Mesozoic tectonics of the Maria fold and thrust belt and McCoy basin : an examination of polyphase deformation and synorogenic response
type: CreativeWork
description: Here we summarize all current knowledge about the Maria Fold and Thrust Belt and McCoy Basin tectonic provinces of southeastern California. We also present new geologic mapping, structural analysis from macroscopic to microscopic scale, U-Pb zircon ages and Ar-Ar hornblende and biotite ages from key areas in the Maria Fold and Thrust Belt and McCoy Basin to resolve kinematics and timing of polyphase deformation events related to the Mesozoic Cordilleran Orogeny in southeastern California. The Maria Fold and Thrust Belt (MFTB) is an east-west trending belt of amphibolite grade metamorphic rocks characterized by largely south-vergent folds and ductile shear zones that place Jurassic and Proterozoic crystalline rocks over Paleozoic and Mesozoic sedimentary and volcanic rocks correlative to strata observed on the Colorado Plateau and in southeastern Arizona. Rocks in the MFTB have undergone polyphase ductile deformation and high grade metamorphism. The McCoy Basin trends subparallel with the MFTB and is defined by exposures of Jurassic-Cretaceous McCoy Mountains Formation, a > 7 km thick siliciclastic wedge of sandstone, siltstone and conglomerate. In contrast with the MFTB, rocks in the McCoy Basin have undergone primarily brittle deformation and have undergone low grade regional metamorphism. Important questions remain regarding the tectonic evolution of these two tectonic provinces, the relationship of these two provinces to each other and their relationship to the Cordillera at large. Resolving kinematics and timing of polyphase deformation in the MFTB and assessing synorogenic response in the McCoy Basin using established and new methods of structural geology and geochronology will resolve these questions and illuminate fundamental geologic processes related to orogenesis. This dissertation is divided into three chapters, with the goal of assessing kinematics and timing of deformation in the MFTB and McCoy Basin. A general encompassing hypothesis for investigations…
abstract: Here we summarize all current knowledge about the Maria Fold and Thrust Belt and McCoy Basin tectonic provinces of southeastern California. We also present new geologic mapping, structural analysis from macroscopic to microscopic scale, U-Pb zircon ages and Ar-Ar hornblende and biotite ages from key areas in the Maria Fold and Thrust Belt and McCoy Basin to resolve kinematics and timing of polyphase deformation events related to the Mesozoic Cordilleran Orogeny in southeastern California. The Maria Fold and Thrust Belt (MFTB) is an east-west trending belt of amphibolite grade metamorphic rocks characterized by largely south-vergent folds and ductile shear zones that place Jurassic and Proterozoic crystalline rocks over Paleozoic and Mesozoic sedimentary and volcanic rocks correlative to strata observed on the Colorado Plateau and in southeastern Arizona. Rocks in the MFTB have undergone polyphase ductile deformation and high grade metamorphism. The McCoy Basin trends subparallel with the MFTB and is defined by exposures of Jurassic-Cretaceous McCoy Mountains Formation, a > 7 km thick siliciclastic wedge of sandstone, siltstone and conglomerate. In contrast with the MFTB, rocks in the McCoy Basin have undergone primarily brittle deformation and have undergone low grade regional metamorphism. Important questions remain regarding the tectonic evolution of these two tectonic provinces, the relationship of these two provinces to each other and their relationship to the Cordillera at large. Resolving kinematics and timing of polyphase deformation in the MFTB and assessing synorogenic response in the McCoy Basin using established and new methods of structural geology and geochronology will resolve these questions and illuminate fundamental geologic processes related to orogenesis. This dissertation is divided into three chapters, with the goal of assessing kinematics and timing of deformation in the MFTB and McCoy Basin. A general encompassing hypothesis for investigations…
author: Salem, Anthony C.
language: English
keywords: structural geology, Mesozoic tectonics, southern Cordillera, Maria Fold and Thrust Belt, middle crustal deformation, Sevier Fold and Thrust Belt, Laramide, Cretaceous deformation, Big Maria Mountains, McCoy Mountains, Palen Pass, McCoy Basin, southeastern California, Cretaceous plutonism
date published: 2009-08-27T07:00:00Z
date modified: 2026-07-24T05:26:14Z
provider: University of New Mexico
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of New Mexico

PropertyValue
property ID: Handle
value: http://hdl.handle.net/1928/9841