AAPG Memoir 75, Chapter 9:
Stratigraphy and Origin of the La Popa Basin, Nuevo Le
n and Coahuila, Mexico, by Timothy F.
Lawton, Francisco J. Vega, Katherine A. Giles, and Carmen Rosales-Dom
nguez, Pages 219
- 240
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.
Stratigraphy and Origin of the La Popa Basin, Nuevo Len and
Coahuila, Mexico
Timothy F. Lawton
Institute of Tectonic Studies, New Mexico State
University, Las Cruces, New Mexico, U.S.A.
Francisco J. Vega
Instituto de Geologa, Universidad Nacional
Autnoma de
Mexico, Mexico City, Mexico
Katherine A. Giles
Institute of Tectonic Studies, New Mexico State
University, Las Cruces, New Mexico, U.S.A.
Carmen Rosales-Domnguez
Instituto Mexicano del Petrleo, Exploracin-
Geociencias, Mexico City, Mexico
ABSTRACT
Strata exposed in the La Popa Basin of northern Mexico range in age from Late Jurassic
through middle Eocene and record the evolution of the region currently lying in the
foreland of the Sierra Madre orogen from extensional to contractional tectonics. The
facies distribution and geometry of the strata demonstrate that salt diapirism was active
at least from late Aptian-middle Eocene. Jurassic rocks include evaporites of the
Oxfordian-Kimmeridgian Minas Viejas Formation, which is exposed only in diapiric bodies in
the basin. The evaporites contain three types of blocks transported to their present
levels during diapirism: (1) mafic to intermediate metaigneous rocks with latest Jurassic 40Ar/39Ar
cooling ages (146 Ma); (2) laminated and nodular gypsum; and (3) Kimmeridgian limestone
(Zuloaga Limestone). This Upper Jurassic lithic assemblage represents different parts of a
formerly thick (at least 1000 m) stratigraphic section deposited in an extensional, or
pull-apart, basin. Post-Jurassic rocks of the basin range from Early Cretaceous to middle
Eocene and record both carbonate and siliciclastic deposition in dominant deltaic,
shallow-marine, and tidal settings, as well as subordinate basinal and coastal-plain
environments. This exposed section is at least 6400 m thick. The Lower Cretaceous section
is thin (~100 m) and locally consists of carbonate biostromes deposited on bathymetric
highs adjacent to a diapiric salt wall. These carbonates are late Aptian-late Albian in
age and much thinner than their regional correlatives. The lower part of the Upper
Cretaceous is represented by the Indidura and Parras Formations, the former a basinal
carbonate, the latter a prodeltaic or basinal shale that underlies the Difunta Group, a
constructional continental-margin clastic wedge or embankment that filled the La Popa
Basin. The Difunta Group in the La Popa Basin spans the Maestrichtian-middle Eocene.
Lenticular carbonate beds as much as 350 m thick are interbedded with mud-rock intervals
of the Difunta Group and represent deposition on bathymetric highs created by rising salt
bodies.
