ABSTRACT

The misuse of stratigraphic information from oil wells in eastern Mexico generated the concept of the Chicontepec paleocanyon (Busch and Govela, 1975, 1978). Its original definition, a paleogeographic entity parallel to the Gulf coastline in the subsurface of the Poza Rica district, Veracruz, was based on the use of petrophysical logs for correlation of stratigraphic sections. The methods used to define the Chicontepec paleocanyon are questioned here, and its existence at the original proposed location is rejected on the basis of the following criteria: (1) the unconformity surface does not reveal the absence of lithologic formations; (2) the correlated stratigraphic sections lack accurate chronostratigraphic control; (3) Paleocene-Eocene lateral facies changes are erroneously considered unconformities; (4) the so-called reference horizon, Horizon C (top lower Eocene), for the stratigraphic correlation is not documented with lithostratigraphic and biostratigraphic data; and (5) the marks on check-shot points used to determine the contact between the Paleocene-lower Eocene formations are not accurate.