Paleomagnetic investigation of quaternary sediment at Tlapacoya, México and at Valsequillo, Puebla, México

Abstract

Paleomagnetic data for Pleistocene and Holocene sediments at two localities in Mexico's Transverse Volcanic Belt record normal polarity. Although the data for Tlapacoya, Mexico, are detailed for about 25,000 - 5,000 yrs B. P., the high scatter of directions within most of the 61 horizons indicates the paleomagnetic field was not recorded well enough that inferences can be made about the pattern of secular variation. Samples from Valsequillo, Puebla, demonstrate that portions of the V alsequillo Gravels are suitable for a magneto stratigraphic investigation, and were used in an unsuccessful attempt to date artifacts at the Hueyatlaco archeological site.