Ontario Geological Survey the rock (bedrock); b) the deposits of sand, gravel, and till left by the glaciers; c) the mineral resources and potential; d) the energy resource potential within the rocks and soils; and e) the groundwater aquifers that contain groundwater resources. An understanding of what is at, and below, our feet is fundamental to human existence on the Earth, to understand the environment and habitats, and our ability to adapt to future changes, such as global warming. This geological knowledge is used to assess Earth resource potential, to attract investment, to ensure the health and safety of Ontario people from geo-hazards,
Dilatancy (granular material) Dilatancy (granular material) Dilatancy is the volume change observed in granular materials when they are subjected to shear deformations. This effect was first described scientifically by Osborne Reynolds in 1885/1886 and is also known as Reynolds dilatancy. Unlike most other solid materials, the tendency of a compacted dense granular material is to dilate (expand in volume) as it is sheared. This occurs because the grains in a compacted state are interlocking and therefore do not have the freedom to move around one another. When stressed, a lever motion occurs between neighboring grains, which produces a bulk expansion of the material.