THIS IS A BOOK ABOUT OUR KNOWLEDGE OF EARLY MAN. THERE ARE TWO SUBPLOTS: EARLY MAN IN THE OLD WORLD AND EARLY MAN IN THE NEW WORLD.
Much is known about Early Man in the Old World, where new discoveries continue to expand our knowledge base. Unfortunately, in the New World our knowledge is largely limited to Clovis and younger cultures. The study of potential pre-Clovis sites is not encouraged, and those who report a possible pre-Clovis site do so at significant risk to their career. An important part of this book reviews what is known about an Early Man site along the shore of Valsequillo Reservoir south of Puebla in central Mexico. It is a fascinating tale with a lot of data--which are accepted by most geologists and not accepted by most archaeologists.
As a scientist I am embarrassed that it has taken over thirty years for archaeologists and geologists to revisit the bone and artifact deposits of the Valsequillo Reservoir. In the late 1960’s and early 1970’s, data were presented that suggested Early Man had been in the New World much earlier than anyone had previously thought. Rather than further investigate the discoveries, which is what should have been done, they were buried under the sands of time, in the hope that they would be forgotten. My idea of science is to investigate anomalous data and hopefully learn something new. Unfortunately, the “Clovis First” mentality was so ingrained in North American archaeology that no further work was undertaken.
My first contact with the bone and artifact deposits of the Valsequillo Reservoir came in the early 1970’s, when I was asked if I would date zircons from some tephra units (layers of volcanic pumice and ash) that overlay the artifact-bearing beds. I agreed to take on the study as I was aware of the controversy regarding the age of the site. At the time I was sharing an office with Barney Szabo, the geochemist who had provided the uranium series dates that started the controversy. His ages suggested that the artifact beds were in excess of 200,000 years old. This did not sit well with the archeologist in charge of the project. The original paper by Szabo, Malde, and Irwin-Williams (1969, Earth and Planetary Science Letters, v. 6, p. 237-244) sets the stage for the controversy--geochronology versus archaeology. This is the only paper of which I am aware where one coauthor submits a rebuttal in the midst of an otherwise straightforward scientific paper.