Ross Brandolino, “Physical Modeling of Glaciomarine and Glaciolacustrine Settings: Ice Scour and Dropstone Soft-Sediment Deformation”
Mentor: John Isbell, Geosciences
Poster #204

Glaciolacustrine and glaciomarine depositional settings have been thoroughly examined through studies utilizing mathematical modelling and samples from field sites. Missing from these studies, however, is exploration of the physical dynamics of deposition and deformation from dropstones and keels. Therefore, it is necessary to physically model these settings on a small and reproducible scale to aid in the understanding of the formation and features associated with ice scouring and dropstones in subaqueous glacial settings. These settings were reproduced in the lab by utilizing tanks filled with water and various substrates, including sand and simulated laminations of silt and clay commonly found glaciolacustrine settings. Dropstones were measured and dropped into the substrates; deformation of the laminations for each test were recorded. For ice scours, icebergs of various sizes were created with ice blocks and shaped with chisels, before setting them into the tanks and inducing an undercurrent to drive the icebergs through the sediment. The icebergs were allowed to move freely and the resultant structures from interactions with the basal surface were recorded. By reproducing these phenomena on a smaller scale, we hope to see similar structures found on larger-scale field sites and in mathematical models. Preliminary results show good progress that will be built upon in the coming weeks; large scale features associated with ice scouring have faithfully been reproduced in the experimental setting. Further models will aim to explore different substrates in an attempt to verify if small-scale structures can be reproduced in the lab. The study of soft-sediment deformation from dropstones is as of yet still inconclusive, however we expect to produce tangible data in the coming weeks. This data will be useful to geologists as a way to further our understanding of subaqueous glacial dynamics, aiding us in the identification of the features studied.