"Rocks are clocks" - the great geomorphologist, William C. Putnam
While radio carbon-dating gives astoundingly accurate dates, it really only reaches back 60,000 years ago. So for triangulating the origins of life, geology supplies a beautiful background context to orienting the branching of life on the planet. This unique approach gives a primitive look at different strains of life reaching back to the Proterozoic era, and compares "major physical changes in earth's surface", "major changes in biological populations", and the "probable climatic changes" of numerous eras. Condition is very good. Overall size is approximately 36.25 x 30.
