English

Noun

glacial till ‎(plural glacial tills)

1. (geology) an unstructured geological deposit composed of boulders, clay, gravel, sand, and silt that is transported by glacial drift.
   • 2016 June 9, Alistair Steele, “Ottawa sinkhole struck in unstable 'rock valley' flagged by engineers”, in CBC News:

     The updated geotechnical data report submitted by Golder Associates to Capital Transit Partners, and then presented to the city, describes the valley as a natural trench in the bedrock filled with between 15 and 37 metres of loose fill, silty clay and "glacial till," or broken, weathered rock.