean chemistry, and biology. Subsequent smaller hyperthermal events appear to have commensurately smaller effects on marine environments, but the scaling of the complementary nonmarine environmental responses is unclear.

The Bighorn Basin of northwest Wyoming contains the most detailed nonmarine record …

Auto-Stratigraphic Evolution Of Experimental Crater-Fill Basins: Implications For Interpreting Mars Sequence Stratigraphy And Paleoclimate, Lexie Stodden

WWU Graduate School Collection

Preserved fluvial and deltaic sedimentary deposits found within martian crater-fill basins are important evidence documenting past warmer, wetter climatic periods on Mars. The morphologic and stratigraphic patterns of these sedimentary deposits are commonly interpreted to record variably complex transgression and regression histories of crater-lake levels, driven by fluctuations in the prevailing hydroclimatic conditions. Yet this tendency for direct inversion of sedimentary characteristics to formative boundary conditions largely neglects large-scale autogenic processes operating in crater-fill basins. The goal of this research is to illustrate an idiosyncratic feature of these basin types, wherein attributes of the sediment source play an outsized role …