AAPG Memoir 75, Chapter 19: Paleocanyons in
the Subsurface of Eastern Mexico: Facts and Uncertainties, by Abelardo Cant
-Chapa, Pages 421 - 430
from:
AAPG Memoir 75: The Western Gulf of Mexico Basin: Tectonics, Sedimentary
Basins, and Petroleum Systems, Edited by Claudio Bartolini, Richard T. Buffler, and
Abelardo Cant-Chapa
Copyright 
2001 by The American Association
of Petroleum Geologists. All rights reserved.
Paleocanyons in the Subsurface of Eastern Mexico:
Facts and Uncertainties
Abelardo Cant-Chapa
Instituto Polit
cnico Nacional, Mexico City, Mexico
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.
