The Geometry and Kinematics of Detachment Folds
in the Northeastern Brooks Range

Principal Investigators: Wesley K. Wallace

Graduate students: Paul Atkinson, Margarete Jadamec

Detachment folds form as a result of shortening and displacement of a layer of strong rock, such as limestone or sandstone, above a weak layer, such as shale or salt. Wes Wallace and several of his graduate students have been studying how detachment folds vary in shape, how they evolve, and what controls their shape and evolution.

One goal of this study is to document the geometry and kinematics of detachment folds in the northeastern Brooks Range, which contains among the world's best-exposed examples of detachment folds.  A second goal is to produce a geometric and kinematic model based on the observed detachment folds.  Such a model will be useful for evaluating assumptions commonly applied in the construction of cross sections when only incomplete information is available, and will have practical applications such as the evaluation of petroleum traps and earthquake hazards.

Our studies in the northeastern Brooks Range have allowed us to define criteria for the recognition of detachment folds, which commonly are misinterpreted as other types of folds. In addition, our observations indicate that fold hinges remain fixed throughout the evolution of detachment folds, and that both the strong and weak layers in these folds vary in thickness as the folds evolve. Both of these results differ from the assumptions used in previously published models for detachment folds, leading us to develop a new model which provides a better fit to our observations.

Detachment models by P. Atkinson

Current news |Research disciplines| People|Current Research Topics|
Student Research Opportunities|Analytical Facilities| Publications | Home Page