The physical properties of basal (lodgement) till were studied in relationship to their excavation on St. Lawrence Seaway Projects, and on Drummond Island in northern Michigan. The data reported were derived from samples of basal till developed on carbonate rocks.
Basal tills of this type are strongly consolidated and cemented, in contrast to superglacial (ablation) tills which are loose, unconsolidated, and easy to move with conventional earth-moving equipment.
Tests performed on the fine matrix of the basal till include flame photometer, X-ray diffraction, petrographic, chemical, soil mechanics, the U.S. Corps of Engineers “pick test”, staining techniques, and microscopic examination. They reveal convincing evidence of cementation of the till and increased density by consolidation.
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Prepared for the Division on Engineering Geology of the Geological Society of America, Engineering Case Histories 4 includes 7 case histories examining land subsidence, foundation treatment, tunnel engineering, grouting alluvial fill, landslides, and more.