Who carved those scratches into the bedrock? Was it THAT rock, carried by the glacier? You may be forgiven for thinking so; after all, that was the photographer’s initial opinion and he has a master’s degree in glacial geology! Glaciers carry rock fragments in two locations: at the bottom of the glacier and on top of the glacier. Rocks at the bottom scratch the bedrock and in turn are scratched by it; thus they have their sides sanded down to quite smooth surfaces. Rocks on top of the glacier are broken into sharp-edged fragments by water alternately freezing and thawing within their cracks. This boulder has many sharp-edged sides and no smooth surfaces; hence it was carried upon the glacier and rocks carried that way cannot scratch the underlying bedrock. Despite initial appearances, this rock is innocent! Photographer: Richard Becker