AN ANALYSIS OF FOLDED STRUCTURES IN GLACIAL KETTLES

Kettles are cup, funnel, or irregular shaped cavities found in the land surface that result from the deposition, burial, and meltout of ice blocks lodged within glacial drift (Whittlesey, 1860). Studying glacial kettles may enhance understanding of unconsolidated sediment response to deformation. A physical model was created to simulate monoclinic folding associated with the ice wasting process. Measurements of planar and three-dimensional geometry, orientation, and wave properties were made to characterize the folds. The presence of faulting was also noted. These measurements were compared to Trishear3D model output for determination of program effectiveness in characterizing kettles. Fold analysis is summarized in tables, graphs, and function sets. Analysis indicates fold geometry, interlimb angle, and axial tilt are a function of depth below land surface and vary with vertical displacement of the sediment overlying the ice block. Trishear3D accurately simulated the general pattern of folding; however it poorly represented primary and secondary faulting. Further analysis is needed to characterize faulting patterns in the physical model.