TitleScaled experimental models of gravitational collapse
NamePoorvin, Emily Rose (author), Schlishe, Roy W (chair), Withjack, Martha O (internal member), Ashley, Gail M (internal member), Rutgers University, Graduate School - New Brunswick,
DescriptionThis thesis presents the results of scaled experimental models of gravitational collapse, the non-catastrophic failure of an oversteepened cliff. The main modeling material is wet clay, which simulates typical lithified, upper-crustal rocks; the nature-to-model scaling factor for size is ~105. Silicone polymer in one model simulates a highly ductile layer (e.g., salt). In all models, scarp creation involves gradual downcutting along a vertical surface. In the standard model (6 cm of clay with a density of 1.60 g/cm3), faults lengthen and link to form a main normal fault that dips towards and strikes parallel to the erosional scarp; the zone of deformation is narrow. Cross sections of the standard model show that the main fault is listric, most minor faults are listric and dip toward the erosional scarp, shallow layers dip toward the scarp whereas deep layers dip away from the scarp, and the base of the scarp bows out. Fault-heave analyses show that differential iii extension (increasing with depth and with proximity to the erosional scarp) accounts for these features. Geometric models of listric faults do not incorporate differential extension, and thus do not predict the layer geometries observed in the standard model. Models with stronger (denser) clay require taller scarp heights to initiate gravitational collapse. In the model with silicone polymer, deformation (conjugate faults and grabens) is distributed over a larger area compared to the standard model. Faults that form during scarp retreat (lateral removal of clay) evolve similarly to faults formed during scarp creation. A preliminary model with a curved erosional scarp yields a deformation zone that closely parallels the scarp. The Statfjord field (Norway), the Sirikit field (Thailand), and the Fairy Dell sea cliffs (Dorset, England) share some similarities with the standard model: listric faults that strike parallel to and dip towards the erosional scarp and layers rotated away from the erosional scarp; however, they do not have layers rotated toward the erosional scarp. Deformation in Canyonlands National Park is similar to that in the model with silicone polymer: conjugate faults and grabens are related to flow of a ductile unit toward the erosional scarp.
Noteincludes bibliographical references
Noteby Emily Rose Poorvin
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.