Skip to Main Content
Book Chapter

Geochronology, Geochemistry, and Tectonic Setting of the Mesozoic Nazas Arc in North-Central Mexico, and its Continuation to Northern South America

By
Claudio Bartolini
Claudio Bartolini
International Geological Consultant, Houston, Texas, U.S.A.
Search for other works by this author on:
Harold Lang
Harold Lang
Jet Propulsion Laboratory, Pasadena, California, U.S.A.
Search for other works by this author on:
Terry Spell
Terry Spell
Department of Geoscience, University of Nevada at Las Vegas, Nevada, U.S.A.
Search for other works by this author on:
Published:
January 01, 2003

Abstract

Volcanic, sedimentary, and granitic plutonic rocks that are part of the early Mesozoic Cordilleran continental magmatic arc are exposed in a belt from the southwestern United States to Guatemala. In the Mexican states of Chihuahua, Coahuila, Durango, Zacatecas, and San Luis Potosí, these rocks form a discontinuous southeast-trending belt across north-central Mexico. Whole-rock geochemical analyses of volcanic and intrusive rocks in north-central Mexico indicate a calc-alkaline suite formed in this continental volcanic arc along the convergent margin of western North America. Paleomagnetism, field relations, and isotopic ages (40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb) of 73 volcanic and intrusive rocks document the Late Triassic–Middle Jurassic age of the arc. In the region, isotopic ages commonly are reset, apparently because of thermotectonic events during the “Laramide” orogeny that led to the development of the Sierra Madre Oriental fold and thrust belt and to deep burial of the arc rocks. Available evidence suggests that the arc underwent two main phases of subsidence. One phase of extensional subsidence created intra-arc basins and a peak of volcanism throughout the arc in the Early–Middle Jurassic. A second phase began in the Oxfordian, with subsidence and initial deposition of the Zuloaga and La Gloria Formations. Continued sedimentation during this phase led to accumulation of 5–7 km of strata above the arc, as Cretaceous seas transgressed westward over inland Mexico.

The similarities in age, depositional environment, clastic composition, magma types, and geochemical affinity and, more importantly, the tectonic settings that gave rise to the Nazas Formation in Mexico and La Quinta and Girón Formations in Venezuela and Colombia suggest that these two volcanic-sedimentary sequences, now hundred of kilometers apart, were once part of the Late Triassic–Jurassic continental magmatic arc. This arc extended from Alaska to South America and evolved during simultaneous subduction along the western margin of Pangea, rifting in the Caribbean–Gulf of Mexico region, and associated large-scale transpressive activity.

You do not currently have access to this article.

Figures & Tables

Contents

AAPG Memoir

The Circum-Gulf of Mexico and the Caribbean: Hydrocarbon Habitats, Basin Formation and Plate Tectonics

Claudio Bartolini
Claudio Bartolini
Search for other works by this author on:
Richard T. Buffler
Richard T. Buffler
Search for other works by this author on:
Jon F. Blickwede
Jon F. Blickwede
Search for other works by this author on:
American Association of Petroleum Geologists
Volume
79
ISBN electronic:
9781629810546
Publication date:
January 01, 2003

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal