This project explores grain-scale signatures of subglacial sediment transport and subglacial hydrologic processes using grain shape and microtexture. We compare grain-shape distributions for grains from meltwater plume deposits to those of subglacial till and ice-proximal diamicton from the same glacial setting. The study incorporates samples from marine sediment cores collected offshore of Ryder Glacier in northwest Greenland, in the central Barents Sea, and Antarctic samples from Marguerite Bay, offshore Thwaites and Pine Island glaciers, and in the western Ross Sea. This dataset contains a MATLAB script used to process grain images and calculate individual grain-shape metrics (including circularity, solidity, and eccentricity), and an Excel spreadsheet containing the grain-shape measurements. Grain images were collected in 2022-23 using a Bettersizer S3 Plus particle size and shape analyzer at the University of Virginia.

File descriptions: The excel file GrainShapeMetrics.xlsx contains the values of grain-shape measurements with each study region in a different tab, with the first tab called READ_ME providing details of the metrics, units, references to documentation, and explanations of each column header. The MATLAB script, GrainShapeAnalysis_Binarized.mlx, which is used to process grain images, convert images to binary, and calculate the measurements presented in the Excel file is also included. Sample metadata is available in the Excel file Events_Metadata.xlsx.