Date of Award

1-1-2010

Document Type

Campus Access Dissertation

Department

Earth and Ocean Sciences

Sub-Department

Geology

First Advisor

David L. Barbeau

Abstract

The links between sedimentary strata, their source regions and accommodation mechanisms enable the testing of tectonic models across a range of temporal and spatial scales. This dissertation presents three studies that interpret the stratigraphic architecture and sediment provenance records of local and regional tectonics from the eastern and southern margins of North America.

Studies 1 & 2: The subsidence and provenance history of the Appalachian foreland basin

Geohistory analysis of the central Appalachian foreland basin indicates that maximum subsidence rates during the Taconic phase were ~1.5 times faster than those of the subsequent Acadian phase. Subsidence rates during the Alleghanian phase were much slower than the preceding Taconic and Acadian phase. The decrease of subsidence rates from the oldest to the youngest orogenic event may reflect that the Appalachian lithosphere obtain its strength over time. Subsidence propagates from the proximal to the distal basin, yielding a flexural propagation velocity of 25 km per million years during the Acadian orogeny.

Whereas geohistory analysis of the Appalachian foreland basin records the evolution of the size of its associated orogen, the provenance of foreland basin sediment provides higher resolution insight into the orogen's tectonic history. The distribution of single-grain detrital-zircon ages collected from the Upper Ordovician through upper Mississippian sandstones records the sedimentary response to Taconic, Acadian and Alleghanian phases of orogenesis. This analysis suggests the Late Ordovician accretion of Dahlonega terrane, the Devonian accretion of Carolina superterrane, and a Visean onset of the Alleghanian orogeny.

Study 3: Stratigraphic response to deformation in a continental margin, Gulf of Mexico

Using a newly developed stratigraphic analysis tool -- kinematic sequence stratigraphy, this study examines the intermediate scale (100-10,000 m) architecture of strata deposited in a tectonically active continental margin basin. The kinematic sequence stratigraphy interpretive framework provides an effective means of subdividing to deltaic Miocene growth strata associated with a listric normal-fault in the northern Gulf of Mexico. This approach effectively tracks variations in sedimentation rate relative to fault slip rate, and accommodation caused by hanging wall block subsidence.

Chapter2_AppendixA1_Sample_Locations.pdf (8 kB)
Appendix A1- Sample Locations

Chapter2_AppendixA2_datasets.pdf (148 kB)
Appendix A2- Datasets

Chapter2_AppendixB.pdf (17 kB)
Appendix B

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