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theses

The Jeanne d’Arc rift basin formed during the breakup of Pangea from Late Triassic through Early Cretaceous time. My study focuses on the Flying Foam region, which lies east of the NNE-striking, ESE-dipping Mercury fault in the northwestern section of the basin. Multiple phases of deformation, along with the presence of evaporites within the latest Triassic to earliest Jurassic Argo Formation, make it difficult to constrain the timing of tectonic activity and the extension direction in the basin. Using 3D seismic data (donated by WesternGeco). I focused on constraining the slip on faults through time to better understand the evolution of the basin. Previous 3D seismic studies have identified corrugations subparallel to the slip direction on the surface of a fault. I identified corrugations on the Mercury fault that indicate an ESE-movement direction during the first phase of rifting from the Late Triassic to the earliest Jurassic. During the second phase of rifting (earliest Jurassic – latest Jurassic), a relay ramp formed in the southern part of the study area, between the basement-involved Mercury and Murre faults, resulting in a northeastward tilt of strata in the hanging wall of the Mercury fault. During the third phase of rifting (latest Jurassic – Early Cretaceous), evaporites within the Argo formation acted as a detachment fault zone. N-directed gravity sliding along the detachment fault zone tilt resulted in NE-oriented extension. Concurrently, the N-striking, basement-involved Flying Foam fault imparted a component of top-to-the east motion on the detachment fault zone. This resulted in geographic and temporal variation in the movement direction on the detachment fault zone from the latest Jurassic through the Early Cretaceous. As the Flying Foam fault propagated southward, the Flying Foam anticline formed above it. Breakup in the northern part of the Jeanne d’Arc basin occurred in the earliest Aptian. However basement-involved faulting with a dip-slip normal component continued through the Aptian, and offset of a late Albian unconformity indicates that NNE-directed detached faulting continued into the Albian.

ETD_7018

M.S.

Includes bibliographical references

by Natalie Elizabeth Stier

doi:10.7282/T3959KM4

ETD graduate

The author owns the copyright to this work.