Age constraints on alleged “footprints” preserved in the Xalnene Tuff near Puebla, Mexico

Research Article| March 01, 2009 Age constraints on alleged "footprints" preserved in the Xalnene Tuff near Puebla, Mexico Joshua M. Feinberg; Joshua M. Feinberg * 11Institute for Rock Magnetism, Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, Minnesota 55455, USA *E-mail: feinberg@umn.edu. Search for other works by this author on: GSW Google Scholar Paul R. Renne; Paul R. Renne 22Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA 33University of California–Berkeley, Department of Earth and Planetary Science, 340 McCone Hall, Berkeley, California 94720, USA Search for other works by this author on: GSW Google Scholar Joaquin Arroyo-Cabrales; Joaquin Arroyo-Cabrales 44Laboratorio de Arqueozoología, Subdirección de Laboratorios y Apoyo Académico, Instituto Nacional de Antropología e Historia, 06060 México, D.F. Mexico Search for other works by this author on: GSW Google Scholar Michael R. Waters; Michael R. Waters 55Center for the Study of the First Americans, Departments of Anthropology and Geography, Texas A&M University, College Station, Texas 77843–4352, USA Search for other works by this author on: GSW Google Scholar Patricia Ochoa-Castillo; Patricia Ochoa-Castillo 66Subdirección de Arqueología, Museo Nacional de Antropología, Reforma y Gandhi s/n, CP 11560, México, D.F. Mexico Search for other works by this author on: GSW Google Scholar Mario Perez-Campa Mario Perez-Campa 77Secretariá Técnica, Instituto Nacional de Antropología e Historia, 06700, México, D.F. Mexico Search for other works by this author on: GSW Google Scholar Geology (2009) 37 (3): 267–270. https://doi.org/10.1130/G24913A.1 Article history received: 06 Mar 2008 rev-recd: 27 Oct 2008 accepted: 06 Nov 2008 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Joshua M. Feinberg, Paul R. Renne, Joaquin Arroyo-Cabrales, Michael R. Waters, Patricia Ochoa-Castillo, Mario Perez-Campa; Age constraints on alleged "footprints" preserved in the Xalnene Tuff near Puebla, Mexico. Geology 2009;; 37 (3): 267–270. doi: https://doi.org/10.1130/G24913A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Impressions in a basaltic tuff located around Valsequillo Reservoir near Puebla, Mexico, have been interpreted as human and animal footprints along an ancient lakeshore, and are cited as evidence of the presence of humans in North America at 40 ka B.P. In this paper, we present new data that challenge this interpretation. Paleomagnetic analyses of the Xalnene Tuff, and lavas from the volcano from which it erupted, yield fully reversed magnetic polarities, indicating that the tuff was deposited prior to the last geomagnetic reversal (the Brunhes-Matuyama ca. 790 ka). 40Ar/39Ar dating of Xalnene lapilli and lava from the source volcano yields indistinguishable ages of ~1.3 Ma, consistent with a period of reversed magnetic polarity (C1r.2r). Additional paleomagnetic measurements of individual millimeter-size lapilli indicate that the pyroclastic grains within the Xalnene Tuff have not been disturbed or rotated since their initial deposition, thereby ruling out the possibility that the tuff was reworked by wave action along the shores of an ancient lacustrine environment. This and other evidence indicate that the marks observed in the stone quarry site are not human ichnofossils. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.