| For most of his life, he worked on preglacial river valleys in Ontario, and the origin and extent of proglacial precursors of the Great Lakes. |
| In the former case the present drainage is through valleys which are preglacial in some places, and postglacial in others. |
| These all originated in preglacial valleys, the two reaches forming part of a system of parallel northeast-southwest valleys. |
| Here and there upon its surface will be found remnants of the deep red residual clays, the subsoils of preglacial times. |
| The stream has not yet reached its preglacial profile, but it has almost reached it. |
| This fact seems to be sufficient to prove the theory of a higher elevation of the North American continent in preglacial times. |
