Deformation of Poorly Consolidated Clastic Sediments of
Varying Grain Size
Personnel: A. Aydin, and P. Eichhubl
Sponsor: National Sciences Foundation, EAR-0229862-NCX
Description: This project is part of a broader attempt to understand the failure modes in granular rocks and their distribution in time and space. In this particular project, the focus is the structure and texture of deformation structures in poorly consolidated sandstones, conglomerates, and mudstones of Miocene/Pleistocene age in northern California to assess the impact of grain size and shape on the micromechanics of deformation and geometry and texture of the resulted structures.

Preliminary results indicate that the fundamental mode of deformation in poorly lithified sediments is strain localization into bands. The micromechanics of localized deformation differs in each rock type but in general involves in grain translation, reduction or increase in porosity, and grain rotation, with only minor grain size reduction.

Former personnel: Xavier de Bernard

Du Bernard, X., Eichhubl, P., and Aydin, A., 2002, Dilation Bands: A New Form of Localized Failure in Granular Media. Geophysical Res. Letters, v. 29, no. 24, p. 29-1.