Push Moraine Deformation - Experimental and Field Studies

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Push Moraine Deformation - Experimental and Field StudiesGEOLOGY & PALEONTOLOGY PROGRAMEAR-0229985SUNY Stony BrookDaniel M. DavisABSTRACT This project is directed toward the study of deformation in Pleistocene push moraines, using a combination of laboratory analog modeling and structural field mapping. The experimental component of the project is designed to explore how the distribution and style of deformation in sediment pushed by a glacier depends upon the kinematics of the push and the composition and frozen or unfrozen state of the deforming sediment. The goal is to use quantitatively analyzed lab models in order to understand better the great variety of folds, faults, and associated structures that are widely observed in push moraines. The field component of the project is directed towards applying to the push moraines of Long Island two techniques potentially capable of shedding light on deformation of the kind being modeled in the lab component of this project. Measurements of clast fabric axes in various parts of the lobate Harbor Hill Moraine allow comparison with the resultsof lab models, testing the idea that clast orientations record the distribution of strain in the moraine. Ground Penetrating Radar (GPR) is ideally suited to porous sediments, but has not been extensively applied to push moraine deformation. Imaging of buried structures using GPR offers the possibility of mapping otherwise unobservable folds and faults. Incombination with the results of lab modeling, these field investigations are intended to advance the application of structural and tectonic techniques to understanding the development of glacial push moraines.