Turning to StoneRocks are the record of our creative planet reinventing itself for four billion years. Nothing is ever lost, just transformed. Marcia Bjornerud's life as a geologist has coincided with an extraordinary period of discovery. From an insular girlhood in rural Wisconsin, she found her way to an unlikely career studying mountains in remote parts of the world. As one of few women in her field, she witnessed the shift in our understanding of the Earth, from