ABSTRACT

We review the history of investigations at the Valsequillo archaeological area south of Puebla, Mexico, from the early 1960s to 2010. Evidence from diatoms, (U-Th)/He measurements, early uranium-series dates, later zircon fission-track dates, mineral weathering, tephra hydration dates, and vertebrate fossils imply that the principal archaeological site, Hueyatlaco, could be older than 250,000 years. Hueyatlaco rests unconformably on Xalnene Tuff (basaltic ash) dated at 1.3 Ma by whole-rock argon-argon analysis. This finding differs greatly from a recent interpretation that the site is 40,000 years old.

Harold E. Malde. (Deceased November 4, 2007.)
Virginia Steen-McIntyre. P.O. Box 1167, Idaho Springs, CO 80452, USA.
Charles W. Naeser. 13503 Clear Lake Ct., Herndon, Virginia 20171, USA.
Sam L. VanLandingham. 1205 West Washington Ave., Midland, TX 79701, USA.

KEY WORDS: Archaeology, Early Man; Valsequillo, Mexico; Hueyatlaco stratigraphy; diatoms; U-Th/He dates; fission-track dates

PE Article Number: 14.3.44A
Copyright: U.S. Geological Survey, Public Domain November 2011
Submission: 15 June 2007. Acceptance: 27 September 2011