Noneustatic controls on sediment accumulation in the upper Cretaceous of western Colorado and Pliocene to Holocene of offshore Louisiana

The Book Cliffs of eastern Utah and western Colorado and the Gulf of Mexico have been pivotal in the development of sequence stratigraphic concepts in nearshore marine and deep-water depositional settings, respectively. An idea that has been generally accepted for more than 30 years is that lithology, facies, stratigraphic architecture and sedimentary cyclicity in general are ultimately controlled by sea-level oscillations (eustasy). According to this view, deposition takes place preferentially inboard of the shelf edge when sea level is rising or high, and in off-shelf locations when sea level is falling or low. Stratigraphic discontinuities are thought to develop as a result of condensation in deep water in the first case, and through bypassing and erosion in nonmarine and shallow marine settings in the second. This dissertation makes use of outcrop, well log, photographic and biostratigraphic data from the Book Cliffs, and two- and three-dimensional seismic reflection and biostratigraphic data from the Gulf of Mexico to evaluate the role of non-eustatic mechanisms in modulating sedimentation.;Chapter 1 focuses on the Couette Sandstone Member of the Mount Garfield Formation (upper Cretaceous) in the eastern Book Cliffs of western Colorado -- sediments that accumulated in a tectonically active foreland basin during a span of geological time in which continental ice and hence glacial eustatic oscillations would have been limited. Our new data show that deposition was controlled primarily by subtle changes in tilting in three dimensions at length scales of greater than 50 km (31 mi) and timescales longer than 100 kyr rather than through interactions between eustasy and longer-term regional patterns of flexural subsidence.;Chapter 2 assesses Fuji basin, a salt-controlled intraslope minibasin in north-central Green Canyon, Gulf of Mexico. This chapter tests competing ideas concerning eustatic and steady-state bathymetric controls on deep-water deposition. We conclude that middle Pleistocene to Holocene passive salt motion was the primary control on the stratigraphic architecture of the basin, rather than either eustasy or bathymetric profiles. The basis for this conclusion concerns the emplacement directions and timing of submarine mass transport complexes.;Chapter 3 takes a broader view of the same region, encompassing both the shelf and the continental slope, and specifically evaluating the concept of reciprocal sedimentation. Our conclusions from this investigation suggest that early Pliocene to Holocene deposition was neither reciprocal nor controlled by eustatic cyclicity, and that the importance of intraslope bypass on salt-withdrawal intraslope minibasins was negligible.